Physiology Exam 4

  1. Cardiovascular System
    Consists of the heart, a pumping organ, closed system of blood vessels (arteries, capillaries, veins)
  2. Cardiac Muscle Fiber(cardiocytes or cardiomyocytes)
    • Striated and branced
    • Have one nucleous
    • Surrounded by a mass of glycogen and lots of mitochondria and myoglobin
    • *Glycogen is a polymer of glucose
    • Fibers are joined by intercalated discs which increase speed of conduction
  3. Cardiac Muscle Metabolism
    • Cardiac muscle depends on aerobic respiration to make ATP
    • It's rich in myoglobin (oxygen store) and glycogen (energy store)
    • The mitocondria fill about 25% of the monocyte
  4. Heart
    • Located between the lungs in the thoracic cavity
    • Also located in mediastinum deep in the sternum between ribs 2-6
    • Base: broad superior portion of the heart
    • All great vessels enter/exit through the base
    • Apex: Inferior end above the diaphram that points to the left
    • Great vessels include superior and inferior venae cavae, pulmonary veins, pulmonary trunk, and aorta
    • Pericardium: double-walled sac that surrounds the heart
    • Pericardial(parietal pericardium) is the two-layered outer wall, inner serous, outer fibrous
    • Serious layer turn inward at the base of the heart and form visceral pericardium is = to the epicardium
  5. Pericardial Cavity
    • Forms between pericardial sac and visceral pericardium
    • Contains pericardial fluid
    • Fluid lubricates the membranes which allow the heart to beat with minimal fraction
  6. Heart wall consists of 3 layers...
    • Epicardium
    • Endocardium
    • Thick Myocardium(cardiac muscle)
  7. More Heart info...
    • Each atria has a ear like extension called auricle which increases the volume (increases the amount of blood that the atria can hold)
    • Thin walled
    • Light work load receive blood from veins and pump blood into ventricle
    • Ventricles are thick-walled
    • Left ventricle is thicker and stronger than right ventricle and pumps blood through the entire body
  8. The Valves
    Ensure one-way flow of blood and consists of flaps that open and close
  9. Atrioventricular (AV) Valves
    • Separate atria from ventricles and prevent back flow into atria
    • Cusps are attached to chordae tendinae and papillary muscles
  10. Semilunar Valves
    • Are at the base of aorta or pulmonary trunk and prevent back flow into ventricles
    • Consist of two cusps
  11. Path of Blood Through the Heart
    • 1) Superior/ Inferior venae cavae
    • Right Atrium
    • 2) Right AV Valve
    • Right Ventricles
    • 3) Contraction of right ventricle forces pulmonary valve open
    • 4) Pulmonary Trunk
    • 5) Blood is distributed by right and left pulmonary arteries to the lungs, where it unloads CO2 and loads O2
    • 6) Blood returns from lungs via pulmonary veins
    • Left Atrium
    • 7) Left AV Valve
    • Left Ventricle
    • 8) Contraction of left ventricle (simultaneous with step 3) forces aortic valve open
    • 9) Ascending Aorta
    • 10) Aorta distributes blood to every body organ, where it unloads O2 and loads CO2
