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[茜提燈時戯画] 参考【生理学】更新02-21

视频来源 Physiology Animation APP- M. P# x; c' d4 ?2 e+ u( y' h
字幕/校对 skyall

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1 y# J5 u! {$ H! ~$ @目录
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  生理学部分 Physiology! ~6 [2 \* R$ p, @1 J* v* Z

3 W& b" E+ |  J     01 Bones and Skeletal Muscles 骨与骨骼肌( \& ?8 n: l' E% e
       -  01 Paired muscle actions 成对的骨骼肌动作 181209
. S& [4 W$ Z% s5 G) j8 V" s, ?% M       -  02-08 Joint 关节 1812119 V2 Y1 z3 P4 i: `. Z# a
       -  09 Involuntary reflexes 先天反射 181213* T  O  d- b/ `) s8 ^
       -  10-12 Skeletal muscle contractions 骨骼肌收缩 181227
0 `, U6 I6 W" g( p. t       -  13 Sound Production 发声 190131
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) w2 D. I. ?  H1 U- k. n) t     02 Cells and Tissues 细胞和组织7 h9 Z1 A% p: G0 R" J- N, z
       -  01 Types of cells 细胞的类型 190203
$ q# C  X3 ~  Z/ G8 R       -  02 Cellular respiration 细胞呼吸 190216. y: w# W! y$ h3 B+ {
       -  03 Cell transport 细胞运输 190304% Q1 a4 L$ \9 L8 u6 G) z
       -  04-05 Transcription and translation 转录和翻译 1907096 ~; c8 W& b2 u+ I9 K$ Q" R
       -  06 Mitosis 有丝分裂 190710/ v) q  b: o& W4 E( w( s0 o$ O, o
       -  07 Red blood cells 血红细胞& n1 L( Q8 ?. X7 Y" N* Y
       -  08 Red blood cells production 血红细胞的产生7 c1 [; W+ m) o
       -  09 Function of plasma 血浆的功能7 `0 \: y, E3 D; W$ m/ {! }
       -  10 Platelets 血小板8 V3 t/ f/ a: N8 P% U: w
       -  11 Heart tissue 心脏组织 190718& b3 ]$ U. N  e0 r
       -  12 Smooth muscle tissue 平滑肌组织 190720: i: J6 o6 \! x! t7 A
       -  13 Neurons 神经元
: Z; D1 f$ K) W( `       -  14-15 Sex cells 生殖细胞
# ~" e2 F) f) |8 q: q# y       -  16 Fetal development 胎儿发育 190721
4 v& C& {4 _- M7 Y       -  17-18 Bone formation 骨的形成
0 N- D; `  }5 b5 v8 O; x! o       -  19 Bone repair 骨修复
8 {+ @4 A# h7 M       -  20 Soft tissue repair 软组织修复: ~7 @. L5 m4 }/ y
       -  21 Phagocytes 吞噬细胞8 h7 c# k/ v% e' F% o, a
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     05 System Overviews 系统概述, ]) p) z8 O! K( p
       -  01 Function of the skin 皮肤的功能 9 |% Y6 r' F5 h0 c- i1 S
       -  02 Function of the skeleton 骨骼的功能 # e2 ?( J& [7 r
       -  03 Muscle Tissue Types 肌肉组织的类型 # p1 e% }: e4 j* X4 U7 r
       -  04 Nervous System Functions 神经系统的功能
+ V7 Z; P, B0 |       -  05 Digestive System Functions 消化系统的功能 8 E1 r5 d  h! M0 w8 F9 x8 u
       -  06 Respiratory System Functions 呼吸系统的功能$ U7 d5 k6 x5 v1 r! u  a3 q
       -  07 Circulatory System Functions 循环系统的功能
3 [# W' W; T" Q) X" v       -  08 Lymphatic System Functions 淋巴系统的功能
% v+ C3 i# K- Z8 Y! b+ I       -  09 Endocrine Gland functions 内分泌的功能
& |. X$ j7 Q7 c7 L       -  10 Reproductive Process 生殖过程 7 |$ y+ |9 K( i' D" ?
       -  11 Hearing 听觉2 b3 O! Y/ j' X
       -  12 Sight 视觉3 y- Q# D. O; ]* Z9 R1 _/ T7 P' |
       -  13 Olfaction 嗅觉

