Physiology Dr.Guy's

  1. How much blood is made of cells? How much is plasma?
    45% cells, 55% plasma
  2. What are the three main types of cells? How many of each do we normally have?
    erythrocyte (RBC - 4.8 to 5.4 million/cubic mm), leukocyte (WBC - 5000 to 9000), thrombocyte (250,000 to 400,000)
  3. What are the different types of WBCs? What % is each?
    Neutrophils (granular - 60%), Eosinophils (granular - 3%), Basophils (granular - 0%), Lymphocytes (agranular - 30%), Monocytes (agranular - 8%)
  4. What is plasma made of?
    water (91.5%), proteins (7%) (albumin is 55% - maintains osmotic pressure, globulin is 38% - antibodies and fibrinogen is 7% - role in blood clotting)
  5. What is hemopoiesis? Where does it occur?
    hematopoiesis (formation of blood cells) in yolk sac of embryo/fetus then liver and spleen then red bone marrow in adults
  6. What is the main regulating factor in RBC production?
    partial pressure of oxygen
  7. What is erythropoiesis?
    formation of RBC's in bone marrow, low partial pressure of oxygen in blood in kidney stimulates the production of erythropoietin (80% made in extraglomerular mesagium, 20% made in lever)
  8. What factors decrease oxygenation?
    low blood volume, anemia, low hemoglobin, poor blood flow, pulmonary disease
  9. What are hematocytoblasts?
    large, nucleated, immature cells which develop into the 5 major types of blood cells
  10. What are the 5 cells hematocytoblast becomes?
    • Rubriblast --> reticulocyte --> erythrocyte
    • Myeloblast --> neutrophils, eosinophils, basophils
    • Megakaryoblast (megakaryocyte) --> thrombocyte (platelet)
    • Lymphoblast --> lymphocytes
    • Monoblast --> monocytes
  11. What stimulates the development of a hematocytoblast into a rubriblast? Describe a rubriblast and reticulocyte.
    erythropoeitin, rubriblast still has a nucleus, reticulocyte contains some hemoglobin but no necleus
  12. Describe a mature erythrocyte?
    anucleated mature RBC, contains hemoglobin, life span = 120 days
  13. What is the function of hemoglobin?
    transports oxygen (oxy Hb to body from lungs), transports carbon dioxide (carboxy Hb to lungs from body) as HCO3-
  14. What is the structure of hemoglobin?
    4 protein chains or subunits (2 alpha and 2 beta), each containing a heme group with one iron, which can bind 1 oxygen each (hemoglobin can bind 4 oxygen)
  15. What are the forms of iron?
    • ferrous - Fe2+ form it is absorbed and carried in hemoglobin
    • ferritin - Fe3+ storage form
    • transferrin - Fe3+ blood transport
  16. How do leukocytes differ from erythrocytes?
    leukocytes are nucleated and do not contain hemoglobin
  17. What are granulocytes?
    • PMN's which develop from red bone marrow
    • Basophils - heparin (vasodilator), tissue inflammation, hypersensitivity, histamine
    • Eosinophils - allergic reactions, parasitic worms
    • Neutrophils - bacterial antibiotic activity, phagocytic
    • "BEN G"
  18. What are the agranulocytes?
    • MN's that develop from lymphoid tissue
    • Lymphocytes - viral, production of antibodies
    • B cells - produced in bone marrow, when they contact an antigen they are converted to plasma cells --> produce antibodies
    • T cells - differentiated in the thymus, release chemicals which stimulate macrophages to migrate toward infects
    • Monocytes - chronic infections, macrophage production, antibiotic reactions
  19. What is the first line of defense in the blood? In the tissue?
    neutrophil (blood), macrophage (tissue - particularly in inflammation reactions, there are no macrophages in the blood)
  20. What is the intrinsic pathway? extrinsic? common?
    • Intrinsic - intravascular, occurs in minutes, contact with collagen - XII, XI, IX, VIII
    • Extrinsic - interstitial, occurs in seconds, tissue thromboplastin - VII, III
    • Common - X, V, II, I
  21. What is vitamin K needed for?
    prothrombin (II), VII, christmas factor(IX), stuart factor (X)
  22. Which coagulation factor has a positive feedback effect?
  23. Who is the universal recipient of blood cells? Universal donor?
    recipient = AB+, donor = O-
  24. What is an antigen? antibody?
    antigen is a chemical introduced into the body, body reacts by producing antibodies (protein that combines specifically with the antigen) or T cells
  25. What ´╗┐is cellular immunity?
    T cells, direct immunity against fungus, parasites, viral, cancer, tissue implants
  26. What is humoral immunity?
    B cells, antibodies, indirect against bacterial and viral infections
  27. What occurs in cellular immunity?
    macrophage binds with the antigen and presents in to the T cell (can only recognize antigen if presented by macrophage), also produces lymphokines (interleukin and interferon)
  28. What are the types of T cells?
    • Cytotoxic - attach to invading cell and secrete lymphotoxins (to kill antigen directly) or lymphokinins (to kill antigen indirectly)
    • Helper - work with B cells to amplify antibody production, release lymphokinin which stimulate killer T cells
    • Memory - programmed to recognize original invading agen for an accelerated response to 2nd exposure
    • Suppressor - damplen the immune response several weeks after infection
  29. What releases lymphokinins?
    • Macrophages - interleukin I
    • Cytotoxic cells - interleukin II
    • Helper - interleukin II
  30. What occurs in humeral immunity?
    an antigen is processed by macrophage and presented to the B cell which induces B cell proliferation and differentiation
  31. Where do B cells mature? differentiate?
    formed and mature in bone marrow, differentiate in spleen
  32. What does an activated B cell enlarge and divide into?
    Plasma cells (secrete antibodies), memory cells
  33. What are the immunoglobulins?
    • gamma globulins
    • IgG - most abundant, protects against bacteria and virus, crosses the placenta, "Gee thanks mom"
    • IgA - provides local protection on mucous membranes (saliva, vitamin A)
    • IgM - first to appear after intitial exposure to antigen on B cell surface, largest
    • IgD - stimulate antibody production
    • IgE - allergic reactions on mast and basophil cells and parasitic infections (along with eosinophils)
  34. What is hapten?
    portion of antigen determining specificity
  35. What is an allergy?
    caused by sensitized lymphocytes (IgE)
  36. What is an arthus reaction?
    severe local inflammatory reaction on blood vessels
  37. What is urticaria?
    localized anaphylaxis (hives)
  38. What is anaphylaxis?
    allergic hypersensivity reaction
  39. What is opsonins?
    stimulate phagocytes
  40. What is chemotaxis?
    attraction of cells to a chemical source
  41. What is diapedesis?
    movement of leukocytes through blood vessel walls
  42. What is natural active immunity?
    make your own antibodies (long term) after an unintentional exposure (ex. you get a cold)
  43. What is Natural passive immunity?
    received from mom, short term (IgG)
  44. What is artificial active immunity?
    Injected with virus, body produces antibodies (long term)
  45. What is artificial passive immunity?
    Injection of antitoxin or antibodies
  46. What is the tricuspid valve? Bicuspid?
    • Tricuspid - between Right atria and ventricle
    • Bicuspid - mitral - between left atria and ventricle
    • "Ride a Tricycle before you Learn to ride a Bicycle"
  47. What innervates the heart?
    autonomic nervous system increases or decreases the heart rate, the actual contraction is intiated within the heart
  48. What is self excitability?
    the ability of the heart to spontaneously and rhythmically generate action potentials
  49. Pathway of the signal in the heart?
    Sinoatrial node (SA) --> internodal pathway --> atrioventricular node (AV) - slowest --> Bundle of his --> left and right branch --> purkinje fibers - fastest
  50. What is the SA node?
    pacemaker of the hear, initiates contractions, located in the right atrium, leaky sodium channels (high permeability), causes depolarization of cardiac tissue
  51. What is the AV node?
    located at the lower right atrium, depolarized by the impulse initiated at the SA node, delay in transmission (allows time for the atria to empty into the ventricles), becomes the pacemaker if the SA node is damaged
  52. What is the bundle of his?
    runs within the interventricular septum, causes conduction of the ventricles, terminate as purkinje fibers
  53. What is the P wave?
    atrial depolarization, spread from SA node through two atria, an enlarged P wave indicates an enlarged atria
  54. What is the QRS wave?
    Ventricular depolarization, enlarged Q wave indicates a myocardial infarction (MI), enlarged R wave indicates ventricular enlargement
  55. What is the T wave?
    ventricular repolarization
  56. What is the dicrotic notch?
    small rise in blood pressure that occurs with closing of the aortic valve
  57. What is systole? Diastole?
    phase of contraction = systole, phase of relaxation = diastole
  58. What are the AV valves?
    bicupsid on left and tricuspid on right (closed during systole of ventricles)
  59. What are the semilunar valves?
    aortic on left and pulmonic on right (open during ventricular systole
  60. What is the sequence of the cardiac cycle?
    atrial systole --> isovolumetric contraction --> ejection period --> isovolumetric relaxation --> ventricular filling --> atrial systole
  61. What occurs during atrial systole?
    both atria contract, blood flows from the atria to the ventricles, contraction of the atria causes the S4 heart sound, semilunar valves are closed, AV valves are open