    • 11) Venae Cavae
    • Heart
  12. Pulmonary Circuit
    R ventricle > lung capillaries > L Atrium
  13. Systemic Circuit
    L Ventricle > Capillary beds in body tissues and organs > R Atrium
  14. Each unit of blood...
    Passes through the heart twice in a complete cycle
  15. The coronary (atrioventricular) sulcus
    • Encircles the heart near the base
    • Separates ateria above from the ventricles below
    • The anterior interventricular sulcus (enters right atrium and rest is emptied into coronary sinus 90%) and posterior interventricular sulcus both lie over the interventricular septum
  16. Coronary Circulation
    • Right and left coronary arteries and their branches supply myocardium with oxygen and nutrients
    • Blockage due to plague or an embolus can cause ischema (no oxygen), hypoxia (low oxygen), myocardial infarction (heart attack), or angina (blockage in coronary artery)
  17. Cardiac Veins
    • Collect oxygen-deficient blood from myocardium and drain it into the coronary sinus and then the right atrium
    • 5-10% empties into heart R ventricle and rest is delivered to R atrium through coronary sinus
  18. Heart Conduction System
    • Myogenic
    • Initiated by the myocyte itself instead of an outside stimulus such as nerve innervation
  19. Cardiac Rhythm
    Normal cardiac cycle averaging 70-80 beats per minute (bpm)
  20. Heat Conduction
    • Initiated at the SA node
    • Impulse spreads through atria (causing atrial systole; contraction) to AV node and into ventricles through AV bundle (bundle of HIS) and purkinje fibers (causes ventricle systole; contraction)
    • In ventricles, impulse spreads from apex up to semi-lunar valves
    • Electrical events om the heart produces cycle of systole (contraction) and diastole (relaxation)
  21. Cardiac Rhythm or Sinus Rhythm
    • Normal heart beat triggered by the SA nodes
    • 1) SA node fires
    • 2) Excitation spreads through atrial myocardium
    • 3) AV node fires
    • 4) Excitation spreads down AV bundle
    • 5) Purkinje fibers distribute excitation through ventricular myocardium
  22. Heart Rate
    • Bpm
    • Pulse
  23. Arrhythmia
    • -Pulse Rhythm Disorder
    • tachycardia, too fast
    • bradycardia, too slow
    • nodal rhythm
    • heart block
    • premature ventricular contraction
    • ventricular fibrillation
  24. Electrocardiograms (ECG)
    • Detect electrical current in the heart by means of electrodes applied to skin using electrocardiograph to amplify these signals and produce a record
    • Present a graphical composite of action potentials from multiple myocardial cells
    • P wave-atrial depolarization
    • QRS complex- ventricular depolarization
    • T wave- ventricular re-polarization
    • PQ- atrial systole
    • ST- ventricular systole
  25. Abnormal ECGs may reveal...
    • nodal rhythm
    • heart block
    • premature ventricular contractions PVCs
    • ventricular fibrillation
    • hypertrophy/enlargement of a chamber (large P or R)
  26. Nodal Rhythm
    • Cardiac rhythm originating in the AV node
    • Heart rate of 40-70 per minute
    • *heart block lack QRS
  27. PVCs are caused by...
    • heart attack
    • high bp
    • heart valve disease
    • medications
  28. Ventricular Fibrillation
    Condition which (heart blooding) there is uncoordinated contraction of the cardiac muscle of the ventricles
  29. Output by ventricles must be equal volume if...
    • Right ejects more > pulmonary hypertension and edema
    • Left ejects more > peripheral hypertension and edema of tissues
  30. Cardiac Output
    Amt blood ejected from heart in 1 min = stoke vol x heart rate
  31. Stroke Volume
    • Volume of blood ejected from the left ventricle at each beat of the heart
    • Can be increased by increasing volume of blood entering chamber and stretching myocardium
    • Decreases with resistance in vessels Ex: from atherosclerosis or scar tissue in lungs
  32. Bp
    • Sometimes referred to as atrial blood pressure
    • Pressure is exerted by circulating blood upon the walls of blood vessels
    • For each heartbeat, bp varies between systolic and diastolic bps.
  33. Systolic pressure
    Peak pressure in arteries, which occurs near the end of the cardiac cycle when the ventricles are contracting
  34. Diastolic pressure
    Minimum pressure in the arteries, which occurs near the beginning of the cardiac cycle when the ventricles are filled with blood
  35. Sphygmomanometer
    • Blood pressure meter
    • Often attached to an inflatable air-bladder cuff and used with a stethoscope, for measuring bp in an artery (brachial)
    • Pressure measured in mmHg
    • Normal resting healthy human is 120/80mmHg
  36. High bp (hypertension)
    • Causing fatty deposits in the walls of arteries (atherosclerosis)
    • Genetics, diet, stress, lack of physical activity contributes to risks for high bp
  37. One Cardiac Cycle
    • .8 sec includes,
    • -atrial systole (.1 sec)
    • -ventricular systole (.3 sec)
    • -overlapping diastole (.4 sec)
    • involves all 4 chambers
  38. Lubb-Dupp
    • Lubb represents the first sound (S1) which is longer and has a lower pitch and is made by the closure of the mitral and tricuspid valves
    • Dupp represents the second sound (S2) that marks the beginning of ventricle diastole. It is produced by the closure of the aortic and pulmonary semilunar valves
    • A brief pause occurs after the second heart sound when the heart is beating at a normal rate.
