Hindbrain - Anatomy & Physiology

Introduction

The hind brain is also called the rhombencephalon and is the brain stem that provides the connection between the spinal cord and the rest of the brain. The hind brain contains many vital structures including the Medulla Oblongata, the Pons (the link between the cerebellum, forebrain and mid-brain) and the majority of the cranial nerves, III to XII. In general the brain stem governs essential functions that are carried out sub-consciously via reflexes.

Hind Brain Functions

Medulla Oblongata

Nuclei in the Medulla Oblongata control the level of heart activity including rate and contractility. The Medulla Oblongata also controls other related functions including blood pressure and distribution of blood to different organs. In conjunction with the nuclei found in the Pons, the Medulla Oblongata also exerts an influence on respiratory movements.

Pons

As shown above, the Pons is able to exert some influence on respiratory movements and in some studies has also been shown to influence many digestive processes.

Structure and Function

	Structures Present	Function
Hindbrain (Rhombencephalon)	Myelencephalon - Medulla Oblongata Metencephalon - Pons and Cerebellum	Medulla Oblongata - Cranial nerves, hearing, visceral fibres Pons - Fibres to cerebrum Cerebellum - Posture, balance etc

Cerebellum

The location of the cerebellum. Image courtesy of BioMed Archive

• The cerebellum:
  • Inhibits upper motor neurons
  • Co-ordinates movement

Species Differences

• The size of the brain differs between species, but otherwise the structure is quite constant.