Digestion

Question 1

Ruminant

What is it?

Answer 1

A ruminant is an animal that has 4 stomachs

Question 2

Rumen

Answer 2

First stomach
Rumen (paunch)
- The rumen is a big vat that stores food.
- A cow’s rumen has a capacity of up to 95 litres and contains billions of bacteria and other microbes. These microbes produce the enzymes that digest cellulose into sugars and fatty acids for their hosts to use.

Question 3

Reticulum

Answer 3

Second stomach 
Reticulum (honeycomb)
- Microorganisms break down food
- Plays part in regurgitation
- Filters the food (takes out wire, staples)

Question 4

Omasum

Answer 4

Third stomach
Omasum (bible)
- The omasum wall is highly folded, giving a large surface area which allows for the efficient absorption of water and salts released from the partially digested food.
- The omasum also acts as a type of pump, moving the food from the reticulorumen to the true stomach, the abomasum, where acid digestion takes place.

Question 5

Abomasum

Answer 5

Fourth stomach
Abomasum (true stomach)
- Cells in the abomasum wall produce enzymes and hydrochloric acid which break down proteins in the food and also in the microbes mixed in with the food. Hydrolysis breaks the proteins into smaller sub-units (e.g. dipeptides and amino acids), ready for further digestion and absorption in the small intestine.

Question 6

Small intestine

Answer 6

Small intestine
The small intestine is an elongated tube running from the abomasum to the large intestine.

• A large proportion of the digestion and absorption of nutrients and water occurs in the small intestine.
• Carbohydrates are broken down to simple sugars (monosaccharides), fats into fatty acids and monoglycerides, nucleic acids into nucleotides and proteins into amino acids.

Question 7

Large intestine

Answer 7

Large intestine
The large intestine eliminates wastes. Undigested and unabsorbed food, as well as other body wastes, leave the intestine in the form of faeces, via the rectum and anus.

Question 8

Gallbladder

Answer 8

Gallbladder

Bile breaks down carbohydrates and fats

Question 9

Pancrease

Answer 9

Pancreases

Pancreatic juices and insulin

Question 10

Monogastric

What special about a horse?

Answer 10

Monogastric

• Animals that only have one stomach.
• Eg) horse, pig, human

Although a horse is a monogastric is can still eat hay. This is because it an enlarged caecum which breaks down the hay.

Question 11

Order of Birds Digestive tract

Answer 11

Oesophagus, Crop, Proventriculus, Gizzard, Small Intestine, Large Intestine, Vent