Cremasteric reflex

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File:Cremasteric Reflex.ogv == Cremasteric Reflex ==

The cremasteric reflex is a superficial reflex observed in human males. It is elicited by lightly stroking or poking the superior and medial (inner) part of the thigh, which results in the contraction of the cremaster muscle that pulls up the testis on the side of the stimulus.

Anatomy and Physiology

The cremasteric reflex involves the genitofemoral nerve, which has both sensory and motor components. The sensory fibers originate from the femoral branch of the genitofemoral nerve, while the motor fibers are part of the genital branch of the genitofemoral nerve. The reflex arc is completed when the sensory input from the thigh is processed in the spinal cord at the level of L1 and L2, leading to the activation of the motor fibers that innervate the cremaster muscle.

Clinical Significance

The presence or absence of the cremasteric reflex can be an important diagnostic tool. It is often tested in cases of suspected testicular torsion, where the reflex is typically absent on the affected side. The reflex can also be diminished or absent in conditions such as upper motor neuron lesions, spinal cord injury, and certain types of neuropathy.

Related Reflexes

The cremasteric reflex is one of several superficial reflexes, which also include the abdominal reflex and the plantar reflex. These reflexes are important in the neurological examination to assess the integrity of the central and peripheral nervous systems.

Examination Technique

To test the cremasteric reflex, the patient should be in a supine position. The examiner uses a blunt instrument to gently stroke the inner thigh from the inguinal region downward. A normal response is the elevation of the testis on the same side as the stimulus.

Related Pages

• Genitofemoral nerve
• Cremaster muscle
• Testicular torsion
• Upper motor neuron lesion
• Spinal cord injury
• Neuropathy
• Abdominal reflex
• Plantar reflex