Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

CV phys > Heller Ch. 7 > Flashcards

Heller Ch. 7 Flashcards

1
Q

How does contraction/relaxation of smooth muscle compare to that of striated muscle?

A

Smooth muscle is slower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Besides rate of contraction, what other differences are there between smooth and striated muscles?

A

Smooth can change contractile activity and can maintain tension for prolonged periods of time (Latch state)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is step 1 of cross-bridge cycling in smooth muscle?

A

Calcium and calmodulin form complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What happens after the calcium/calmodulin complex is formed in cross-bridge cycling of smooth muscle?

A

The complex activates myosin light-chain kinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does the myosin light-chain kinase do in cross-bridge cycling of smooth muscle?

A

Phosphorylates the light chain (at head of myosin) via an ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does the phosphorylated myosin head do for cross-bridge cycling of smooth muscle?

A

Uses energy from ATP to develop tension and shorten

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which two potassium channels are used in determining the RMP of smooth muscle cells?

A

Inward rectifying-type

ATP dependent–open if ATP levels fall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What kind of calcium channel is used in depolarization of smooth muscle cels?

A

Voltage-operated (VOC)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What two potassium channels are used in REpolarization of smooth muscle cells?

A

Delayed

Calcium-activated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What type of channel is used in electromechanical coupling?

A

VOCs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What type of channel is used in pharmacomechanical coupling?

A

Receptor-Operated Channels (ROCs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How does electrochemical coupling lead to contraction?

A

Membrane depolarization–>increased open-state of channels–>contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What causes changes in calcium influx rate? What does changing the influx rate cause?

A

Changes in RMP cause changes in calcium influx rate

Changes in calcium influx rate changes the basal contractile state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is basal tone?

A

Constant state of partial constriction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does ACh effect the vascular system?

A

If endothelium is intact, it dilates

If endothelium is stripped, it constricts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does ACh stimulate vasodilation?

A

Increases concentration of NO–>increased GMP production–>vasodilation (process is unknown)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What other vaso-effectors are affiliated with endothelial cells?

A

Prostacyclin (vasodilator)

Endothelin (vasoconstrictor)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the local metabolic vasodilator hypothesis?

A

Tissue cells secrete vasodilator factors to increase flood flow proportional to how much they need

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does prostaglandin effect vascular tone?

A

Can be a dilator (inflammation) or constrictor (from platelets)…just depending

20
Q

What does histamine do to vasculature?

A

Vasodilator via cAMP pathway

Increases vascular permeability (causes edema)

21
Q

Which is a better vasodilator, histamine or bradykinin?

A

Bradykinin by 10 fold

22
Q

What is the active response to hyperemia?

A

Increased blood flow (exercise) causes slight dilation to reduce pressure followed by a quick constriction back to normal

23
Q

What is the reactive response to hyperemia?

A

Blood flow is reduced (tourniquet), then the obstruction is removed and the artery over-compensates blood flow and then constricts back to normal size

24
Q

What is autoregulation of blood flow?

A

Keep blood flow constant

25
What is the metabolic theory of autoregulation?
A "washout" of vasodilators from the interstitium by the excess initial blood flow
26
What is the myogenic theory of autoregulation?
Increase in arteriole tone stimulated by the increase in stretching forces
27
That is the tissue pressure theory of autoregulation?
Increased arterial pressure-->increased transcapillary fluid filtration-->increased interstitial fluid volume and pressure-->compression of vessels
28
What is neurogenic tone?
Tonic activity of sympathetic vasoconstrictor increases contractile tone
29
What does epinephrine binding to β2-adrenergic receptor cause?
Vasodilation (opposite of most catecholamine actions)
30
What does norepinephrine binding to β2-adrenergic receptor cause?
Nothing...β2-adrenergic receptors are not innervated
31
What does vasopressin do?
Decreases renal excretion of water | Potent arteriolar constrictor
32
What does angiotensin II do?
Regulates aldosterone release from the adrenal cortex...regulates blood volume Very potent vasoconstrictor
33
Do vasodilators have much of an effect on veins?
No...veins lack basal tone
34
Which organs primarily regulate blood flow by metabolic control?
Brain Cardiac muscle Skeletal muscle
35
Which organs primarily regulate blood flow by neurogenic control?
Kidneys Skin Splanchnic organs
36
When can sympathetic control effect skeletal muscle blood flow?
Both during rest and during exercise--to prevent BP from dropping too much (prevent fainting)
37
How much oxygen does resting muscle need?
Not much | Flow can be greatly reduced without damaging tissue
38
What has a greater effect on venous return, contracting muscles or sympathetic activity?
Contracting muscles
39
How much does brain blood flow change throughout a day?
Hardly at all...pretty constant
40
How much of an effect does sympathetic stimulation have on renal blood flow?
A huge amount...flow can be reduced to basically nothing
41
What is pulmonary arterial pressure relative to the rest of the arteries in the body?
Significantly lower (1/7)
42
How can the pulmonary arterial pressure be so low?
There is very little resistance...there can be the same amount of flow with a lower pressure
43
What do pulmonary arterioles do during hypoxia?
Constrict (systemic arterioles would dilate)
44
What possibly causes the pulmonary response to hypoxia?
Prostaglandin synthesis
45
What is the effect of vasoconstriction during pulmonary hypoxia?
Greater vascular resistance and pulmonary arterial hypertension
46
What is the role of autonomic nerves in the pulmonary system?
Very little

CV phys (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions