Human Nutrition and Digestion Vocabulary

Comprehensive vocabulary flashcards covering the human digestive system, metabolic processes, and nutritional disorders based on Life Sciences Grade 11 notes.

Ingestion

The intake of food through the mouth.

Mastication

Also called chewing; the process where food is physically broken down and mixed with saliva in the mouth.

Digestion

The mechanical and chemical breakdown of food into smaller molecules.

Peristalsis

The rhythmic, wavelike contraction of the parts of the gut to move food along the digestive tract.

Absorption

The diffusion or movement of simple food molecules into the blood.

Defecation

The removal of undigested, unabsorbed waste from the body through the anus in the form of faeces; also known as egestion.

Balanced diet

A diet that includes all types of nutrients in the correct proportions according to age, gender, and activity level.

Bolus

A ball of food formed by the tongue and pushed towards the back of the mouth for swallowing.

Salivary amylase

An enzyme in saliva that digests cooked starch into maltose.

Epiglottis

The structure that closes the entry to the trachea when food is swallowed to prevent it from entering the lungs.

Oesophagus

A narrow muscular tube linking the pharynx to the stomach that moves food via peristalsis.

Goblet cells

Cells in the digestive tract wall that secrete mucus to lubricate the passage of food and protect the lining.

Gastric juice

A secretion of the stomach containing enzymes and hydrochloric acid ($HCl$).

Chyme

A watery mixture of half-digested food formed by the churning action of the stomach.

Pepsin

The main enzyme in the stomach responsible for digesting proteins into polypeptides.

Villi

Finger-like extensions of the mucosa in the small intestine that increase the surface area for nutrient absorption.

Lacteal

A vessel found within a villus used to transport absorbed fats into the lymphatic system.

Deamination

The process in the liver where excess amino acids are broken down to form urea.

Emulsification

The process where bile breaks fat globules into smaller droplets to increase the surface area for enzymes.

Islets of Langerhans

Special groups of endocrine cells in the pancreas that secrete the hormones insulin and glucagon.

Insulin

A hormone secreted by the pancreas that lowers blood sugar levels by converting glucose to glycogen.

Glucagon

A hormone secreted by the pancreas that raises blood sugar levels.

Hydrolysis

A chemical process used in digestion to break down large food molecules into smaller molecules with the aid of enzymes and water.

Hepatic portal vein

The blood vessel that carries absorbed sugars and amino acids from the small intestine to the liver.

Kwashiorkor

A condition of malnutrition in children fed on high carbohydrate and low protein diets, marked by a swollen abdomen and retarded growth.

Anorexia nervosa

A psychological disorder where a person refuses to eat, leading to excessive weight loss.

Marasmus

A form of starvation in children receiving insufficient carbohydrates, proteins, and fats, characterized by loss of mass and large staring eyes.

Bulimia

An eating disorder involving episodes of binge eating followed by self-induced vomiting.

Obesity

A condition caused by excessive accumulation of adipose tissue from eating too much carbohydrates and fats.

Peptic ulcer

A painful 'hole' in the stomach wall caused by excess acid or the bacterium $Helicobacter\,pylori$.

Diabetes mellitus

A condition resulting from a defective pancreas failing to secrete enough insulin, causing elevated blood glucose levels.