Nutrition in Humans – Digestive System & Homeostasis Vocabulary

A set of key vocabulary flashcards covering structures, enzymes, processes, and hormonal regulation related to human nutrition and homeostasis.

Mouth

Entry point of food; site of ingestion and mechanical digestion by chewing and saliva mixing.

Salivary Glands

Glands that secrete saliva containing amylase to begin starch digestion in the mouth.

Oesophagus

Muscular tube that transports food from mouth to stomach via peristalsis.

Stomach

Muscular sac secreting gastric juice (HCl, mucus, protease) for protein digestion and food churning.

Duodenum

First section of small intestine where chyme mixes with bile and pancreatic juice for further digestion.

Ileum

Coiled section of small intestine specialized for nutrient absorption through villi and microvilli.

Colon

Part of large intestine that absorbs remaining water and mineral salts from undigested matter.

Rectum

Terminal portion of large intestine that temporarily stores faeces before egestion.

Anus

Exit of alimentary canal where faeces are expelled during egestion.

Liver

Largest gland; produces bile, stores glycogen, deaminates amino acids, detoxifies substances, and regulates blood glucose.

Gall Bladder

Organ that temporarily stores bile and releases it into the duodenum via the bile duct.

Pancreas

Gland that secretes pancreatic juice (amylase, protease, lipase) and the hormones insulin and glucagon.

Hepatic Portal Vein

Blood vessel that carries nutrient-rich blood from the small intestine to the liver.

Ingestion

Process of taking food into the body through the mouth.

Digestion

Breakdown of large food molecules into smaller, soluble molecules by mechanical and chemical actions.

Absorption

Uptake of digested nutrients into bloodstream or lymph through intestinal lining.

Assimilation

Utilisation of absorbed nutrients for energy, growth, and repair within body cells.

Egestion

Removal of undigested and unabsorbed food as faeces through the anus.

Peristalsis

Rhythmic contractions of circular and longitudinal muscles propelling food along the alimentary canal.

Bile

Alkaline fluid containing bile salts that emulsifies fats to increase surface area for lipase action.

Amylase

Carbohydrase enzyme that hydrolyses starch into maltose; found in saliva and pancreatic juice.

Maltase

Enzyme in intestinal juice that converts maltose into glucose molecules.

Protease

Enzyme group that breaks proteins into polypeptides and amino acids; active in stomach and small intestine.

Lipase

Enzyme that digests fats into fatty acids and glycerol in the small intestine.

Deamination

Liver process removing amino groups from excess amino acids to form urea and glucose residues.

Insulin

Pancreatic hormone that lowers blood glucose by promoting glycogen synthesis and cellular uptake of glucose.

Glucagon

Pancreatic hormone that raises blood glucose by stimulating glycogen breakdown to glucose in the liver.

Hormone

Chemical substance produced by a gland, transported in blood, altering activity of specific target organs.

Villi

Finger-like projections lining the ileum that increase surface area for nutrient absorption.

Microvilli

Microscopic extensions on epithelial cells of villi further enlarging absorptive surface area.

Lacteal

Lymphatic capillary within each villus that absorbs fats as minute fat globules.

Glycogen

Storage polysaccharide formed from excess glucose in liver and muscles; reconverted when glucose is needed.

Type 2 Diabetes Mellitus

Condition of persistently high blood glucose due to insulin resistance or insufficient insulin production.

Risk Factors for Type 2 Diabetes

Obesity, sedentary lifestyle, poor diet, age, family history, and adverse blood lipid profiles.

Management of Type 2 Diabetes

Healthy high-fibre diet, regular physical activity, weight control, and reducing prolonged inactivity.

Emulsification

Physical dispersion of large fat droplets into tiny droplets by bile salts to aid lipase digestion.

Chyme

Semi-liquid mixture of partially digested food and gastric juice leaving the stomach.

Epiglottis

Flap that closes over the glottis during swallowing to prevent food entering the trachea.

Islets of Langerhans

Cell clusters in the pancreas that secrete insulin (β-cells) and glucagon (α-cells).

Active Transport (in absorption)

Energy-requiring uptake of nutrients (e.g., glucose, amino acids) against concentration gradients into intestinal cells.

Diffusion (in absorption)

Passive movement of molecules such as glucose and amino acids from higher to lower concentration into blood.