Costanzo Phys

Question 1

What part of the circulation is the most dynamic in size

Answer 1

Arterioles

Question 2

What receptor found in arterioles causes them to constrict

Answer 2

α1 receptors

Question 3

What receptor in arterioles causes them to relax

Answer 3

β2 receptors

Question 4

What are the general category of chemicals that cause changes in arteriole size

Answer 4

Catecholamines

Question 5

What is the volume of blood inside the arteries called

Answer 5

Stressed volume

Question 6

What is the volume of blood inside veins called

Answer 6

Unstressed volume

Question 7

How is blood flow to one area altered

Answer 7

1. Increase CO
2. Divert blood from other structures to it
3. Combine 1 and 2

Question 8

What is velocity of blood related to?

Answer 8

Flow/area

Question 9

What is the major mechanism for changing blood flow in CV system

Answer 9

Increasing or decreasing arteriole resistance

Question 10

The most susceptible variable in the resistance equation?

Answer 10

Radius

Stuff/(pi*r^4)

Question 11

What is resistance to flow directly correlated to

Answer 11

Length of vessel (length inc = resistance inc)

Viscosity (hematocrit)

Question 12

Which resistance system shows the system as a whole? Closed loop?

Answer 12

Parallel = system
-no decrease in pressure among organs

One loop = series (A->ariole->cap->vule->V)
-sum of pressures is sum of system

Question 13

What are turbulent sounds of blood called

Answer 13

Kortokoff sounds

Question 14

What are audible murmurs

Answer 14

Turbulent flow sounds caused by disruptions of laminar flow

Question 15

Reynolds number less than what is laminar

Answer 15

2000

Question 16

Anemia can cause what changes in blood flow

Answer 16

Decreased hematocrit means less viscosity means less resistance

Question 17

Thrombi cause what relating to blood flow

Answer 17

Decreased diameter means increased velocity means more likely turbulent flow

Question 18

At what part of a blood vessel is viscosity and blood cells lowest

Answer 18

Walls

Question 19

Where is the largest pressure drop seen

Answer 19

Small A to arterioles

Question 20

What causes the small dip in systolic pressure? (Dicrotic notch or incisura)

Answer 20

The aortic valve closing

Question 21

Stroke volume is…

Answer 21

The volume ejected from the LV in one stroke

Question 22

Why is pressure higher in large A than aorta

Answer 22

The pressure wave from the contraction travels faster than flow; the large A need to contract to keep the blood moving

Question 23

Where is pulse pressure lost

Answer 23

Arterioles due to increased resistance and more compliant vessels

Question 24

What changes do we see to BP in arteriosclerosis? Aortic stenosis? Aortic regurgitation?

Answer 24

1. Hardened vessels are less compliant causing a larger change in pressure than normal
2. Valve stenosis causes decreases pressure because less blood can leave the ventricle
3. Same as stenosis

Question 25

Which portion of cardiac conduction ensures that the ventricles have time to fill

Answer 25

Slow conduction through AV node

Question 26

What are the components of normal sinus rhythm

Answer 26

SA node initiates, 60-100 bpm, correct sequence

Question 27

What phase is the upstroke?

Answer 27

0

Question 28

What is phase 1 of the cardiac AP

Answer 28

The initial repolarization

Question 29

What is phase 2 of cardiac AP

Answer 29

The plateau (longer in vent)

Question 30

What is phase 3 of cardiac cycle

Answer 30

Repolarization

Question 31

What is phase 4 of cardiac AP

Answer 31

Rest

Question 32

What ultimately controls the HR

Answer 32

The pacemaker cell with the fastest phase 4 depolarization

Question 33

What causes a latent pacemaker to take over

Answer 33

1. SA node inhibited by drugs or disease
2. Signal from SA node cannot reach the heart
3. Latent pacemaker cell becomes faster than SA node