The nervous system comprises of the brain and the network of neurons. Brain is one of the most important organs of our system. Also nicknamed as the grey cells, brain system is divided into forebrain (Cerebrum), midbrain and hindbrain (cerebellum). Other organs closely located and connected to this brain system are pons, spinal cord and medulla oblongata. Medulla oblongata is placed in between pons and spinal cord and is an integral part of the overall brain system.
What is the Medulla Oblongata?
Medulla oblongata which is also called myelencephalon or medulla is the lowermost part of brain placed in its lowest portion. It is connected to midbrain by the pons and runs continuous with spinal cord posterior. Here it becomes one at the skull base near the opening of foramen magnum. Medulla consists of myelinated (white matter) and also unmyelinated (gray matter) nerve fibers. The normal anatomic relationship is reversed in medulla with white matter present on the outside whereas the gray matter is towards inside placed circling the fourth ventricle.
What is the anatomical structure of Medulla Oblongata?
In medulla oblongata the anterior surface is in connection with the basilar portion of occipital bone whereas the posterior portion is placed deep inside the anterior notch’s lower part of cerebellum The upper half of medulla oblongata is bounded with the fourth ventricle of brain whereas its lower half portion is tunneled by the central canal connecting the ventricle with central canal.
What are the functions of Medulla Oblongata?
Medulla oblongata forms main pathway by making provision for the nerve impulses to enter and leave skull. The reflex response that controls heart beat, breathing, blood pressure and other involuntary functions are regulated by medulla oblongata. It also comprises of reticular formation that performs the important role in arousal states like attention and wakefulness and also generates carnial nerves VI-XII. General anesthesia brings numbness by depressing the activities of medulla.
What are the different parts associated with Medulla Oblongata?
Some of the organs which are an integral part of medulla oblongata are,
Median fissures: Medulla oblongata consists of anterior median fissures and posterior median fissures. The anterior median fissure is placed at the upper portion of medulla while posterior median fissure is placed only at the lower area.
Pyramid: The pyramid is made up of corticospinal fibers and is a small bunch placed alongside anterior median fissure.
Olive: It is placed in the upper part of medulla and resembles a smooth oval swelling. It is made up of nerve cell mass which is mostly gray matter.
Inferior cerebellar peduncle: It is a rope like thick bundle placed postero-lateral to olive.
Spinal tract of trigeminal nerve: The separating portion between the peduncle and olive is a group of sensory fibers that form a sensory tract of trigeminal nerve.
Auditory nerve: This nerve is important for equilibration and consists of two nerves- cochlear nerve and vestibular nerve.
Nucleus gracilis and cuneatus: The gracile and cuneate tubercles are placed just below inferior cerebellar peduncle’s lower end.
Spinocerebellar tracts: These are divided into anterior and posterior spinocerebellar tracts and are placed in between spinal tract and trigeminal nerve.
What are the nerves associated with Medulla Oblongata?
The medulla is connected with the lower eight cranial nerves are and also with the upper fibers of the anterior root
The spinal tract of fifth cranial nerve runs down medulla into You do not have access to view this node
The sixth nerve pierces the upper pyramid portion of the medulla
The motor nucleus is placed in the seventh nerve of the pons; but the sensory nucleus is located in the upper part of medulla
The ninth, tenth, and twelfth nerves belong completely to the medulla oblongata whereas only the upper part of eleventh nerve rises in medulla