Skeletal Muscle Flashcards Preview

Histology > Skeletal Muscle > Flashcards

Flashcards in Skeletal Muscle Deck (48):
1

Black arrows?

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Type I fibers

2

What is alpha actinin

protein that attaches thin filaments to the Z-line

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3

Blue arrows?

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Type II fibers

4

Arrows?

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Myocyte nuclei

5

What is alpha-beta crystallin?

a heat shock protein that protects desmin from mechanical stress.

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6

What is nebulin?

A molecule that lies on top of actin filaments in the sarcomere. It regulates the length of an actin filament.

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7

Identify

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Cardiac muscle, Acute MI

8

What are satellite cells?

Cells that attach to myotubes before the basal lamina is laid down. They function as stem cells and give rise to myogenic precursor cells (replaces damaged muscle).

9

What is the dystroglycan complex?

It links dystrophin (intracellular) to laminin-2 (extracellular).

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10

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smooth muscle

11

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Smooth muscle

12

What is type I myofiber also known as?

red/dark fibers

13

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skeletal muscle

14

What are the 3 types of muscle tissue?

smooth, skeletal and cardiac

15

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Smooth muscle

16

What is speed of contraction of type I myofibers?

slow and continuous

17

What is one way that smooth muscle and skeletal muscle differ?

Smooth muscle has single mononucleated cells and skeletal muscle has many cells.

18

Why are type IIB myofibers light?

They have little to no myoglobin; type IIA uses ANAEROBIC respiration.

19

Blue arrows?

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Type II fibers

20

Identify

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Muscle spindle

21

Why is type I myofiber dark?

due to the large armount of hemoglobin in the fibers; type I myofibers use OXIDATIVE PHOSPHORLYATION. They also have high ATP, and NADH

22

What are the components of a neuromusclar spindle?

extrafusal fibers, intrafusal fibers, alpha motor neurons, gamma motor fibers, primary and secondary afferent fibers.

23

If NAD stain is dark in myofibers, what does that indicate?

The myofiber is high NAD, and hence uses oxidative phosphorylation. It is probably at type 1 myofiber.

24

what are two features of cardiac muscle visible in a picture?

intercalated discs and sarcomeric arrangement.

25

Identify

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Cardiac muscle

26

What are type IIB myofibers also known as?

white/light fibers

27

C?

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Myofibril

28

How do the contraction of type IIA myofibers compare to type I and IIB contractions?

Type IIA contracts faster than type I, but slower than type IIA.

29

Black arrows?

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Type I fibers

30

What is type IIA myofiber also known as?

intermediate fibers

31

What are the gap junctions called that are found in cardiac muscle?

intercalated discs.

32

What is titin?

A molecule that extends from the Z disc to the end line. It maintains the position of the myosin filaments in the sarcomere.

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33

Arrowhead?

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Satellite cell

34

A?

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Fascicle

35

What is the contraction mechanism of skeletal muscle?

all or none

36

Identify

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muscle spindle

37

What is dystrophin?

A molecule that links alpha-actin/desmin to the cytoplasmic side of the sarcolemm and anchors actin to it as well. It also reinforces sarcolemma during muscle contraction.

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38

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Skeletal Muscle

39

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Cardiac Muscle

40

E?

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Epimysium

41

B?

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Myofiber

42

Do type IIB myofibers fatigue quickly or slowly?

slowly

43

What are the similarities between smooth and cardiac muscle?

Both use gap junctions, do not conduct an "all or nothing" signal and are not directly innervated.

44

G?

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Perimysium

45

D?

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Endomysium

46

F?

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Blood vessels

47

What kind of respiration does type IIA myofiber use?

BOTH aerobic and anaerobic resiration.

48

How are skeletal muscle cells formed?

When individual myoblasts form a myotube.