  62. How much blood enters the ventricles during atrial systole? What occurs at the end of atrial systole?
    30% of blood, at end pressure in the ventricles becomes greater than the pressure in the atria causing the AV valves to slam shut causing the S1 heart sound
  63. What occcurs during isovolumetric contraction (part of ventricular systole)?
    rise in ventricular pressure, All valves are closed --> there is no change in volume (isovolumetric - volume stays the same), at the end the pressure in the ventricles becomes greater than the pressure in the pulmonic artery and aorta
  64. What occurs during the ejection period (part of ventricular systole)?
    phase begins with the opening of the semilunar valves, AV valves remain closed, ventricles empty into systemic and pulmonic circulation, pressure in the pulmonic artery and aorta causes the semilunar valves to shut (S2 sound), this phase is marked by a drop in ventricular pressure and a rise in pulmonic and systemic pressure
  65. What is isovolumetric relaxation (part of ventricular diastole)?
    All valves are closed, dicrotic notch appears during this phase (brief rise in aortic pressure during the T wave), atria fill with blood, at the end pressure in the atria becomes greater than the pressure in the ventricles --> AV valves open
  66. What is ventricular filling (part of ventricular diastole)?
    begins with the opening of the AV valves, 70% of blood enters from atria even though they have not contracted yet, increased diastolic pressure, S3 heart sound occurs when blood enters ventricles
  67. What is cardiac output?
    the amount of blood pumped by either ventricle per minute = Stroke volume (SV - amount of blood pumped per contraction) X Heart rate (HR - number of beats per minute)
  68. What determines stroke volume?
    • End systolic volume - amount of blood remaining in a ventricle following systole (determined by atrial pressure and force of ventricular contraction
    • High ESV = low SV
    • End diastolic volume - amount of blood remaining in the ventricle after diastole (determined by length of ventricular diastole and venous pressure)
    • High EDV = High SV
  69. What is starling's law?
    what flows in must flow out (CO depends on venous return) - as cardiac muscle fibers are stretched a greater contraction is generated
  70. What is heart rate? How is it controlled?
    the body's principal mechanism of short term control over cardiac output and blood pressure, controlled by the inhibitory effects of the parasympathetic nerves and the stimulating effects of the sympathetic nerves
  71. What are cardiovacular centers? What are they stimulated by?
    groups of neurons in the medulla oblongata which regulate heart rate and blood vessel diameter (cardioacceleratory and cardioinhibitory center), stimulated by higher brain regions, baroreceptors (carotid sinus and aortic sinus) and chemorepectors (carotid body and aortic body)
  72. What is the cardioacceleratory center?
    sympathetic fibers which innervate the SA node when stimulated they release Norepinephrine (NE) --> increased heart rate and greater strength of contraction, increasing cardiac output and blood pressure, under normal conditions this center will dominate
  73. What is the cardioinhibitory center?
    gives rise to the vagus nerve (parasympathetic) which innervates the SA node, when stimulated they release acetylcholine which decreases the heart rate, cardiac output and blood pressure
  74. What is the carotid sinus?
    widening of the internal carotid artery just above the common carotid branch, baroreceptors are located in the wall of the sinus which are stimulated when stretched
  75. What does the carotid sinus do if blood pressure is too high?
    stimulate the cardioinhibitory center and inhibit the cardioacceleratory center --> decreased heart rate, cardiac output, blood pressure
  76. What does the carotid sinus do if blood pressure is too low?
    baroreceptors do not stiumlate the cardioinhibitory center leaving the cardioacceleratory center free to dominate --> heart will beat faster and more forcefully to restore normal blood pressure
  77. What is the aortic sinus reflex?
    moniters systemic blood pressure, operates like the carotid sinus reflex
  78. What can effect the heart rate?
    • Autonomic control: carotid reflex, aortic reflex, atrial reflex
    • Chemicals: epinephrine, potassium, calcium
    • Other: Temperature, emotions, gender, age
  79. An increase in cardiac output will have what effect on blood pressure?
  80. What are the arteries?
    carry blood away from the heart toward the organs, have the greatest blood pressure
  81. What are the arterioles?
    small vessels, which carry blood from the arteries to the capillaries, they have the greatest resistance and greatest capacity to change their diameter, they are innervated by the sympathetics
  82. What are the capillaries?
    have the greatest cross sectional area, permit the exchange of nutrients and waste between blood and tissues
  83. Waht are the veins?
    carry blood to the heart, one way valves prevent backflow, storage depot for blood
  84. What is ohms law?
    blood flow = change in pressure/resistance
  85. What determines resistance?
    amount of friction from viscosity (increases), vessel length (increases), vessel diameter (decreases)
  86. What is the principal determinanat of blood pressure?
    cardiac output
  87. What is heart rate regulated by? How will it effect blood pressure?
    carotid and aortic reflexes, increase in heart rate increases blood pressure (indirectly)
  88. How is resistance of vessels controlled? How does it effect blood pressure?
    change the diameter of the arterioles through sympathetic innervation, decreased diameter increases resistance, directly decreasing blood pressure
  89. What is the vasomotor center?
    located in the medulla, controls the vasomotor tone (diameter) of the arterioles
  90. How does sympathetic stimulation affect the arterioles? Where?
    constricts those on the skin and viscera (note: parasympathetic has no effect on blood vessels)
  91. How do baroreceptors regulate blood pressure?
    • if too high: decrease sympathetic stimulation to arterioles (affect the vasomotor center) resulting in vasodilation and a decrease in blood pressure
    • if too low: (below 80 mmHg) increase sympathetic stimualtion, resulting in vasoconstriction and increased blood pressure
  92. What do the chemoreceptors do?
    detect levels of oxygen and carbon dioxide and hydrogen ions (pH), activated by hypoxia, acidity or hypercapnia (excess carbon dioxide) --> increase sympathetic (via the cardiovascular centers and vasomotor centrers) --> vasoconstriction, increased heart rate, increased force of contraction, increased blood pressure
  93. What is the aortic body most sensitive to?
  94. Where does urine flow?
    collecting ducts --> renal papillae --> papillary ducts --> minor calyx --> major calyx --> renal pelvis --> ureter --> bladder --> urethra
  95. What is a nephron? Flow of urine through a nephron.
    functional unit of the kidney, Renal corpuscle (Bowman's capsule/glomerulus) --> proximal convuluted tubule --> descending limb (thin) of loop of Henle --> ascending limb (thick) of loop of Henle --> distal convuluted tubule --> collecting duct
  96. What are the two types of nephrons?
    cortical nephron (all in cortex except part of collecting duct) and juxtamedullary nephron (part in cortex, part in medulla)
  97. What are the functions of a nephron?
    control blood concentration and volume (blood pressure), regulate blood pH, remove toxic wastes from blood, formation of urine (not urea, urea is formed in the liver)
  98. What two systems is the nephron connected to?
    renal and vascular
  99. Blood supply to the kidney.
    renal artery --> segmental arteries --> interlobular arteries --> arcuate arteries --> interlobular arteries --> afferent arteriole --> glomerulus --> efferent arteriole --> peritubular capillaries (vasa recta) --> interlobular vein --> arcuate veins --> interlobular vein --> segmental vein --> renal vein
  100. What are peritubular capillaries?
    each efferent arteriole divides to form a network of capillaries (peritubular) around the convoluted tubules then empty into the interlobular veins
  101. What is the vasa recta?
    theses peritubular capillaries form long loops of thin walled vessels that dip down alongside the loop of the nephron
  102. What are the functions of the vasa recta?
    tubular reabsorption (renal to vascular), tubular secretion (vascular to renal) and concentration of urine
  103. What are the three steps of urine formation?
    glomerular filtration, tubular reabsorption, tubular secretion
  104. What is glomerular filtration?
    substances in the blood are filtered through the glomerular capillary membrane into Bowman's capsule then into the proximal convoluted tubule
  105. What is glomerular filtrate?
    consists of all materials in the blood except formed elements and most proteins, proteins can't pass through the basement membrane of the glomerulus
  106. What is the Glomerular filtration rate?
    quantity of glomerular filtrate formed each minute in all nephrons (normal = 125mL/min or 180 L/day), depends on glomerular capillary pressure, colloidal osmotic pressure, Bowman's capsule pressure
  107. What is normal glomerular capillary pressure?
    60 mmHg (2 to 3 times higher than normal capullary), promotes filtration into Bowman's capsule
  108. What will constriction of the afferent arteriole do?
    decrease blood flow, decrease glomerular pressure, decrease filtration rate
  109. What will constriction of the efferent arteriole do?
    increase glomerular presssure, increase flitration rate
  110. What is the normal colloidal osmotic pressure?
    32 mmHg, protein in blood causes a sucking pressure back into the glomerular capillary network
