Human Diet and Digestion Vocabulary

Comprehensive vocabulary flashcards detailing human diet requirements, deficiency diseases, digestive organs, physical/chemical digestion, digestive enzymes, and small intestine adaptations.

Carbohydrate

A food type that acts as a primary source of energy, found in foods such as bread, cereals, pasta, rice, and potatoes.

Protein

A food type required for growth and repair, sourced from meat, fish, eggs, pulses, and nuts.

Lipid

A food type used for insulation and energy storage, found in butter, oils, and nuts.

Dietary fibre

A component of diet that provides bulk (roughage) for the intestine to push food through it, sourced from vegetables and whole grains.

Balanced diet

A diet that consists of all of the necessary food groups (carbohydrates, proteins, lipids, vitamins, minerals, dietary fibre, water) in the correct proportions.

Vitamin C

A vitamin that forms an essential part of collagen protein found in skin, hair, gums, and bones; sourced from citrus fruit, strawberries, and green vegetables.

Vitamin D

A vitamin that helps the body absorb calcium for strong bones and teeth, obtained from oily fish, eggs, liver, dairy products, or synthesized in sunlight.

Calcium

A mineral needed for strong bones and teeth and involved in blood clotting, deficiency of which can lead to osteoporosis.

Iron

A mineral needed to make haemoglobin, the pigment in red blood cells that binds oxygen to transport it around the body.

Scurvy

A severe vitamin C deficiency condition caused by a lack of vitamin C for over $3\,\text{months}$, causing anaemia, exhaustion, spontaneous bleeding, gum ulcerations, and tooth loss.

Rickets

A condition in children characterised by poor bone development, causing soft, weak, or deformed bones, resulting from severe lack of vitamin D.

Alimentary canal

The passage along which food directly passes through the body, consisting of the mouth, oesophagus, stomach, small intestine, and large intestine.

Accessory organs

Digestive structures through which food does not directly pass, but which assist in digestion; includes salivary glands, liver, gall bladder, and pancreas.

Ingestion

The process of taking food and drink into the body through the mouth.

Mechanical digestion

The physical breakdown of food into smaller pieces without chemical change to the food molecules.

Chemical digestion

The breakdown of large, insoluble molecules into small, soluble molecules using enzymes.

Absorption

The movement of small food molecules and ions through the wall of the intestine into the blood or lymph.

Assimilation

The process where absorbed digested food molecules are taken up by body cells and used for growth, repair, and energy production.

Egestion

The passing out of food that has not been digested or absorbed as faeces through the anus.

Peristalsis

Muscular contractions of the walls of the oesophagus and digestive tract that force food downwards.

Types of human teeth

Structures with specialized shapes for physical digestion: incisors for biting/cutting, canines for tearing/holding/biting, and premolars/molars for chewing and grinding.

Structure of a tooth

Anatomy consisting of outer enamel, underlying dentine protecting nerves, an inner pulp cavity with blood capillaries and nerves, and cement anchoring it to jawbone.

Enamel

The hard outer layer of a tooth that protects the inner tissues.

Dentine

The layer beneath the tooth enamel that protects the nerves.

Pulp cavity

The soft internal tissue of a tooth containing nerves and blood vessels.

Cement

A hard layer around the root of a tooth that helps to anchor it within the jawbone.

Stomach tissue layers

Comprises smooth muscle (contracts to churn food), glandular tissue (secretes enzymes and hormones), and epithelial tissue (covers inside and outside parts).

Emulsification

The physical breakdown of large drops of fat into smaller droplets by bile to increase surface area for lipase action without breaking chemical bonds.

Bile

An alkaline substance produced in the liver and stored in the gall bladder that neutralises stomach acid and emulsifies fats in the duodenum.

Amylase

An enzyme produced in the salivary glands and pancreas that digests starch into maltose.

Maltase

An enzyme on the epithelium membrane lining of the small intestine that digests maltose into glucose.

Pepsin

A protease enzyme produced in the stomach that breaks down protein in acidic conditions at an optimum pH of around $\text{pH } 2$.

Trypsin

A protease enzyme produced in the pancreas and secreted into the duodenum that breaks down protein in alkaline conditions.

Lipase

An enzyme produced in the pancreas and secreted into the duodenum that digests lipids into fatty acids and glycerol.

Hydrochloric acid

Acid produced in the stomach that destroys pathogens in food by denaturing their enzymes and provides an optimum low pH for pepsin.

Adaptations of the small intestine

Features including a long folded surface, villi, microvilli, single-cell thick walls, lacteals, and dense capillary networks to maximize rate of nutrient absorption.

Lacteal

A lymphatic vessel running through the centre of a villus that transports absorbed fatty acids and glycerol away from the small intestine.