Transportation systems in animals and plants

Health and Social Education Unit 4 Unit title: Human body in war against diseases Area of interaction: Health and Social Education MYP unit question: How does my body defend itself against the HIV virus?

In insects, other arthropods, and most molluscs Fig. 42-3 In insects, other arthropods, and most molluscs Heart Heart Blood Hemolymph in sinuses surrounding organs Interstitial fluid Small branch vessels In each organ Pores Dorsal vessel (main heart) Tubular heart Auxiliary hearts Ventral vessels (a) An open circulatory system (b) A closed circulatory system

Gill capillaries Single Circulation Bony fishes, rays, and sharks have single circulation with a two-chambered heart Artery Gill circulation Ventricle Heart Atrium Systemic circulation Vein Systemic capillaries

Double Circulation Amphibian, reptiles, and mammals have double circulation Oxygen-poor and oxygen-rich blood are pumped separately from the right and left sides of the heart Amphibians Reptiles (Except Birds) Mammals and Birds Lung and skin capillaries Lung capillaries Lung capillaries Right systemic aorta Pulmocutaneous circuit Pulmonary circuit Pulmonary circuit Atrium (A) Atrium (A) A A A A Ventricle (V) V V Left systemic aorta V V Right Left Right Left Right Left Systemic circuit Systemic circuit Systemic capillaries Systemic capillaries Systemic capillaries Fig. 42-5

What is the circulatory system? A network of 100,000 km of blood vessels It transports: 1. Nutrients and oxygen for the cells 2. Carbon dioxide and waste products removed from cells 3. Transports hormones, antibodies, heat Plays an important role repairing tissues and protecting the body from infection

Our circulatory system is a double circulatory system. This means it has two parts . Lungs Body cells the right side of the system deals with deoxygenated blood. the left side of the system deals with oxygenated blood.

How does this system work? pulmonary vein lungs pulmonary artery head & arms aorta Vena cava Right Left liver digestive system kidneys legs Circulatory System

HEART STRUCTURE Its walls are composed of cardiac muscle. Contraction of cardiac muscle is MYOGENIC. Coronary arteries supply heart muscle with oxygen and nutrients.

The Heart This is a vein. It brings blood from the body to the heart. These are arteries. They carry blood away from the heart. 2 atria Coronary arteries, the hearts own blood supply 2 ventricles The heart has four chambers

The Heart Artery to Lungs Artery to Head and Body Vein from Head and Body Vein from Lungs Right Atrium Left Atrium valve valve Left Ventricle Right Ventricle

STEP ONE blood from the body blood from the lungs The heart beat begins when the heart muscles relax and blood flows into the atria.

How does the Heart work? the valves open to allow blood STEP TWO The atria then contract and the valves open to allow blood into the ventricles.

The cycle then repeats itself. How does the Heart work? STEP THREE The valves close to stop blood flowing backwards. The ventricles contract forcing the blood to leave the heart. At the same time, the atria are relaxing and once again filling with blood. The cycle then repeats itself.

2 Atrial systole; ventricular diastole Semilunar valves closed 0.1 sec Fig. 42-8 2 Atrial systole; ventricular diastole Semilunar valves closed 0.1 sec Semilunar valves open AV valves open 0.4 sec 0.3 sec Figure 42.8 The cardiac cycle 1 Atrial and ventricular diastole AV valves closed 3 Ventricular systole; atrial diastole

Blood from the heart gets around the body through blood vessels There are 3 types of blood vessels a. ARTERY b. VEIN c. CAPILLARY

The ARTERY Arteries carry blood away from the heart. the elastic fibres allow the artery to stretch under pressure thick muscle and elastic fibres The thick muscle can contract to push the blood along.

Veins carry blood towards from the heart. The VEIN Veins carry blood towards from the heart. veins have valves which act to stop the blood from going in the wrong direction. thin muscle and elastic fibres body muscles surround the veins so that when they contract to move the body, they also squeeze the veins and push the blood along the vessel.

The CAPILLARY Capillaries link Arteries with Veins they exchange materials between the blood and other body cells. the wall of a capillary is only one cell thick The exchange of materials between the blood and the body can only occur through capillaries.