Muscle- Lecture 9/21/21

Question 1

Myocytes/fibers

Answer 1

Muscle cells, can be feet long

Question 2

Satellite cells

Answer 2

Muscle stem cells

Question 3

Somatic motor control

Answer 3

For voluntary muscles

Question 4

Visceral motor control

Answer 4

For involuntary muscles

Question 5

Skeletal muscle

Answer 5

Striated muscle that are voluntary, usually associated with skeletal movement

Question 6

Visceral muscle

Answer 6

Striated, voluntary visceral muscles (Upper esophagus, pharynx, tongue)

Question 7

Cardiac muscle

Answer 7

Striated, under autonomic (sympathetic/parasympathetic) control

Question 8

Smooth muscle

Answer 8

Non-striated, under autonomic control

Question 9

Epiysium

Answer 9

Fibrous edge surrounding entire skeletal muscle

Question 10

Perimysium

Answer 10

Surrounds muscle fascicles

Question 11

Endomysium

Answer 11

Surrounds each muscle fiber

Question 12

Fascicle

Answer 12

Group of muscle fibers

Question 13

Skeletal muscle fibers

Answer 13

Multinucleated, giant cells

Question 14

Myofibrils

Answer 14

Packed in each muscle, packed with myofilaments repeating sarcomere

Question 15

Sarcomere

Answer 15

Consisting of actin and myosin fibers

Question 16

Z line

Answer 16

The place where all the branched actin lines up

Question 17

M line

Answer 17

The middle of a sarcomere

Question 18

H band

Answer 18

In the middle, only myosin fibers

Question 19

A band

Answer 19

Where the are both myosin and actin fibers

Question 20

I band

Answer 20

Only actin fibers

Question 21

Muscle contraction

Answer 21

Ca2+ causes troponin to sequester tropomyosin, allowing myosin to bind and shorten sarcomeres (contract0

Question 22

Sarcolemma

Answer 22

Muscle plasma membrane

Question 23

T-tubules

Answer 23

Allow electric impulse to travel into the muscle cell

Question 24

DHP receptors

Answer 24

Line T-tubule, signal for the sarcoplasmic reticulum to let Ca2+ out

Question 25

Dystrophin complex

Answer 25

How contractile proteins are linked to the ECM, defective in muscular dystrophy

Question 26

Red muscle fibers

Answer 26

Many mitochondria, myoglobin, aerobic (can contract for long periods of time without fatigue)

Question 27

White muscle fibers

Answer 27

Oxidative enzymes, anaerobic, quick to fatigue but very powerful

Question 28

Motor unit density

Answer 28

Can be coarse or fine, 1:1000 motor units per fiber or 1:3 for fine control

Question 29

Muscle spindle

Answer 29

Specialized muscle fibers that provided proprioception info and mediate stretch reflex

Question 30

Golgi tendon organs

Answer 30

Found within the tendon, spontaneous relaxation if too much load

Question 31

Cardiac muscle organization

Answer 31

Highly branched, does not run the length of the heart

Question 32

End to end junction of cardiac cell

Answer 32

Fascia adherins, desmosomes

Question 33

Lateral cell-cell junctions

Answer 33

Gap junctions, desmosomes, discontinuous lamina

Question 34

Specialized myocardial cells

Answer 34

Endocrine action, can secrete ANF

Question 35

Purkinje fibers

Answer 35

Run just under endocardium, used for contraction and signal transduction

Question 36

Dense bodies

Answer 36

The contractile unit of smooth muscle cells

Question 37

Single unit smooth muscle

Answer 37

Nerve has caricosities that release signals, does not work immediately cuz diffusion

Question 38

Multi unit smooth muscles

Answer 38

Junctions more resemble skeletal muscle

Question 39

Ways to make smooth muscle contract

Answer 39

1. Electrical
2. Mechanical
3. Hormone

Question 40

Leiomyomas

Answer 40

Benign tumor of the smooth muscle cells, ex: fibroids in uterus

Question 41

Skeletal muscle repair

Answer 41

Satellite cell activation

Question 42

Cardiac muscle repair

Answer 42

Some satellite cell activation, but most repair us fibrotic

Question 43

Smooth muscle repair

Answer 43

Actively proliferates in response to damage of physiological needs