Cardiovascular Physiology

Question 1

The cardiovascular system divides into the

Answer 1

Heart and blood vessels

Question 2

bulk flow

Answer 2

All components of blood flow together

Question 3

Highly efficient exchange of nutrients, oxygen and metabolic waste occurs between cells and regional capillaries

• Mediated by

Answer 3

Starling Equilibrium

Question 4

Small proportion of blood is in the __________ at any given time

Answer 4

capillaries

Question 5

Cell/capillary interface is the

Answer 5

powerhouse of the circulatory system

• tremendous feat of nutrient/oxygen supply, hormone delivery & waste removal

Question 6

Organization of the Cardiovascular System

Answer 6

• closed circulation
  Two circuits:
• pulmonary circulation
• systemic circulation
• arteries: carry blood away form heart
• veins: carry blood back to heart

Question 7

Systemic Circulation

Answer 7

• Blood moves into the aorta from the left ventricle

• Aorta branches successively into main
arteries supplying organ systems

• Further branching into arterioles and then
capillaries

• Venules coalesce to form progressively larger veins
• Veins draining the organ systems join into the inferior and superior vena cava
• Blood then moves into the right atrium

Question 8

Pulmonary Circulation

Answer 8

• Blood moves from right ventricle through the pulmonary trunk – divides into two pulmonary arteries
• Blood returns to the heart via 4 pulmonary veins to enter the left atrium

Question 9

Where do lung receive all blood form?

Answer 9

Right ventricle

Question 10

As blood passes through capillaries, it is

Answer 10

Oxygenated

Question 11

There is lower oxygen levels in

Answer 11

Systemic venous blood (and pulmonary arterial blood)

Question 12

Each organ system received blood form the

Answer 12

Left ventricle

Question 13

Hepatic portal system

Answer 13

• Sometimes organs obtain blood secondhand form another organ. Supports the unique functions for the organs. Liver part of the largest portal system. Transport blood, nutrient, and hormones.

Question 14

Hemodynamics

Answer 14

Relationship between blood pressure, blood flow, and vascular resistance

Question 15

Pressure gradients

Answer 15

• drives flow of blood form one region to another

- blood flow always form a region of higher pressure to lower pressure

Question 16

Hydrostatic pressure

Answer 16

Blood contained within vessel excerpts a force

• origin of blood pressure is force generated by heart contractions

Question 17

Determinants of blood flow

Answer 17

• Differences in pressure between two points determines blood flow
• pressure gradient
• measured blood flow in L/min (F)

Question 18

Formula for blood flow

Answer 18

Flow = (pressure)/(resistance)

Flow direct with pressure, inverse with resistance

Question 19

3 determinants of resistance

Answer 19

• viscosity (direct)
• vessel length (direct)
• vessel radius (inversed)

Question 20

Viscosity varies with

Answer 20

Hematocrit, protein

Question 21

Vessel length is relatively

Answer 21

Constant, doesn’t control vascular resistance

Question 22

________ the most important regulator for vascular resistance

Answer 22

Radius

Question 23

Radius is very

Answer 23

Dynamic and changes a lot

Question 24

Heart muscle called

Answer 24

Myocardium

Question 25

Heart is enclosed by

Answer 25

epicardium and pericardium

Question 26

Layers of the heart layered by the

Answer 26

Endothelium

Question 27

Atrioventricular valves have

Answer 27

One way flow to prevent flooding

Question 28

As valves open when the

Answer 28

Pressure is higher in the atrium compared to the ventricle

Question 29

When ventricle pressure rises during contraction, the Av valves

Answer 29

Close

Question 30

Blood only moves form atrium ton

Answer 30

Ventricle

Question 31

Valves tethered to papillary muscles by

Answer 31

Chordate tendinae

Question 32

Right ventricle separated form the pulmonary trunk by the

Answer 32

Pulmonary valve (blood flows into pulmonary circulation)

Question 33

Left ventricle separates form the aorta by the

Answer 33

Aortic valves (blood flows into the systemic circuit)

Question 34

What determines whether the valves are open or closed

Answer 34

Pressure gradient

Question 35

Properties of valves

Answer 35

- low resistance to blood flow | - small pressure gradient can facilitate large flow

Question 36

Are there other valves at other entries of the heart

Answer 36

No

Question 37

Without valves, in some openings, how is back flow prevented?

Answer 37

Atrial contraction partially occluded the blood entry points, high resistance

Question 38

Cardiomyocytes comprise cardiac muscle that

Answer 38

Never rest and are arranged in layers

Question 39

Electrical Excitability of Cardiomyocytes

Answer 39

Generated ATP, Ca2+ enters cytosol, activates actin myosin cross-bridge formation

Question 40

Other types of cardiac cells are required for cardiomyocyte function in the conduction system:

Answer 40

- electrical contact with cardiomyocyte | - through gap junctions

Question 41

Parasympathetic

Answer 41

- inner age cells in atria | - release Ach

Question 42

Sympathetic

Answer 42

- entire heart | - release NE

Question 43

Parasympathetic travelling via

Answer 43

vagus nerves

Question 44

Blood within the chambers dont

Answer 44

Supply cardiac tissue directly

Question 45

Coronary arteries branch form the

Answer 45

aorta behind the aortic valve cusps - supplies myocardium within coronary blood flow

Question 46

Venous blood collects in the

Answer 46

Coronary sinus, blood flows into the right atrium

Question 47

The heart is essentially two pumps in that

Answer 47

The left and right pump simultaneously

Question 48

Atria must contract first to fill ventricles, then the ventricles must

Answer 48

rapidly contract to pump blood to pulmonary and systemic circulation

Question 49

Cardiac muscle contraction stimulated by

Answer 49

Plasma membrane depolarization, APs transmitted across all cells by gap junctions

Question 50

Initial depolarization originates form the

Answer 50

SA node, then spreads through atria, then into the ventricles last

Question 51

SA node is pacemaker for heart, depolarization generates AP which is then coupled with

Answer 51

Cardiac muscle contraction, SA node discharge thus determines heart rate

Question 52

Rapid conduction form the SA node ensures contraction

Answer 52

Of both atria

Question 53

Modified cardiac cells comprise the

Answer 53

AV node and dont contract

Question 54

Where do AP move form ?

Answer 54

Form the SA node to the AV node via intermodal pathways

Question 55

AV node links

Answer 55

atrial and ventricular depolarization (base of the atrium)

Question 56

AV node conducts slowly, permitting completion of

Answer 56

Atrial conduction before the ventricular contraction

Question 57

Purkinje fibres rapidly conduct AP to

Answer 57

- Ventricular myocytes | - Purkinje fibres have large diameters and low resistant gap junction

Question 58

Purkinje fibres cause simultaneous depolarization of all

Answer 58

left and right ventriclular cells, permits coordinated contraction begins at the apex, spreading upwards

Question 59

Cardiac cell types feature different ion channels, determining the

Answer 59

Shape of the AP

Question 60

3 main ion channel mechanisms of pacemaker potential

Answer 60

- slow decrease in K+ permeability - funny Na+ channels - T-type Ca+ channels