The Joint Between the Head of the Radius and the Proximal

question 123

Multiple Choice

The joint between the head of the radius and the proximal end of the ulna is a ________ joint.

• A) plane
• B) saddle
• C) hinge
• D) pivot
• E) ball and socket

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Definitions:

Calmodulin

Protein receptor for Ca2+ that plays a role in many Ca2+-regulated processes, such as smooth muscle contraction.

Steroid Hormones

Lipid-soluble molecules derived from cholesterol that regulate a variety of physiological functions including metabolism, inflammation, and sexual function.

Plasma Membrane

The lipid bilayer that surrounds a cell, controlling the passage of substances in and out of the cell.

Phosphodiesterase

Enzyme that splits phosphodiester bonds—that is, that breaks down cyclic AMP to AMP.