(a) Enumerate three major organs in each of the thoracic and abdominal cavities of farm animals (b) State two functions of the nervous and one function of t...

(a) Three major organs in each cavity [6 marks]

• Thoracic (chest) cavity: heart, lungs and the wind-pipe/oesophagus (also large blood vessels).
• Abdominal cavity: stomach, liver and intestines (also kidneys, spleen and pancreas).

(b) Functions of the nervous and reproductive systems [3 marks]

Two functions of the nervous system:

• It receives stimuli through sense organs and coordinates/controls the activities of the body.
• It transmits impulses (messages) and directs the response of the animal, controlling movement and involuntary body processes.

One function of the reproductive system:

• It produces sex cells (gametes) and enables the animal to reproduce and give rise to offspring, continuing the species.

(c) Importance of the following systems [importance]

• (i) Circulatory system: It transports digested food, oxygen, water and hormones to all body cells and carries away waste products (carbon dioxide, urea) to the excretory organs; it also distributes heat and helps defend the body against disease. Without it, cells would not be nourished or cleansed.
• (ii) Respiratory system: It takes in oxygen needed for the release of energy (respiration) in the cells and gives out carbon dioxide, a waste gas. This gaseous exchange keeps the animal alive and provides energy for growth, work and production.
• (iii) Digestive system: It breaks down (digests) the feed the animal eats into simple soluble substances that can be absorbed into the blood for growth, energy and body maintenance, and it removes the undigested waste. Good digestion means good use of feed and better production.