  111. What is the normal Bowman's capsule pressure?
    18 mmHg, hydrostatic pressure of filtrate inside Bowman's capsule pushes fluid back into the glomerular capillary
  112. What will decrease glomerular filtration rate?
    decreased glomerular pressure (efferent arteriole dilation or afferent arteriole constriction), increased plasma colloidal pressure, increased Bowman's capsule pressure
  113. What will increase glomerular filtration rate?
    increased glomerular pressure (efferent arteriole constriction (if not severe) and afferent arteriole dilation), decreased plasma colloidal pressure, decrease Bowman's capsule pressure
  114. What is the plasma clearance?
    ability of the kidney to clear the plasma of various substances, glucose has the lowest plasma clearance value (slowest removal from the blood)
  115. What is tubular reabsorption?
    movement of the filtrate back into the blood of the peritubular capillaries or vasa recta (99% of the filtrate is reabsorbed), this allows the body to retain most of its nutrients
  116. Which substances are absorbed by active transport? Where are they reabsorbed?
    Sodium, glucose, amino acids, calcium, potassium, chloride, bicarbonate, phosphate, mostly reabsorbed in the proximal convoluted tubule
  117. Where does passive water reabsorption occur?
    proximal tubule (66% - permeable to water), loop of henle, distal tubule (impermeable to water except in the presence of ADH), collecting duct
  118. What occurs with low water concentration?
    increased osmotic pressure, increased osmolarity, high solute concentration (concentrated solution)
  119. What occurs with high water concentration?
    decreased osmotic pressure, decreased osmolarity, low solute concentration (dilute solution)
  120. What does high serum osmolarity mean?
    low water concentration in the blood
  121. What is another name for Antidiuretic hormone (ADH)? What triggers its synthesis? What does it do?
    vasopressin, when body is dehydrated osmotic pressure increases, osmoreceptors in hypothalamus detect this and synthesize ADH which is transported to the posterior pituitary then released into the blood, in the kidneys it increases the permeability of the distal convoluted tubule and the collecting duct to water
  122. What occurs as a result of ADH?
    decreased urine volume, increase water concentration in the blood, lower blood osmotic pressure
  123. What is aldosterone? What will stimulate its release?
    the main mineralcorticoid released from the zona glomerulosa of the adrenal cortex, released when angiotensin II increases in the blood, potassium ion concentration increases, sodium ion concentration decreases
  124. What are the main actions of aldosterone?
    increases reabsorbtion of sodium at the distal convoluted tubule and the collecting duct (increases sodium ion concentration in the blood) and secrete potassium ion into the lumen of the distal convoluted tubule and the collecting duct (decrease potassium ion concentration) --> reabsorption of sodium causes the retention of water --> blood volume increases --> blood pressure increases
  125. What do the juxtaglomerular cells of the kidney make? What does it do?
    renin when blood pressure or volume is low --> cleaves angiotensinogen into angiotensin I, ACE in lungs converts angiotensin I to II --> angiotensin II constricts the arterioles and stimulates the zona glomerulosa to release aldosterone
  126. What is the descending limb permeable to?
    permeable to water but impermeable to solutes such as NaCl, medullary interstitium has hyperosmotic compared to filtrate --> water leaves the descending limb --> filtrate becomes hyperosmotic (equalizes with interstitium)
  127. What is the ascending limb permeable to?
    impermeable to water but permeable to solutes, NaCl leaves the tubule, medullary interstitium becomes hypertonic which allows water to leave the descending limb
  128. What is acidic? basic? How is the balance between them maintained?
    acidic is low pH and high hydrogen ion concentration, basic is high pH and low hydrogen ion concentration, balance is maintained by controlling the hydrogen ion concentration of body fluids
  129. What is aerobic respiration?
    krebs cycle/citric acid cycle - process that produces energy and carbon dioxide which diffuses out of the cell and reacts with water to yield carbonic acid (H2CO3) via the enzyme carbonic anhydrase which ionizes to relaease hydrogen and bicarbonate ions
  130. What is anaerobic respiration?
    glycolysis - produces energy and lactic acid, increasing the hydrogen ion concentration
  131. What are the three mechanism which control pH of the body?
    buffer systems, respiration, kidney
  132. What is a buffer? What buffers are used in the body?
    substance that resists change in pH when an acid or base is added, bicarbonate buffer (blood - 7.35 to 7.45), phosphate buffer (urine), protein buffer (powerful and plentiful)
  133. How does respiration affect pH?
    • Hypoventilate --> more acidic
    • Hyperventilate --> more basic
    • eliminates more acid or base than all other buffers combined, adjustment takes 1 to 3 minutes
  134. How do kidney's control pH (summary)?
    secrete hydrogen ions into the urine, reabsorb bicarbonate inons into the blood stream
  135. How can tubular secretion affect pH?
    adds substances to the filtrate from the blood such as potassium, hydrogen and ammonium ion
  136. Where does secretion of hydrogen ions occur?
    proximal and distal convoluted tubule and collecting duct, secretion of hydrogen into the urine cuases blood pH to rise, and urine pH to drop, hydrogen cannot be secreted alone, must be combined with buffers
  137. What can cause respiratory acidosis?
    injury to the respiratory center of the brain causing decreased rate and depth of breathing, obstruction oin air passages, pnumonia/emphysema --> amount of carbon dioxide in the body fluids is increased and pH drops (acidic)
  138. What can cause respiratory alkalosis?
    hyperventilation from oxygen deficiency due to high altitude, severe anxiety, asprin overdoes, treat by breathing into a bag
  139. What causes metabolic acidosis?
    An abnormal increase in acidic metabolic products from kidney failure (acids are not excreted) or diabetes mellitus (fats are converted to keto acids); or an abnormal loss of bicarbonate ions from prolonged diarrhea or vomiting (loss of intestinal juices)
  140. What causes metabolic alkalosis?
    Non-respiratory loss of acids by the body (excessive vomiting of gastric juices --> loss of HCl) or excessive intake of alkaline drugs (symptoms include nervousness, muscle spasm and convulsions)
  141. How does body compensate for acidosis?
    chemical buffers, increase rate and depth of breathing, increase secretion of Hydrogen ions into the urine --> raise blood pH, lower urine pH
  142. How does body compensate for alkalosis?
    Chemical buffers, decrease rate and depth of breathing, decrease secretion of hydrogen ions into the urine, decrease reabsorption of bicarbonate ions --> lower blood pH, higher urine pH
  143. Where is the trachea?
    located anterior to the esophagus, extends from the larynx (C6) to the carina (sternal angle, T4 disc)
  144. What is the trachea made of?
    mucosa is pseudostratified consisting of ciliated columnar cells, there are 16 to 20 incomplete rings (C shaped, open posteriorly)
  145. What is the carina?
    the last tracheal cartilage, seperates the openings of the right and left main bronchi
  146. What are the primary or main bronchi?
    One passes to each lung from the carina, the right is shorter, wider and more vertical and thus receives more foreign bodies, upon entering the lung hilus each main bronchi divides into secondary or lobar bronchi
  147. What are the secondary or lobar bronchi?
    3 on the right and 2 on the left
  148. What are the tertiary or segmental bronchi?
    bronchioles, 10 on the right and 8 on the left, each supplies a bronchopulmonary segment of the lung, subdivide smaller and smaller until they terminate as alveolar ducts which terminate as alveolar sacs made up of alveoli (functional unit of the lung
  149. What are the 2 parts of the pleura of the lungs?
    parietal and visceral, with pleural cavity between them
  150. What is the parietal layer of the pleura of the lungs?
    attached to and lining the thoracic wall, covers the diaphragm and lateral surface of the mediastinum, can be divdied according to its location into: costal, mediastinal, diaphragmatic and cervical pleura
  151. What is the visceral layer of the pleura of the lungs?
    covers the outer surface of the lungs and extends into the interlobar fissures, becomes continuous wiht the parietal layer at the root of the lung, they hang down to form the pulmonary ligament
  152. How do intraplueral pressure and intraalveolar pressure compare?
    intrapleural pressure is lower than the intraalveolar
  153. What is boyles law?
    pressure is inversely proportional to the volume of the container --> when we breathe in we increase lung volume so that the pressure inside the lungs is less than the air pressure in the atmosphere, when we breathe out the opposite happens
  154. What muscles are involved in lung expansion?
    muscles of inspiration: diaphragm, external intercostal muscles, accessory inspiratory muscles (forced inspiration only), sternocleidomastoid (elevates the sternum), scalenus (elevates the superior rib)
  155. What is the diaphragm?
    a sheet of skeletal muscle tha forms the floor of the thoracic cavity, it is dome shaped and when it contracts the dome becomes flattened increasing the vertical diameter of the throracic cavity
  156. What do the external intercostal muscles do?
    when contract they pull the ribs up and sternum forward --> increase the A-P diameter of the thoracic cavity
  157. What part of breathing is active?
    inspiration is active, expiration is normally passive
  158. What is the intraalveolar pressure?
    the intrapulmonic pressure, the pressure inside the lungs
  159. What is the intrapleural pressure?
    the pressure between the two pleural layers (always less than the atmosphere pressure to prevent collapse of the alveolar walls
