Muscle Physiology

Myofibrils are composed primarily of

• actin and myosin

• ATP and ADP

• Troponin

• Tropomyosin

When a muscle undergoes atrophy in response to disuse,

• The number of mitochondria decrease

• There is reduction in capillary networks

• The size of actin and myosin fibers decrease

• All of the above

Neurotransmitters are stored in vesicles within

• motor units

• motor neuron endings

• myofibrils

• motor end plates

The botulinus toxin that causes botulism acts by

• preventing the release of acetylcholine

• promoting the release of acetylcholine

• Preventing decomposition of acetylcholine

• none of the above

The enzyme cholinesterase causes acetylcholine to

• be secreted from the motor end plate.

• form cross bridges.

• bind to actin.

• decompose.

What chemical helps to regenerate ATP?

• acetylcholine

• cholinsterase

• creatine phosphate

• ADP

Skeletal muscles are responsible for moving

• The heart

• The skeleton

• the pancreas

• The brain

Which of the following muscle types are voluntary?

• Skeletal

• Cardiac

• Smooth muscle

What are the three types of muscles?

• voluntary, smooth, cardiac

• cardiac, skeletal, nervous

• cardiac, smooth, skeletal

• smooth, cardiac, stomach

Which cell organelle provides energy for muscle contraction?

• lysosome

• nucleus

• endoplasmic reticulum

• mitochondria

Tags

NGSS.HS-LS1-7