01 Bones and Skeletal Muscles 骨与骨骼肌8 M8 O( x, @! d6 [* b
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* q# i. Q5 e' \4 }#01 Paired muscle actions 成对的骨骼肌动作: s1 O; N" g/ W" q
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在线视频 https://v.youku.com/v_show/id_XMzk1NzEwMzU4NA==.html
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Movement of the skeleton often involves pairs of muscles that perform opposing actions, like flexing and extending or bending and straightening. Muscles involved in these paired actions are categorized as agonists and antagonists.
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骨架的运动往往涉及执行相反操作的配对肌肉,如屈曲和伸展,弯曲和伸直。参与这些成对动作的肌肉被分为激动肌和拮抗肌。
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3 Y  l8 n+ q; |& j7 T. jA muscle that contracts to generate the main force of an action is called the prime mover, or the agonist for that action. Muscles that perform the paired and opposing action are called the antagonists. The agonists in elbow flexion are the muscles that contract to bring the elbow joint into a flexed position. The antagonists are the muscles that perform the opposite action, elbow extension. When the action of elbow extension occurs, the roles switch. The triceps brachii is now the agonist and contracts to extend the limb, while the biceps brachii muscle is relaxed and becomes the antagonist.
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收缩产生动作主要力量的肌肉称为该动作的原动肌或激动肌,执行配对和反作用的肌肉称为拮抗肌。肘关节屈曲的激动肌为收缩使肘关节处于弯曲位置的肌肉,拮抗肌则是执行相反动作伸肘的肌肉。当肘关节伸直时,角色互换。上肢伸展时,肱三头肌收缩,是激动肌,而肱二头肌松弛,是拮抗肌。
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Muscle interactions throughout body regions involve paired actions. These include flexion and extension, elevation and depression, and pronation and supination.
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# v. m' U' h  s8 c, b* o全身的肌肉相互作用,完成配对动作。这些动作包括屈伸、抬高和压低,以及旋前和旋后。1 ?0 H: c& M; n: |3 u& \  o
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载点 https://pan.baidu.com/s/1-KeOLiU9AyXvGdNSkS0DRg
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01 Bones and Skeletal Muscles 骨与骨骼肌
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6 P' s  j- w0 P/ L& q#02-08 Joint 关节. t0 S' }) B& K+ h

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#02 Ball and socket  球窝式
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The ball-and-socket joint, found in the shoulder, is a freely moving joint that can rotate on any axis., s+ n1 E0 ~% g% E8 W

  |' p, \& e9 b! {& _2 S; k肩部的球-窝关节,是一个自由活动的关节,可以在任何轴线旋转。
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2 W3 z; ^. Q; E- f, S#03 Condyloid  骨踝
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) U# w) s" p! p1 e* yThe wrist joint is a condyloid joint that allows for circular motion, flexion, and extension.
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* R1 m# y5 I! [3 M腕关节是一个椭圆形关节,能够进行圆周运动、前屈和扩展。7 ?- A( U0 f1 Q. T4 j- d
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#04 Gliding  滑动
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+ }! q& [" T( {( [As the body moves, the vertebrae of the spine move against each other as gliding joints.
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随着身体的移动,脊柱的椎骨犹如滑动关节,彼此活动。
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#05 Hinge  铰链
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& b9 g$ O5 Y) oHinge joints, like the elbow, move on just one axis. These joints allow for flexion and extension.; S) c) Z8 w& D9 q+ f* w3 Q$ y( I

, G0 Q- P9 Y, ]铰链关节只能在一个轴上活动,如肘关节。这些关节可进行屈及伸。
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1 C$ m2 c. s5 F% O0 G& z- v9 a#06 Pivot  枢轴% p) T' A7 n/ I4 f

, ^: m1 `) ?0 V% [5 XAt the top of the spine, the atlas and axis form a pivot joint that allows for rotation of the head.
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在脊柱的顶部,寰和轴形成一个枢轴关节,允许头部转动。
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( A& f1 l  e* H#07 Saddle  马鞍型
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In the hand, the thumb’s saddle joint lets the thumb cross over the palm, making it opposable.
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拇指的鞍状关节让拇指交叉于掌心,与掌心相对。0 p2 A7 R7 ]& q- [4 c( x: E

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#08 Sutures  缝合! o" q9 m3 B: o6 x; E& L! B
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Sutures are nonmoving joints that connect bones of the skull. These joints have serrated edges that lock together with fibers of connective tissue. The interlocking edges make sutures strong and fracture-resistant. All skull joints are sutures, except for the joint connecting the mandible to the temporal bone, which is a movable synovial joint. + O; Y& [- e& t) m

2 Z* V3 R: G5 k9 {骨缝是连接颅骨的非活动性关节。这些关节有锯齿边缘,通过结缔组织纤维相互锁合在一起,相互锁合的边缘使骨缝变强,不容易断裂。连接下颌骨和颞骨的关节是一个可活动的滑膜关节,除此之外,所有颅骨的接头都是骨缝。! |, I' r8 v. C. k5 E