  160. What is the transpulmonic pressure? When is it the greatest?
    The difference between the intrapulmonic pressure and the intrapleural pressure, greatest at the end of ispiration
  161. What occurs normally during expiration?
    inspiratory muscles relax --> ribs move down, diaphragm moves up --> thoracic cavity decreases in size --> lungs recoil --> air is forced out of lungs
  162. What are the muscles of expiration?
    contract during higher levels of ventilation and when air movement out of the lungs is impeded - internal intercostal muscles (move the ribs downward) and abdominal muscles (move the inferior ribs down, compresses the abdominal viscera forcing the diaphragm upward)
  163. What is atelectasis?
    collapse lung, at the end of expiration alveoli attempt to recoil inward and collapse on themselves, which would obstruct air movement
  164. What prevents atelectasis?
    maintenance of a subatmospheric intrapleural pressure keeping the alveoli inflated and surfactant (a phospholipid produced by the type II alveolar cells or pneumocyte type II) decreases surface tension in the lungs preventing the alveoli from sticking together
  165. What is compliance?
    the ease with which the lungs and thoracic wall can be expanded (high compliance --> lungs expand easily), it is related to elastic fibers in lung tissue, surfactant lowering the surface tension
  166. What is tidal volume?
    the volume of air which moves through the respiratory passages with each normal breath, it is equal to 500mL (note: only 350mL reaches the alveoli, 150mL remains in the nose, pharynx, trachea and bronchi, this is known as dead air volume)
  167. What is the inspiratory reserve volume?
    the extra volume of air that can be inspired beyond the normal tidal volume, usually about 3000mL
  168. What is the expiratory reserve volume?
    the air that can be expired forcefully beyond the normal tidal volume, usually 1100mL to 1200mL
  169. What is the residual volume?
    the voume of air still remaining in the lungs after forceful expiration (about 1200mL)
  170. What is the inspiratory capacity?
    the amount of air a person can breath begining at the normal expiratory level and distending the lungs to the maximum amount (tidal volume + inspiraotry reserve volume = 3500mL)
  171. What is the functional residual capacity?
    the amount of air remaining in the lungs at the end of normal expiration (expiratory reserve volume and residual volume = 2300mL)
  172. What is the vital capacity?
    maximum amount of air that a person can expel after first filling the lungs to the max extent then expiring to max extent (inspiratory reserve volume + tidal volume + expiratory reserve volume = 4600mL)
  173. What is the total lung capacity?
    the max volume to which the lungs can be expandedd with the greatest possible inspiratory effect (vital capacity + residual volume = 5800mL)
  174. How do pulmonary volumes and capacities vary from men to women?
    20 to 25% less in women
  175. What are partial pressures?
    the pressure each gas within a mixture of gases exerts
  176. What is external respiration?
    the exchange of oxygen and carbon dioxide between the alveoli and the pulmonary capillaries, results in the conversion of deoxygenated blood to oxygenated blood
  177. What is the partial pressure of oxygen in alveolar air? In deoxygenated blood flowing through pulmonary capillaries?
    105 mmHg in alveoli, 40mmHg in blood --> oxygen diffuses from the alveoli into the blood
  178. What is the partial pressure of carbon dioxide in alveolar air? In deoxygenated blood flowing through pulmonary capillaries?
    40 mmHg in alveoli, 45 mmHg in blood --> carbon dioxide will move from blood to alveoli
  179. What is internal respiration?
    exchange of oxygen and carbon dioxide between tissue blood capillaries and tissue cells, results in the conversion of oxygenated blood into deoxygenated blood
  180. What is the partial pressure of oxygen in the tissue capillaries? In the intersistial fluid? In the cells?
    105 mmHg in blood, 40 mmHg in interstitial fluid, 23 mmHg in cells --> oxygen diffuses from blood to fluid to cells
  181. What is carbon dioxide partial pressure in tissue capillaries? Interstitial fluid? Cells?
    40 mmHg in blood, 45 mmHg in fluid, 46 mmHg in cells --> carbon dioxide diffuses from cells to fluid to blood
  182. How do the diffusion rates of carbon dioxide and oxygen compare?
    carbon dioxide diffuses 20X faster than oxygen --> pressure difference required for carbon dioxide is much less than for oxygen
  183. How is oxygen transported?
    97% is carried by hemoglobin in RBCs, 3% is dissolved in plasma and cells
  184. How is carbon dioxide transported?
    7% dissolved in plasma, 23% carried by hemoglobin, 70% carried as bicarbonate ion (requires carbonic anhydrase)
  185. What is the haldane effect?
    binding of oxygen to hemoglobin tends to displace carbon dioxide from the blood
  186. What is the chloride shift?
    necessary for carbon dioxide transport as bicarbonate ions
  187. What is the respiratory center?
    groups of neurons located in the medulla and pons dorsal respiratory center, divided into 3 areas (medullary thythmicity area, pneumotaxic area, apneustic area)
  188. What is medullary rhythmicity area?
    controls the basic rhythm of breathing --> inspiration = 2 seconds, expiration = 3 seconds
  189. What is the pneumotaxic area?
    located in the pons, sends inhibitory impulses to the inspiratory area, limits inspiration to facilitate (increase) expiration
  190. What is the apneustic area?
    located in the lower pons, send stimulatory signals to the inspiratory area, inhibiting expiration, occurs only when the pneumotaxic area is inactive, otherwise the pneumotaxic area overrides
  191. What is the inflation reflex?
    hering breurer reflex - prevents overstretch, stetch resceptors are located in the walls of the bronchi and bronchioles, when stimulated they inhibit the inspiratory area and the apneustic area via the vagus nerve --> expiration follows
  192. What is the chemosensitive area of the respiratory center?
    area most sensitive to changes in carbon dioxide and hydrogen ions
  193. What are the peripheral chemoreceptrs most sensitive to?
    changes in oxygen
  194. What will stimulate the carotid and aortic bodies? What will this result in?
    decreased oxygen from 105 to 50 mmHg, increased carbon dioxide above 40mmHg (hypercapnia), increased hydrogen ion concentration --> stimulation of the inspiratory area, increasing respiration and correcting the imbalance
  195. What does the afferent nervous system do?
    convey sensory information from receptors to the CNS
  196. What does the efferent nervous system do?
    convey information from the CNS to the muscles and glands
  197. What does the somatic nervous system do?
    conveys information from the CNS to sketetal muscle
  198. What does the autonomic nervous system do? What are its two divisions?
    conveys information from the CNS to smooth muscle, cardiac muscle and glands; sympathetic and parasympathetic
  199. What are neuroglia? What are the types?
    cells of the CNS that support and protect the neurons; astrocytes, oligodendrocytes, microglia, ependyma
  200. What are astrocytes?
    fibrocytes - star shaped, form the blood brain barrier, support network and neurotransmitter metabolism
  201. What are oligodendrocytes?
    shorter, form the myelin sheath, analogous to schwann cells in the PNS
  202. What are microglia?
    small cells, brain macrophages, migrate to area of injury to destroy microbes
  203. What are ependyma?
    single layer of epithelial cells, ciliated, squamous, columnar, line the ventricles, assist in circulation of CSF
  204. What are the two ends of a neuron?
    dendrites (carry nerve impulses toward the cell body) and axons (carry nerve impulses away from the cell body)
  205. What is a nerve impulse?
    a self propagating wave of electrical negativity that travels along the surface of neuron membrane, dependent on membrane potentials
  206. What is a resting membrane potential?
    the difference between the ion concentration outside and inside the plasma membrane, normal resting membrane potential is -70mV, normal muscle resting potential is -90mV
  207. What factors contribute to the resting membrane potential?
    ion concentration gradients between the ICF and the ECF and the membrane permeability to specific ions, potassium is the most important
  208. What two ions are present in the highest concentration?
    sodium and potassium, thus these two have the greatest effect on membrane potential
  209. Where is sodium concentrated?
    there are 10X as many sodium ions outside the cell as inside, concentration forces tend to move sodium ions into the cell
  210. Where is potassium concentrated?
    there are 30X as many potassium ions inside the cell as outside, concentration forces tend to move potassium ions outside the cell
  211. What does the sodium-potassium pump do?
    maintains the concentration gradients by the active transport of 3 sodium out and 2 potassium in
  212. What channels are open when the membrane is at rest?
    potassium ion channels are open, sodium channels are closed --> potassium, with its positive charge, maintains the resting membrane potential
  213. What happens when a neuron until it is stimulated? What can stimulate it?
    a nerve fiber remains polarized (charged) until stimulated by electrical, chemical, mechanical and thermal factors then it is depolarized (intensity of the stimulus exceedes the threshold of the fiber and the membrane becomes more permeable to sodium ions and that diffuse in
  214. What happens when depolarization occurs?
    positive sodium ions move into the cell and the cell becomes more positive (less negative) until it reaches about -35mV
  215. What is repolarization?
    the membrane becomes more permeable to potassium ions and impermeable to sodium ions, this allows potassium ions to move out of the cell --> inside of the cell becomes more negative (less positive)
