BIO250 Lec 1st Exam.txt

• 1. Sinoatrial (SA) node
  3. Atrioventricular (AV) node
  5. AV bundle (bundle of His)
  7. Subendocardial branches (Purkinje fibers)

• written - ECG
• spoken - EKG

70-75

If the SA node fails for any reason and AV (Atrioventricular) node takes over:

    40-60 BPM

Plasma membrane of a striated muscle cell (including cardiac)

Meaning "joined cells", the connections of individual heart muscle cells via intercalated disks results in a continuous and electrically coupled impulse of myocardial tissue.

NOTE: Heart muscle "cannot summate to produce tetanus and thus do not fatigue".

    P

    QRS

    T

Sometimes, an additional U wave may be seen in the electrocardiogram. The U wave, when visible, appears as a tiny "hump" at the end of the T wave. The U wave results from late repolarization of Subendocardial branches (Purkinje fibers) in the papillary muscle of the ventricular myocardium. If not too big, U waves are usually considered to be normal. Sometimes, however, U waves can be a sign of hypokalemia (low blood potassium) or too much digoxin (a heart medication).

• 1. Atrial systole
  3. Isovolumetric ventricular contraction
  5. Ejection
  7. Isovolumetric ventricular relaxation
  9. Passive ventricular filling

Starts at R and ends just past S

Starts at the end of T

• The first or systolic sound
• is a contraction of the ventricles and vibrations from the closing of the Atrioventricular or cuspid valves.
• It is longer and lower than the DUBB sound.

• • The second or diastolic sound
  • is caused by vibrations from the closing semilunar valves.
  • It is shorter and sharper than the LUBB sound.

Any deviation from the normal is an indication of an improperly functioning valve. A "swishing" sound may mean an incomplete closing of the value (valvular insufficiency) or a stenosis (constriction or narrowing).

Perfusion pressure, which means "flow through"

Pressure increases with increases in volume and vice versa.

Cardiac output and peripheral resistance.

5000

= SV (stroke volume)

    in (volume/beat)

X HR (heart rate)

    in (beats/minute)

This volume of blood is also known as the "systolic discharge".

Pressure increases in direct relationship with increases in volume, so as CO increases, volume will increase, and as PR (in the arterioles) increases, the amount of blood leaving the arteries is REDUCED, thus increasing the volume REMAINING inside, and increasing arterial BP.

As SV or HR change, so to do CO, ABV and BP tend in the same direction.

The reason for tend is because the book wanted to point out that the relationship only works if the are no other changes in a conflicting direction.

SV (stroke volume)

/ EDV (end diastolic volume)

X 100

• Somatic - under your control
  • Somatic Sensory - afferent
  • Somatic Motor = efferent
  Autonomic - NOT under your control
  • Visceral Sensory - afferent
  • Sympathetic - efferent - "Fight or Flight"
  • Parasympathetic - efferent - "Rest and Repair"

Ratio of sympathetic and parasympathetic nerve impulses (autonomic) conducted to the SA node.

• sympathetic (fight/flight)
  1. Through: distal end of cardiac nerve
  3. Action: stimulatory
  5. Mode: release of norepenepherine
  Parasympathetic (rest/repair)
  1. Through: chiefly by vagus nerve
  3. Action: inhibitory
  5. Mode: release of acetylecholine

Barroreceptors in the aortic arch and carotid sinuses send signals to the cardioregulatory centers of the medula oblongata via the Vagus (cranial nerve X) and Nerve of Hering (branch of cranial nerve IX) respectively.

A negative feedback loop there sends control impulses via ratio of sympatheic and parasympathetic action.

These are "carotid sinus reflex" and "aortic reflex" feedback loops.

• left and right atria, or recieving chambers
• left and right ventricles, or major pumping chambers

left and right atria are thin-walled pumps, which take blood input from veins: pulmonary, oxygen-rich to the left, and vena cavas and coronary sinus, oxygen-poor to the right. 20% of this blood is "pumped" into the ventricles, while 80% flows due to gravity.

left and right ventricles, are major (left) systemic and (right) pulmonary pumping chambers, with the walls of the left venticle being significantly thicker than the right because of the distance the left has to pump through.

The left ventricle recieves blood through the mitral or bicuspid valve and outputs it to the aorta via the aortic semilunar valve, while the right recieves blood through the tricuspid valve and outputs it to the pulmonary trunk via the pulmonary semilunar valve.

epithelial, connective, muscle and bone. Blood is CONNECTIVE

• ~55% (46-63%) is non living plasma
• • 91% water
  • 7% plasma proteins
  • • Albumins 57%
    • Globulins 38%
    • Fibrinogen 4%
    • Prothrombin 1%
  • 1% other solutes
  • • enzymes, ions nutrients, waste products, and gasses

(counts are per cubic millimeter)

• ~45% (37-54%) is living cells
  • 99.9% RBC, 4.2-6.2 million eruthrocytes
  • <0.1% WBC, 5000-9000 leukocytes
  • <0.1% WBC, 140-340k platekets

• NEVER LET MONKEYS EAT BANANAS
• • Neutrophils    60-70%
  • Lymphocytes    20-25%
  • Monocytes    3- 8%
  • Eisinophils    2- 4%
  • Basophils    0.5-1%