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载点 https://pan.baidu.com/s/1__vfgbUfXgSb7nArdTPa3Q8 G2 P! \% g" `  {' R0 q) y

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01 Bones and Skeletal Muscles 骨与骨骼肌  T( q/ {9 c% I: k9 Q9 s2 F  Q7 m
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- z/ K3 g) q/ q! |#09 Involuntary reflexes 先天反射
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Somatic reflexes are automatic responses to stimuli that allow for fast reactions, before messages reach the brain. These reflex actions occur in a series of steps known as the reflex arc.
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躯体反射是对刺激的自动反应,使得人体在信息到达大脑之前能做出快速反应。这些反射通过一系列被称为反射弧的步骤完成。
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- n3 J" R1 g. j2 m2 FFirst a sensory receptor detects a stimulus and a signal travels through afferent neurons towards the spinal cord. When the signal passes through the fray matter of the spinal cord, a message is relayed from the afferent neuron through an association neuron to an efferent neuron. This leads to a quick, automatic reflex reaction that occurs without the need for processing in the brain.
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先由感觉器感受到刺激,随后通过传入神经元向脊髓传入信号,当信号通过脊髓灰质时,信息从传入神经元,通过关联神经元传到传出神经元。这引起快速的自动反射反应的发生,不需要大脑的处理。7 f$ t# G0 O+ \- `0 e
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载点 https://pan.baidu.com/s/1NuVawtJAIvgu-RPWZolUkA
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01 Bones and Skeletal Muscles 骨与骨骼肌
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#10-12 Skeletal muscle contractions 骨骼肌收缩: U' f3 X7 f# m/ o8 {! |. _  ]  u$ Z
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在线视频 http://v.youku.com/v_show/id_XMzk4NDI2MDY0MA==.html- {  q( x6 H0 ?3 W+ b. K, G" t# k

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#10 Skeletal muscle contractions 骨骼肌收缩
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The muscular, nervous, and skeletal systems interact to produce movement. Messages travel through the nervous system to the skeletal muscles that attach to bones throughout the body. The fibrous appearance of skeletal muscles is created by the arrangement of proteins inside the cells that form muscle tissue.
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6 \* j" v; D% r# m" Z肌肉、神经和骨骼系统的相互作用产生运动。信号通过神经系统传递到附着于全身骨骼的骨骼肌。骨骼肌的纤维外观是由形成肌肉组织的细胞内蛋白质排列所致。+ S8 p' O9 M0 h: M
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Motor neurons of the nervous system connect with these skeletal muscles. Movement occurs through a series of steps. Impulses from the nervous system reach the neuromuscular junction. The neuron releases a neurotransmitter called acetylcholine. It binds to receptors on the muscle and begins a chemical reaction within its fibers. The muscle filaments slide across each other and the muscle shortens, or contracts. This action produces movement.
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+ l$ b; q5 U' b1 `2 q3 S神经系统的运动神经元与这些骨骼肌连接,运动通过一系列步骤完成。冲动从神经系统传到神经-肌接头,神经元释放一种叫乙酰胆碱的神经递质,与肌肉的受体结合,促发肌纤维内的化学反应。肌丝相对滑动,肌肉缩短或收缩,这个作用形成运动。& L3 P* u. F. c, ~$ d3 N5 f1 w

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#11 Muscle contraction: Action potential  肌肉收缩:动作电位
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) x0 }% h4 J$ y: |3 Z+ p2 yIn order to produce movement in the body, the muscular, nervous, and skeletal systems interact in a process called muscle contraction. Muscle contraction begins when the nervous system generates a signal. : {  p- I8 k/ t# O3 x6 ?4 |
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为了让机体产生运动,肌肉、神经和骨骼系统通过称为肌肉收缩的过程相互作用。神经系统产生信号时,肌肉收缩即开始。" s, n+ k- G6 w/ O; M5 N: o

1 H- z) ]9 q( o' J6 Z3 iA motor neuron conducts an action potential to its link with a muscle fiber. At the neuromuscular junction, a neurotransmitter called acetylcholine is released. This chemical binds to receptors on the muscle fiber. Acetylcholine receptors are chemically-gated ion channels, allowing an influx of sodium ions into the muscle fiber. This stimulates the sarcolemma and generates another action potential that travels through tiny folds know as transverse tubules. The action potential reaches myofibrils within the muscle fiber. Surrounding the myofibrils are membranous sacs called the sarcoplasmic reticulum. The arrival of the action potential triggers the release of calcium ions stored in the sarcoplasmic reticulum. They diffuse into the muscle fiber and the next phase of muscle contraction begins.
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+ q# b) J' K- x) d" A9 n1 j7 S运动神经元将动作电位传导至与其相连的肌纤维,在神经-肌接头释放一种叫乙酰胆碱的神经递质,这些化学物质与肌纤维受体结合。乙酰胆碱受体为化学门控离子通道,与乙酰胆碱结合使通道开放,让钠离子内流到肌纤维内。这刺激了肌膜,产生另一个动作电位,跨过横小管的细小折叠,动作电位抵达肌纤维内的肌原纤维。包绕肌原纤维的是称为肌质网的膜囊,动作电位抵达后,促发释放肌质网中储存的钙离子,弥散分布到肌肉纤维内,开始肌肉收缩的下一阶段。! |6 B4 }  a- e% ]$ m