  216. What is hyperpolarization?
    membrane potential becomes even more negative than the resting membrane potential (-95mV) after an action potential due to potassium gates remaining open
  217. What is an action potential?
    a membrane potential that temporarily reverses then returns to resting potential
  218. What is the absolute refractory period?
    time during which a second action potential cannot be initiated, even with a very strong stimulus, it lasts about 1msec and corresponds with sodium permeability changes
  219. What is the relative refractory period?
    time during which a second action potential can be generated, but only by a stronger than normal stimulus, lasts about 10 to 15 msec and corresponds to the hyperpolarization period
  220. What is the all or none principle?
    action potentials occur maximally or not at all, if a stiumulus is strong enough to generate an action potential the impulse is conducted along the entire neuron
  221. What is rheobase?
    the minimal voltage required to stimulate a response
  222. What is chronaxie?
    the minimum time an electrical current must flow at a voltage twice the rheobase to cause a muscle to contract
  223. What is continuous conduction?
    unmyelinated fibers - nerve impulses are transmitted step by step depolarization
  224. What is saltatory conduction?
    occurs in myelinated nerve fibers, propagation of an action potential along the exposed portions of the fiber (neurofibril node or node of ranvier). the myelin sheath (created by neurolemmocytes or schwann cells) insulates the fiber and allows for faster conduction
  225. What factors determine the velocity?
    fiber diameter (longer --> faster conduction) and degree of myelination (more myelin --> faster conduction)
  226. What are the Gasser Scheme nerve classifications?
    Aα, Aβ, Aλ, Aδ, B and C, classifies all peripheral nerve fibers
  227. What are the Lloyd Scheme classification?
    Ia, Ib, II, III, IV, classifies sensory fibers only
  228. What is group Aα?
    Ia and Ib, fastest and biggest, 72 to 120m/sec, muscle spindle primary afferent (annulospiral) (Ia), golgi tendon organ afferent (Ib) and skeletal muscle efferent
  229. What is group Aβ?
    II, 36 to 72m/sec, touch pressure receptor afferent, muscle spindle secondary (flowerspray) afferent
  230. What is group Aλ?
    12 to 48m/sec, muscle spindle efferent
  231. What is group Aδ?
    III, 6 to 30 m/sec, pricking pain, fast pain, cold afferent
  232. What is group B?
    2 to 18 m/sec, preganglionic autonomic efferent
  233. What is group C?
    IV, slowest, smallest, <2m/sec, aching pain, slow pain, hot afferent, postganglionic autonomic efferent
  234. What is adaptation?
    the firing frequency of a receptor declines after constant stimulation
  235. What is accomodation?
    the firing frequency of a nerve fiber declines after constant stimulation
  236. What occurs when an action potential reaches an axon terminal of a presynaptic neuron?
    calcium channels open, calcium diffuses into the axon terminal, synaptic vesicles release neurotransmitter into the synapse, the neurotransmitters diffuse across the synapse and bind to the receptors on the post-synaptic membrane
  237. What occurs at the post-synaptic membrane when the neurotransmitter binds to the receptor?
    specific ion channels are opened, at excitatory synapses there is a flow of positive ions into the cell, at inhibitory synapses there is a flow of positive ions out of the cell
  238. What is the trigger zone?
    The junction of an axon hillock and the axon, the first axon potential occurs here
  239. What is an excitatory postsynaptic potential (EPSP)?
    sodium channels are opened, inside of the cell becomes more positive (depolarized) --> increases the likelihood that the postsynaptic membrane will reach threshold
  240. What is an inhibitory postsynaptic potential (IPSP)?
    potassium or chloride channels are opened --> inside of cell becomes more negative --> more difficult for the neuron to generate an impulse
  241. What is facilitation?
    if the excitatory effect is greater than the inhibitory effect, but less than the threshold level of stimulation (allows subsequent stimuli to more easily generate a nerve impulse)
  242. What is a temporal summation?
    the sum of all the excitatory and inhibitory effects of a single presynaptic end bulb firing 2 or more times in rapid succession
  243. What is spatial summation?
    summation of the excitatory and inhibitory effects from several presynaptic end bulbs
  244. What are the dorsal columns?
    fasiculus gracilis (legs) and fasiculus cuneatus (arms), medial leminiscus system (DRG --> nuclei --> thalamus --> sensory cortex); detect proprioception, vibration and 2pt discrimination
  245. What is the posterior spinocerebellar tract?
    unconscious proprioception to the cerebellum from lower limb (DRG --> nucleus of clark C8 to L3 --> inferior cerebellar peduncle)
  246. What is the anterior spinocerebellar tract?
    stretch from spindle cells of lower limbs (DRG --> nucleus of clark C8 to L3 --> inferior cerebellar peduncle)
  247. Fredeicks ataxia occurs from damage to which fibers?
  248. What is the lateral spinothalamic pathway?
    pain and temperature (DRG --> crosses over --> thalmus --> cerebral cortex)
  249. What is the anterior spinothalamix pathway?
    light touch and pressure (DRG --> crosses over --> thalmus --> cerebral cortex), sexual feelings and foreplay
  250. What is the spinotectal tract?
    tactile stimulation causing visual reflexes (DRG --> crosses over --> tectum (superior colliculus), tectum is in the midbrain
  251. What are the pyramidal tracts?
    anterior and lateral corticospinal, a lesion here can casue an UMNL
  252. What is the lateral corticospinal tract?
    voluntary motor movements from the cerebral cortex (motor cortex --> contralateral pyramid medulla --> SC anterior horn)
  253. What is the anterior corticospinal tract?
    fine motor movements, especially of the hands (motor cortex --> ipsilateral medulla --> contralateral SC anterior horn)
  254. What is the rubrospinal tract?
    facilitates flexors, inhibits extensors, coordinates movement (red nucleus in tegmentum - floor of the midbrain)
  255. What is the reticulospinal tract?
    control of respiration and heartbeat, facilitates muscles, inhibits antagonists, involuntary (reticular formation - arousal and maintenance of consciousness), some fibers cross a termination
  256. What is the vestibulospinal tract?
    posture and balance, head and eye coordinated mov, extension of the erector spinae, involuntary (vestibular nucleus)
  257. What is the tectospinal tract?
    postural reflexes to sight and sound (tectum of the midbrain, superior colliculus) --> turns head toward sight and sound
  258. What is the the law of bell magendie?
    anterior spinal roots are motor and posterior spinal roots are sensory
  259. Describe the stretch reflex.
    reflex arc is monosynaptic (2 neurons), ipsilateral, receptor is muscle spindle, response is contraction
  260. What si reciprocal innervation?
    an impulse from a single sensory neuron will stimulate contraction of one muscle (effector) and simultaneously inhibits the contraction of another muscle (antagonist)
  261. Describe the tendon reflex.
    reflex arc is polysynaptic, ipsilateral, receptor is tendon organ (type Ib), response is relaxation
  262. Why do we have a tendon reflex?
    to protect the muscle from damage if we try to lift something too heavy (triggered by more stretch than the stretch reflex)
  263. What are the primary stretch receptors?
    annulospiral intrafusal fibers (detect dynamic stretch - rate of stretch) - innervate both bag and chain fibers
  264. What are the secondary stretch receptors?
    flower-spray intrafusal fibers (detect static stretch - amount of stretch) - innervate chain only
  265. What makes up the autonomic nervous system?
    Sympathetic (lateral horns of T1 to L2) and parasympathetic (CN III, VII, IX, X and S2, S3, S4), each division has a preganglionic and a postganglionic neuron
  266. What is a preganglionic neuron?
    visceral efferent neuron whose cell body is in the brain or spinal cord, it terminates at an autonomic ganglion where it synapses with a postganglionic neuron (exception is innervation to the adrenal medulla)
  267. What is a postganglionic neuron?
    lies entirely outside the CNS, cell body located in an autonomic ganglion, axon is unmyelinated and it terminates in a visceral effector
  268. What neurotransmitters are used by the autonomic nervous system?
    All are cholinergic (acetylcholine) except most postganglionic sympathetic which is adrenergic (epinephrine and norepinephrine) (note: postganglionic sympathetic to sweat glands, erector pilae and blood vessels are cholinergic)
  269. What is the parasympathetic NS?
    craniosacral division, rest and digest
  270. What does parasympathetic division of CN 3 innervate?
    occulomotor nerve --> ciliary ganglion --> intrinsic eye muscles (sphincter pupillae constricts, ciliary muscles constrict)
  271. What does parasympathetic division of CN 7 innervate?
    Facial nerve --> submandibular, pterygopalantine ganglion --> lacrimal (tears) and salivary glands (saliva)
  272. What does parasympathetic division of CN 9 innervate?
    Glossopharyngeal nerve --> otic ganglion --> parotid gland (stensons duct is opposite second molar) - saliva
  273. What does parasympathetic division of CN 10 innervate?
    Vagus nerve --> myenteric and auerbach plexus --> smooth muscle and glands of the thoracoabdominal cavity up to the left colic (splenic) flexure
