Question

muscular system test
multiple choice. select the best answer for each question below.

1. which of these is not a major task of the muscular system?

a) movement for your body e) maintaining posture
b) heat production for the body d) making red blood cells

1. which of the following words means \the ability to recoil or bounce back to the original shape\?

a) excitability c) extensibility
b) contractability d) elasticity

1. which type of muscle is involuntary and makes up many of your internal organs?

a) skeletal c) gastrointestinal
b) smooth d) cardiac

1. which type of muscle(s) is/are nonstriated?

a) skeletal muscle d) a & b
b) cardiac muscle e) b & c
c) smooth muscle f) a & c

1. which membrane covers an individual muscle fiber?

a) endomysium
b) epimysium
c) perimysium

1. what type of channel on the axon terminal is stimulated by an incoming action potential and allows calcium to enter the axon?

a) chemically - gated
b) voltage - gated
c) myosin - gated

1. when calcium ions enter the neuromuscular junction, what neurotransmitter is released across the synaptic cleft?

a) calcium c) k+
b) acetylcholine d) na+

1. what attaches muscle to bone?

a) ligaments c) sliding filaments
b) tendons d) sarcomeres

1. which two structures block the active site on an actin filament?

a) z - disc & the m - line c) troponin & tropomyosin
b) calcium & myosin d) actin & perimysium

1. the ____________ separate one sarcomere from another.

a) cross bridges c) m - lines
b) z - discs d) active sites

1. when myosin heads make a cross bridge and bend pulling the actin myofilament toward the center of the sarcomere, it is called the ____________.

a) power stroke c) return stroke
b) neuromuscular junction d) atp contraction

1. the deltoid is attached to the clavicle and the humerus. which one of these points is the insertion?

a) clavicle b) humerus c) neither, the deltoid doesnt have an insertion

Explanation:

1. The muscular system is not responsible for making red blood cells (that's the job of bone - marrow). Movement, heat production, and maintaining posture are major tasks of the muscular system.
2. Elasticity is the ability to recoil or bounce back to the original shape.
3. Smooth muscle is involuntary and makes up many internal organs.
4. Smooth muscle is non - striated. Skeletal and cardiac muscles are striated.
5. Endomysium covers an individual muscle fiber.
6. Voltage - gated channels on the axon terminal are stimulated by an incoming action potential and allow calcium to enter the axon.
7. When calcium ions enter the neuromuscular junction, acetylcholine is released across the synaptic cleft.
8. Tendons attach muscle to bone. Ligaments attach bone to bone.
9. Troponin and tropomyosin block the active site on an actin filament.
10. Z - discs separate one sarcomere from another.
11. When myosin heads make a cross - bridge and bend pulling the actin myofilament toward the center of the sarcomere, it is called the power stroke.
12. In muscle attachment, the insertion is the more movable point. The humerus is the insertion point for the deltoid muscle as the humerus moves more freely than the clavicle.

Answer:

1. d. Making red blood cells
2. d. elasticity
3. b. smooth
4. c. smooth muscle
5. a. endomysium
6. b. voltage - gated
7. b. Acetylcholine
8. b. tendons
9. c. troponin & tropomyosin
10. b. Z - discs
11. a. power stroke
12. b. humerus