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7 J1 x! y/ U2 ~$ A* x6 b& a" @. R  N# k#12 Muscle contraction: Cross bridge formation  肌肉收缩:横桥形成
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When an action potential travels to a muscle fiber, a series of steps begin within the fiber that result in contraction. Muscle fibers are organized into units called sarcomeres that contain two types of filaments. Thick filaments consist of myosin. Thin filaments consist of actin. Eventually these two filaments will come together, creating a cross bridge. In response to an action potential, the sarcoplasmic reticulum within a muscle fiber release calcium ions. These ions bind to protein complex causing it to shift and expose the myosin binding sites. The myosin head then binds to actin and the cross bridge is established.; Z5 c8 n, Y" I$ R

8 b! Q# C! y( o当动作电位传到肌纤维,在纤维内会发生一系列步骤而造成收缩。肌纤维以肌节为单位排列,含有两类细丝,粗肌丝含有肌球蛋白,细肌丝含有肌动蛋白,这两种肌丝最终结合在一起,构成横桥。肌纤维内的肌质网对动作电位作出反应,释放钙离子。这些钙离子与肌钙蛋白结合,使其转变并暴露肌球蛋白结合位点,肌球蛋白头部与肌动蛋白结合,建立起横桥。
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* L- J: Z% R* ]4 J# l4 xIn the next step, ADP and phosphate are released. Their energy powers the movement of the myosin head. This step is called the power stroke. Actin moves toward the center of the sarcomere. ATP then binds again to myosin and it detaches from actin. ATP breaks down into ADP+Phosphate and the myosin head cocks back. Myosin heads continue to deactivate and reactivate. This causes the myosin filaments to pull together and slide across one another, contracting the muscle., K" M0 Z5 c/ E( ^3 K8 |& l& W1 r6 y1 ]' K
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下一步便是释放ADP和磷酸盐,其能量驱动肌球蛋白头部运动,这一步骤称为动力冲程,肌动蛋白朝肌节中心运动。肌球蛋白再与ATP结合,从肌动蛋白分离。ATP降解为ADP与磷酸盐,肌球蛋白头部复位。肌球蛋白头部持续失活并复活,这样让粗肌丝一起牵拉,彼此相互滑行,从而收缩肌肉。
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  U6 b# ^+ q7 |. d载点 https://pan.baidu.com/s/15uy6HRBDKdqyXJNsdExddw- ~# z% @6 Y' N: ^0 ^8 L" w8 X
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01 Bones and Skeletal Muscles 骨与骨骼肌! N) {( i/ T6 `: V9 R" C

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* K4 @9 K0 e+ J& D3 I0 B#13 Sound Production 发声
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在线视频 http://v.youku.com/v_show/id_XNDAzOTg5OTg4NA==.html
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Phonation is the production of sound by structures in the upper respiratory tract. During exhalation, air passes from the lungs through the larynx. Muscles in the larynx can act to move the arytenoid cartilages that then move the cords. The cords are pushed together and air passes between them in such a way as to make them vibrate, creating sound.
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2 r* u; J2 u! X/ j发音是由上呼吸道的结构产生的。在呼气过程中,空气通过喉部呼出肺部。喉部的肌肉可以移动杓状软骨,带动声带活动。声带被推到一起,空气从它们之间通过,以这样的方式使声带振动,产生声音。
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1 u9 P! a' W% m8 {1 ?& @Greater tension in the vocal folds creates more rapid vibrations and higher-pitched sounds. Lower tension causes slower vibration and a lower pitch.( J3 u' ?" z$ Y( z3 D" E

, I" a  i0 c5 _& A5 @- g% Y声带张力越大,产生的振动越快,音调越高。声带张力越小,产生的振动越慢,音调越低。
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Sounds can also be altered by other factors: High pressure creates louder sound, shorter folds produce lower pitch sounds, and longer folds produce higher pitch. Structures in the oral and nasal cavities can also modify the sounds produced by the vocal folds.) L6 Q, e8 y/ ?; j6 V  q

