Chapter 2/ The Muscular System

Question 1

Muscular system

Answer 1

Series of muscles that moves the skeleton.

Question 2

Tendons

Answer 2

Connective tissue that attaches muscle to the bone and provide an anchor for muscles to produce force. Tendons connect muscle to bone. (They are similar to ligaments when it comes to poor vascularity and blood flow, meaning longer recovery period)

Question 3

Sarcomere

Answer 3

The functional unit of muscle that produces muscular contraction and consists of repeating sections of actin and myosin.

Question 4

Neural activation

Answer 4

The contraction of a muscle generated by neural stimulation.

Question 5

Motor unit

Answer 5

A motor neuron and all of the muscle fibers it innervates. tested alot

Question 6

Neurotransmitters

Answer 6

Chemical messengers that cross the neuromuscular junction (synapse) to transmit electrical impulses from the nerve to the muscle.

Question 7

Sliding filament theory

Answer 7

1) a sarcomere shortens as a result of the Z lines moving closer together.
2) The Z lines converge as the result of myosin heads attaching to the actin filament and asynchronously pulling (power strikes) the actin filament across the myosin, resulting in shortening of the muscle fiber.

Question 8

Motor units and the “all or nothing” law.

Answer 8

Know that motor units either all fire or none will fire. A motor unit is one or motor neuron and the muscle fibers that it innervates(supply with nerves). A unit cannot partially fire.

Question 9

There are two main categories of muscle fibers

Answer 9

Type I is slow (think weak, aerobic, running) and Type II is fast(think strong, anaerobic, weight-lifting)

Question 10

Type I (slow twitch)

Answer 10

Contain large number of capillaries, mitochondria(transforms energy from food into ATP, energy), myoglobin(increased delivery of oxygen) Red fibers.
• type I are smaller in diameter, slow to produce maximal tension, more resistant to fatigue. Produce long term contractions. Think marathons. Maintaining posture against gravity.

Question 11

Type II (fast twitch)

Answer 11

Subdivided into Type IIa and Type IIx. Contain fewer capillaries, mitochondria, and myoglobin. White fibers.
• Type IIx have low oxidative capacity and fatigue quickly.
• Type IIa higher oxidative capacity and fatigue more slowly than IIx. IIa are known as intermediate fast-twitch fibers.
• Type II are larger in size, quick to produce maximal tension, fatigue more quickly. Sprint muscles.

Question 12

Muscles as movers

Answer 12

• Agonist muscles act as prime movers.
• Synergist muscles assist prime movers. Synergist, think synergy. Assists with.
• Stabilizer support and stabilize the body.
• Antagonist muscles perform opposite action of prime mover.