1. Transportation systems in animals and plants

2. 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?

3. 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

4. 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

5. 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

6. 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

7. 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.

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

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

10. 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

11. 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

12. 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.

13. 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.

14. 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.

15. 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

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

17. 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.

18. 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.

19. 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.