Medulla Oblongata, Teachmeanatomy image |
Medullar oblongata simply known as
Medulla, is the, Teache most posterior (caudal) part of the brain stem, it is continuous
with the spinal cord, extending from the lower body of the decussation of the
pyramid to the pons. Its ventral surface resembles that of a spinal cord except
for the bilateral prominence of the olive.
It has thick walls and floor but with
thin roof, the dorsal surface of its half forms part of the floor of the fourth
ventricle. It has motor nuclei which
include the hypoglossal nuclei, dorsal motor nuclei, inferior salivatory and
the ambiguus nucleus.
It also has sensory nuclei which include
the nuclei of the posterior column (gracile and cuneate), the cochlear and the
vestibular nuclei, the mild and the caudal portions of the spinal trigeminal
nucleus and nucleus of the solitary tract.
Functions
of Medullar Oblangata
The medullar oblongata is primarily
concerned with coordination of impulses from lateral line, ear taste and touch
receptors.
It is important in the controls
involuntary actions such as heart beats, respiration (breathing), movement and
peristaltic action of the intestine.
It is the site where glossopharyngeal
and vagus nerve arise from.
Definitions
of terms
Caudal:
Caudal is the tail or posterior part of the body.
Cuneate
: cuneate, is used to describe something that is wedge shape, and having a
narrow part at the base.
Olive:
Body part of the medullar.
Vagus:
Vagus is any one of the tenth pair of the cranial nerve originating the brain
stem and extending down into the abdomen, they are the nerve that supply the
tongue, larynx, lung , gut and heart.
Glossopharyngeal:
Glossopharyngeal, simply means, relating to the tongue and pharynx.
Pons:
The pons is a band of nerve fiber found in the brain stem.
Decussation:
crossing of lines.
Ambiguus
nueleus:
Ambiguus nucleus is a large group of motor neurons located deep in the
medullary reticular formation, it contains the cell body of nerves that
innervate the muscles of the soft plate, pharynx and larynx which are
associated with speech and swallowing.
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