H: Muscle Tissue Flashcards Preview

F16: Anatomy Test 3 > H: Muscle Tissue > Flashcards

Flashcards in H: Muscle Tissue Deck (42):
1

What is the name for the cytoplasm in a muscle cell?

Sarcoplasm

2

Smooth ER in a muscle cell?

Sarcoplasmic Reticulum

3

Plasma membrane in a muscle cell?

Sarcolemma

4

What are two alternate names for a muscle cell?

Muscle fiber or Myofiber

5

What are the three hierarchies of muscles?

Muscle cell -> muscle tissue -> muscle organ

6

What are the four special characteristics of muscle tissue?

1. Excitability
2. Contractility
3. Extensibility
4. Elasticity

7

What are the four major functions of muscle tissue?

1. Producing movement
2. Maintaining Posture
3. Stabilizing joints
4. Generating heat

8

Which type of muscle tissue is under voluntary control?

Skeletal muscle

9

Skeletal Muscle cells produce _____ and ______ contractions.

Strong; quick

10

What is a major defining characteristic of skeletal muscle?

Long multinucleate fibers. One cell can span the entire length of the muscle.

11

Cardiac muscles produce _____ and _____ contractions.

Strong; quick

12

What is a defining characteristic of cardiac muscle?

Intercalated discs that joint the branched uninucleate cells.

13

________ muscle fibers are striated but are very uniform, while _______ muscle fibers are striated but do not follow a uniform shape.

Skeletal; cardiac

14

_______ muscle fibers produce weak, slow contractions.

Smooth

15

Which muscle fiber does not have striations?

Smooth muscle

16

Which muscle fibers have central nuclei and arrange closely to form sheets?

Smooth muscle

17

Where is smooth muscle found?

In the walls of hallow organs.

18

Type I muscle fibers are ____, while type II muscle fibers are ____.

Slow; fast

19

Type I muscle fibers derive energy from what process?

Aerobic oxidative phosphorylation of fatty acids

20

Type I muscle fibers have many _______ and lots of _______ (give it its dark red color).

Mitochondria; myoglobin

21

T/F: Type IIb muscle fibers have more mitochondria and myoglobin, but less glycogen.

False!

Type IIa: many mitochondria, lots of myoglobin and glycogen

Type IIb: fewer mitochondria and myoglobin, but LOTS of glycogen (gives it pale color)

22

Which types of skeletal muscle fibers are adapted for rapid contractions, but fatigue quickly?

Type IIb

23

As fibers go from red (type I) to white (type IIb) what are the major physiological changes that occur?

Go from primarily aerobic oxidation (red, type I) --> oxidative metabolism and anaerobic glycolysis (intermediate, type IIa) --> primarily anaerobic glycolysis (white, type IIb)

24

A __________ __________ is a chemical synapse between a motor neuron and a skeletal muscle fiber.

Neuromuscular junction (aka motor end plate)

25

What does a motor unit consist of?

The motor neuron and all the muscle fibers it innervates.

26

What are the lateral boundaries of a sarcomere?

Z lines

27

What is the center line of a sarcomere?

M line

28

What are the thin filaments?

Actin

29

What are the the thick filaments?

Myosin

30

What is found in the A band?

Combination of myosin and actin

31

What is found in the I bands?

Only actin. No myosin.

32

The lengths of what do not change during muscle contraction?

Thin and thick filaments.

33

The ______ ______ and ______ _______ shrink and eventually disappear during muscle contraction.

H zone; I band

34

Describe the "excitation" steps in excitation-contraction coupling?

1. Action potential moves along sarcolemma and down the T tubules
2. Ca2+ release from terminal cisternae of SR
3. Ca2+ binds to troponin, troponin changes shape removing binding sites of tropomyosin, exposing actin active sites

35

Describe the "contraction" steps in excitation-contraction coupling.

1. Myosin cross bridges alternately attach and detach to actin, pulling the actin toward the m line. ATP powers the process.
2. Removal of Ca2+ by active transport into SR once action potential ends.
3. Tropomyosin blockage restored and muscle fiber relaxes ending contraction

36

What chemicals are released during the working stroke of myosin?

ADP and phosphate

37

What does a skeletal muscle organ consist of?

1. Skeletal muscle tissue
2. Vessels
3. Nerve fibers
4. Connective tissue

38

Where is endomysium found in skeletal muscle?

Between the fibers

39

Where is the perimysium found in skeletal muscle?

Around fascicles (bundles of muscle fibers).

40

Where is the epimysium found in skeletal muscle?

Surrounding the entire organ

41

T/F: Cardiac muscle cells contain larger mitochondria than skeletal muscle cells.

True

42

T/F: Terminal cisternae forms triads with t tubules in skeletal muscles, but form diads in cardiac muscles.

True