Handout #1 – Intro to CVS

Question 1

Pulmonary circuit provides BF to ___ and is a ___ pressure circuit.

Answer 1

Lungs; low

Question 2

Systemic circuit provides BF to ___ and is a ___ pressure circuit.

Answer 2

Tissues; high

Question 3

Why are arteries and veins well suited to provide BF to/from tissues?

Answer 3

Larger, thicker walls to prevent O2 diffusion

Question 4

Microcirculation include…

Answer 4

Arterioles, capillaries, and venules

Question 5

Microcirculation regulates…

Answer 5

BF, BP, and exchange*

Question 6

What are the three CV adjustments to exercise?

Answer 6

1. Increase CO
2. Redistribute CO to working muscles
3. Increase Venous Return

Question 7

Pacemaker of the heart

Answer 7

SA node

Question 8

Delay station (to allow heart to fill)

Answer 8

AV node

Question 9

What is the role of gap junctions?

Answer 9

Electrically connect myocytes so ventricles can contract in unison

Question 10

Prolonged AP…

Answer 10

Aids in LV filling and prevents tetany (constant contraction)

Question 11

Coronary arteries are critical to providing BF to ___

Answer 11

Myocytes

Question 12

Capillaries in the heart are responsible for…

Answer 12

O2 exchange

Question 13

What is the role of mitochondria in the heart?

Answer 13

To produce ATP

Question 14

Nerves in the heart are innervated by…

Answer 14

Autonomic nervous system (ANS)

Question 15

Two branches of autonomic nervous system are…

Answer 15

1. Parasympathetic
2. Sympathetic

Question 16

PNS is innervated via ____ nerve and has ___ attachments on the heart. The PNS is also known as the ______.

Answer 16

Vagus nerve
2
“Brake”

Question 17

SNS is innervated via ____ nerve and has ___ attachments on the heart. The SNS is also known as the ______.

Answer 17

Sympathetic nerve
3
“Accelerator”

Question 18

How does PNS regulate the heart?

Answer 18

1. ACh binds to M2 receptors, which activates Gi protein.
2. Gi protein is inhibitory, which decreases AC activity that decreases cAMP.
3. HR and conduction velocity decline as a result

Question 19

How does SNS regulate the heart?

Answer 19

1. NE binds to B receptors, which activates Gs protein.
2. Gs protein is stimulatory, which increases AC activity that increases cAMP.
3. Increase cAMP increases Ca++ entry
4. HR and contractility increase

Question 20

Why is cAMP so influential?

Answer 20

1. cAMP regulates protein kinase A (PKA)
2. PKA determines phosphorylation state of Ca++
3. Ca++ is critical to excitation and contraction coupling.

Question 21

All blood vessels except for ____ have the same three layer design.

Answer 21

Capillaries

Question 22

What are the three layer of a blood vessel and what do they contain?

Answer 22

1. Intima (inner) - endothelium
2. Media (middle) - smooth muscle, collagen
3. Adventitia (outside) - connective tissues and nerves (anchors artery)

Question 23

Only blood vessel layer in direct contact with blood?

Answer 23

Intimia - Endothiel cells

Question 24

Arteries have large _____ that provide ____ resistance to blood flow

Answer 24

Lumens; low

Question 25

Why are artery walls thick?

Answer 25

1. Withstand high pressure 2. Prevent gas exchange

Question 26

Arteries have _____ fibers to propel blood forward.

Answer 26

Elastic

Question 27

Primary function of arteries vs. arterioles vs. capillaries

Answer 27

1. Arteries - BF from heart to tissues 2. Arterioles - Regulate BP and BF distribution 3. Capillaries - gas/nutrient exchange

Question 28

Arterioles are AKA as the _____ because of their dilation and constrictive responses.

Answer 28

"Stopcox"

Question 29

______ cells regulate the diameter in arterioles.

Answer 29

Smooth muscle

Question 30

The arterioles are heavily innervated by ____ nerves and have no _____ nerves.

Answer 30

Sympathetic; parasympathetic

Question 31

Arteries ____ to effectively spread/deliver BF to tissues.

Answer 31

Branch

Question 32

______ are the only cell that doesn't have three layers

Answer 32

Capillaries

Question 33

Key adaptations for capillaries are...

Answer 33

1. Thin walls - increase exchange 2. Large surface area for exchange 3. Large CSA reduces BF velocity to absorb more O2

Question 34

Is capillary density the same in all muscles?

Answer 34

No. CD is low in glycolytic CD is high in oxidative

Question 35

What percentage of blood is housed in the veins?

Answer 35

70%

Question 36

What are the primary functions of veins?

Answer 36

1. BF from tissues to heart 2. Regulate CO and core body temp** **Different job compared to other blood vessels

Question 37

Vein walls are comprised of _______ cells that are innervated by ____ nerves.

Answer 37

Smooth muscle; Sympathetic

Question 38

The smooth muscles cells in veins only contain ____ receptors.

Answer 38

Adrenergic (a)

Question 39

Do veins have parasympathetic innervation?

Answer 39

No.

Question 40

Why do veins have valves?

Answer 40

To prevent back flow of blood

Question 41

Muscarinic receptors respond to the binding of....

Answer 41

Acetylcholine (ACh)

Question 42

Adrenergic receptors respond to the binding of....

Answer 42

Norepinephrine (NE)

Question 43

Muscarinic receptors are G-coupled protein receptors involved in the ____ nervous system

Answer 43

parasympathetic