2j - Homeostasis

Blood glucose level

血糖水平 (xuètáng shuǐpíng) The concentration of glucose in the blood; maintained within a narrow range by homeostatic mechanisms involving insulin and glucagon.

Denaturing

（酶的）变性 ((méi de) biànxìng) The process where extreme conditions (e.g., high temperature, non-optimal pH) cause an enzyme to lose its specific three-dimensional shape (especially the active site), making it non-functional.

Dermis

真皮 (zhēnpí) The middle layer of the skin, below the epidermis, containing blood vessels, sweat glands, hair follicles, sensory receptors, and connective tissue.

Epidermis

表皮 (biǎopí) The outermost layer of the skin, providing a protective barrier. The very top layer consists of dead cells.

Effector

效应器 (xiàoyìngqì) A muscle or gland that carries out a response to a stimulus, as directed by the nervous or endocrine system, to help restore homeostasis.

Glucagon

胰高血糖素 (yí gāo xuètáng sù) Hormone from the pancreas that raises blood glucose levels by stimulating the liver to convert glycogen to glucose. (Part of blood glucose homeostasis).

Glycogen

糖原 (tángyuán) A polysaccharide; the main storage form of glucose in animals (liver and muscles). Mobilized to glucose when blood glucose levels are low.

Hair erector muscles

立毛肌 (lìmáojī) Small muscles attached to hair follicles in the skin that contract in response to cold, causing hairs to stand on end, trapping a layer of insulating air.

Homeostasis

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

Homeothermic (Endothermic)

恒温的 (héngwēnde) / 温血的 (wēnxuède) Describes organisms (e.g., mammals, birds) that can maintain a constant internal body temperature largely independent of the external environmental temperature, through metabolic processes.

Hypodermis

皮下组织 (píxià zǔzhī) The layer of tissue beneath the dermis, primarily composed of adipose (fatty) tissue, which provides insulation, energy storage, and cushioning.

Insulin

胰岛素 (yídǎosù) Hormone from the pancreas that lowers blood glucose levels by promoting glucose uptake by cells and its conversion to glycogen. (Part of blood glucose homeostasis).

Internal environment

内环境 (nèihuánjìng) The conditions within an organism's body, particularly the composition of blood and tissue fluid, which are kept relatively constant by homeostasis.

Negative feedback

负反馈 (fù fǎnkuì) A primary homeostatic control mechanism where a change in a monitored variable triggers a response that counteracts the initial change, bringing the variable back to its set point.

Osmoregulation

渗透调节 (shèntòu tiáojié) The homeostatic control of the water potential (water and salt balance) of the body's fluids, primarily regulated by the kidneys and hormones like ADH.

Pancreas

胰腺 (yíxiàn) Organ that plays a key role in blood glucose homeostasis by producing and secreting the hormones insulin and glucagon. (Also has exocrine digestive functions).

Receptor

感受器 (gǎnshòuqì) A cell or group of cells that detects changes (stimuli) in the internal or external environment and sends signals to a control center (e.g., thermoreceptors in skin/brain).

Shivering

颤抖 (chàndǒu) Involuntary rapid muscle contractions and relaxations in response to cold, which generate heat to help raise body temperature.

Sweat glands

汗腺 (hànxiàn) Glands in the skin (dermis) that secrete sweat onto the skin surface. Evaporation of sweat cools the body.

Thermoregulation

体温调节 (tǐwēn tiáojié) The homeostatic process by which organisms maintain their internal body temperature within a certain range, even when the surrounding temperature is very different.

Thermoregulatory centre

体温调节中枢 (tǐwēn tiáojié zhōngshū) Region in the brain (part of the hypothalamus) that acts as a thermostat, monitoring blood temperature and initiating responses to maintain core body temperature.

Vasoconstriction

血管收缩 (xuèguǎn shōusuō) The narrowing of blood vessels (especially arterioles near the skin surface). Reduces blood flow to the skin, conserving body heat in cold conditions.

Vasodilation

血管舒张 (xuèguǎn shūzhāng) The widening of blood vessels (especially arterioles near the skin surface). Increases blood flow to the skin, promoting heat loss from the body in warm conditions.