1. Growth and Development of different organisms
National 5 Biology
Key Area 6:
The Need for Transport
(b) Animal Transport Systems
National 4 Biology
Key Area 4
Growth and Development of different organisms

2. By the end of this lesson you will be able to ....
Describe the function of the circulatory system in animals
Describe (and be able to identify in a diagram) the features of the heart and associated vessels.
To include right and left atria, left and right ventricles, valves, aorta, vena cava, pulmonary artery, pulmonary vein and coronary artery.
Describe the pathway of oxygenated blood through the heart, lungs and body.
Describe the pathway of deoxygenated blood through the heart, lungs and body.

3. The Circulatory System
The circulatory system consists of the heart (a muscular pump) and the blood vessels (a system of tubes), which carry essential materials (in the blood) to all parts of the body.

4. Coronary artery supplies the heart muscle with oxygen and glucose.
External Structures
Aorta (biggest artery in the body)
Vena Cava (biggest vein in body)
Coronary artery
supplies the heart
muscle with
oxygen and glucose.

5. Internal Structures: Chambers
The heart has 4
chambers.
Right Atrium
(pl. atria)
Left Atrium
(pl. atria)
Right Ventricle
Left Ventricle
The left ventricle wall is thicker than the right ventricle wall because it pumps blood all around the body. The right ventricle only pumps to the lungs.

6. The heart has ___ valves.
Internal Structures: Valves
The heart has ___ valves.
Valves help to ________ THE _________ OF BLOOD.
They make sure the blood flows in ____ __________. 4
one direction
BACKFLOW
PREVENT
Valves (between ventricles and vessels)
Valves (between atria and ventricles)

7. Veins carry _____________ blood ___________ the heart.
Internal Structures: Blood Vessels
Veins carry _____________ blood ___________ the heart.
Arteries pump ___________ blood _________ from the heart.
deoxygenated
away
towards
oxygenated
Aorta
Pulmonary Artery
Pulmonary vein (superior and inferior)
Vena Cava (superior and inferior)
Right side – deoxygenated blood
(low O2, high CO2)
Left side – oxygenated blood
(high O2, low CO2)

8. Blood flow through the Heart

9. Blood flow through the Heart
PULMONARY ARTERY (TO LUNGS)
AORTA (TO THE BODY)
PULMONARY VEIN (from lungs)
VENA CAVA (from the body)
Deoxygenated blood
Oxygenated blood
The heart has 4 chambers!
Cardiac muscle

10. The “Double Circulatory” System
2. The blood receives oxygen and is pumped back to the _____ _____ of the heart in the _____ _____
1. Deoxygenated blood is pumped from the heart to the lungs in the _______ _______
4. The oxygen leaves the blood and enters body cells. Carbon dioxide enters the blood and it then goes back to the heart in the _______
3. The oxygenated blood is then pumped to the rest of the body in the _______