你一定需要的IB生物考试考点介绍——Transport全梳理-唯寻国际教育

很多学员觉得IB生物考试的重点就和大海里的水一样难以数记。那么今天我们先从Transport这个知识点讲起，希望能帮助大家找到IB生物考试复习方向。距离明年5月的IB考试还有半年的时间，每天复习一点点，再多考点也不用害怕啦。

你一定需要的IB生物考试考点介绍——Transport全梳理内容图片_1

IB生物考试简介

一共考查3张试卷。试卷1为选择题卷，SL为30道选择题，HL是40道选择题。SL考试时间为45分钟，占总成绩的20%；HL考试时间为60分钟，占总成绩20%。考试过程中不允许使用计算器。

试卷2考查的是简答题和 extended-response问题。SL考试时间为1小时15分钟，占总成绩32%；HL考试时间为2小时15分钟，占总成绩36%。

试卷3分为两部分， Section A考的是数据分析题和两到三道简答题， Section B考的是简答题和 extended-response问题。SL考试时间为1个小时，占总成绩的24%；HL考试时间为1个小时15分钟，占总成绩的20%。

IB生物考试重点精讲

Transport

Blood system:

The main transportsystem. (circulatory system)

血液循环系统

Include bloodvessels and heart.

血管，心脏

Mechanism:

Beginning at lungs,blood flows from the left- hand side ofthe body toward the whole body. Oxygen diffuses from the blood into the cells,deoxygenated blood returns to the right-hand side of the body and then flows towardsthe lung. This is called a double circulatory system. Because bloodtravels through the heart twice in one full journey.

脱氧的血液，双循环系统。

充氧的血液从肺部出发，首先流经左半部分心脏（左心室和左心房），之后流经全身，血液中的氧气扩散入细胞中。脱氧的血液流经右半部分心脏，最终流入肺部

Oxygenation process:

The blood comesthrough the lung picks up oxygen from thecapillaries surrounding the alveoli and becomes oxygenated.

毛细血管，肺泡，充氧的

Deoxygenation process:

Some of the oxygen inthe blood is taken by body cells which need oxygen for respiration, When thishappens, blood becomes deoxygenated, and is brought back to the lungs foranother journey.

人体细胞会为呼吸作用而吸收氧气，进而使血液脱氧

Heart:

he function of theheart is to pump blood around the body, it is made of a special muscle called cardiacmusclewhich contracts and relaxes regularly throughout one’s life.

心肌

The heart is dividedinto four chambers, the two upper chambers areatria (atrium forsingular), the lower two are ventricles. A septum separates theleft-hand side and the right-hand side of the heart.

心房，心室，隔膜（心房在上，心室在下）

Both of the atria receive blood, the left one receives blood from thepulmonaryveins, which comes from the lungs. The right one receives blood from therest of the body,arriving through the venae cavae(vena cava forsingular)

肺静脉，腔静脉

充氧血从肺静脉流入左心房，脱氧血从腔静脉流入右心房

From the atria, the blood flows into the ventricles. The ventricles thenpump it out of the heart by contracting the muscle in their walls.

The blood in the leftventricle is pumped into the aorta, which takes the blood around thebody. The right ventricle pumps blood into thepulmonary artery, whichtakes it to the lungs.

主动脉，肺动脉

左心室将血液通过主动脉输送到全身，右心室将血液( 脱氧的)通过肺动脉输送到肺部

Differences between the function of ventriclesand atria:

Atria: Receive bloodfrom either the lungs or the body, and supply it to the ventricles.

Ventricle: Pump bloodout of the heart and all around the body.

心房接收血液，输送至心室。心室将血液通过挤压输送（泵）至全身\肺。

Features:

Ventricles have much thicker, more muscular walls than atria.

The left ventricle hasespecially thick wall because it has to pump blood all around the body whilethe right ventricle only pumps blood toward the lung which is very close to theheart.

The blood flowing intothe lungs in the pulmonary artery has a much lower pressure than the blood inthe aorta.

心室一般有更厚的肌肉，尤其是左心室。因为右心室只需将血液输送至离心脏很近的肺部而左心室则需要将血液输送至全身。

Coronaryarteries

Blood veins outsidethe heart is called coronary arteries. These vessels supply blood to theheart muscles.

he muscles of theheart are so thick that the nutrients and oxygen in the blood inside the heartwould not be able to diffuse to all the muscles quickly enough. The heartmuscle needs a constant supply of nutrients and oxygen, so that it can keepcontracting and relaxing. The coronary arteriessupply this.

冠状动脉

冠状动脉在心脏的外侧，它们为心肌提供血液。因为心肌超乎寻常的厚度，氧气和营养不能在其中足够快速地扩散，因此心肌需要一个持续的供给源来保持它的日常收缩与放松。

Diseases related to the coronary arteries:

If coronary arteriesare blocked—for example,by a blood clot—the cardiac muscles run short ofoxygen. They cannot respire, so they cannot obtain energy to allow them tocontract and the heart will stop beating. This is called a heart attack or cardiac arrest.

血凝块，心力衰竭，心脏停跳

如果冠状动脉被堵塞，例如血液凝块产生，心肌会因为缺氧而无法继续工作，最终导致心脏停跳。

Several factors of the disease:

Smoking cigarettes

Several componentsof the cigarette including nicotine cause damage to the circulatorysystem.

Diet

Diet high in salt,saturated fats (fats from animals) or cholesterolincreases the chanceof getting heart diseases.

Obesity

Increase risk ofgetting heart diseases

Stress

Long term stress canincrease the chance of developing heart diseases.

Genes

Some people havegenes that make it more likely they will get coronary heart diseases.

尼古丁，胆固醇

Cure:

A type of drug called statin can reduce the risk of the coronary arteries being blocked.

他汀

Systole and diastole:

When the cardiacmuscles contract, the heart becomes smaller, squeezing blood out. This iscalled systole.

When they relax, theheart becomes bigger, allowing blood to flow into the atria and ventricles.This is called diastole.

收缩期，舒张期（顾名思义）

Pacemaker:

The rate at which theheart beats is controlled by a patch of muscle in the atrium called pacemaker.It sends electrical signals through the walls of the heart at regularintervals, which make the muscle contract. It’s rate (rate of the heart beat)changes according to the needs of the body. For example, when one is doingexercise, when extra oxygen is needed by the muscle, the brain will sendmessages along the nerves to the pacemaker, to make the heart beat faster.

心率是由心脏起搏点（窦房结）来控制的，它会在一个恒定的间隔透过心肌发送电讯号，命令其收缩。心率会随着人体的需求而改变，例如在运动时，人体需要的氧气量变大，大脑就会通过神经向起搏点发送讯号，从而加速心脏的跳动。

Artificial pacemaker can be places in one person’s heart to keep his orher heart beating. It produces an electrical impulse at a regular rate of aboutone pulse per second.

有时人工制作的起搏器也会被放置入人的心脏来使得心脏正常跳动。它会产生约一秒一次的电子脉冲来刺激心脏跳动。

怎么样，Transport这块的思路大家都理清了吗？如果都掌握了，就可以去攻克下一个IB生物考试重点啦，加油，IB人！

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你一定需要的IB生物考试考点介绍——Transport全梳理内容图片_2