Connection lost. Please refresh the page.
Online
Get help How to study Login Register

Overview and surface anatomy of the brainstem

Learning objectives

Completing this study unit will allow you to: 

  1. Describe the three parts of the brainstem.
  2. Identify the anatomical features of the medulla oblongata, pons and midbrain seen from an external view. 
  3. Explore the main functions of the brainstem.

Watch videos

The brainstem is a stalk-like projection which extends caudally from the base of the diencephalon, connecting it with the spinal cord. It is the oldest part of the brain and is composed of three parts: the midbrain, pons and medulla oblongata.  

The midbrain is the shortest segment of the brainstem. It extends caudally from the base of the the diencephalon to the pons. Its functions are associated with motor coordination (in particular eye movements), visual and auditory processing, arousal/consciousness as well as behavioural responses to fear and danger. 

The pons is located between the midbrain and medulla oblongata and forms the largest component of the brainstem. It houses the nuclei of cranial nerves V-VIII, as well as the pontine nuclei which facilitate corticopontocerebellar communication. It also participates in the regulation of sleep and breathing.

The medulla oblongata is the narrowest and most caudal part of the brainstem. It has a tapered appearance that extends from the pons to the spinal cord. It houses the nuclei of cranial nerves IX-X, and XII, and is involved in controlling respiratory function, the cardiovascular system, as well as gastrointestinal and digestive activities. 

Find out more about the surface anatomy of the brainstem from an anterior view by watching the video below.

Take a closer look now at the surface anatomy of the brainstem from a dorsal perspective.

Take a quiz

Information overload? Put your knowledge to the test with the quiz below.

Looking for a broader array of questions on the brain? Try out our custom quiz below.

Browse atlas

Take a closer look at the surface anatomy of the brainstem in the galleries.

Summary

Key points about the brainstem
Midbrain Sulci: Lateral groove

Landmarks
: Cerebral peduncles, interpeduncular fossa (mamillary body, posterior perforated substance), quadrigeminal plate (inferior colliculus, superior colliculus) 

Functions: 
Processes and directs visual/auditory information to thalamus, monitors movement with basal nuclei, contains nuclei of cranial nerves III/IV
Pons Sulci: Pontomesencephalic (/superior pontine) sulcus, basilar sulcus, medullopontine(/inferior pontine) sulcus, sulcus limitans, median sulcus of rhomboid fossa

Landmarks
: Upper rhomboid fossa (median sulcus, sulcus limitans, medial eminence (facial colliculus), upper part of vestibular area, caerulean nucleus,) intermediate rhomboid fossa (medullary striae of fourth ventricle)

Functions:
 Relays cerebral input to cerebellum, contains nuclei of cranial nerves V-VII, regulates breathing, sleep-wake cycle
Medulla oblongata Parts: Superior/open (caudal part of fourth ventricle), inferior/closed (contains central canal)

Sulci
: Anterior median fissure, anterolateral sulcus, posterior median sulcus, retroolivary groove, preolivary groove

Landmarks
: Pyramids, decussation of pyramids, olives (olivary nuclei), gracile/cuneate tubercles, lateral funiculus, obex

Functions:
Relays sensory input to cerebellum, regulates several homeostatic functions (e.g. heart/breathing rate), contains nuclei of cranial nerves VIII-XII

(all parts of the brainstem carry information (via white matter tracts) between upper and lower parts of the CNS)

Well done!

Related articles

Continue your learning

Register now and grab your free ultimate anatomy study guide!