身体如何把血液pH稳定维持在7.35～7.45？
How does the body keep blood pH between 7.35 and 7.45?
第一道防线是化学缓冲，血液中的碳酸氢盐/二氧化碳系统最重要，血红蛋白、磷酸盐和蛋白质也参与，作用在数秒内。第二道是呼吸调节：化学感受器感知pH和二氧化碳变化后改变通气量，数分钟内排出或保留二氧化碳。第三道是肾脏，通过排泌氢离子、重吸收和再生碳酸氢盐进行调节，需要数小时到数天但能力最强。任何一环失衡就出现呼吸性或代谢性酸中毒、碱中毒，临床通过血气分析判断类型和代偿程度。
The first line is chemical buffering, dominated by the bicarbonate-carbon dioxide system with help from haemoglobin, phosphate and proteins, acting within seconds. The second is respiratory control: chemoreceptors sense pH and carbon dioxide and adjust ventilation to blow off or retain CO2 within minutes. The third is the kidney, which excretes hydrogen ions and reabsorbs or regenerates bicarbonate - slower, taking hours to days, but the most powerful. Failure at any level produces respiratory or metabolic acidosis or alkalosis, which clinicians classify by arterial blood gas analysis along with the degree of compensation.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-10-03 · 3 条独立证据
来源 · Source
Guyton 与 Hall，《医学生理学教科书》（第13版，Elsevier，2016）
Guyton & Hall, Textbook of Medical Physiology (13th ed., Elsevier, 2016)
独立核验依据 · Independent verification: 核验依据 1 ISBN 978-0-323-59712-8 · 核验依据 2 ISBN 978-1-4557-4377-3 (3rd ed., Elsevier) · 核验依据 3 ISBN 978-1-319-45541-5 (8th ed., Macmillan Learning)
#酸碱平衡 #碳酸氢盐缓冲 #呼吸补偿 #肾脏调节
血红蛋白的氧解离曲线“右移”意味着什么？
What does a right shift of the haemoglobin-oxygen dissociation curve mean?
右移表示血红蛋白对氧的亲和力下降，在同样的氧分压下更容易把氧释放给组织。引起右移的因素包括二氧化碳升高与pH下降（波尔效应）、体温升高和红细胞内2,3-二磷酸甘油酸增多，这正是运动肌肉周围的环境，因此供氧效率提高。相反，一氧化碳结合、碱中毒、体温降低和胎儿血红蛋白会使曲线左移，有利于在肺部或胎盘处摄取氧但不利于组织释放。
A right shift means haemoglobin's affinity for oxygen falls, so it releases oxygen to tissues more readily at the same partial pressure. Right-shifting factors include rising carbon dioxide and falling pH (the Bohr effect), higher temperature and more 2,3-diphosphoglycerate inside red cells - precisely the conditions around exercising muscle, where oxygen delivery therefore improves. Conversely, carbon monoxide binding, alkalosis, cooling and fetal haemoglobin shift the curve left, favouring oxygen uptake in the lung or placenta but hindering release to tissues.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-10-03 · 3 条独立证据
来源 · Source
Guyton 与 Hall，《医学生理学教科书》（第13版，Elsevier，2016）
Guyton & Hall, Textbook of Medical Physiology (13th ed., Elsevier, 2016)
独立核验依据 · Independent verification: 核验依据 1 ISBN 978-0-323-59712-8 · 核验依据 2 ISBN 978-1-4557-4377-3 (3rd ed., Elsevier) · 核验依据 3 ISBN 978-1-319-45541-5 (8th ed., Macmillan Learning)
#氧解离曲线 #波尔效应 #2,3-DPG #氧亲和力
血液由哪些主要成分组成？
What are the main components of blood?
