Cardio Physiology Intro

Question 1

Where is the apex of the heart?

Answer 1

At the bottom of it

Question 2

Two-thirds of the heart lies _____ of the midline.

Answer 2

left

Question 3

The two pumps of the heart are arranged in ________ (series or parallel).

Answer 3

series

Question 4

Do both ventricles squeeze in a similar manner?

Answer 4

No, not really. The right squeezes against the septum and the left squeezes concentrically.

Question 5

Which side of the heart is the tricuspid valve found?

Answer 5

Right

Question 6

What is another name for the bicuspid valve? What side is it on?

Answer 6

Mitral - left side

Question 7

What are the fibrous strands called that attach to the AV valves? What do the other ends of these attach to?

Answer 7

Chordae tendinae attach to papillary muscles on the ventricle walls.

Question 8

When the ventricles contract, papillary muscles ______ to prevent valve _______.

Answer 8

contract to prevent valve eversion

Question 9

How many layers of fibers make up the myocardium?

Answer 9

5

Question 10

What is the fiber arrangement of all the myocardial layers?

Answer 10

Inner (endocardium) is longitudinally arranged
2nd is oblique
3rd (middle) is circumferentially arranged
4th is oblique
Outer (epicardium) is longitudinally arranged

Question 11

The end-to-end connections of the myocardial cells are called the _________.

Answer 11

intercalated disks

Question 12

A drop in pressure at the capillary level is due to high ________ in the arterioles.

Answer 12

resistance

Question 13

How does fluid flow (Q) relate to pressure drop and resistance?

Answer 13

Q = ΔP / R

Question 14

Define cardiac output.

Answer 14

The volume of flow through the entire systemic or pulmonary circulation.

Question 15

What does Poiseuille’s law state regarding the radius of a cylinder and flow resistance? What is the equation?

Answer 15

That there is a 4th power relationship between changes in radius and fluid flow (a 2-fold change in resistance changes fluid flow by 16x).

Q = ΔPπr^4 / 8ηL

Question 16

What is the simple equation for mean arterial pressure?

Answer 16

MAP = DP + (SP - DP) / 3

Question 17

What is pulse pressure?

Answer 17

The difference between systolic and diastolic pressures

Question 18

Why does fluid velocity actually decrease in the capillaries of the body? Does Q change throughout the different sectors of the vascular system?

Answer 18

Because the total cross sectional area of the capillaries is much larger than in the large arteries. Total fluid flow does not change

Question 19

What is the mathematical relationship among velocity, flow, and cross-sectional area?

Answer 19

V = Q/A

Question 20

Doppler ultrasound measures the ________ _______ in sound waves reflected off RBCs.

Answer 20

frequency change

Question 21

Do large arteries have a physiologic role in BP regulation?

Answer 21

No, not really.

Question 22

Which vessels are the primary vessels involved in BP regulation? What is another name for these?

Answer 22

Small arteries and arterioles are. Also called resistance vessels.

Question 23

Does solute exchange happen in the post-capillary venules?

Answer 23

Yeah, for macromolecules and fluid especially.

Question 24

What purpose does smooth muscle in venules serve?

Answer 24

To help regulate capillary pressure (by reducing or increasing outflow speed)

Question 25

_______ hold 70-80% of the body’s blood volume.

Answer 25

Veins

Question 26

How does one calculate the total peripheral resistance for vessel segments in series?

Answer 26

Add them up

Question 27

How does one calculate the total peripheral resistance for vessel segments in parallel?

Answer 27

Sum the reciprocals of the resistances:

1/TPR = 1/R1 + 1/R2 + 1/R3…

Question 28

What is the LaPlace equation and what does the law help explain?

Answer 28

T ( vessel wall tension) = P (pressure) x r (radius)

Explains how the thin capillaries can withstand relatively high pressure without bursting.