Movements of the body are usually smooth and occur at differing rates because

A. of the all-or-none principle.
B. most muscle contractions closely resemble individual muscle twitches.
C. they are a mixture of isotonic and isometric contractions.
D. motor units contract out of phase at their own particular rates.
E. muscles of different sizes contract at different rates.


Answer: D

Anatomy & Physiology

You might also like to view...

The concentration of a hormone in the blood can affect the number of receptors for that hormone on or in a target cell

Indicate whether the statement is true or false.

Anatomy & Physiology

A protein is formed from a sequence of amino acids.

Answer the following statement true (T) or false (F)

Anatomy & Physiology

Where is the thickest part of the myocardium?

A. The walls of the left atrium B. The walls of the right ventricle C. The walls of the left ventricle D. The walls of the right atrium E. The interventricular septum

Anatomy & Physiology

Where does gas exchange occur in the lung?

A) alveolus B) primary bronchus C) pulmonary artery D) terminal bronchiole E) trachea

Anatomy & Physiology