Olivary body
Encyclopedia
In anatomy
, the olivary bodies or simply olives (Latin oliva and olivae, singular and plural, respectively) are a pair of prominent oval structures in the medulla oblongata
, the lower portion of the brainstem. They contain the olivary nuclei.
, from which it is separated by the antero-lateral sulcus
and the fibers of the hypoglossal nerve
.
Behind, it is separated from the postero-lateral sulcus by the ventral spinocerebellar fasciculus. In the depression between the upper end of the olive and the pons
lies the vestibulocochlear nerve
.
In humans, it measures about 1.25 cm. in length, and between its upper end and the pons there is a slight depression to which the roots of the facial nerve
are attached.
The external arcuate fibers wind across the lower part of the pyramid and olive and enter the inferior peduncle.
which is a part of the olivo-cerebellar
system and is mainly involved in cerebellar motor-learning and function.
The inferior olive in itself is divided to 3 main nuclei:.
small additional inferior olivary structures consist of the dorsal cap of Kooy and the ventrolateral outgrowth.
Anatomy
Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...
, the olivary bodies or simply olives (Latin oliva and olivae, singular and plural, respectively) are a pair of prominent oval structures in the medulla oblongata
Medulla oblongata
The medulla oblongata is the lower half of the brainstem. In discussions of neurology and similar contexts where no ambiguity will result, it is often referred to as simply the medulla...
, the lower portion of the brainstem. They contain the olivary nuclei.
External anatomy
The olivary body is located on the anterior surface of the medulla lateral to the pyramidPyramid of medulla oblongata
The anterior or ventral portion of the medulla oblongata is named the pyramid and lies between the anterior median fissure and the antero-lateral sulcus....
, from which it is separated by the antero-lateral sulcus
Antero-lateral sulcus
The Anterolateral sulcus of spinal cord is a landmark on the anterior side of the spinal cord. It denotes the location at which the ventral fibers leave the spinal cord.The anteriolateral sulcus is less visible than the posterolateral sulcus....
and the fibers of the hypoglossal nerve
Hypoglossal nerve
The hypoglossal nerve is the twelfth cranial nerve , leading to the tongue. The nerve arises from the hypoglossal nucleus and emerges from the medulla oblongata in the preolivary sulcus separating the olive and the pyramid. It then passes through the hypoglossal canal...
.
Behind, it is separated from the postero-lateral sulcus by the ventral spinocerebellar fasciculus. In the depression between the upper end of the olive and the pons
Pons
The pons is a structure located on the brain stem, named after the Latin word for "bridge" or the 16th-century Italian anatomist and surgeon Costanzo Varolio . It is superior to the medulla oblongata, inferior to the midbrain, and ventral to the cerebellum. In humans and other bipeds this means it...
lies 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...
.
In humans, it measures about 1.25 cm. in length, and between its upper end and the pons there is a slight depression to which the roots of the facial nerve
Facial nerve
The facial nerve is the seventh of twelve paired cranial nerves. It emerges from the brainstem between the pons and the medulla, and controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue and oral cavity...
are attached.
The external arcuate fibers wind across the lower part of the pyramid and olive and enter the inferior peduncle.
Olivary nuclei
The olive consists of two separate parts:- The inferior olivary nucleusInferior olivary nucleusThe inferior olivary nucleus is the largest nucleus situated in the olivary body, part of the medulla oblongata.-Function:It is closely associated with the cerebellum, meaning that it is involved in control and coordination of movements, sensory processing and cognitive tasks likely by encoding the...
or the inferior olivary complex,
which is a part of the olivo-cerebellar
Olivocerebellar tract
The olivocerebellar tract, also known as olivocerebellar fibers, are neural fibers which originate at the olivary nucleus and pass out through the hilum and decussate with those from the opposite olive in the raphé, then as internal arcuate fibers they pass partly through and partly around the...
system and is mainly involved in cerebellar motor-learning and function.
- The superior olivary nucleusSuperior olivary nucleusThe superior olivary complex is a collection of brainstem nuclei that functions in multiple aspects of hearing and is an important component of the ascending and descending auditory pathways...
is considered part of the ponsPonsThe pons is a structure located on the brain stem, named after the Latin word for "bridge" or the 16th-century Italian anatomist and surgeon Costanzo Varolio . It is superior to the medulla oblongata, inferior to the midbrain, and ventral to the cerebellum. In humans and other bipeds this means it...
and is a part of the auditory system, aiding the perception of sound.
The inferior olive in itself is divided to 3 main nuclei:.
- The primary olivary nucleus (PO) which consist of the major laminar structure.
- The medial accessory olivary nucleus (MAO) lies between the primary olivary nucleus and the pyramid, and forms a curved lamina, the concavity of which is directed laterally.
- The dorsal accessory olivary nucleus (DAO) is the smallest, and appears on transverse section as a curved lamina behind the primary olivary nucleus.
small additional inferior olivary structures consist of the dorsal cap of Kooy and the ventrolateral outgrowth.