Cardiovalsular Physiology Part 1

Question 1

pulmonary circulation

Answer 1

right ventricle to pulmonary trunk which divides into 2 pulmonary arteries (one for right and left lung) to lungs to pulmonary veins (4) back to left atrium

Question 2

microcirculation

Answer 2

artery –> arterioles –> capillaries –> venules –> veins
gas, substrate, and waste exchange between blood and extracellular fluid

Question 3

systemic circulation

Answer 3

left ventricle to aorta to systemic arteries to organs and tissues to 2 systemic veins (superior and inferior vena cava) to right atrium

Question 4

the branching of the systemic arteries in a parallel pattern ensures that

Answer 4

independent regulation of
blood flow through tissues as their activities change
all systemic tissues receive freshly oxygenated blood

Question 5

portal system

Answer 5

one capillary bed to veins to second capillary bed to veins

Question 6

flow rate is in
pressure difference is in

Answer 6

L/min
mmHg

Question 7

FR equation

Answer 7

(Change in P)/Resistance

Question 8

Resistance equation

Answer 8

R= (8Ln)/(pir^4)
n is fluid viscosity

Question 9

viscosity

Answer 9

changes depending on increased or decreased hematocrit
* typically viscosity and Length remain the same, the radius of blood vessels is what greatly affects the the resistance

Question 10

pericardium

Answer 10

protective fibrous sac that encloses the heart

Question 11

epicardium

Answer 11

fibrous layer closely affixed to the heart

Question 12

myocardium

Answer 12

wall of the heart
composed of muscle cells

Question 13

endothelial cells/ endothelium

Answer 13

inner surface of the cardiac chambers
inner wall of all blood vessels

Question 14

interventricular septum

Answer 14

muscular wall separating the two ventricles

Question 15

atrioventricular (AV) valves

Answer 15

between atrium and ventricle, one way from atrium to ventricle

Question 16

right AV valve is called

Answer 16

tricuspid valve (3 fibrous flaps or cusps)

Question 17

left AV valve is called

Answer 17

bicuspid valve (2 flaps)
aka mitral valve (bishop head)

Question 18

opening and closing of AV valves

Answer 18

• passive
  pressure in atrium greater than ventricle valve opens
  pressure in ventricle greater than atrium, vakve remains closed

Question 19

to prevent AV valves from opening back up

Answer 19

• called prolapse
• valves fastened to papillary muscles and chordae tendinae which limit valves movements

Question 20

valve at the opening of the right ventricle into pulmonary trunk

Answer 20

pulmonary valve

Question 21

valve at the opening of the left ventricle into the aorta

Answer 21

aortic valve

Question 22

heart valves

Answer 22

• prevent back flow
• when open have very resistance to flow

Question 23

there are no valves at the entrance of the

Answer 23

superior/ inferior vena cava into the right atrium and pulmonary veins into the left atrium

Question 24

there is no valves there because

Answer 24

atrial contraction constricts the entry into the atria

Question 25

unlike skeletal muscle cells cardiac muscle cells are joined

Answer 25

- every heart muscle cell contracts with every beat if the heart - by gap junctions that permit conduction of AP from cell to cell

Question 26

conducting system of the heart

Answer 26

specialized cardiac muscle cells that initiate cardiac action potentials and regulate their spread through the heart

Question 27

sympathetic nerve fibers that innervate

Answer 27

the entire heart and release norepinephrine

Question 28

parasympathetic nerve fibers

Answer 28

terminate on special cells on the atria and release acetylcholine

Question 29

myocardial cells receive their blood supply from

Answer 29

arteries that branch from the aorta

Question 30

arteries supplying the myocardium and the blood flowing through them is called

Answer 30

- coronary arteries - coronary blood flows

Question 31

Sinoatrial (SA) Node

Answer 31

- pacemaker of the heart - small group of conducting system cells - causes initial depolarization of heart muscle cells - located in the right atrium near the entrance of the superior vena cava

Question 32

the discharge rate of the SA node determines the

Answer 32

heart rate (contractions per minute)

Question 33

SA node depolarization generates

Answer 33

AP that leads to depolarization of all other cardiac muscle cells

Question 34

location of atrioventricular node

Answer 34

base of right atrium

Question 35

the AV node is the link between

Answer 35

atrial and ventricular depolarization

Question 36

internodal pathways

Answer 36

AP is conducted rapidly through these pathways between SA and AV node

Question 37

AV node structure and characteristic

Answer 37

- elongated structure - propagation of AP is relatively slow, which allows atrial contraction to complete before ventricular excitation

Question 38

pathway of the AP

Answer 38

SA to AV to bundle of his (only electrical connection between the atria and ventricles), this divides into left and right bundle branches at the apex of the heart which each lead to purkinje fibers

Question 39

purkinje fibers

Answer 39

these are cells with gap junctions that conduct action potential rapidly through myocytes throughout the ventricles to cause simultaneous depolarization to produce a single coordinated contraction. Faster depolarization in the apex of the ventricles to push blood towards the exit valves