血液由血浆和血细胞组成：血浆运输物质，红细胞运氧，白细胞抗感染，血小板参与止血。它们共同维持人体的运输和防御功能。
Blood consists of plasma and blood cells: plasma transports substances, red cells carry oxygen, white cells fight infection, and platelets help stop bleeding. Together they maintain the body's transport and defense functions.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
王庭槐 主编,《生理学》第9版,人民卫生出版社,2018
Wang Tinghuai ed., Physiology, 9th ed., People's Medical Publishing House, 2018
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787117266598（豆瓣书目条目: 生理学）
#血液 #血细胞 #生理
人体正常体温大约是多少？
What is the normal human body temperature?
健康成年人的口腔温度大约在36.5到37.2摄氏度之间，会因测量部位和时间略有波动。体温超过37.3摄氏度通常被视为发热。
A healthy adult's oral temperature is about 36.5 to 37.2 degrees Celsius, varying slightly by site and time of day. A reading above 37.3 degrees Celsius is generally considered a fever.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
王庭槐 主编,《生理学》第9版,人民卫生出版社,2018
Wang Tinghuai ed., Physiology, 9th ed., People's Medical Publishing House, 2018
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787117266598（豆瓣书目条目: 生理学）
#体温 #发热 #生理
为什么运动后心跳会加快？
Why does the heart beat faster after exercise?
运动时肌肉需要更多氧气和能量，心脏便加快跳动以输送更多含氧血液。运动停止后，心率会逐渐恢复正常。
During exercise muscles need more oxygen and energy, so the heart beats faster to deliver more oxygen-rich blood. After stopping, the heart rate gradually returns to normal.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
王庭槐 主编,《生理学》第9版,人民卫生出版社,2018
Wang Tinghuai ed., Physiology, 9th ed., People's Medical Publishing House, 2018
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787117266598（豆瓣书目条目: 生理学）
#心率 #运动 #生理
夹在手指上的脉搏血氧仪是怎么测出血氧的？
How does a fingertip pulse oximeter measure blood oxygen?
探头一侧发出红光（约660 nm）和红外光（约940 nm），另一侧的感受器测量透过手指的光量。氧合血红蛋白与去氧血红蛋白对这两种波长的吸收差别很大，仪器只分析随脉搏搏动变化的那部分信号，从而估算动脉血氧饱和度。它无创方便，但在灌注差、发凉、剧烈活动、涂深色指甲油时可能不准，一氧化碳中毒时读数会假性偏高，深色皮肤人群的准确性也需注意。
One side of the probe emits red light (about 660 nm) and infrared light (about 940 nm), while a detector on the other side measures how much passes through the finger. Oxygenated and deoxygenated haemoglobin absorb these two wavelengths very differently, and the device analyses only the pulsatile component of the signal to estimate arterial oxygen saturation. It is convenient and non-invasive but can read inaccurately with poor perfusion, cold hands, motion or dark nail polish; in carbon monoxide poisoning it reads falsely high, and accuracy in people with darker skin also warrants caution.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
王庭槐 主编,《生理学》第9版,人民卫生出版社,2018
Wang Tinghuai ed., Physiology, 9th ed., People's Medical Publishing House, 2018
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787117266598（豆瓣书目条目: 生理学）
#脉搏血氧仪 #血氧饱和度 #光吸收 #一氧化碳中毒
心脏跳动有什么作用？
What is the purpose of the heartbeat?
心脏通过有节奏的收缩把血液泵送到全身，输送氧气和营养物质。正常成年人静息时心率约为每分钟60到100次。
The heart pumps blood throughout the body with rhythmic contractions, delivering oxygen and nutrients. A normal adult resting heart rate is about 60 to 100 beats per minute.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
王庭槐 主编,《生理学》第9版,人民卫生出版社,2018
Wang Tinghuai ed., Physiology, 9th ed., People's Medical Publishing House, 2018
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787117266598（豆瓣书目条目: 生理学）
#心跳 #循环 #生理
输液为什么用生理盐水而不是纯水？
Why are intravenous fluids saline rather than pure water?
