CVD Phys III

Question 1

What are the 3 effects that sympathetic/parasympathetic stim of the heart produces

Answer 1

1. Cardiac rate (pos chronotropic effect)
2. Contractility (pos inotropic effect)
3. Conductivitity (pos dromotropic effect)

vise versa for para

Question 2

What are the 2 control ceneters for modulating the heart and where are they found

Answer 2

Cardioacceleratory center (vasomotor)

Cardioinhibitory center (depressor center)

Question 3

What is cardiac output

Answer 3

Amount of blood pumped by each ventricle in one min

HR x SV

Question 4

what is the bpm limit of cardiac output

Answer 4

180Bpm

Question 5

What factor effect ESV (2)

Answer 5

Contractility

Afterload (more aortic pressure causes a decreased SV)

Question 6

What are causes of left ventricle hypertrophy + main complication associated

Answer 6

High bp
Valve disease
Athletic hypertrophy
congenital heart disease

The ventricle stiffens and loses elasticity

Question 7

What are 3 factors that exercise modulates in cardiac output

Answer 7

increased HR

increased Venous return (more preload)

increased contractility (sympathetic n system)

Question 8

What is the cariac output in trained and non trained indv

Answer 8

trained- 30-35l/min

untrained- 20-25l/min

Question 9

What is low output vs high output failure

Answer 9

low- could be systolic/diastolic dysfunction

high- increased cardiac demand

Question 10

Elastic artieries- ex and characteristics

Answer 10

Aorta and other big arteries

-large diameter allows low resistance, vessels also recoil which help move blood forward (pressure stores)

Question 11

Muscular arteries- ex and characterisics

Answer 11

brachial, femoral, renal arteries

-low resistence vessels rapidly deliver blood to specific organs (more varied diameters to regulate blood flow)

Question 12

Resistence artieries charactereristics

Answer 12

Provide high resistence to blood flow and accounts for a major component of peripheral resistance (arterioles etc)

Question 13

What is at entry of capillaries to modulate blood flow

Answer 13

Precapillary sphincters

Question 14

Where are baroreceptors and chemoreceptors found and sense for

Answer 14

baroreceptors- walls of aortic arch + int carotid (BP)

Chemoreceptors- carotid + aortic bodies (blood chem)

Question 15

How much blood leaves the aorta during systole

Answer 15

SV leaving artery is 1/3 of volume that entered (2/3 is used to stretch)

Question 16

During ventricular diastole what happens to the blood in aorta

Answer 16

the recoild ejects most of the remaining 2/3 of blood

Question 17

What is systolic vs diastolic bp

Answer 17

systolic- max pressure during systole

diastolic- min pressure during diastol

Question 18

What are the 2 factors that determine blood flow thru a vessel

Answer 18

Pressure difference

resistence

Question 19

What are resistence factors

Answer 19

Blood viscosity (anemia decreases, dehydration increases)

Vessel radius

Question 20

What 2 factors induce bp

Answer 20

Blood volume (cariac output)
Peripheral resistence

Question 21

How does the sympathetic nervous system affect bp (3)

Answer 21

1. Vasocontriction (increase resis)
2. Venocontriction (increase venous return= increase SV)
3. Stims all properties of heart (rhymaticity, contractility, conductivity)

Question 22

Baroreceptor feedback when MAP rises

Answer 22

1. inhibition of vasomotor center (atrial dialation, venodialation, decrease properties of heart)
2. Increased cardiac inhibitory center action

Question 23

Barorecptor feedback when MAP drops

Answer 23

1. decreased inhibition of vasomotor center (vasocontriction, venocontraction, increase all props of heart)

Question 24

When does chemoreceptors kick in and what does it do

Answer 24

when bp drops below 80mmhg (low o2)

-stims vasomotor center (vasocontriction, venoconstiction, inrease aspects of heart)