Topic 7: Human Nutrition

The movement of useful substances through the wall of the intestine into the bloodstream.

A long, hollow, muscular tube running through the body where digestion and absorption takes place.

An enzyme found in saliva and pancreatic juice that breaks down starch to simpler sugars (i.e. maltose).

The opening at the far end of the alimentary canal that controls egestion.

The movement of simple food molecules into the cells of the body where they are used.

A green, watery fluid produced by the liver that is stored in the gallbladder and secreted via the bile duct into the duodenum. It consists of bile salts which emulsify fats, increasing the surface area for lipase action, and an alkaline fluid which neutralises gastric juices from the stomach.

A mineral salt found in milk, cheese, eggs and fresh green vegetables that is required to maintain healthy teeth and bones, for muscle contraction and for blood clotting.

Teeth with a pointed tip positioned either side of the incisors that are adapted for cutting pieces of food.

A class of food that is used as an energy source in cells. Carbohydrates are abundant in potatoes, bread, pasta, rice etc.

A tissue covering the surface of the root that allows connection of the tooth to the bony socket in the jaw.

A type of digestion that involves breaking down large, insoluble molecules into smaller, soluble molecules using enzymes.

the first section of the large intestine that reabsorbs water and bile salts from the waste material.

A hard bony tissue underlying the enamel. It is softer than enamel.

The first section of the small intestine which receives pancreatic juice for the chemical digestion of proteins, lipids and starch, and the neutralisation of stomach acid. It also receives bile from the gall bladder.

The removal of undigested waste material as faeces from the body.

The hard outer coating of the crown of the tooth.

A class of food that has a variety of roles in organisms including insulation, structure, protection of organs and energy storage. Animal fats are abundant in meat, milk, cheese and egg yolk. Plant fats are found as oils in fruits and seeds and are used to make margarine.

A complex carbohydrate found in plant-based foods that provides bulk, softening the faeces and supporting regular bowel movements. A diet lacking in fibre may result in constipation.

An organ that stores bile produced in the liver. It secretes bile into the duodenum via the bile duct.

A digestive juice secreted from glands in the stomach lining that contains proteases for the chemical digestion of proteins to amino acids. Hydrochloric acid dissolves in gastric juice, forming a weak solution.

The tissue that overlies the jaw bone inside of the mouth.

A chemical found in gastric juice that kills harmful microorganisms in food (via enzyme denaturation) and provides an optimum pH for enzyme (pepsin) activity.

Chisel-shaped teeth at the front of the mouth adapted for cutting pieces of food.

The process by which organisms take food and drink into their bodies through the mouth.