. M8 r! r! t# i/ s9 l2 X其他因素也可改变声音:高压产生更响亮的声音;较短的声带产生较低的音调,较长的声带产生较高的音调;口腔和鼻腔的结构也可以改变由声带产生的声音。
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02 Cells and Tissues 细胞和组织
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#01 Types of cells 细胞的类型5 f, O) w, x  ~: [1 O
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Cells are the basic living units of tissue. The human body is composed of trillions of cells. There are over 200 different cell types. Each specializes to perform essential functions.! b$ f: o# s& |5 W9 X- a! X

" ^" ~  i5 J1 e0 N) m" \细胞是组织的基本活单位。人体由数万亿细胞组成,有超过200种不同类型的细胞,每种细胞执行特有的功能。
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Bone cells form and regenerate the bones in the body. Nervous system cells send messages within the brain and throughout the body to produce actions. Cells in the blood carry oxygen and help the immune system. Male and female sex cells unite to produce offspring. # o  Z. v. I* k! N8 V! }, D# {% D

( s4 V$ B/ H+ w" b4 v/ Z  N骨细胞在体内形成和再生骨骼。神经系统细胞在大脑和全身传递信息,产生动作。血液中的细胞携带氧气和促进免疫系统。男性和女性的生殖细胞联合产生后代。
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The genetic information inside each type of cell acts as an instruction manual telling a cell how to function and replicate.
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每个类型细胞内的基因信息充当了说明书,告诉细胞如何运作和复制。8 O7 {3 i4 X' f2 l' [9 ]
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02 Cells and Tissues 细胞和组织
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: j( [, O$ G) w: U. M* ?7 X#02 Cellular respiration 细胞呼吸
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Cellular respiration is comprised of three main steps. It begins when glycolysis breaks down 6-carbon glucose molecule producing two 3-carbon pyruvic acid molecules and a net gain of two ATP molecules, which the body uses as cellular energy. High-energy electrons are released.5 Y( [8 _* D4 W- G& A' N

! x# I+ Q* J  @5 m3 m* y% J细胞呼吸包括三个步骤。始于糖酵解6-碳葡萄糖,生成两个3-碳丙酮酸分子,并净增两个ATP分子,机体用作细胞能量,释放高能电子。
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* R4 W# a' J# j& EEach 3-carbon pyruvic acid molecule then enters the mitochondria as part of the second step, the citric acid cycle. Two more ATP are created and carbon dioxide is released as a waste product. High-energy electrons are again released.7 d9 K% U6 N& ], i9 j/ y, q* d

* v& O& S1 D6 ^8 S# w) g) t每个3-碳丙酮酸分子进入线粒体,作为第二步三羧酸循环的一部分,再生成两个ATP分子,二氧化碳作为废物释放出,再次释放高能电子。4 _0 Z- Z( f/ b, ^9 P0 I& ~0 }3 A3 ~

+ c6 i7 n( l+ q- y0 cThe third and final step is the use of high-energy electrons in the electron transport chain, located in the mitochondrial membrane. It is during this phase that most the ATP molecules are created. The previously released electrons interact with a series of enzymes that store the energy in the electrons in ATP molecules.
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9 N. V/ T& h2 f+ q7 V第三步也是最后一步,使用电子转运链中的高能电子,这些电子位于线粒体膜上。多数ATP分子是在这一阶段产生的。之前释放的电子与一系列酶相互反应,这些酶将能量储存于ATP分子的电子中。/ Y# P6 l+ d- u0 P- X! a; `1 i
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The three steps of cellular respiration can produce up to 38 ATP molecules from one glucose molecule.  U4 i8 Y6 r2 O. C2 f; t$ X+ z: P

* `4 l8 Q- _( `5 I细胞呼吸的这三个步骤,利用1个葡萄糖分子最多可产生38个ATP分子。
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02 Cells and Tissues 细胞和组织3 {3 @0 ]+ f0 n) P5 q! M, d5 W

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% ^6 u# ^0 f3 L5 R: n" Q+ w5 v#03 Cell transport 细胞运输
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Substances such as nutrients, gases, and waste are constantly moving into and out of cells. When the concentration of a substance is higher on one side of the cell’s permeable barrier, its molecules use osmosis or diffusion to move through the barrier without the cell using any energy. This process is called passive transport.6 d3 t' g8 H& S

6 K2 @0 R9 l/ T% X( L2 ]# K营养成分、气体和废弃物等物质不断进出细胞。当细胞渗透性屏障一侧的某种物质浓度升高时,其分子通过渗透或扩散穿过屏障,细胞无需耗用能量,该过程称为被动运输。+ ?; h' Y( |; z) N9 s

