Muscular System

Question 1

Perimysium

Answer 1

Connective tissue surrounding a fascicle

Question 2

Epimysium

Answer 2

Connective tissue ensheathing the entire muscle

Question 3

Sarcomere

Answer 3

The contractile unit of muscle

Question 4

Muscle fiber

Answer 4

Same as muscle cell

Question 5

Endomysium

Answer 5

Thin connective tissue investing each muscle cell

Question 6

Sarcolemma

Answer 6

Plasma membrane of muscle cell

Question 7

Myofibril

Answer 7

A long, filamentous organelle found within muscle cells that have a banded appearance

Question 8

Myofilament

Answer 8

Actin- or myosin-containing structure

Question 9

Tendon

Answer 9

Cordlike extension of connective tissue beyond the muscle, serving to attach it to the bone

Question 10

Fascicle

Answer 10

Bundle of muscle cells

Question 11

Contraction Mechanism

Answer 11

1. Acetylcholine released into neuromuscular junction.
2. Acetyl. diffuses across junction; binds to receptors on sarcolemma.
3. Depolarization; action potential generated
4. Action potential=SR release Ca ions.
5. Ca ion concentration at myofilaments increases; myofilaments slide.
6. Ca reabsorbed into SR; concentration at myofilaments decreases.
7. Muscle cell relaxes and lengthens.

Question 12

Prime Mover

Answer 12

Muscle that provides the major force for producing a specific movement (AKA agonist)

Question 13

Antagonist

Answer 13

Muscle that opposes or reverses a particular movement

Question 14

Synergists

Answer 14

Help prime movers by (1) adding extra force to same movement or (2) reducing undesirable or unnecessary movements that might occur