Advanced Ex Phys Exam 2

Front 1

1. What are the 4 primary components of the cardiovascular system?

Back 1

a. Pump (heart)
b. High pressure distribution circuit (arteries and arterioles)
c. Exchange Vessels (capillaries)
d. Low pressure collection and return circuit (veins and venules)

Front 2

2. Where is most of the bodies blood volume located at rest?

Back 2

a. 75% in small aa, vv, and capillaries.
b. Most bld is in the vv. (the bld reservoirs)

Front 3

3. What factors distinguish cardiac myocytes from skeletal and smooth myocytes?

Back 3

a. Cardiac myocytes interconnect in a latticework fashion
i. Intercalated discs
ii. Gap jxns
iii. T-systems occur at the z-lines
b. Also individual cardiac myocytes cannot contract independently like skeletal muscle.

Front 4

4. Define syncytium and ephaptic conduction. How are these terms related?

Back 4

a. Syncytium – Network of cardiac muscle cells connected by IC discs and Gap jxns that allows for the coordinated contraction of the heart. (info passes from cytosol to cytosol)
b. Ephaptic conduction – transfer of impulse from one cell to another.
i. Allows entire heart to contract together and ring out in a spiral motion.
c. Because the heart is a syncytium of cells it allows for Ephatic conduction.

Front 5

5. Know the anatomical components of the heart (valves, chambers, and immediate vessels) and be able to trace the pathway for a drop of blood throughout the heart and lungs.\

Back 5

a. Pathway
i. R Atrium
ii. R AV valve (tricuspid)
iii. R Ventricle
iv. Pulmonary semilunar Valve
v. Pulmonary A
vi. Lungs
vii. Pulmonary V
viii. L Atrium
ix. L AV valve (mitral/bicuspid)
x. L Ventricle
xi. Aortic Semilunar Valve
xii. Aorta
b. Atrioventricular Valves – separate atria from vents. Allows for bld flow in only one direction.
c. Semilunar Valves – Allow blood to exit the ventricles. Prevents backflow.
d. Atria – thin walled, sac like chamber. Recieves/stores blood during ventricular contraction.

Front 6

6. How do the atria function to deliver blood to the ventricles?

Back 6

a. About 70% of bld flows directly thru atria to ventricles (gravity)
b. Simultaneous atria contraction forces the remaining blood into the ventricles.

Front 7

7. How do the ventricles function to deliver blood?

Back 7

a. AV valves snap shut as vent pressure builds
b. All four heart valves remain closed for about 0.02-0.06 seconds.
i. During this brief interval of rising ventricular tension.
1. Heart volume stays the same.
2. Muscle fiber length remains unchanged.
3. Called “Isovolumetric contraction period”
ii. When vent pressure exceeds arterial pressure, semilunar valves are forced open
iii. Ventricles contract: Spiral and circular arrangements of bands of cardiac muscle “wrings out” blood from ventricles.