0.9%氯化钠溶液的渗透压约308 mOsm/L，与血浆接近，输入后不会让红细胞内外产生明显水分转移。若直接输入纯水，水会顺渗透压梯度大量进入红细胞使其胀破，造成溶血和高钾、肾损伤等严重后果。临床还常用乳酸林格液等“平衡晶体液”，其电解质组成更接近细胞外液，大量补液时对酸碱平衡更友好。
A 0.9% sodium chloride solution has an osmolality of about 308 mOsm/L, close to plasma, so infusing it causes no major water shift across the red cell membrane. Pure water infused directly would flow down the osmotic gradient into red cells until they burst, causing haemolysis with dangerous potassium release and kidney injury. Balanced crystalloids such as lactated Ringer's are also widely used, since their electrolyte composition is closer to extracellular fluid and gentler on acid-base balance during large-volume resuscitation.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-10-03 · 3 条独立证据
来源 · Source
Guyton 与 Hall，《医学生理学教科书》（第13版，Elsevier，2016）
Guyton & Hall, Textbook of Medical Physiology (13th ed., Elsevier, 2016)
独立核验依据 · Independent verification: 核验依据 1 ISBN 978-0-323-59712-8 · 核验依据 2 ISBN 978-1-4557-4377-3 (3rd ed., Elsevier) · 核验依据 3 ISBN 978-1-319-45541-5 (8th ed., Macmillan Learning)
#生理盐水 #渗透压 #溶血 #平衡晶体液
为什么冬天会更容易觉得冷、起鸡皮疙瘩？
Why do we feel cold and get goosebumps more in winter?
当环境温度下降，身体会收缩皮肤血管减少散热，并让汗毛竖起形成保温层，于是出现鸡皮疙瘩。这是身体维持体温的本能反应。
When the temperature drops, the body narrows skin blood vessels to reduce heat loss and raises body hairs to form an insulating layer, causing goosebumps. This is an instinctive response to maintain body temperature.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
王庭槐 主编,《生理学》第9版,人民卫生出版社,2018
Wang Tinghuai ed., Physiology, 9th ed., People's Medical Publishing House, 2018
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787117266598（豆瓣书目条目: 生理学）
#体温 #寒冷 #生理
天热的时候为什么会出汗，出汗为什么能凉快？
Why do we sweat when it is hot, and how does sweating cool us down?
天热或运动时身体会变热，大脑就命令皮肤上的汗腺把汗排出来。汗水在皮肤上变成水蒸气时会带走很多热量，就像出水的地面干了会变凉一样，所以我们才觉得凉爽。空气又湿又热时汗不容易蒸发，人就会觉得特别难受，这时要多喝水、到阴凉通风的地方休息。
When it is hot or you are running around, your body heats up and your brain tells the sweat glands in your skin to release sweat. As the sweat turns into vapour it carries a lot of heat away with it - just as wet ground feels cool while it dries - and that is what cools you down. On hot, humid days sweat cannot evaporate easily, so you feel much more uncomfortable and should drink water and rest somewhere shady and airy.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
王庭槐 主编,《生理学》第9版,人民卫生出版社,2018
Wang Tinghuai ed., Physiology, 9th ed., People's Medical Publishing House, 2018
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787117266598（豆瓣书目条目: 生理学）
#出汗 #蒸发散热 #体温调节 #防暑
我们为什么要呼吸？
Why do we need to breathe?
呼吸把氧气送进身体，让细胞产生能量，同时把废气二氧化碳排出去。没有氧气，我们的细胞很快就无法工作。
Breathing brings oxygen into the body so cells can make energy, and it expels the waste gas carbon dioxide. Without oxygen, our cells soon stop working.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
王庭槐 主编,《生理学》第9版,人民卫生出版社,2018
Wang Tinghuai ed., Physiology, 9th ed., People's Medical Publishing House, 2018
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787117266598（豆瓣书目条目: 生理学）
#呼吸 #氧气 #生理