• 1. Heart
  3. Blood vessels
  5. Blood

• • About 7.5 um in diameter
  • Biconcave - very lare surface area to volume
  • No nucleus, ribosomes or mitochondria
  • One-third of the cell volume is the red protein pigment: hemoglobin
  • Can fit through capillaries often smaller in diameter than 7.5 um
  • Flexibility through stretchable fibers of protein spectrin
  • Circulating life: 105-120 days
  • Each RBC has 200-300 million molecules of hemoglobin and 95% of the dry weight of each cell

• • Each hemoglobin molecule is made up of 4 globin protein chains, each with a "red pigment" heme group with one iron atom
  • Each of the 4 iron atom can combine with an oxygen molecule to form a reversible reactant oxyhemoglobin
  • Each globin can form a reversible reactant with carbon dioxide to for carbaminohemoglobin
  • Additionally RBCs contain an enzyme carbonic anhydrase (CA), which catalyzes a reaction that joins carbon dioxide and water to form carbonic acid. This then dissociates to bicarbonate ions and hydrogen ios, which diffuse out of the RBC to be excreted or used to buffer the bloods pH.

Normal men have 14-16 g of hemoglobin per 100 ml of blood, while women have 12-14 g. Anyone with less than 10g/100ml is diagnosed as having anemia.

• • All formed blood elements are generated from adult blood-forming stem cells known as hematopoietic stem cells, which are called hemocytoblasts.
  • Maturation from these nucleated cells begins in the red bone marrow.
  • The differentiated daughter cell created via mitosis for erythrocytes is the proerythroblast.
  • Development states progress until the cell no longer has a nucleus and is called a reticulocyte.
  • The complete process takes about 4 days.
  • RBC are created at a rate of 200 billion per day to replace worn out/damaged RBCs.

• Fibrous Pericardium
• Attached to the diaphram and to the major blood vessels exiting the top of the heart.

• Fibrous Pericardium
• Parietal layer of the serous pericardium
• Pericardial space filled with 10-15 ml of pericardial or serous fluid
• Epicardium or visceral layer of the serous pericardium
• Fatty connective tissue with coronary vessels
• Myocardium
• Endocardium covering beamlike protrussions of the myocardium called trabeculae cardeae

• • Tough
  • Loose fitting
  • Inelastic
  • Not attached to the heart, only to blood vessels exiting the heart.

Consiting of the Parietal layer, attached to the fibrous pericardium, and the Visceral layer or Epicardium and the very important lubricating fluid in between them, they provide and environment wherein the heart can easily move with no danger from friction.

• • Delicate layer of endothelium - simple squamous cells.
  • Lines the heart and all of the blood vessels.
  • Covers muscular projections of myocardium called trabeculae cardeae or "fleshy beams", which help to add force to the inwar contraction of the heart wall.
  • Inward folds of endocardium make of the flaps or cusps of the heart valves.

Turnica Intima

• Lining endothelial cells

Turnica Media

• Elastic fibers
• Smooth muscle cells
• Arteries thicker than veins
• Missing in capillaries

Turnica Externa

• Collagen fibers
• Arteries thicker than veins
• Missing in capillaries

Capillaries have only an endothelial cell lining surrounded by a basement membrane.

Continuous

• Has "Pinocytic vessicles", which can transport subsytances rapidly.

Fenestrated

• Has many "fenestrations" or pores.

Sinusoid

• Many intercellular clefts (lrge gaps or openings), and an incomplete or missing basement membrane.

• 1. Sinoatrial (SA) node - alone or with influence from syparthetic/parasympathetic
  3. Three internodal bundles, including an interatrial bundle to the left atrium
  5. Atrioventricular (AV) node - impulse SLOWS here to allow complete contraction of both atria
  7. AV bundle (bundle of His)
  9. Left and right AV bundle branches (septum)
  11. Subendocardial branches (Purkinje fibers) to lateral walls

• 1. Returns to Right Atrium via the superior and inferior Vena Cava, as well as the Coronary Sinus.
  3. Through AV Tricuspid Valve to Right Ventricle.
  5. Out the Pulmonary Semilunar Valve to the Pulmonary Trunk.
  7. To Lungs or Pulmonary Circuit.
  9. Returns to Left Atrium via the Left and Right Pulmonary veins.
  11. Through AV Mitral or Bicuspid Valve to Left Ventricle.
  13. Out the Aortic Semilunar Valve to the Ascending Aorta.
  15. To Body or Systemic Circuit.

English physiologists Ernest Starling, expanding earlier work of Otto Frank (Frank-Starling), found that, within limits, i.e. normal conditions, the longer or more stretched myocardial fibers are at the beginning of a contraction, the stronger that contraction will be.

What influences how stretched these muscle fibers get is directly related to how much venous blood is returned to the ventricles, or venous return. The effect is that under normal conditions, the heart will pump out the amount of blood that is returned to it.

norepinephrin (NE) releasd by sympathetic fibers in the cardiac nerve and epinepherin released into the blood by the adrenal medulla can both increased the strength of contraction or contractility, of the heart

• YOU
  
  I
  
  LOVE
  
• NOTE:The bove represents an example of RPN or 'Reverse Polish Notation', wherein the operands precede the operator. That is YOU and I are the 'operators' and LOVE is the 'operand'. (Leave it to an engineer to muck up an early Valentine.)