Brainscape's Knowledge GenomeTM

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


See full index

caps 390 > muscle > Flashcards

muscle Flashcards

1
Q

skeletal muscle function (striated)

A
  • body movement
  • posture
  • respiration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

smooth muscle function

A
  • peristalsis
  • constriction of blood vessels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

cardiac muscle function (striated)

A

heart beat

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

organization of skeletal muscle

A

one myofibril (cell)-> one muscle fiber -> a fascicle of muscle fibers -> a muscle

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

epimysium

A

dense collagen CT surrounding entire muscle

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

perimysium

A

collagen CT surrounding a fascicle

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

endomysium

A

fine reticular fiber CT that surrounds ind muscle fibers

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

myotendinous junction

A

finger-like extensions of muscle fibers that extend into tendon CT

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

basal lamina of muscle fibers

A

external, contains glycoproteins and collagen
- binds to myofiber via dystrophin-containing

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

myofibril organization

A

long, cylindrical, striated
- multinucleated, nuclei at periphery
- aligned in parallel
- separated by mitochondria and SR
- composed of myofilaments

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

sarcoplasmic reticulum

A

smooth ER of muscle
- interconnected tubules surrounding each myofibril
- store Ca2+ when muscle is at rest
- release Ca2+ into sarcoplasm when muscle is stimulated

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

T-tubule

A

invaginations of sarcolemma (membr)
- perpendicular to length of myofiber

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

triad junction

A

single T tubule and two terminal cisternae of the SR on either side
- ryanodine receptor on terminal cisternae, attached to
- dihydropyridine receptor (voltage-gated) on T-tubule
- Ca2+ passes through

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

sarcomeres

A

contractile unit of myofibrils
- from Z disc to Z disc
- actin filaments on the outside
- myosin on the inside
- elastic titin filaments on edges of myosin

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

myosin filament

A

thick myofilament
- monomer: long tail with two heads; actin and myosin ATPase binding sites

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

actin filament

A

think myofilament
- two tropomyosin filament helix, with actin balls attached through troponin complex
- troponin complex: 3 types of troponin, each one binding to actin, tropomyosin, or calcium

17
Q

binding of myosin head to actin

A

Low Ca2+: myosin binding sites on actin are blocked by tropomyosin
High Ca2+: calcium binds to troponin complex, induces conformational change, and unmasks myosin binding sites on actin

electrical stimulation ->
SR releases Ca2+ into sarcoplasm ->
Ca2+ binds troponin ->
conformational change uncovers myosin binding site ->
myosin head binds to actin

18
Q

skeletal muscle contraction

A
  1. myosin attaches to actin, ADP and Pi released
  2. myosin head bends and pulls actin filament towards the center of the sarcomere
  3. new ATP binds to myosin head, myosin unbends and detaches from actin
  4. ATP hydrolysis occurs, myosin attaches again
19
Q

sliding filament model

A

actin and myosin filaments overlap slightly
- actin filaments slide along myosin -> greater overlap -> sarcomere shortening

20
Q

skeletal muscle

A
  • voluntary
  • controlled by motor neurons
21
Q

motor unit

A

motor neuron and all the muscle fibers it innervates

22
Q

motor endplate

A

domain of sarcolemma responsible for initiating action potential
- AP propagates along myofiber, causing muscle contraction

23
Q

neuromuscular junction

A

junction of the axon terminal of MN and motor end plate of muscle

24
Q

excitation-contraction coupling

A
  1. ACh released and binds to nicotinic acetylcholine receptors
  2. Na+ gated channels open, intiating AP
  3. AP propagates along sarcolemma and into t tubules
  4. AP triggers dihydropyridine receptors to trigger release of Ca2+ into sarcoplasm from ryanodine receptors
  5. Ca2+ binds to troponin; troponin changes shape and uncovers myosin binding site
  6. myosin cross bridges attach to actin, bend when ATP is hydrolyzed, pulling actin filaments toward center of sarcomere; cyclic process powered by ATP hydrolysis
  7. Ca2+ actively transported into SR after AP
  8. low Ca2+ in sarcoplasm so tropomyosin blocks myosin binding site again
25
Q

botox

A

causes acetylcholine vesicles to not fuse to presynaptic membrane
- paralyzes muscles

26
Q

duchenne muscular dystrophy

A

mutation of dystrophin gene
- muscle wasting, mental disability
- dystrophin is part of dystroglycan complex which links actin cytoskeleton to basal lamina
- CT and adipose tissue takes over muscles

27
Q

cardiac muscle

A

forms thick layer in heart = myocardium
- rhythmic, involuntary
- short + branched striated fibers = cardiomyocytes
- one central nucleus per fiber

28
Q

intercalated disks

A

Join cardiomyocytes together (junctional complex)
- step-like pattern
- transverse and lateral part

29
Q

transverse part

A

runs across fibers
- zonula adherens: anchor actin of terminal arcomeres to plasma membr
- desmosomes: bind fibers tgt to prevent separation during contraction

30
Q

lateral part

A

runs parallel to myofilaments
- gap junctions: flow of info between fibers

31
Q

smooth muscle

A

involuntary + non-striated
- spindle-shaped fibers
- one central nucleus (corkscrew-shaped when contracted)
- No t-tubules

32
Q

smooth muscle of arteries and veins

A

part of tunica media (smooth muscle + elastic tissue)
- thicker in arteries than veins
- control diameter

33
Q

smooth muscle of intestine

A

longitudinal and circular layers
- peristalsis
- stomach also has oblique layer

34
Q

smooth muscle fiber junctions

A

gap junctions

35
Q

thin filaments of smooth muscle

A

arranged diagonally in cell
- attach to dense bodies in sarcoplasm or dense plaques on sarcolemma

36
Q

contractile units of smooth muscle

A

myosin and actin filaments attached to dense bodies in sarcoplasm or dense plaques on sarcolemma

37
Q

caveolae

A

flask-shaped invaginations of sarcolemma which are near peripheral SR

caps 390 (13 decks)

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