Special somatic afferent
Encyclopedia
Special somatic afferent (SSA) refers to afferent nerves that carry information from the special senses
of vision
, hearing
and balance
. The cranial nerves containing SSA fibers are the optic nerve
(II) and the vestibulocochlear nerve
(VIII). "SSA" may also stand for "special sensory afferent", however this term encompasses both special somatic and special visceral afferent
s.
Special senses
In medicine and anatomy, the special senses are the senses that have specialized organs devoted to them:*vision *hearing and balance *smell *taste...
of vision
Visual system
The visual system is the part of the central nervous system which enables organisms to process visual detail, as well as enabling several non-image forming photoresponse functions. It interprets information from visible light to build a representation of the surrounding world...
, hearing
Hearing (sense)
Hearing is the ability to perceive sound by detecting vibrations through an organ such as the ear. It is one of the traditional five senses...
and balance
Equilibrioception
Equilibrioception or sense of balance is one of the physiological senses. It helps prevent humans and animals from falling over when walking or standing still. Balance is the result of a number of body systems working together: the eyes , ears and the body's sense of where it is in space ideally...
. The cranial nerves containing SSA fibers are the optic nerve
Optic nerve
The optic nerve, also called cranial nerve 2, transmits visual information from the retina to the brain. Derived from the embryonic retinal ganglion cell, a diverticulum located in the diencephalon, the optic nerve doesn't regenerate after transection.-Anatomy:The optic nerve is the second of...
(II) and the vestibulocochlear nerve
Vestibulocochlear nerve
The vestibulocochlear nerve is the eighth of twelve cranial nerves, and is responsible for transmitting sound and equilibrium information from the inner ear to the brain...
(VIII). "SSA" may also stand for "special sensory afferent", however this term encompasses both special somatic and special visceral afferent
Special visceral afferent
' refers to afferent nerves that develop in association with the gastrointestinal tract. They carry the special senses of smell and taste . The cranial nerves containing SVA fibers are the olfactory nerve , the facial nerve , the glossopharyngeal nerve and the vagus nerve...
s.