1 z3 \- x7 E' a% S+ ZWhen the molecules of a substance need to move from an area of low concentration to one of high concentration, they use specialized proteins in the cell membrane. This process expends energy and is called active transport.
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当一种物质的分子需要从低浓度一侧移动到高浓度一侧时,需要使用细胞膜上专门的蛋白质。这个过程需要消耗能量,被称作主动运输。
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02 Cells and Tissues 细胞和组织! \, S2 j7 o+ q5 ^3 y: q

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#04-05 Transcription and translation 转录和翻译
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- P" Y' q! i5 R+ C( j#04 Transcription  转录
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All cellular gene expression and protein building occurs through the two principal steps called transcription and translation.) l  s- |7 a3 ^, E+ S% q: g8 t1 }& u

/ p- O; X1 L9 h8 E+ b所有细胞基因表达和蛋白质构建,主要通过两个步骤,称为转录和翻译。
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In transcription, DNA’s information is encoded or “transcription” into messenger RNA or mRNA. The process begins when RNA polymerase opens the double helix of DNA, like the slider on a zipper. It unwinds the DNA double helix and pries the two DNA strands apart. As the RNA polymerase continues down the length of the DNA, several actions take place.
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+ L4 ^$ l; s+ e4 [转录时,DNA的信息被编码或“转抄”到信使RNA或mRNA内。这一过程开始于RNA聚合酶打开的双螺旋之时,就像一条拉链的拉头。将DNA双螺旋解旋,将两条DNA链撬开。随着RNA聚合酶继续缩短DNA的长度,发生了几种作用。
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It reads one strand of the DNA and transcribes the DNA’s information. It creates an mRNA version of the DNA or “transcript”. The mRNA transcript is a complementary copy of the DNA sequence. When the transcription ends and the mRNA template is complete, it separates from the DNA template, and exits the nucleus through pores. The template enters the cytoplasm on its way to the next step in the process of polypeptide synthesis: translation. " @' m8 N: a5 ~, d3 g

4 j) E1 [3 o5 F4 w* W7 B9 C/ Q只读取一条DNA链并转录DNA信息,构成DNA或“转录本”的mRNA版本。mRNA转录本是DNA序列的互补副本。转录结束,mRNA模板完成后,便从DNA模板分离,通过核孔退出细胞核。模板进入胞质内,接着下一步称为多肽合成的过程:翻译。1 O0 h) W: M( Y' ?, s
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#05 Translation  翻译  v# V/ v" R: b: S$ j

; \7 W8 z& \* ^* t+ x+ s) L7 zTranslation begins when the mRNA enters the cytoplasm and a small ribosomal subunit attaches itself to the end of the mRNA strand. At the same time, a transfer RNA (tRNA) molecule recognizes and binds to the “start” codon on the mRNA strand. tRNA recognizes the mRNA codon through its “anticodon”, which has a sequence complementary to the mRNA codon. It is the tRNA molecules that carry the amino acid building blocks of the protein. * M- ^8 h- ?- T

* f, X, C& w& b0 q  \; \翻译开始于mRNA进入胞质时,小型核糖体亚单位附着于mRNA链的末端,与此同时,转运RNA分子识别mRNA链上的“启动”密码子并与之结合。tRNA通过自身具有与mRNA密码子互补的“反密码子”序列来识别mRNA,这种tRNA分子携带构建蛋白块的氨基酸。
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: o+ k; z8 w  F& W1 A/ NNext, a large ribosomal subunit joins and forms the fully functional ribosome that will join the amino acids on the tRNAs to synthesize the protein. When the amino acids of the two tRNA molecules are joined, the tRNA in the first position is released to get a new amino acid. The growing protein is attached to the tRNA in the second position.
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, P/ ?: }% O; q! N; H3 R下一步是大型核糖体亚单位联结,形成功能完整的核糖体,与tRNA上的氨基酸联结合成蛋白质。当两个tRNA分子的氨基酸联结后,第一个位置上的tRNA便释放,获取一个新的氨基酸。长出的蛋白质附着于第二个位置的tRNA。
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The mRNA is then pulled through the ribosome so that the tRNA with the protein chain is now in the first position. Now a new tRNA with the proper anticodon can come into the ribosome at the open position. This pattern continues as tRNA after tRNA bind to the mRNA codons and their amino acids are added to the growing protein chain. Toward the end of the mRNA sequence, the ribosome gets to a “stop” codon, which does not code for any amino acid. This signals the end of the protein and that the translation process is complete.
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+ A: M" D! l  T: Y然后mRNA从核糖体拉出,带有蛋白链的tRNA便位于第一个位置。带有正确反密码子的新tRNA便在开放位置进入核糖体。这一方式不断继续,tRNA接着tRNA与mRNA密码子结合,其氨基酸加入生长中的蛋白质。在这个mRNA序列的末端,核糖体得到“停止”密码子,此密码子并不编码任何氨基酸。这标志着蛋白质的末端,说明翻译转录过程已经完成。
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The ribosome then releases the finished protein from the tRNA, and detaches from the mRNA as  the two ribosomal subunits separate. The protein will then be further modified in other cellular structures or directly used by the body.
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7 s$ c4 o. a/ K1 }2 U之后核糖体从tRNA释放已经完成的蛋白质,并随着两个核糖体亚单位分离,从mRNA脱离。蛋白质在其他细胞结构内进一步修饰,或者直接被机体利用。# g5 Q$ G! N2 H/ E3 z. K2 f
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1 }0 k, g3 h3 A  I, P( G0 ~1 w! Vhttps://pan.baidu.com/s/1Vk2yE9hE9SKTGjD89zPH3w(Simple Ver.)% x0 w+ B4 U, ?4 I- V$ f2 H& Y