  274. What does parasympathetic division of S2,3,4 innervate?
    Pelvic splanchnics of hypogastric plexus --> pelvic plexus --> colon below the splenic flexure (descending colon, sigmoid, rectum) and sex organs, kidney and bladder
  275. What nerves maintain erection?
    S2,3,4 keep your penis off the floor
  276. What is the sympathetic nervous system?
    thoracolumbar or "fight or flight" system, T1 to L2 spinal nerves
  277. Where do sympathetic fibers originate, where do they go?
    • cell bodies in lateral horn leave through white rami communicantes and go to sympathetic chain then:
    • fibers synapse in the chain and return to all spinal nerves via gray rami communicantes or
    • pass through the sympathetic chain without synapsing and leave via splanchnic nerves (still preganglionic)
  278. What is the greater splanchnic nerve?
    T5-9, celiac ganglion --> thoracoabdominal cavity through the small intestine
  279. What is the lesser splanchnic nerve?
    T10-11, superior mesenteric ganglion --> ascending colon
  280. What is the lumbar splanchnic nerve?
    L1-3, inferior mesenteric ganglion --> descending colon, sigmoid, rectum, sex organs, bladder
  281. What vessels have what innervation?
    Arteries and veins have sympathetic innervation only, capillaries have no innervation, blood vessesl have NO parasympathetic innervation
  282. Overall effects of sympathetic.
    constrict blood vessels of skin and viscera, dilate blood vessels of muscles, increase heart rate, dialte lung bronchi, dilate pupils, inhibit peristalsis
  283. Overall effect of parasympathetic.
    no effect on blood vessels, decrease heart rate, constrict or normalize bronchi and pupils, stimulate peristalsis
  284. What receptors are present in autonomic nervous system?
    postganglionic receptors are nicotinic (Ach), effectors are muscarinic (Ach) (except those that recieve NE - adrengeric)
  285. What are the types of ACh receptors?
    nicotinic (also stimulated by nicotine) and muscarinic (also stimulated by muscarine - mushroom poison)
  286. What are cholinergic fibers?
    fibers which release ACh, somatic motor neurons to skeletal muscles, parasympathetic (all) and sympathetic (all pre and some post) --> ACh is excitatory
  287. What is acetylcholinesterase?
    inactivates ACh by breaking it down into its components
  288. What is norepinephrine (NE)?
    can be excitatory or inhibitory, adrenergic fibers (release NE), most postganglionic sympathetic neurons and the adrenal medulla
  289. What types of receptors are there for NE?
    alpha adrenergic and beta adrenergic
  290. What are the functions of the medulla?
    consciousness and arousal (reticular), reflex centers for heart rate, breathing and vessel diameter, equilibrium (vestibular)
  291. What are the functions of the pons?
    pneumotoxic and apneuctic area (and w/medulla) controls breathing
  292. What are the functions of the midbrain?
    eyeball, head and trunk movements
  293. What are the functions of the thalamus?
    relay station for all sensory (except smell), emotions and memory, pain, temperature, light touch, pressure interpretation
  294. What are the functions of the hypothalmus?
    mind-over-body regulation of hormones, integrates autonomic NS, rage, aggression, temperature, food intake, thirst, wakefulness, sleep
  295. What are the main functions of the cerebrum?
    sensory interpretation, motor control, emotions, intellect, basal ganglia (gross muscle movement and muscle tone) and limbic system (emotions related to survival)
  296. What are the main functions of the cerebellum?
    subconscious skeletal muscle for coordination, posture and balance, emotional development and modulate anger and pleasure
  297. What are the functions of the reticular formation?
    contains reticular activating system, concerned with arousal and wakefulness/consciousness
  298. CN 1
    olfactory, sensory, exits through the cribiform plate of the ethmoid bone, function is smell (mitral cells)
  299. CN 2
    Optic, sensory, exits through the optic canal, function is vision (ganglion cells)
  300. CN3
    occulomotor (parasympathetic), motor, exits through superior orbital fissure (SOF), function is pupil constriction, eye movement except LR (CN 6) and SO (CN 4)
  301. CN 4
    Trochlear, motor, Superior orbital fissure, SO muscle
  302. CN 5
    • V1 (opthalamic) - sensory, SOF, sensation from upper face
    • V2 (maxillary) - sensory, foramen rotundum, sensation from middle face
    • V3 (mandibular) - both, foramen ovale, sensation from lower face and motor to muscles of mastication
  303. CN 6
    Abducens, motor, SOF, LR muscle
  304. CN 7
    Facial (parasympathetic), both, sensory exits through internal auditory meatus to taste to ant. 2/3 of tongue, motor exits through the styloid foramen to muscles of fascial expression
  305. CN 8
    Vestibular-cochlear, sensory, internal auditory meatus, equilibrium and hearing
  306. CN 9
    Glossopharyngeal (parasympathetic), both, jugular foramen, stylopharyngeus muscle, taste to post. 1/3 of tongue
  307. CN 10
    Vagus (parasympathetic to 90% of the body), both, jugular foramen, taste to epiglottis, motor to pharynx and larynx
  308. CN 11
    Accessory, motor, jugular foramen, SCM and trapezius
  309. CN 12
    Hypoglossal, motor, hypoglossal canal, motor to the tongue
  310. What are 2 of the muscles supplied by the hypoglossal nerve?
    styloglossus (retracts and elevates the tongue) and genioglossus (protrudes the tongue)
  311. What do the two pterygoid muscles do?
    Medial (internal) closes the mouth "MMMM" and the lateral (external) opens the mouth "Lalala"
  312. What are the TMJ muscles? Who supplies them?
    "BITE'M" Buccinator (CN 7), internal pterygoid, temporalis, external pterygoid, masseter (all CN 5) "ITEM"
  313. What do Meissner's corpuscles detect?
    light touch, pressure, low frequency vibrations
  314. Where are root hair plexuses?
    around the hair follicles
  315. What do merkel discs detect?
    discrimination touch
  316. What do end organ ruffini detect?
    continuous touch and pressure
  317. What do pacinian corpuscles detect?
    pressure and high frequency vibrations
  318. What do free nerve endings detect?
    itch and tickle
  319. What receptors detect temperature?
    ruffini corpuscles detect warmth, Krause corpuscles detect cold
  320. What receptors detect pain?
    nociceptors - free nerve endings
  321. What is proprioception?
    the awareness of the precise postition of body parts
  322. What is kinesthesia?
    the awareness of directions of movement
  323. What are muscle spindles?
    stretch receptors embedded in the skeletal muscle detecting muscle length, they consist of intrafusal fibers (3 to 10 specialized muscle fibers within the capsule) and extrafusal fibers (normal muscle fibers surrounding the capsule
  324. What are golgi tendon organs?
    located in the tendons near the junction with the muscle, they monitor muscle tension
  325. What are the types of muscle tissue?
    skeletal (striated, voluntary, skeletal movement), cardiac (striated, involuntary, controlled by autonomic NS and hormones), smooth (nonstriated, involuntary, visceral, controlled by autonomic NS)
  326. What is sarcolemma?
    plasma membrane of the individual muscle fiber or cell
  327. What is sarcoplasm?
    cytoplasm of a muscle cell (note: skeletal muscle is multinucleated)
  328. What is sarcoplasmic reticulum?
    membrane enclosed tubules which capture and release calcium
  329. What are T tubules?
    carry the depolarization from the end plate to the sarcoplasmic reticulum, not found in smooth muscle
  330. What myofilaments are found in muscle?
    thin (actin) and thick (myosin in a ratio of 2:1 in skeletal and 15:1 smooth muscle
  331. What is the sliding filament theory?
    during muscle contraction neither the thick filaments or the thin filamnets change in length, instead the thin filaments slide past the thick
  332. What is the A band?
    corresponds to the length of the thick filament only (it's width remains constant)
  333. What is the I band?
    corresponds to the portions of the thin filaments that do not overlap thick filaments, it's width decreases during contraction
  334. What is the H zone?
    corresponds to the center of the dark band where only thick filaments are present, it's width decreases during contraction
  335. What is the neuromuscular junction?
    myoneural junction, where the synaptic end bulb and motor end plate meet
  336. What is the motor end plate?
    the portion of the muscle fiber that is adjacent to the synaptic end bulb of the motor neuron, it contains receptors for acetylcholine
  337. What occurs when the action potential reaches the synaptic end bulb?
    calcium channels open, calcium diffuses into synptic end bulb causing ACh to be released into the synapse, ACh binds with a receptor on the motor end plate causing an end plate potential
  338. What happens after the end plate potential is created?
    the remaining ACh is destoyed by acetylcholinesterase and the end plate potential causes a muscle action potential, which passes into the muscle fiber by way of the transverse tubules, which are not found in smooth muscle, the action potential triggers the release of calcium from the sarcoplasmic reticulum, calcium binds to the troponin which initiates the muscle contraction
  339. What occurs in a relaxed state of muscle?
    tropomyosin covers the myosin binding site on troponin (note: tropomyosin and troponin are part of the thin filaments - actin)