  39. The Respiratory System
    • In humans and other mammals, the anatomical features of the respiratory system includes airways, lungs, and the respiratory muscles
    • Coordinates the exchange by diffusion, of oxygen and carbon dioxide between an organism and its environment
    • The airways (conducting portion) of respiratory system brings air into the body and consists of: nose, nasal cavity, nasopharynx, larynx, trachea, bronchi, and bronchioles
    • Gas exchange portion contains: microscopic alveoli
  40. The Respiratory System has numerous functions such as...
    Gas exchange, smell, control pH, and vocalization
  41. Larynx
    Voice box consists of several cartilages
  42. Glottis
    The opening between the vocal cords
  43. Epiglottis
    Flap of tissue guarding the superior opening of the larynx
  44. Vocal folds/cords
    Twin infolding of mucous of membrane stretched across the larynx
  45. Mechanical Respiration
    • Ventilation
    • Gas Exchange
  46. Cellular Respiration
    metabolic process in cells
  47. Trachea
    • C-shaped rings of cartilage
    • Smooth muscles
    • A mucous with mucous glands, goblet cells, and cillia
    • It branches into right and left main bronchi at the carina
  48. Lungs
    • Spongy mass composed of 300 million alveoli
    • Located in thorax
  49. Alveoli
    • Sites of gas exchange deep with in the lungs
    • Very thin walls
    • Surrounded by a rich network of blood vessels
  50. Hilum
    Slit on the lung's surface where pulmonary vessels and bronchi enter and exit
  51. Lungs hound the division of the bronchi...
    • Main bronchi > lobar bronchi > segmental bronchi (tertiary) > bronchioles > terminal bronchioles > respiratory bronchioles > alveolar ducts and sacs (alveoli)
    • 10 segmental bronchi in R lung and 8 in left lung
  52. Pleural Sacs
    • Outer parietal pleura against ribcage
    • Inner visceral pleura against lung
    • The space between the pleural cavity contains fluid that allows for lung expansion and reduces friction
  53. Types of cells associated with Alveoli are...
    Pneumocytes type I and II and macrophages (dust cells)
  54. Alveolar Sacs
    Have walls that are one cell thick and composed of type I and II pneumocytes
  55. Type I pneumocytes
    Build wall
  56. Type II pneumocytes have 2 funtions:
    • Repair type I cells when are damaged
    • secrete surfactant, coats the alveoli and smallest bronchioles and prevent them from collapsing when we exhale
    • Without surfactant the alveoli will adhere together
  57. Macrophages
    • Most numerous of all cells foudn with in alveoli
    • They keep alveoli free of debris by phagocytosis (ingest particles)
  58. Gases (oxygen, carbon dioxide)
    Diffuse across the respiratory membrane, which consists of the alveolar wall (type I pneumocytes) and the capillary endothelial wall
  59. Ventilation
    • Includes inspiration and expiration
    • One complete cycle in and out is called a respiratory cycle
  60. Quiet Respiration
    Relaxed unconscious automatic breathing
  61. Inspiration
    Pleural sacs expand, lung volume increases, intrapulmonary (IP) pressure decreases, higher atmospheric pressure pushes air into lungs
  62. Expiration
    Diaphram relaxes and domes, lung volume decreases, IP pressure increases, air is pushed out
  63. Forced Respiration
    • Deep or rapid breathing
    • Requires aid of internal intercoastals and abdominal muscles
  64. Spirometry
    • Pulmonary function can be assessed clinically through this technique
    • Useful in the diagnosis of lung diseases on the basis of pulmonary function
  65. Main Respiratory Muscles
    • Diaphram and intercoastals (internal and external)
    • Other muscles of the chest and abdomen also aid in breathing are called accessory muscles of respiration
  66. Tidal Volume (TV)
    Amt of air inhaled and exhaled normally at rest
  67. Total Lung Capacity (TLC)
    Max vol of air present in lungs
  68. Minute Ventilation
