What reflex is associated with deep tendon response for the extensor digitorum?

The reflex associated with the deep tendon response for the extensor digitorum is primarily linked to the C7 nerve root. The extensor digitorum is innervated by the radial nerve, which originates from the posterior cord of the brachial plexus and includes contributions from spinal nerves C6, C7, and C8. When assessing deep tendon reflexes, the C7 segment plays a crucial role in the extension of the fingers via this muscle.

When stimuli are applied, such as tapping on the tendon of the extensor digitorum, the C7 nerve root is activated, leading to an immediate reflexive contraction of the muscle that results in finger extension. This response is essential for evaluating neurological function and can help identify any potential issues with the nerve pathways.

Taking this into account, C7 is identified as the correct response because it is the nerve root responsible for mediating the reflex action associated with the extensor digitorum, highlighting the significance of this segment in evaluating upper extremity function through deep tendon reflex testing.