  340. What occurs when calcium binds to troponin?
    shape change (muscle contraction begins), causing tropomyosin to move which uncovers the myosin cross bridge binding sites on actin, ATP attaches to a binding site on the myosin cross bridge, giving energy to activate the cross bridge, the remaining ADP stays attached to myosin
  341. What occurs after the myosin cross bridge is activated?
    it attaches an adjacent actin molecule, this produces a power stroke --> myosin pulls actin toward the center of the sarcomere, as the myosin cross bridge swivels it releases the ADP, another ATP attaches causing the myosin link to break and the cross bridge can attatch to another actin, one power stroke of a cross bridge results in a small movement of the thin filament
  342. What is a motor unit?
    a motor neuron and the muscle fibers it stimulates (2 to 2000 muscle fibers), fine muscle control --> one neuron stimulates a few fibers, coarse muscle control --> one neuron stimulates many muscle fibers
  343. What is motor unit recruitment?
    the process of increasing the number of active motor units --> more muscle fibers involved in the contraction, the various motor neurons to a given muscle fire at different times to prevent fatigue of individual fibers
  344. What is a twitch?
    a brief contraction of all the muscle fibers in a motor unit in response to a single motor neuron action potential, it is a rapid, jerky response
  345. What is tetanus?
    a rapid succession of seperate twitches due to summation (2 seperate stimuli to the same motor unit cause a stronger contraction)
  346. What is an isometric contraction?
    muscle length remains constant, tension changes
  347. What is an isotonic contraction? What are the types?
    tesnion remains constant, muscle length changes, concentric (the muscle undergoing the strongest contraction shortens) or eccentric (the muscle that generates less tension is stretched)
  348. What are slow twitch fibers?
    type I oxidative - found in postural muscles, red due to high concentrations of myoglobin, high level of aerobic enduracne, slow ATPase, well suited for prolonged low intensity work
  349. What are fast twitch fibers?
    • Type IIa - oxidative/glycolytic - this is a red muscle fiber and is known as intermediate fast because it can sustain activity for longer periods OR it can contract with a burst of force then fatigue - used for one mile
    • Type IIb - glycolytic - provides rapid force production and fatigues quickly, used in highly explosive events (100meters)
  350. Where is smooth muscle found?
    walls of hollow viscera, blood vessels, iris and ciliary muscles
  351. Describe smooth muscle.
    non-stiated, uninucleated, no sarcomere, slow contraction, no transverse tubules, involuntary 15 actin: 1 myosin
  352. What are the two types of smooth muscle?
    • single unit (visceral) is the most common, connected by Gap junctions which help to facilitate nerve impulse conduction producing a wave of contraction instead of individual contractions (as occur in skeletal muscle)
    • multi unit - fibers act independently, each fiber is directly innervated by an axon terminal
  353. Describe cardiac muscle.
    striated, uninucleated, with intercalated discs, involunatry, same arrangement of actin and myosin as skeletal
  354. What are intercalated discs?
    thickenings of the sarcolemma that connect adjacent cardiac muscle fibers, they contain gap junctions for support and spread of action potentials between cells
  355. What is autorhythmicity?
    cardiac muscle fibers can contract without extrinsic stimulus from nerves or hormones, however, nervous and hormonal input alter the rate of discharge
  356. What is the contraction time for cardiac muscle?
    cardiac fibers remain contracted longer than skeletal muscle, also cardiac muscle tissue has an extra long refractory period which allows time for the heart to relax between beats, also permits the heart to be increased significantly but prevents the heart itself from undergoing tetany
  357. What digestion occurs in the mouth?
    mastication (forms bolus), salivary amylase (ptyalin) digests starch to maltose
  358. What digestion occurs in the esophagus?
    muscular tube (starts as skeletal and ends as smooth - peristalsis), stratified squamous with mucous glands, secretes mucous and transports food
  359. What is heartburn?
    lower esophageal sphincter doesn't close and HCl irritates esophagus
  360. What are the types of cells in the stomach?
    • zymogenic or peptic (chief) cells - secrete pepsinogen which is converted to pepsin by HCl, pepsin will aide in protein digestion
    • Parietal (oxyntic) cells - secrete HCl and intrinsic factor (B12 absorption)
    • Mucous cells - secrete mucus
    • Enteroendocrine cells - secrete stomach gastrin which stimulates HCl and pepsinogen (zymogen) release, pepsin converts proteins to peptides
  361. What stimulates the cells of the stomach? What inhibits it?
    • Stimulate: vagus, cephalic reflex (thinking, smelling food), distention and hormones
    • Inhibit: food in small intestine (enterogastric reflex), cholestokynin, secretin
  362. What digestion occurs in the small intestine?
    majority of digestion and abosrption (90% - length and microvilli enhance it), crypts of lieberkuhn (intestinal juice - water and mucous), brunner's glands (mucous)
  363. What mechanical digestion occurs in the small intestine?
    sementation (localized contraction to mix enxymes and chyme and not to push it along), peristalsis (propels chyme through the intestinal tract)
  364. What digestion of carbohydrates occurs?
    • first salivary amylase in mouth then from pancreas breaks complex carbs into disaccharides
    • maltase breaks maltose into 2 glucose
    • sucrase breaks sucrose into glucose and fructose
    • lactase breaks lactose into glucose and galactose
  365. How are proteins digested?
    pepsin (stomach), trypsin, chymotrypsin, carboxypeptidase, peptidases
  366. How are lipids digested?
    bile salts and pancreatic lipase
  367. What is absorbed from the small intesine?
    monosaccharides, amino acids, chylomicrons, majority of water (mostly in jejunum) and electrolytes, vitamins
  368. What mechanical digestion occurs in the large intestine?
    haustral churning (distention causes contraction and squeezes contents onward), peristalsis (slow, first part of large intestine), mass peristalsis (strong peristaltic wave from mid-transverse colon onward)
  369. What absorption occurs in the large intestine?
    some water (cecum, ascending colon), some electrolytes and vitamins
  370. What is gastric emptying?
    emyptying of the stomach into the small intestine, occurs within 2 to 6 hours
  371. What will increase gastric emptying (peristalsis)?
    distention, gastrin
  372. What will decrease gastric emptying?
    excessive food in the duodenum, increased acidity of the duodenum
  373. Where do secretions from pancreas go?
    secreting cells --> small ducts --> pancreatic duct or accesoory duct --> common bile duct --> hepatopancreatic ampulla --> duodenum
  374. What part of the pancreas are islets of langerhans? What are they?
    1% (endocrine portion) - alpha (glucagon), beta (insulin), delta (somatostatin)
  375. What part of the pancreas is exocrine?
    acini cells - makes amylase, trypsinogen, chymotrypsinogen, procarboxypeptidase
  376. What activates pancreatic enzymes?
    enterokinase activates trypsin, trypsin activate the rest
  377. What does vagus stimulate?
    enzyme secretion
  378. What does acidic chyme stimulate?
    secretin --> sodium bicarbonate
  379. What do fat and proteins stimulate?
    cholecystokinin --> pancreatic enzymes
  380. What are the cells of the liver? What do they do?
    Hepatic cells (produce bile - emusify and absorb fats), Kuppfer cells (filter portal blood, phagocytic action on old WBC, RBC, bacteria, toxins), overall liver function is to store nutrients, make new materials, detoxify, metabolize and phagocytosis
  381. How does the liver participate in carbohydrate metabolism?
    glycogenesis (glucose --> glycogen), glycogenolysis (glycogen --> glucose), gluconeogenesis (AA to glucose, fructorse and galactose to glucose), glucose to fat
  382. How does the liver participate in fat metabolism?
    synthesize cholesterol, cholesterol to bile salts, increase acetyl-CoA --> ketones (ketogenesis), fatty acids --> acetyl-CoA
  383. How does the liever participate in protein metabolism?
    ammonia --> urea, synthesis of plasma proteins
  384. What drugs and hormones does the liver remove from the blood?
    antibiotics, estrogen, aldosterone, thyroxine
  385. What does the liver store?
    glucagon, vitamins (A,D,E,K,B12), minerals (iron and copper), apoferratin --> ferratin (storage)
  386. What enzymes are in the liver?
    LDH, SGPT, SGOT, arymase, alkaline phophatase
  387. What does the gall bladder do?
    store and concentrate bile by removing water and ions, releases bile when high fat content in duodenum
  388. What are the layers of the GI tract?
    mucosa (inner), submucosa, muscularis, adventia
  389. What nerve plexuses are in the GI tract?
    meisners (submucosa) and myenteric (auebachs)
  390. What provides parasympathetic innervation to GI tract?
    vagus until splenic flexure, sacral plexus (S2-4) from spenic flexure caudal
  391. What is endocrine secretion?
    secretion of horomones into blood and maintains homeostasis. organs with endocrine function include the pancreas, ovaries, testes, kidneys, stomach, small intestine and placenta
  392. What is exocrine secretion?
    secretion of products directly into ducts which carry the secretions to target tissue organs (ex. sweat glands, digestive, oil and mucus)
  393. What are two actions hormones can take?
    plasma membrane receptors (polypeptide hormones, neurotransmitters), activation of genes (steroid hormone, thyroid hormone)
