LESSON 3The Circulatory System

人体血液循环系统

The circulatory system:Comprises of the heart and the network blood vessels.Main Functions:1. Supply oxygen to all parts of the body.2. Distribute heat3. Distribute （分配） the absorbed nutrients.4. Collect and carry waste materials to the organs

concerned with their discharge （排遗物）

Position and structure of the heart Position:1. lies in the chest cavity between two lungs.Structure :2. muscular organ, acts as double pump.3. Divided into left and right side(right : upper collecting , left : lowers pumping)

The Factor which increase the heartbeat1. Exercise2. Fever3. Emotional Stress4. The consumption of alcohol5. Severe bleeding

The Average heartbeat Adult 60~80/min children 80~100/minInfant 100~120/min

The structure and function of blood vessels and Blood

Arteries （动脉） * 有氧• Strongest blood vessels• Carry blood away from heart.Capillaries （微血管）• Very small blood vessels• Exchange of fluids and gases to and from tissues of body.Veins （静脉） * 无氧• Very small vessels.• Returning blood to right chamber of heart.

  Artery 动脉 Capillaries 微血管

Veins 静脉血管的大小 小 最小 大血管的厚度 厚 最薄 薄血液 充氧血 充氧和缺氧血 缺氧血

血流的流速 快 最慢 慢血压 高 低 中功能 将有氧血输

送至全身交换体内物质 将缺氧血带

回心脏

Blood• Red , white blood cell and platelets.• Blood carry nutrient from digestive organs and

carry waste products to excretory 排出 organs.

Red Blood Cell carry oxygen

White Blood Cell remove germs and dead cells

Platelets help blood clot

Carotid Radial

FemoralBrachial

The pulseCarotid 颈动脉Brachial 上臂脉Radial 手腕Femoral 大腿内侧

Practical

• 量自己的脉搏