Learners should have a fair understanding open and closed circulatory system. Also learners should have a fair understanding of arteries, veins and capillaries. There are pictures which will engage learners interests

1. LIFE SCIENCE
Transport system in animals

2. CIRCULATORY SYSTEMS IN ANIMALS
 Many invertebrates do not have a circulatory
system at all.
 Their cells are close enough to their environment
for oxygen, other gases, nutrients, and waste
products to simply diffuse out of and into their
cells.
 E.G. Hydra

3. PICTURE OF A HYDRA

4. CIRCULATORY SYSTEMS IN ANIMALS
• In animals with multiple layers of cells, their cells
are too far from the external environment for simple
osmosis and diffusion.
• In higher animals, there are two primary types of
circulatory systems -- open and closed.

6. CIRCULATORY SYSTEMS IN ANIMALS
OPEN

7. • OPEN-
• The circulatory fluid – Hemolymph (is the same as
interstitial tissue fluid)
• The heart pumps hemolymph through vessels into sinuses
(open fluid-filled spaces)
• Certain substances are exchanged between the hemolymph
and the cells.
• