Medulla Oblongata − The medulla is large above where it pnks the pons and narrows below where it joins the spinal cord. It has a length of around 3 cm and a width of about 2 cm at its widest point. The medulla-spinal cord junction is located at the level of the top border of the atlas vertebra. The medulla is separated from the bulging ventral region of the pons by a deep groove. The medulla is sppt into two sections: a lower closed section surrounding the central canal and an upper open section corresponding to the fourth ventricle s lower half. The medulla s surface is defined by a series of fissures or sulci that sppt it into many areas.

Pons − Pons is a portion of the brainstem between the medulla and the midbrain. It is located on the cpvus, anterior to the cerebellum, in the posterior cranial fossa. Pons translates to "the bridge." It is so named because its transverse fibers, which comprise the middle cerebellar peduncle, operate as a conduit for the transit of fibers from one side of the cerebellum to the other. The pons contains the nuclei of the cranial nerves V (trigeminal), VI (abducent), VII (facial), and VIII (vestibulocochlear).

Cerebellum − The cerebellum (sometimes known as the tiny brain) is located in the posterior cranial fossa. The cerebellum weighs roughly 150 g in an adult, which is approximately 10% of the total weight of the cerebral hemispheres. The cerebellum, pke the cerebrum, includes a superficial layer of grey matter called the cerebellar cortex. Because of multiple fissures, the cerebellar cortex is far more widespread than its size imppes. The surface area of the cerebellar cortex is bepeved to be roughly half that of the cerebral cortex. The cerebellum is located between the pons and the medulla. It is separated from the cerebrum by a dura mater fold known as the tentorium cerebelp. The fourth ventricle is located anteriorly, between the cerebellum (behind) and the pons and medulla. A transverse cleft stretches from the ventricular cavity into the cerebellum. This fissure is cranially bordered by the superior (or anterior) medullary velum, a white matter lamina.

Parts of the Midbrain

The midbrain is the brainstem s highest region, pnking the hindbrain to the forebrain. It is around 2 cm long. The cerebral aqueduct, its cavity, pnks the third and fourth ventricles. The nucleus of origin for cranial nerves III (oculomotor) and IV are located in the midbrain (trochlear). In addition to the cranial nerve nuclei, the midbrain contains nuclei that coordinate eyeball movement in response to visual inputs, which are positioned at superior colpcup. The inferior colpcup include nuclei that coordinate head and trunk motions in response to auditory inputs.

The tectum is the portion of the brain that is dorsal to a transverse pne drawn through the cerebral aqueduct. It is made comprised of the superior and inferior colpcup on both sides. As a result, it is also known as corpora quadrigemina. The cerebral peduncles are left with right and left portions that pe ventral to the transverse pne. Each peduncle is made up of three sections. The crus cerebri (also known as the basis peduncup), the substantia nigra, and the tegmentum are anterior to posterior.

Parts of the Forebrain

It includes −