Human Brain Stem

Quick Answer: The human brain stem model is an anatomical replica of the brainstem, the stalk that joins the cerebrum to the spinal cord, made up of the midbrain, pons and medulla oblongata. It is used to teach where the cranial nerves emerge and how this region controls breathing, heart rate and consciousness.

Midbrain, Pons and Medulla

The brainstem is small but carries every pathway between the brain and the body. The midbrain sits at the top, with the cerebral peduncles in front and four small bumps behind, the superior and inferior colliculi, which relay visual and auditory reflexes. Below it the pons forms a rounded swelling linked to the cerebellum by thick fibre bundles, and the medulla oblongata tapers down to meet the spinal cord at the foramen magnum.

Ten of the twelve pairs of cranial nerves arise from the brainstem, and a model is the easiest way to learn their order: the oculomotor and trochlear from the midbrain; the trigeminal from the pons; the abducens, facial and vestibulocochlear at the junction of pons and medulla; and the glossopharyngeal, vagus, accessory and hypoglossal from the medulla. On the front of the medulla two ridges, the pyramids, carry the motor pathway that crosses to the other side just above the spinal cord.

The title does not say whether the brain stem model is enlarged, whether the cerebellum or thalamus is attached, or whether it separates into parts. Nerve roots on models of this region are often shown as short coloured stumps, so a labelled key is useful.

Care & Handling

• Hold the brain stem model by its base or widest part; nerve stumps and the lower medulla are thin.
• Do not tie labels to the cranial nerves, which can snap; use a separate numbered key instead.
• Keep it boxed with the other brain models so small parts are not lost.

Specifications

Applications

• Learning the order of cranial nerve origins in medical and dental neuroanatomy
• Explaining the vital centres for breathing and heart rate in physiology lessons
• Locating the crossing of motor pathways at the pyramids
• Discussing why brainstem injury or compression is life-threatening

Why Choose LabEquip

Neuroanatomy teachers in medical, dental and nursing colleges buy a separate brainstem because the region is small and partly hidden on whole-brain models. LabEquip lists it with the human brain model in its anatomy models range; ask about scale through the contact page.

Frequently Asked Questions

Where does the brainstem end and the spinal cord begin?

The medulla oblongata becomes the spinal cord at about the level of the foramen magnum, the large opening in the base of the skull. The crossing of the pyramids marks this junction.

Which cranial nerves come from the brainstem?

Cranial nerves III to XII arise from the brainstem. The olfactory and optic nerves, I and II, connect directly to the forebrain instead.

What happens at the decussation of the pyramids?

Most fibres of the corticospinal tract, which carries commands for voluntary movement, cross from one side to the other in the lower medulla. That is why each side of the brain controls muscles on the opposite side of the body.

What does the reticular formation do?

It is a network of neurons running through the core of the brainstem. It helps keep the brain awake and alert, and it contains the centres that regulate breathing, heart rate and blood pressure.

How is the brainstem linked to the cerebellum?

By three pairs of fibre bundles, the cerebellar peduncles. The superior peduncle joins the midbrain, the middle the pons and the inferior the medulla, carrying signals that coordinate balance and movement.

Why is brainstem damage so serious?

The brainstem holds the centres that keep breathing and circulation going and the pathways for consciousness. Swelling of the brain above can push it down through the foramen magnum and compress these centres, which is a medical emergency.

Last Updated: September 2026