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02 Cells and Tissues 细胞和组织
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8 p( u& B& Q+ z7 X! u#06 Mitosis 有丝分裂$ [- k' A1 ?) A: ~) B! U
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' y# O) p7 h2 [2 a! V9 r  KThe human body develops, replaces old cells with new cells, and repair itself, with the help of cells that constantly multiply by dividing. The process begins in the cell nucleus.
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在细胞不断增生和分裂的帮助下,人体发育,新陈代谢,并进行自我修复。该过程始于细胞核。  k7 f# p1 N# l8 _' W4 z. B
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Identical copies of DNA molecules organize into chromatid pairs within the chromosome structure. These pairs are connected to each other at the chromosome’s centromere.$ [6 n/ L4 k! z

% }; s4 A7 T* uDNA分子的相同复制构成染色体结构中的染色体配对。这些配对在染色体的着丝粒互相连接。
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2 d: L% l/ d0 XIn the next steps, spindle fibers attach to the centromeres, and the chromatids line up along the cell’s midline. The chromatids are then pulled apart. A nuclear membrane forms around the two exact sets of DNA and eventually cleaves.
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& B' Q! ~6 {2 v5 y接下来,纺锤丝附着于着丝粒,染色单体排列于细胞中线,随后染色单体被拉开。两套相同的DNA周围形成核膜并最终分开。
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: X  `/ J& e8 O% nThe process through which a cell divides the genetic information and instructions within its nucleus into two exact sets within independent nuclei is called mitosis.% \& s8 G. c6 A9 M* }( `! Q
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细胞核内的遗传信息和结构分离成两套的过程,称为有丝分裂。! a& V  }/ P$ P0 i: F
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02 Cells and Tissues 细胞和组织
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. h' f, p* z4 C/ Q#07 Red blood cells 血红细胞4 d1 g0 t" G% `# ~) i+ Q

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* }+ A2 i. [! u; S! F/ @" FThe bloodstream delivers oxygen to cells and removes carbon dioxide waste through a process called internal respiration., }  F+ V' e) d) K2 ]3 S

) H# N! x. V: l' l) i. U0 [血流将氧气提供给细胞,并清除废弃的二氧化碳的过程,称为内呼吸。
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% S5 l- A0 v* NIn the lungs, oxygen is absorbed into the erythrocytes in the bloodstream. These cells, commonly called red blood cells, contain gas-transporting molecules called hemoglobin. Oxygen binds to these molecules. The oxygenated blood then moves through the vasculature.
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在肺部,氧被吸收到血流中的红细胞。这些细胞通常被称为血红细胞,含有气体输送分子血红蛋白。氧气与这些分子结合后,含氧血通过脉管移动。" G# R' A! a+ _
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At the narrow capillaries within body tissues, red blood cells release oxygen, which then diffuses through the capillary wall into tissue.
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, v3 x; t! S/ A; W+ ?2 W在身体组织中的狭窄毛细血管内,血红细胞释放出氧气,通过毛细血管壁扩散进入组织;
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- ~( }: D; _( P, A' q! F2 yMeanwhile, the waste product carbon dioxide diffuses into the bloodstream, where it is carried inside red blood cells and in plasma. The deoxygenated blood travels through the vasculature and back to the lungs, where carbon dioxide is expelled from the body.
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8 ~3 a$ O0 |  t与此同时,废弃的二氧化碳扩散到血液中,由血浆中的红细胞携带。脱氧的血液通过脉管流回肺部,二氧化碳从体内排出。
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8 s) h. f, H% q9 m* N, v#08 Red blood cells production 血红细胞的产生( M+ p7 X! R: \6 p2 R3 M

