Body Systems
Session 4 - The Nervous System

This resource is suitable to support Level 2 Agriculture courses.

The Nervous System

The nervous system in an animal coordinates body movement, sends and receives messages that allow reaction to stimuli e.g. pain, noise, smells, and monitors organ activity.

Structure of the Nervous System

The nervous system is made up of 2 parts:

The central nervous system – the brain and the spinal cord.
The peripheral nervous system –the rest of the animal’s nerves.

The Spinal Cord Protected by the Vertebrae

Stimulus

Stimuli travel along the peripheral nervous system to the central nervous system.

This can invoke a voluntary response after the stimuli are processed by the brain or a more rapid involuntary response when the stimuli are processed in the spinal cord and brain.

Problems in the Nervous System

Problems may be seen in farm animals when the nervous system is damaged or not functioning properly. Examples include:

Physical damage.

Nutritional causes.

Infections.

Physical Damage to the Nervous System

Gid

This occurs when tapeworm cysts develop and cause pressure on the brain.

Fighting

Brain damage due to fighting e.g. two rams at tupping time.

Nutritional Causes of Nervous System Problems

Swayback

Swayback in young lambs where copper deficiency in the ewe during pregnancy has prevented the complete formation of the spinal cord.

Metabolic Disorders

Magnesium deficiency (grass staggers) where the lack of magnesium upsets the transmission of messages along the neurons (special chain of cells that transmit messages).

Infections Causing Problems in the Nervous System

BSE and scrapie where the brain is damaged.

Tetanus and botulism produce toxins which damage the nervous system.

Body Systems Session 4 - The Nervous System