H: Muscle Tissue

Question 1

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

Answer 1

Sarcoplasm

Question 2

Smooth ER in a muscle cell?

Answer 2

Sarcoplasmic Reticulum

Question 3

Plasma membrane in a muscle cell?

Answer 3

Sarcolemma

Question 4

What are two alternate names for a muscle cell?

Answer 4

Muscle fiber or Myofiber

Question 5

What are the three hierarchies of muscles?

Answer 5

Muscle cell -> muscle tissue -> muscle organ

Question 6

What are the four special characteristics of muscle tissue?

Answer 6

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

Question 7

What are the four major functions of muscle tissue?

Answer 7

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

Question 8

Which type of muscle tissue is under voluntary control?

Answer 8

Skeletal muscle

Question 9

Skeletal Muscle cells produce _____ and ______ contractions.

Answer 9

Strong; quick

Question 10

What is a major defining characteristic of skeletal muscle?

Answer 10

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

Question 11

Cardiac muscles produce _____ and _____ contractions.

Answer 11

Strong; quick

Question 12

What is a defining characteristic of cardiac muscle?

Answer 12

Intercalated discs that joint the branched uninucleate cells.

Question 13

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

Answer 13

Skeletal; cardiac

Question 14

_______ muscle fibers produce weak, slow contractions.

Answer 14

Smooth

Question 15

Which muscle fiber does not have striations?

Answer 15

Smooth muscle

Question 16

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

Answer 16

Smooth muscle

Question 17

Where is smooth muscle found?

Answer 17

In the walls of hallow organs.

Question 18

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

Answer 18

Slow; fast

Question 19

Type I muscle fibers derive energy from what process?

Answer 19

Aerobic oxidative phosphorylation of fatty acids

Question 20

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

Answer 20

Mitochondria; myoglobin

Question 21

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

Answer 21

False!

Type IIa: many mitochondria, lots of myoglobin and glycogen

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

Question 22

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

Answer 22

Type IIb

Question 23

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

Answer 23

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

Question 24

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

Answer 24

Neuromuscular junction (aka motor end plate)

Question 25

What does a motor unit consist of?

Answer 25

The motor neuron and all the muscle fibers it innervates.

Question 26

What are the lateral boundaries of a sarcomere?

Answer 26

Z lines

Question 27

What is the center line of a sarcomere?

Answer 27

M line

Question 28

What are the thin filaments?

Answer 28

Actin

Question 29

What are the the thick filaments?

Answer 29

Myosin

Question 30

What is found in the A band?

Answer 30

Combination of myosin and actin

Question 31

What is found in the I bands?

Answer 31

Only actin. No myosin.

Question 32

The lengths of what do not change during muscle contraction?

Answer 32

Thin and thick filaments.

Question 33

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

Answer 33

H zone; I band

Question 34

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

Answer 34

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

Question 35

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

Answer 35

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

Question 36

What chemicals are released during the working stroke of myosin?

Answer 36

ADP and phosphate

Question 37

What does a skeletal muscle organ consist of?

Answer 37

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

Question 38

Where is endomysium found in skeletal muscle?

Answer 38

Between the fibers

Question 39

Where is the perimysium found in skeletal muscle?

Answer 39

Around fascicles (bundles of muscle fibers).

Question 40

Where is the epimysium found in skeletal muscle?

Answer 40

Surrounding the entire organ

Question 41

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

Answer 41

True

Question 42

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

Answer 42

True