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' _# C- h7 N: s. lRed blood cells, also called erythrocytes, make up 40-50% of blood volume and function to transport oxygen from the lungs to the cells of the body.
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血红细胞,也被称为红细胞,占血容量的40-50%,其功能是从肺部向身体细胞运送氧气。$ ^7 O  |1 m! \# o
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Red blood cells are produced inside the bones of the skeletal system, particularly in the vertebrae, sternum, ribs, and pectoral and pelvic girdles. Inside the red bone marrow of spongy bone, stem cells known as hemocytoblasts give rise to the different types of blood cells, including red blood cells.
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红细胞在骨骼系统的骨内产生,特别是椎骨、胸骨、肋骨和骨盆。在松质骨的红骨髓中,被称为造血干细胞的干细胞,产生不同类型的血细胞,包括红细胞。/ [/ z. z) y# b1 z

# N7 Q" }4 m3 u- q4 h( oDuring the development process, the hemocytoblast ejects its nucleus, allowing the cell to carry more oxygen to the tissues.
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6 J5 ~5 k' Z' ~) C, ~在发育过程中,造血干细胞丢弃细胞核,使细胞能携带更多的氧气到组织。
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Mature red blood cells enter the bloodstream via enlarged capillaries known as sinusoids.
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8 N8 G" o9 z# ~成熟红细胞通过增大的毛细血管血窦进入血流。
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02 Cells and Tissues 细胞和组织
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5 @5 p5 Z, O1 D( g! Z#09 Function of plasma 血浆的功能
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2 B6 K0 R8 Q- g3 a9 u5 o在线视频 https://v.youku.com/v_show/id_XNDI2ODU0NjA4MA==.html
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- p* I9 h2 y, ~5 D+ xThe largest component of blood is plasma, a yellowish liquid that is 90% water. Plasma carries suspended blood cells and other substances.
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血液的最大成分是血浆,一种浅黄色液体,90%是水。血浆携带悬浮的血细胞和其他物质。
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Nutrients that pass from the digestive system into the body are transported in the blood plasma. These nutrients include glucose, amino acids, vitamins, minerals, and fatty acids.
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从消化系统进入体内的营养物质由血浆输送。这些营养物质包括葡萄糖、氨基酸、维生素、矿物质和脂肪酸。2 k  `6 v7 O5 p0 f- Z

7 X/ u8 C# p) ?In the plasma of the blood that enters the kidneys are waste products from body tissue. The kidneys process blood by filtering waste products such as urea, uric acid, and creatinine out of the blood plasma and into the urinary system.
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进入肾脏的血浆是人体组织的废产物。肾脏将血液中的废产物过滤出血浆,排入尿路系统,如尿素、尿酸和肌酐。
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Plasma also transports electrolytes, components of the immune system, enzymes, and hormones, and it maintains homeostasis by releasing heat.0 I9 F1 J5 `/ }9 ]4 K
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血浆还转运电解质、免疫成分、酶和激素,并通过释放热量保持其动态平衡。
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02 Cells and Tissues 细胞和组织/ M0 r8 K; m; K3 p8 V1 X

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0 d8 m' M- V/ }#10 Platelets 血小板  G# _7 p5 B. Z6 l7 J: G0 D

: U7 l. Q& j1 o1 h+ `在线视频 http://v.youku.com/v_show/id_XNDI2ODYzNTg2MA==.html
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Cell fragments called platelets, or thrombocytes, make up about 2% of blood. Platelets stop blood loss from damaged vessels.
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被称为血小板的细胞碎片,约占血液的2%。血小板可阻止损坏的血管失血。
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5 R+ d! C' m2 S' c! B* ?4 mWhen a blood vessel tears, platelets at the site adhere to the wall of the vessel to close the tear. The shape of the platelets changes as they liberate the contents of their vesicles. The enables them to connect to one another. Platelets also release chemicals that activate the coagulation system to promote blood clotting.+ o/ Y# `4 B1 F3 k8 y
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当血管撕裂时,该处的血小板粘附到血管壁闭合裂口。随着内容物的释放,血小板的形状发生改变,这使它们能够彼此连接。血小板还可释放化学物质,激活凝血系统,促进血液凝固。
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) |0 n2 i2 e( j3 ^0 h! ?Blood proteins known as clotting factors form fibrin threads. Millions of platelets, together with the fibrin threads, form a platelet plug. If the tear is small enough, the plug can stop blood loss completely.$ f% u% e: V! D

' _4 R5 A8 Y/ o% ~0 n' D被称为凝血因子的血液蛋白形成血纤维蛋白。数以百万计的血小板,连同纤维蛋白,形成血小板栓,如果撕裂足够小,血小板栓可以完全阻止失血。
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