Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CPR Exam 1 > Smooth Muscle Physiology > Flashcards

Smooth Muscle Physiology Flashcards

1
Q

Do we see more actin in smooth muscle or skeletal muscle?

A

Much more actin in smooth muscle

(There is a lot more myosin in skeletal muscle)

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

Where does most of the calcium for contraction of a smooth muscle cell come from?

A

Outside the cell (not the sarcoplasmic reticulum)

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

What are the three methods for getting calcium out of a smooth muscle cell (that were covered in class)?

A

SERCA

Sodium / Calcium antiporters

Sarcolemmal Ca2+ ATPase

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

What does calcium bind to in smooth muscle cells to initiate a contraction?

A

Calmodulin

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

What is activated by Calmodulin after it binds to calcium?

A

Myosin light chain kinase

(Phosphorylates myosin light chains)

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

What are the functions of angiotensin II, vasopressin, and endothelin I?

A

They contract smooth muscle

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

What is the function of adenosine on smooth muscle?

A

Relaxes smooth muscle

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

What ion is primarily responsible for generating action potential in smooth muscle?

A

Calcium

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

What is different about the length tension curve between skeletal and smooth muscle?

A

Smooth muscle can adjust its length tension curve in order to maintain closer to the ideal.

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

histology:

Sk. M

Sm. M.

A

large, multi nucleated, striated cells

small, single nucleus, no striations

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

Sarcoplasmic reticulum

Sk. M.

Sm. M.

A

Sk. M: large, well developed, SR with triads, well developed T tubules

Sm. M: poorly developed SR, T tubules, membrane with caveoli

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

thin filaments

Sk. M

Sm. M

A

Sk. M actin, tropomyosin, tropinin

actin and tropomyosin

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

Thin filament number

Sk. m

Sm. M

A

fewer thin filaments in skeletal muscle than in smooth muscle

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

thick filaments

Sk. M

Sm. M

A

Sk. M. myosin, ATPase faster

Sm. M. myosin, ATPase slower, myosin light chain prominence

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

thick filament number

Sk. M.

Sm. M

A

Sk. M greater than in Sm, M

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

innervation

Sk. M

Sm. M

A

sk. M. a-motor neurons

Sm. M, multiple, intrinsic and autonomic nervous system

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

NTMs

Sk. M

Sm.M

A

Sk. M-ach, excititory

Sm. M-Ach, epi, NE, excite or inhibit

18
Q

Transmission specialization

Sk. M

Sm. M

A

SK. M. NMJ

Sm. M. No NMJ, uses varicosties, no endplate specialization

19
Q

NTM receptors

Sk. M

Sm. M

A

SK. M nicotinic cholinergic

Sm. M. muscarinic cholinergic, adrenergic, others

20
Q

Other forms of activation

Sk. M

Sm. M

A

sk. M-none

Sm. M-blood borne, paracrine, intrinsic

21
Q

ACtion potential

Sk. M

Sm. M

A

Sk. M-required

Sm. M-No, pacemaker activity, hormonal

22
Q

Source of Ca

Sk. M

Sm. M

A

Sk. M-release from SR

Sm. M-release from SR and ECF influx

23
Q

role of calcium

Sk. M

Sm. M

A

Sk. M-binds to troponin

Sm. M-binds to calmodulin, activates MLCK

24
Q

Mechanism to alow actin and myosin binding

SK. M

Sm. M

A

Sk. M-tropomuposin moved by troponin

Sm. M-pi of myosin light chain

25
Q

Relaxation

SK. M

Sm. M

A

Sk. M-removal of Ca from troponin

Sm. M-activation of light chain phosphatase, dephos.

26
Q

describe multi-unit smooth muscle

A

fibers operate individually, innervated by a single nerve

ex: ciliary muscle of eye, iris, piloeretor muscle

27
Q

Describe unitary smooth muscle

A

visceral smooth muscle that works as a unit

cell membranes adhere and contain gap junctions

ex: GI, bile ducts, uterus

28
Q

In smooth muscle, what does actin attach to?

A

dense bodies/adherens junctions

29
Q

describe smooth muscle contraction

A

cycling of myosin cross bridges is slower than SK. M.

the time myosin and actin are attached is greater which leads to a greater force while demanding less ATP

30
Q

Describe the latch mechanims

A

as excitation in the smooth muscle slows, contraction remains

31
Q

How does calcium enter the smooth muscle cell for contraction?

A

calcium enters cytosol via plasma membrane calcium channels

release from SR is minor

some comes in through ryanodine receptors or IP3 gates

32
Q

Most calcium enters the smooth muscle cell via

A

sarcolemma-K type voltage gated Ca channels and receptor activated ca channels

33
Q

CA leaves the cell via

A

SERCA

3Na/Ca antiporter

sarcolemma Ca ATPase

34
Q

What does intracellular Ca bind to reversibly and what does that complex activate?

A

Ca binds reversible to calmodulin which activates MLCK which Pi the myosin head

contraction strength is generally proportional to Ca levels

Now actin and myosin can bind and contract the muscle

35
Q

What does myosin light chain phosphatase do?

A

removes Pi group from MLC and along with calcium pumps to remove calcium ushers in the relaxation state of the smooth muscle

36
Q

How does NE/Epi control SM. M?

A

adrenergic

excitatory (contract) via A1 receptors

inhibitory (relax) via B2 receptors

37
Q

How does Ach control SM. M?

A

PSN

excitatory or inhibitory

contraction is a direct effect while relaxation is an indirect effect

38
Q

How does angiotenin II, vasopressin and endothelin control smooth muscle?

How does adenosine and NO control smooth muscle?

A

Contract!

Relax!

39
Q

What are some environmental cues of smooth muscle control and their effect?

A

hypoxia

excess Co2

increased H

adenosine, LA, increased K, etc

can call local dilation in vasculature sm.m.

40
Q

what are spike potentials?

what are slow waves?

What are plateaus?

A

stimulated by hormones, NTMs, stretch and spontaneously

oscillating Ca influx and K efflux, have pacemaker capabilities

stimualted by NTMs, stretch

41
Q

Describe the latch mechanism

A

it is a way to increase tension while decreasing ATP usage during Sm. M contraction

light chain gets dephoshp.

cycle proceeds slowly, and attached cross bridges are still generating tension (20-30%)

overall-increases time of contraction

CPR Exam 1 (31 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions