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Flashcards in Muscle Deck (53)
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1

3 types of muscle

Cardiac, smooth, skeletal

2

Voluntary muscle

Skeletal

3

Involuntary muscle

Cardiac, smooth

4

what are myofilaments made of?

actin, myosin

5

What is the epimysium

Connective tissue that surrounds the entire muscle

6

What is the perimysium

Connective tissue that surrounds the fasicle

7

What is the endomysium

Connective tissue that surrounds each muscle fiber (muscle cell)

8

What is a synctium?

A multinucleated cell that was created through the fusion of unicellular cells

9

Characteristics of skeletal muscle

Each cell has multiple, peripherally located nuclei

Striated

10

How vascularized is skeletal muscle?

Extensive capillary network due to high energy requirement

11

What is a sarcomere?

Single contraction unit (Z dsk to Z disk)

12

What are thin filaments of the sarcomere

Actin

13

What are thick filaments of the sarcomere

Myosin

14

What filament is most abundant in I band?

Actin, troponin, tropomyosin

15

What filament is most abunant in A band?

Myosin and Actin

16

What is the M line?

Where no actin filaments connect with myosin and two myosin filaments cross connect

17

Where are troponin and tropomyosin located?

I band

18

What filament is in the H band?

Myosin only

19

Which bands shorten during contraction?

I and H bands

20

How is troponin and tropomyosin configured?

Tropomyosin is wrapped around actin covering myosin binding sites

Troponin is attached to tropomyosin

21

Is troponin present in smooth muscle?

No

22

What is troponin C

Troponin C binds the calcium to activate movement of tropomyosin

23

How are myosin filaments arranged?

Two heavy chain tails are connected together with cross bridge heads

These heads move back during contraction

24

What 2 structures are important for calcium and muscle contraction?

Sarcoplasmic reticulum and T-tubules

25

What does the sarcoplasmic reticulum do?

Calcium storage

26

What do transverse tubules do?

Cell membrane invaginations that extend between the myofibrils and ensure high calcium inside every cell

27

What are terminal cisternae?

Expansions of sarcoplasmic reticulum

Located adjacent to T-tubules

28

What is a triad?

One T-tubule and its adjacent terminal cisternae

29

What happens at the neuromuscular junction?

ACh causes depolarization which spreads via T-tubules to triad junction to the dihydropyridine receptor activates the ryanodine receptor on the SR

30

What action does myosin have on ATP?

Hydrolyzes ATP