Question

The biceps reflex tests a muscle spindle reflex arc (like the patellar reflex). The biceps brachii is innervated by the musculocutaneous nerve and the triceps brachii is innervated by the radial nerve. When the biceps tendon is tapped with a hammer, action potential generation ___________ in the musculocutaneous nerve and _____________ in the radial nerve.

Answer 1

The biceps reflex tests a muscle spindle reflex arc (like the patellar reflex). The biceps brachii is innervated by the musculocutaneous nerve and the triceps brachii is innervated by the radial nerve. When the biceps tendon is tapped with a hammer, action potential generation increases in the musculocutaneous nerve and decreases in the radial nerve.

Step-by-step explanation:

The biceps reflex test is performed to evaluate the functionality of the C5 and C6 reflex arcs and is done by quickly depressing the biceps brachii tendon by using a reflex hammer.

When the biceps brachii tendon is stimulated, the normal response would be a reflex contraction of the biceps brachii muscle, producing the flexion of the elbow. The contraction of this muscle is produced thanks to an increase in the action potential generated in the musculocutaneuous nerve -because this is the nerve that innervates this muscle-, which also generates a decrease in the action potentials in the radial nerve -given that this nerve innervates the antagonist muscle of the biceps brachii, the triceps brachii-.