Muscle

Question 1

Skeletal muscle speciality?

Answer 1

Multinucleated at periphery. Striated, arranged in fascicles.

Question 2

Smooth muscle characteristics?

Answer 2

Single corkscrew nucleus, not striated, in sheets, gap junctions

Question 3

Cardiac muscle characteristics?

Answer 3

Single central nucleus, striated and branched fibers, intercalations. Much mitochondria

Question 4

Myofiber makeup?

Answer 4

Muscle cell composed of myofibrils

Question 5

Myofibril makeup?

Answer 5

Primary structural unit composed of myofilaments.

Question 6

What are myofilaments made of?

Answer 6

Actin and myosin

Question 7

Type one muscle characteristics?

Answer 7

Red, slow twitch. Small fibers, oxidative metabolism, high myoglobin

Question 8

Type 2a muscle characteristics?

Answer 8

Medium, mix of oxidative and glycolysis. High glycogen

Question 9

Type 2b muscle characteristics?

Answer 9

White, fast twitch. Glycolysis only. Fast ATPase.

Question 10

How far does a sarcomere extend?

Answer 10

From Z line to Z line.

Question 11

When contracting, does A band contract? H?

Answer 11

No. Yes

Question 12

What masks the myosin binding sites? How is it unmasked?

Answer 12

Tropomyosin. Ca binds troponin C, exposing binding sites on actin

Question 13

Where is myosin 2 found?

Answer 13

Only in the A band.

Question 14

What does desmin do?

Answer 14

Attaches sarcomeres to each other at Z line

Question 15

What does titin do?

Answer 15

Anchors thick filaments to the Z line

Question 16

Sarcoplasmic reticulum structure and function?

Answer 16

Triads in skeletal have terminal cisternae, t-tubule, terminal cisternae. Cis holds calcium, nerve impulse to release Ca through t-tubule. Diads in cardiac

Question 17

When can muscular hypertrophy happen?

Answer 17

Only after age 1

Question 18

What do satellite cells in skeletal muscle do?

Answer 18

Myogenic cells, help regenerate muscle after injury. Between sarcolemma and Lamina

Question 19

Purkinje fiber characteristics?

Answer 19

Large, binucleate. Conduct electrical impulse

Question 20

How does smooth muscle get calcium?

Answer 20

By caveolae

Question 21

Smooth muscle activation proteins?

Answer 21

MLCK- activates myosin 2

Calmodulin-binds Ca and MLCK to regulate contraction

Question 22

Neuromuscular junction characteristics?

Answer 22

Axon branches into muscle fiber, covered in Schwann cells. Uses ACh

Question 23

Muscle spindle purpose?

Answer 23

Has stretch receptors, which are proprioreceptors. Encapsulated