2i - Excretion

Anti-diuretic Hormone (ADH)

抗利尿激素 (kànglìniào jīsù) Hormone released from the pituitary gland that increases water reabsorption in the kidney tubules (especially collecting ducts), making urine more concentrated. Released when the body is dehydrated.

Bladder

膀胱 (pángguāng) A muscular, elastic organ that stores urine produced by the kidneys before it is eliminated from the body.

Bowman's capsule

鲍曼氏囊 (Bàomànshì náng) / 肾小囊 (shènxiǎonáng) Cup-shaped structure at the start of a nephron that surrounds the glomerulus and collects the glomerular filtrate.

Collecting duct

集合管 (jíhéguǎn) Part of the nephron system where urine from several nephrons is collected; site of further water reabsorption (regulated by ADH) before urine passes to the renal pelvis.

Cortex

皮质 (肾脏) (pízhì (shènzàng)) The outer region of the kidney, containing the glomeruli, Bowman's capsules, and convoluted tubules of the nephrons.

Deamination

脱氨基作用 (tuō'ānjī zuòyòng) The process in the liver where the amino group (-NH₂) is removed from excess amino acids, forming ammonia (which is then converted to urea).

Dialysis

透析 (肾透析) (tòuxī (shèn tòuxī)) A medical procedure to remove waste products and excess fluid from the blood when the kidneys stop working properly. Uses a dialysis machine (artificial kidney).

Excretion

排泄 (páixiè) The removal from organisms of toxic materials, the waste products of metabolism (e.g., urea, carbon dioxide), and substances in excess of requirements.

Excretory Organs

排泄器官 (示例) (páixiè qìguān (shìlì)) Organs involved in excretion, e.g., kidneys (urea, excess water/salts), lungs (carbon dioxide), skin (small amounts of urea, salts in sweat).

Glomerular filtrate

肾小球滤液 (shènxiǎoqiú lǜyè) The fluid that is filtered out of the blood from the glomerulus into the Bowman's capsule. Contains water, glucose, urea, salts, and other small molecules.

Glomerulus

肾小球 (shènxiǎoqiú) A tiny ball-shaped network of capillaries within the Bowman's capsule of a nephron, where blood is filtered under high pressure (ultrafiltration).

Homeostasis

体内平衡 (tǐnèi pínghéng) / 稳态 (wěntài) The maintenance of a constant internal environment within an organism, despite changes in the external environment (e.g., temperature, water balance, glucose levels).

Hypothalamus

下丘脑 (xiàqiū'nǎo) A region of the brain that plays a key role in homeostasis, including monitoring blood water concentration and controlling the release of ADH from the pituitary gland.

Kidney

肾脏 (shènzàng) One of a pair of organs in the abdomen that filters waste products (like urea) from the blood, regulates water and salt balance (osmoregulation), and produces urine.

Kidney tubule / Nephron

肾小管 (shènxiǎoguǎn) / 肾单位 (shèndānwèi) The functional filtering unit of the kidney, responsible for removing waste from the blood and producing urine. Each kidney contains millions of nephrons.

Loop of Henlé

亨利氏袢 (Hēnglìshì pàn) / 肾单位袢 (shèndānwèi pàn) U-shaped section of the nephron tubule that descends into the medulla and then ascends back to the cortex; plays a crucial role in concentrating urine by creating a salt gradient for water reabsorption.

Medulla

髓质 (肾脏) (suǐzhì (shènzàng)) The inner region of the kidney, containing the loops of Henlé and collecting ducts, organized into pyramid-shaped structures.

Nitrogenous waste

含氮废物 (hándàn fèiwù) Waste products containing nitrogen, resulting from the metabolism of proteins and nucleic acids (e.g., urea in mammals, ammonia in fish, uric acid in birds/reptiles).

Osmoregulation

渗透调节 (shèntòu tiáojié) The homeostatic control of the water potential (water and salt balance) of the body's fluids (e.g., blood, tissue fluid).

Pelvis

肾盂 (shènyú) The funnel-shaped central cavity of the kidney where urine collects from the collecting ducts before passing into the ureter.

Renal artery

肾动脉 (shèndòngmài) Blood vessel that supplies oxygenated blood (containing waste products) to the kidney for filtration.

Renal vein

肾静脉 (shènjìngmài) Blood vessel that carries deoxygenated blood (which has been filtered and had wastes removed) away from the kidney.

Selective reabsorption

选择性重吸收 (xuǎnzéxìng chóngxīshōu) The process in the nephron where useful substances (e.g., glucose, amino acids, some salts, most water) are reabsorbed from the glomerular filtrate back into the blood, mainly in the proximal convoluted tubule.

Ultrafiltration

超滤作用 (chāolǜ zuòyòng) The filtration of blood under high pressure in the glomerulus, forcing water and small solutes (but not large proteins or cells) out of the capillaries and into the Bowman's capsule.

Urea

尿素 (niàosù) The main nitrogenous waste product in mammals, formed in the liver from the breakdown of excess amino acids (via deamination and the ornithine cycle), and excreted by the kidneys in urine.

Ureter

输尿管 (shūniàoguǎn) Tube that carries urine from each kidney to the urinary bladder.

Urethra

尿道 (niàodào) Tube that carries urine from the urinary bladder out of the body.

Urine

尿液 (niàoyè) Liquid waste product produced by the kidneys, consisting mainly of water, urea, and salts, which is stored in the bladder and eliminated from the body via the urethra.