Muscle Physiology Pt. 1

Question 1

What are the three types of muscles?

Answer 1

1. Smooth muscle
2. Skeletal muscle
3. Cardiac muscle

Question 2

This type of muscle is non-striated, has one nucleus, and is spindle/fusiform-shaped.

Answer 2

Smooth muscle

Question 3

This type of muscle is striated, multi-nucleated, and rectangular/elongated.

Answer 3

Skeletal muscle

Question 4

This type of muscle is striated, has one nucleus, and is branching.

Answer 4

Cardiac muscle

Question 5

TRUE OR FALSE: Skeletal muscles have only a single mitochondria.

Answer 5

FALSE: Skeletal muscle fibers have many mitochondria for the creation of ATP.

Question 6

TRUE OR FALSE: Skeletal muscle fibers have transverse tubules.

Answer 6

TRUE

Question 7

It is the specific term for plasma membrane in intracellular structures.

Answer 7

Sarcolemma

Question 8

It is the specific term for cytoplasm in intracellular structures.

Answer 8

Sarcoplasm

Question 9

It is the specific term for smooth ER in intracellular structures.

Answer 9

Sarcoplasmic Reticulum

Question 10

These are structures that give cardiac and skeletal muscles the striated appearance.

Answer 10

Myofibrils

Question 11

This filament is thin and bead/pearl-like.

Answer 11

Actin

Question 12

This filament is thick and has paired club heads used to form cross bridges.

Answer 12

Myosin

Question 13

Myosin heads with actin binding sites; will bind with actin

Answer 13

Cross bridges

Question 14

This mechanism does not necessarily mean “shortening”

Answer 14

Contraction

Question 15

This mechanism is a result of the shortening of a skeletal muscle fiber and the overlapping of thick and thin filaments.

Answer 15

Sliding Filament Mechanism

Question 16

The ability of muscle fibers to generate force and movement depends on the interaction of the __________ and __________.

Answer 16

Actin; myosin

Question 17

What are the three types of thin filaments and associated proteins?

Answer 17

1. Actin
2. Tropomyosin
3. Troponin

Question 18

This is a contractile protein with each G actin possessing a bonding site for myosin.

Answer 18

Actin

Question 19

This is a regulatory protein that overlaps binding sites on actin for myosin and inhibits interaction when in relaxed state.

Answer 19

Tropomyosin

Question 20

This is a regulatory protein that binds Ca+ reversibly.

Answer 20

Troponin

Question 21

TRUE OR FALSE: One motor neuron innervates many muscle fibers, but one muscle fiber is innervated by only one motor neuron.

Answer 21

TRUE

Question 22

These neurons propagate action potentials at high velocities.

Answer 22

Motor neurons (somatic efferent neurons)

Question 23

What are the steps to Neuromuscular Junction?

Answer 23

1. Ca2+ enters
2. Acetylcholine binds with ion channels
3. Allow entry of sodium ions to motor end plate – depolarization
4. Depolarization allows next action potential of the next muscle

Question 24

This stores Ca2+ to be released following membrane excitation.

Answer 24

Sarcoplasmic Reticulum

Question 25

T-tubules and sarcoplasmic reticulum are connected by __________

Answer 25

Integral membrane proteins

Question 26

This receptor is a t-tubule protein and modified voltage-sensitive Ca2+ channels.

Answer 26

Dihydropyridine (DHP) Receptor

Question 27

This receptor is a sarcoplasmic reticulum protein that forms Ca2+ channels.

Answer 27

Ryanodine Receptor

Question 28

This binds strongly to nicotinic ACh receptors, causes skeletal muscle paralysis, and death from asphyxiation.

Answer 28

Curare

Question 29

This blocks neuromuscular transmission by inhibiting acetylcholinesterase, causes skeletal muscle paralysis, and death from asphyxiation.

Answer 29

Organophosphate

Question 30

This causes ACh to build up at muscarinic synapses.

Answer 30

Nerve gases

Question 31

Two antidotes for OP and nerve gas exposure:

Answer 31

Pralidoxime and Atropine

Question 32

This reactivates acetylcholinesterase

Answer 32

Pralidoxime

Question 33

This is a muscarinic receptor antagonist

Answer 33

Atropine

Question 34

This acts as an antagonist to ACh receptors, producing depolarizing or desensitizing block-like acetylcholinesterase inhibitors

Answer 34

Succinylcholine

Question 35

This is a nondepolarizing neuromuscular junction blocking drugs that act more like curare and last longer

Answer 35

Rocuronium and vecuronium