  394. What will plasma membrane receptors do?
    Hormone (first messenger) --> receptor --> activates adenylate cyclase to convert ATP to cAMP --> protein kinase --> physiological response
  395. How are genes activated by hormones?
    hormone --> passes through membrane --> intracellular receptors --> specific gene interaction --> physiological response
  396. What are prostaglandins?
    local tissue hormones (not circulatory hormones) - potent in minute quantities, produced by mammalian cells, participate in inflammation response, dilation and constriction of blood vessels
  397. What will increase prostagladins? inhibit?
    chemical, mechanical, anaphylasix increase, asprin and acetaminophen inhibit
  398. What is the main method of hormonal control? What other method is used?
    negative feedback (stimulus initiates action to reduce stimulus - primary control) and postive feedback (stimulus initiates action to increase stimulus)
  399. What are examples of negative feedback?
    low blood calcium --> increase PTH --> increase blood calcium --> inhibits PTH (blood sugar and insulin work the same way)
  400. What is an example of positive feedback?
    uterine contractions during labor --> increase nerve impulse --> hypothalamus --> posterior pituitary --> release oxytocin --> increase uterine distention and contractions
  401. Where is the pituitary located and what are its parts?
    located in the sella turcica - adenohypophysis (anterior pituitary - glandular), neurohypophysis (posterior - nervous tissue) and pars intermedia (avascular zone between the lobes)
  402. What is the anterior pituitary made of?
    glandular epithelium, hormones are released and inhibited by factors produced in the hypothalamus
  403. What is the posterior pituitary pituitary made of?
    neuroglial cells, ADH and oxytocin are made in hypothalamus and stored here
  404. What is diabetes insipidous?
    hypo ADH
  405. Where is the thyroid? What type of cells does it have?
    located below the larynx, consists of follicular cells (secrete thyroid hormones thyroxin/T4 and triiodothyronine/T3) and parafollicular cells (secrete calcitonin)
  406. What are thyroid hormones made from? What are they released in response to? What do they regulate?
    synthesized from iodine and tyrosine, they are released in response ot thyroid releasing factor, they regulate metabolism
  407. What disorders are associated with the thyroid?
    Cretinism (hypo, child), myxedema (hypo, adult), graves (hyper), exopthalmic goiter, simple goiter
  408. What does calcitonin do?
    lowers the blood level of calcium, controlled by its own level in the blood
  409. Where is the parathyroid? What type of cells does it have?
    located on the posterior surface of the lateral lobes of the thyroid, consists of principal and oxyphil cells, secretes parathyroid hormone
  410. What are the functions of PTH?
    increase blood calcium and decrease blood phosphate levels, stimulates osteoclasts (reabsorb bone), causes the kidney to conserve calcium and excrete phosphate
  411. What disorders are associated with PTH?
    Hyperparathyroidism (excessive loss of bone) and hypoparathyroidism (drop in blood calcium and tetany)
  412. Where is the thymus? What does it do?
    lies behind the sternum, between the lungs, size diminishes with age, secretes several hormones related to immunity (thymosin, thymic humoral factor, thymic facotr, thymopoietin --> all promote maturation of T cells)
  413. Where are the adrenals? What are its parts?
    suprarenal (superior to the kidney), consists of an outer cortex (zona glomerulosa, zona fasciculata and zona reticularis) (all release hormones in response to ACTH from anterior pituitary) and an inner medulla
  414. What does the zona glomerulosa do?
    outermost layer, secretes mineralcorticoids (aldosterone - reabsorb sodium and water, excrete potassium)
  415. What is aldosteronism?
    Conn's disease, hypersecretion of aldosterone
  416. What does the Zona fasciculata do?
    middle layer of cortex, secretes glucocorticoids such as cortisol which helps to promote normal metabolism (activates gluconeogenesis, mobilizes AAs and mobilizes and catabolizes fatty acids), resist stress and anti-inflammatory
  417. What pathologies are associated with cortisol?
    Addisons disease (hyposecretion of glucocorticoids and mineral corticoids) and cushings disease (hypersecretion of glucocorticoids)
  418. What does the zona reticularis do?
    inner layer of the cortex, secretes gonadocorticoids (estrogen and androgens - secondary sex characteristics in the adolescent, normally barely present in adult)
  419. What does the adrenal medulla consist of?
    chromaffin cells (develop from same origin as the postganglionic cells of sympathetics) which are innervated by preganglionic sympathetic neurons
  420. How is the adrenal medulla controlled?
    directly controlled by the autonomic NS, specifically the hypothalamus, responds rapidly to produce Epinephrine (adrenaline) or norepinephrine (noradrenalin) during stress
  421. Where is the pancreas? What is its functions?
    posterior and inferior to the stomach, it is both an endocrine and exocrine gland, endocrine portion consists of pancreatic islets or islets of langerhans (alpha - glucagon, beta - insulin, delta - somatostatin or growth hormone inhibiting factor which inhibits glucagon)
  422. What are the functions of glucagon?
    increase blood glucose levels by activating glycogenolysis and gluconeogenesis and inhibiting glycolysis and glycogenesis, secretion of glucagon is controlled by blood glucose levels
  423. What are the functions of insulin?
    decrease blood glucose levels by activating glycolysis, glycogenesis, lipogenesis, protein synthesis and inhibiting glycogenolysis, gluconeogenesis, beta oxidation of lipids, protein breakdown, secretion of insulin is controlled by blood glucose levels
  424. What is the function of somatostatin?
    inhibit insulin and glucagon
  425. What hormones do the ovaries produce?
    estrogen/progesterone (female sex characteristics, menstrual cycle, pregnancy, mammary glands for lactation) and relaxin (relaxes the symphysis pubis, helps dilate the uterine cervix near the end of pregnancy, increases sperm motility)
  426. What hormones do the testes produce?
    testosterone (develop and maintain male sex characteristics) and inhibin (inhibits secretion of FSH to control sperm production)
  427. Where does the adenohypophysis come from? How is it connected to the hypophysis? What hormones does it produce?
    Rathke's pouch, blood, growth hormone, prolactin, thyroid stimulating hormone, adrenocorticotrophic hormone, follicle stimulating hormone, leutinizing hormone, melanocyte stimulating hormone
  428. Where does the neurohypophysis come from? How is it connected to the hypophysis? What hormones does it produce?
    neurohypophyseal bud, neural and blood, oxytocin and antidiuretic hormone
  429. What female horomones are released by hypothalamus, anterior pituitary and ovaries?
    Gonadotropin-releasing hormone (GnRH)/Luteinizing hormone releasing hormone (LHRH) from hypothalamus --> follicle stimulating hormone (FSH) and luteinizing hormone (LH) in anterior pituitary --> estrogen and progesterone in ovaries
  430. How long is the menstrual cycle? What are the phases?
    24 to 35 days (about 28), Menstrual phase (days 1-5), proliferative phase (days 6-13) and secretory phase (days 15-28) or progestational phase
  431. What occurs during the menstrual phase?
    discharge of blood (degeneration of the stratum functionalis layer of the endometrium caused by a sudden reduction in estrogen and progesterone), approximately 40 mm of blood are lost
  432. What is the proliferative phase?
    under the influence of estrogen from the ovary the endometrium begins to thicken, at the time of ovulation (day 14) the endometrium is 4 mm thick, endometrial glands secrete a mucous which helps guide the sperm to the ovum
  433. What is the secretory phase?
    progesterone and estrogen are secreted in large quantities by the corpus luteum causing additional cellular proliferation of the endometrium to about 6 mm
  434. What are the phases of the ovarian cycle?
    follicular phase (days 1-13), ovulation (day 14), luteal phase (days 15-28)
  435. What occurs during the follicular phase?
    • anterior pituitary increases secretion of FSH and LH --> accelerated growth in 6 to 12 primary follicles which release estrogen stimulating more development
    • after a week or more one follicle outgrows the others and the others begin to involute (atresia), the more developed follicle secretes more estrogen
    • large amounts of estrogen stimulate negative feedback on the hypothalamus to inhibit secretion of FSH and LH from the anterior pituitary (blocks further growth of the less developed follicles) --> FSH and LH decrease
  436. What occurs during ovulation?
    About 2 days before ovulation the rate of secretion of LH rises dramatically, without this rise ovulation will not occur, FSH levels also rise but not as much, the LH causes the follicle to rupture, the follicle secretes more progesterone and less estrogen
  437. What occurs during the luteal phase?
    the secretory cells of the follicle develop into the corpus luteum which secretes large quantities of estrogen and progesterone (more progesterone) and inhibin (inhibits FSH and LH secretion from anterior pituitary) --> corpus luteum will degenerate (involute) at day 26
  438. What occurs after the involution of the corpus luteum?
    estrogen and progesterone levels decrease, removing the negative feedback on the anterior pituitary so it can secrete large quanities of FSH and LH again, follicular growth is initiated and a new ovarian cycle begins
  439. What is chorionic gonadotropin?
    secreted by the placenta, will maintain the corpus luteum for the first 2 to 4 months of pregnancy
Card Set
Physiology Dr.Guy's
Flashcards for NBCE study based on Dr.Guy's study guide for Physiology