Overview

Question 1

What are the functions of the muscular system?

Answer 1

1. body movement
2. generate heart beats
3. propel body fluids
4. distribute heat

Question 2

What are the three types of muscles?

Answer 2

1. skeletal
2. smooth
3. cardiac

Question 3

What is the skeletal muscle composed of?

Answer 3

1. skeletal muscle tissue
2. nervous tissue
3. blood
4. connective tissue

Question 4

Sarcolemma =

Answer 4

= cell membrane

Question 5

Sarcoplasm =

Answer 5

= cytoplasm

Question 6

Sarcomere =

Answer 6

= segment of a myofibril that extends from one Z-line to the next

Question 7

Mysosin =

Answer 7

= thick filament

Question 8

Actin =

Answer 8

= thin filament

Question 9

Steps of muscle contraction

Answer 9

1. Motor neuron releases acetylcholine
2. Acetylcholine diffuses across the neuromuscular junction and binds to receptors on the muscle fiber membrane
3. Muscle fiber membrane is stimulated and the muscle impulse travels deep into the fiber through the transverse tubules and reaches the sarcoplasmic reticulum
4. Calcium ions diffuse from the sarcoplasmic reticulum into the sarcoplasm and bind to troponin molecules
5. Troponin and tropomyosin expose the binding sites on actin
6. Actin and myosin filaments form links
7. Myosin cross bridges pull actin filaments inward
8. Muscle fiber shortens as a contraction occurs.