The Bulbocavernosus reflex is a spinal reflex which can be used to assess the integrity of the sacral spinal cord and it's associated nerves, most particularly after a spinal cord injury.
A bulbocavernosus reflex is a polysynaptic reflex, which means that it involves multiple nerve connections and can also be elicited by stimulating your genitalia or anus, which causes contraction of your bulbospongiosus muscle that is involved in penile erection as well as ejaculation.
The bulbocavernosus is a reflex arc that involves sensory input from your genitalia or anus, a synapse in the sacral spinal cord and motor output to your bulbospongiosus muscle.
the reflex is often elicited by stimulation of your penis or clitoris "or your perianal region" and observing for a contraction of your bulbospongiosus muscle, that can be felt or seen or even measured using electromyography, "EMG".
The clinical significance of bulbocavernosus is spinal shock as the presence or absence of the BCR is also used to help to determine if you're in spinal shock, which is a temporary state of reduced reflexes that follow a spinal cord injury.
The bulbocavernosus reflex is also used as part of a neurological assessment after spinal cord injury to evaluate the extent and potential for recovery.
And the bulbocavernosus reflex can also provide information about the function of the sacral plexus, which is a network of nerves in your lower back which innervate your pelvic organs and lower limbs.
And it can also be used during surgeries to monitor the integrity of your sacral nerves and your spinal cord.
Alternatives to the bulbocavernosus reflex are the anal wink reflex which is also a sacral reflex that is often used alongside of or instead of the bulbocavernosus reflex in clinical practice.