Medulla oblongata

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The medulla oblongata or simply referred as medulla is the lower half portion of the brainstem. Its archaic term, the bulb, sometimes includes the pons in the modern clinical usage. The term bulbar actually is referring to the nerves, tracts and muscles associated to the medulla.

The motor and sensory neurons from the forebrain and midbrain passes through the medulla.

Location

The medulla is located at the front of cerebellum. It is about 3 cm long which continue upwards to the lower border end of the pons.

Structure

The medulla oblongata, also known as the myelencephalon, looks like a swelling tip at the spinal cord above the foramen magnum of the occipital bone.

In the front of medulla oblongata is the basilar portion of the occipital bone and the back part is the lower anterior notch of cerebellum.

The upper half connects with the fourth ventricle of the brain and the lower half is the central canal connecting to the spinal cord.

The medulla, like the cerebrum and cerebellum, consists of both the white matter (myelinated) and the gray matter (unmyelinated) nerve fibers. However, the anatomic relationship of the white and gray matter is reversed- the white on the outside and the grey on the inside.

Function

The medulla oblongata has the following body functions:

Regulate autonomic nervous system functions such as respiration, blood pressure, heart rate and reflex such as breathing, vomiting, sneezing, coughing and swallowing

Relay nerve signals or messages from and to the brain and spinal cord

Coordinate bodily movements

It is associated with the reticular formation which has a role in arousal states like attention and wakefulness; and it is also linked to the cranial nerves VI-XII.

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