运动时骨骼肌如何帮助静脉回流？
How do skeletal muscles help venous return during exercise?
骨骼肌收缩会挤压包裹其中的静脉，配合单向瓣膜把血液推向心脏，这称为“肌肉泵”。运动越多，泵作用越强，下肢血液回流越快。久卧不动则回流减慢，易形成血栓。
Skeletal muscle contraction squeezes the veins running through them, and with one-way valves pushes blood toward the heart—the 'muscle pump'. More movement means stronger pumping and faster return from the legs. Prolonged immobility slows return and raises clot risk.
难度 专业 · 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
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#肌肉泵 #静脉回流 #骨骼肌
淋巴系统如何与循环系统协作？
How does the lymphatic system cooperate with the circulatory system?
淋巴系统收集组织间隙中漏出的组织液，过滤后通过淋巴管回流入静脉。它既维持体液平衡，又借助淋巴结清除病原体。淋巴液最终汇入锁骨下静脉，重新进入血液循环。
The lymphatic system collects tissue fluid that leaks out of capillaries, filters it, and returns it via lymphatic vessels to the veins. It maintains fluid balance and, with lymph nodes, clears pathogens. Lymph finally joins the subclavian veins and re-enters blood circulation.
难度 专业 · 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
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#淋巴系统 #体液平衡 #淋巴结
为什么久站会腿肿（静脉曲张）？
Why do legs swell and get varicose veins after long standing?
站立时血液需克服重力回流心脏，主要靠静脉瓣膜和腿部肌肉挤压。久站使瓣膜长期受压、功能减弱，血液淤积在下肢静脉，导致肿胀和静脉扩张迂曲。活动小腿肌肉有助于促进回流。
When standing, blood must return to the heart against gravity, relying on venous valves and leg-muscle pumping. Long standing weakens the valves over time, letting blood pool in leg veins and causing swelling and twisted, enlarged veins. Moving the calf muscles helps promote return flow.
难度 专业 · 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
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#静脉曲张 #静脉瓣 #下肢水肿
胎儿还没用肺呼吸，血液是如何绕过肺循环的？
How does fetal circulation bypass the lungs before the baby breathes?
胎儿肺尚未通气，血液经三个"分流"绕过肺：卵圆孔让右心房血直接进左心，动脉导管把肺动脉血分流到主动脉，静脉导管绕开肝脏。出生后呼吸启动、阻力改变，这些通道关闭，循环才转为成人模式。
Because fetal lungs are not yet aerated, blood bypasses them through three shunts: the foramen ovale sends right-atrial blood straight to the left heart, the ductus arteriosus diverts pulmonary blood to the aorta, and the ductus venosus bypasses the liver. After birth, with breathing and shifted resistances, these close and circulation switches to the adult pattern.
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)
#胎儿循环 #卵圆孔 #动脉导管 #分流
为什么毛细血管管壁很薄？
Why are capillary walls so thin?
毛细血管是动脉和静脉之间最细的血管，管壁仅由一层内皮细胞构成。这种极薄的结构让氧气、营养物质和废物能快速在血液与组织之间扩散交换。几乎所有物质交换都发生在毛细血管。
Capillaries are the smallest vessels between arteries and veins, with walls just one endothelial cell thick. This extreme thinness lets oxygen, nutrients, and wastes diffuse quickly between blood and tissues. Nearly all exchange happens in capillaries.
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
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#毛细血管 #物质交换 #内皮
为什么静脉有瓣膜而动脉没有？
Why do veins have valves but arteries do not?
动脉承受心脏泵血的高压、管壁厚而有弹性，靠自身压力推动血流，所以不需要瓣膜；静脉压力低、血流慢，靠静脉瓣防止血液倒流，尤其下肢要对抗重力把血送回心脏。
Arteries withstand the high pressure of the heart's pumping with thick, elastic walls and need no valves because pressure drives the flow; veins have low pressure and slow flow, so one-way valves prevent backflow—especially important in the legs fighting gravity to return blood to the heart.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-10-04
来源 · Source
Tortora 与 Derrickson，《解剖生理学原理》（第15版，Wiley，2021）
Tortora & Derrickson, Principles of Anatomy and Physiology (15th ed., Wiley, 2021)
独立核验依据 · Independent verification: 核验依据 1 ISBN 978-1-119-32064-7 (15th ed., Wiley)
#静脉瓣 #动脉 #血液回流 #重力
血小板在止血中起什么作用？
What role do platelets play in stopping bleeding?
血小板是血液中很小的细胞碎片，遇到伤口会迅速聚集并黏附在破损处。它们释放信号激活凝血因子，形成血栓堵塞裂口。这是身体防止失血的第一道防线。
Platelets are tiny cell fragments in blood that quickly gather and stick to a broken vessel at an injury site. They release signals that activate clotting factors, forming a plug that seals the gap. This is the body's first defense against blood loss.
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
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#血小板 #止血 #凝血
运动时心率为什么会加快？
Why does heart rate increase during exercise?
运动时肌肉需要更多氧气和能量，身体通过神经和激素信号让心脏跳得更快更强。这样能在单位时间内输送更多含氧血到肌肉。运动结束后心率会逐渐恢复正常。
During exercise, muscles need more oxygen and energy, so the body uses nerve and hormone signals to make the heart beat faster and stronger. This delivers more oxygen-rich blood to muscles per unit time. After exercise, 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
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#运动 #心率 #供氧
血压的两个数值分别代表什么？
What do the two numbers in a blood pressure reading represent?