    Tidal Volume x respiratory rate
  69. Forced Expiratory Volume (FEV)
    % of vital capacity that can be exhaled in the first second (FEVl) if it is less than 75% to 85% suggesting pulmonary disease
  70. Utilization Co-efficient
    Amt oxygen is released from blood (22%)
  71. Dalton's Law
    • The total pressure of a gas mixture (such as air) is equal to the sum of the pressure that each gas in the mixture would exert independently
    • The pressure of a particular gas in the mixture exerts independently it is the partial pressure of that gas, which is equal to the product of the total pressure and the fraction of that gas in the mixture Ex: since o2 consitutes about 21% of atmosphere then its partial pressure (PO2) is 21% of 760 (at sea level) mmHg or 159mmHg. PO2=(760x20)/100. Nitrogen constitutes 78% of atmosphere then its PN2 is 78% of 760 mmHg or 593mmHg
  72. Respiratory Volumes and Capacities for an Average Young Adult Male
    Values are all affected by age, fitness, pulmonary disease, and body size
  73. Tidal Volume (TV)
    Typical Value: 500mL
    Amt air inhaled and exhaled in one cycle during quiet breathing
  74. Inspiratory Reserve Volume (IRV)
    Typical Value: 3,000mL
    Amt of air in excess of TV that can be inhaled with maximum effort
  75. Expiratory Reserve Volume (ERV)
    Typical Value: 1,200mL
    Amt air in excess of TV that can be exhaled with max effort
  76. Residual Volume (RV)
    Typical Value: 1,300mL
    Amt air remaining in lungs after max expiration; amt that can never voluntarily be exhaled
  77. Vital Capacity (VC)
    Typical Value: 4,700mL
    Amt air that can be inhaled and then exhaled with max effort; deepest possible breath (VC=ERV+TV+IRV)
  78. Inspiration Capacity (IC)
    Typical Value: 3,500mL
    Max amt air that can be inhaled after a normal tidal expiration (IC=TV+IRV)
  79. Functional Residual Capacity (FRC)
    Typical Value: 2,500mL
    Amt air remaining in the lungs after a normal tidal expiration (FRC=RV+ERV)
  80. Total Lung Capacity (TLC)
    Typical Value: 6,000mL
    Max amt air lungs can maintain (TLC=RV+VC)
  81. Loading
    O2 binds to Hb, in lung capillaries and form oxyhemoglobin (HbO2)
  82. Unloading
    Occurs in the tissue capillaries
  83. Factors affecting rate of O2 unloading
    • Dissociation: of oxyhemoglobin also affected by tissue level og activity (heavy exercise), metabolic byproducts, high temp, low pH of tissues
    • Factor needed to increase oxygen unloading is temperature and increase of temperature promotes O2 unloading curve is shifting to the right. Sigmoid curve='s'.
    • The Bohr effect: active tissue generate more CO2 that decrease pH (concentration of hydrogen ions) promotes O2 unloading, curve is shifting to the right. pH decreases as hydrogen ions increase. normal blood pH is 7.40
  84. Systemic Gas Exchange
    • CO2 is produced in tissue in normal metabolism
    • It diffuses into blood capillaries, increasing blood PCO2
    • CO2 + H2O > H2CO3 > HCO3- + H+
    • The H+ released in blood by carbonic acid reduced Hbs affinity for O2 and since there is less O2 in tissues, Hb releases O2 to tissues called the utilization co-efficient.
  85. Alveolar Gas Exchange
    • Low in oxygen
    • High in carbon dioxide
    • Same details as systemic gas exchange, completely flipped opposite order.
  86. Little carbon dioxide....
    Bound to Hb(5%); most forms carbonic acid in blood, which releases H+ and lowers pH of blood (more acidic)
  87. Acidosis
    • Sensed by chemoreceptors
    • Causes medulla to activate respiratory centers to increase ventilation
  88. Carbon Monoxide (C E 0)
    • Colorless
    • Odorless
    • Tasteless
    • Toxic
    • Produce from partial oxidation of carbon containing compounds
    • Complete with O2 to bind to heme group
    • Stronger than O2 binding
  89. Hypoventilation
    The higher pressure of CO2 is the lower the pH
  90. Hyperventilation
    The lower the pressure of CO2 the higher the pH
Card Set
Physiology Exam 4