2e - Human Nutrition

Ingestion

摄入 (shèrù) Taking food into the body through the mouth.

Digestion

消化 (xiāohuà) The mechanical and chemical breakdown of large, insoluble food molecules into small, soluble molecules that can be absorbed.

Peristalsis

蠕动 (rúdòng) Wave-like muscle contractions that move food along the gut.

Absorption

吸收 (营养学) (xīshōu (yíngyǎngxué)) The process where small, soluble digested food molecules move from the small intestine into the bloodstream.

Assimilation

同化作用 (tónghuà zuòyòng) When absorbed food molecules are taken into cells and used to build new parts or for energy.

Egestion

排遗 (páiyí) The removal of undigested food waste (faeces) from the body.

Amylase

淀粉酶 (diànfěn méi) Enzyme that digests starch into maltose; found in saliva and pancreatic juice.

Maltase

麦芽糖酶 (màiyátáng méi) Enzyme in the small intestine wall that digests maltose into glucose.

Lipase

脂肪酶 (zhīfáng méi) Enzyme (mainly from pancreas) that digests lipids (fats/oils) into fatty acids and glycerol.

Proteases

蛋白酶 (dànbái méi) Enzymes that digest proteins. Example: Pepsin in the stomach digests proteins into peptides.

Mouth

口腔 (kǒuqiāng) Where food is mechanically broken down (chewing) and mixed with saliva.

Saliva

唾液 (tuòyè) Liquid in the mouth that moistens food and contains amylase to start starch digestion.

Oesophagus (Gullet)

食道 (shídào) Tube connecting the mouth to the stomach; food moves down by peristalsis.

Stomach

胃 (wèi) Muscular organ that stores food, mixes it with hydrochloric acid and pepsin to start protein digestion.

Sphincter muscle

括约肌 (kuòyuējī) Ring of muscle that controls the passage of food, e.g., between the stomach and small intestine.

Hydrochloric acid (HCl)

盐酸 (yánsuān) Acid in the stomach that kills bacteria and provides the optimal pH for pepsin.

Small intestine

小肠 (xiǎocháng) Long tube (duodenum and ileum) where most chemical digestion and absorption of nutrients occurs.

Duodenum

十二指肠 (shí'èrzhǐcháng) First part of the small intestine; receives enzymes from the pancreas and bile from the liver/gallbladder for digestion.

Ileum

回肠 (huícháng) Latter part of the small intestine, adapted with villi and microvilli for efficient absorption of digested food.

Villi (singular: Villus)

绒毛 (róngmáo) Tiny finger-like projections lining the ileum, greatly increasing surface area for absorption.

Microvilli

微绒毛 (wēi róngmáo) Microscopic projections on the surface of villi cells, further increasing surface area for absorption.

Large intestine (Colon)

大肠 (dàcháng) Part of the gut that absorbs water from undigested food, forming faeces.

Rectum

直肠 (zhícháng) Final section of the large intestine, where faeces are stored before egestion.

Pancreas

胰腺 (yíxiàn) Organ that produces digestive enzymes (amylase, protease, lipase) released into the duodenum, and hormones like insulin.

Bile

胆汁 (dǎnzhī) Greenish alkaline liquid made by the liver and stored in the gall bladder; emulsifies fats and neutralises stomach acid in the duodenum.

Gall bladder

胆囊 (dǎnnáng) Small organ that stores and concentrates bile.

Balanced Diet

均衡饮食 (jūnhéng yǐnshí) A diet containing all essential nutrients (carbohydrates, lipids, proteins, vitamins, minerals, water, fibre) in the correct amounts and proportions for health.

Functions of Food

食物的功能 (shíwù de gōngnéng) Provides: 1. Energy (fuel). 2. Materials for growth and tissue repair. 3. Substances to maintain health and fight disease.

Carbohydrates

碳水化合物 (膳食) (tànshuǐ huàhéwù (shànshí)) Main energy source. Includes sugars and starch. Sources: bread, pasta, rice, fruits.

Proteins

蛋白质 (膳食) (dànbáizhì (shànshí)) Needed for growth and repair of tissues, and making enzymes. Sources: meat, fish, eggs, beans, dairy.

Lipids (Fats & Oils)

脂质 (膳食) (zhīzhì (shànshí)) Source of energy, insulation, protection, and cell membrane component. Sources: oils, butter, nuts, meat.

Vitamin A

维生素A (wéishēngsù A) For good vision (makes retinal chemical), healthy skin, and immune system. Deficiency: night blindness. Sources: liver, carrots, dairy.

Vitamin C

维生素C (wéishēngsù C) For healthy skin, gums, and connective tissues; helps absorb iron. Deficiency: scurvy. Sources: citrus fruits, fresh vegetables.

Vitamin D

维生素D (wéishēngsù D) Helps absorb calcium for strong bones and teeth. Deficiency: rickets (children), osteomalacia (adults). Sources: oily fish, eggs; made in skin by sunlight.

Calcium

钙 (矿物质) (gài (kuàngwùzhì)) For strong bones and teeth, muscle contraction, blood clotting. Sources: dairy products, leafy green vegetables, fish with bones.

Iron

铁 (矿物质) (tiě (kuàngwùzhì)) Needed to make haemoglobin in red blood cells for oxygen transport. Deficiency: anaemia. Sources: red meat, liver, eggs, leafy green vegetables.

Water

水 (营养素) (shuǐ (yíngyǎngsù)) Essential for bodily functions; acts as a solvent, transport medium, and involved in chemical reactions (hydrolysis).

Fibre

膳食纤维 (shànshí xiānwéi) Indigestible part of plant foods; adds bulk to faeces, aids peristalsis, prevents constipation. Sources: whole grains, fruits, vegetables.

Calorimeter

量热器 (liàngrèqì) Device used to measure the energy content of food by burning it and measuring the heat released.

Energy Requirements

能量需求 (影响因素) (néngliàng xūqiú (yǐngxiǎng yīnsù)) The amount of energy a person needs, influenced by activity level, age, sex, and body size/pregnancy.

Kilojoules (kJ)

千焦 (qiānjiāo) A unit used to measure energy, including the energy content of food.