血压写成“收缩压/舒张压”两个数值。收缩压是心脏收缩把血液泵出时血管承受的最高压力，舒张压是心脏放松充盈时的最低压力。成年人正常血压通常低于120/80 mmHg。
Blood pressure is written as 'systolic/diastolic'. Systolic is the highest pressure when the heart contracts and pumps blood out; diastolic is the lowest pressure when the heart relaxes and fills. Normal adult pressure is usually below 120/80 mmHg.
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
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#血压 #收缩压 #舒张压
什么是先天性心脏病？
What is congenital heart disease?
先天性心脏病是出生时就存在的心脏结构异常，如房间隔缺损或动脉导管未闭。它多因胚胎期心脏发育受影响所致，可影响血液循环效率。轻度可能无症状，重度需手术矫治。
Congenital heart disease is a structural heart defect present at birth, such as a hole between chambers or a persistently open duct. It usually arises from disrupted heart development in the embryo and can impair circulation. Mild cases may be silent; severe ones need surgery.
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
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#先天性心脏病 #心脏缺陷 #发育
血型A、B、O、AB是怎么决定的？
How are blood types A, B, O, and AB determined?
血型由红细胞表面的A、B抗原决定，受第9对染色体上的基因控制。A型有A抗原，B型有B抗原，AB型两者都有，O型都没有。输血时需匹配血型以避免免疫反应。
Blood type is set by A and B antigens on red cells, controlled by genes on chromosome 9. Type A has A antigen, B has B, AB has both, and O has neither. Matching types in transfusion avoids immune reactions.
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
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#血型 #抗原 #输血
什么是血液循环的体循环和肺循环？
What are the systemic and pulmonary circulations?
体循环把含氧血从左心室送到全身，再把缺氧血带回右心房。肺循环把缺氧血从右心室送到肺部释放二氧化碳并摄取氧气，再回到左心房。两套循环接力运行，保证血液持续获氧。
Systemic circulation sends oxygen-rich blood from the left ventricle to the body and returns oxygen-poor blood to the right atrium. Pulmonary circulation sends oxygen-poor blood from the right ventricle to the lungs to release carbon dioxide and pick up oxygen, then back to the left atrium. The two circuits work in series to keep blood oxygenated.
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
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#体循环 #肺循环 #心脏
什么是贫血，常见原因有哪些？
What is anemia and what are common causes?
贫血是指血液中红细胞数量或血红蛋白含量低于正常，导致携氧能力下降。常见原因包括缺铁、缺乏维生素B12或叶酸、慢性失血等。患者常感到乏力、头晕和面色苍白。
Anemia means the blood has too few red cells or too little hemoglobin, reducing its oxygen-carrying capacity. Common causes include iron deficiency, lack of vitamin B12 or folate, and chronic blood loss. People often feel tired, dizzy, and look pale.
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
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#贫血 #血红蛋白 #缺铁
动脉和静脉有什么区别？
What is the difference between arteries and veins?
动脉把血液从心脏运送到全身，多数携带含氧血，管壁较厚有弹性。静脉把血液送回心脏，管壁较薄，常有瓣膜防止血液倒流。两者共同构成闭合的循环网络。
Arteries carry blood away from the heart, mostly oxygen-rich, with thick elastic walls. Veins return blood to the heart, with thinner walls and often valves that prevent backflow. Together they form a closed circulation network.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#动脉 #静脉 #血管
主动脉是人体最大的动脉吗？
Is the aorta the largest artery in the body?
是的，主动脉是人体最粗大的动脉，它直接从心脏左心室发出。主动脉把含氧血输送到全身各处的主要分支。它的弹性帮助缓冲每次心跳产生的压力波动。
Yes, the aorta is the largest artery in the body, arising directly from the left ventricle. It distributes oxygen-rich blood to the major branches that supply the whole body. Its elasticity helps cushion the pressure surges of each heartbeat.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#主动脉 #动脉 #心脏
心脏一天大约跳动多少次？
How many times does the heart beat in a day?
成年人安静时心率约为每分钟60到100次。按平均每分钟70次计算，一天大约跳动10万次。心脏通过这种持续跳动把血液泵送到全身。
At rest, an adult heart rate is about 60 to 100 beats per minute. Averaging 70 beats per minute, that is roughly 100,000 beats per day. This steady pumping pushes blood throughout the body.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#心脏 #心率 #循环系统
医生用听诊器听到的"咚-嗒"心跳声是哪来的？
Where does the "lub-dub" heartbeat sound come from?
心脏里的瓣膜像小门，血液冲过并关闭瓣膜时会产生振动声，医生听到的"咚-嗒"（lub-dub）就是瓣膜规律开合的声音。每次心跳，就是瓣膜有节奏地开关、把血推向下一站。
The heart's valves act like little doors; as blood rushes past and the valves snap shut they make vibrating sounds. The "lub-dub" a doctor hears is the rhythmic opening and closing of these valves, pacing each beat as blood is pushed to the next station.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-10-04
来源 · Source
Tortora 与 Derrickson，《解剖生理学原理》（第15版，Wiley，2021）
Tortora & Derrickson, Principles of Anatomy and Physiology (15th ed., Wiley, 2021)
独立核验依据 · Independent verification: 核验依据 1 ISBN 978-1-119-32064-7 (15th ed., Wiley)
#心音 #心脏瓣膜 #心跳