21.3B Vocabulary

Which of the following best describes the dermis?

• The outer protective layer of skin
• The inner layer of the two main layers of skin
• A layer of fat beneath the skin
• The topmost layer of muscle tissue

What is a key characteristic of smooth muscles?

• They are voluntary muscles
• They are striated muscles
• They are involuntary, non-striated muscles
• They only exist in skeletal system

The basic contractile unit of muscle fiber is called:

• Myosin
• Sarcomere
• Actin
• Neuron

What is the primary function of joints in the body?

• To produce blood cells
• To store calcium
• To protect internal organs
• To allow movement where bones meet

An axon is responsible for:

• Carrying nerve impulses toward the cell body
• Storing nutrients for the neuron
• Carrying nerve impulses away from the cell body
• Producing hormones

Which protein is found most abundantly in eukaryotic cells?

• Actin
• Myosin
• Collagen
• Keratin

A stimulus is defined as:

• A voluntary muscle movement
• A detectable environmental change
• A type of hormone
• A nerve cell structure

When muscles contract, they:

• Always lengthen
• Remain the same length
• Either shorten or increase in tension
• Only increase in width

The primary purpose of the skeleton is to:

• Produce blood cells only
• Provide structural support for the body
• Generate heat
• Store water

The myelin sheath functions as:

• A muscle fiber
• A hormone producer
• An insulating layer around nerves
• A bone connector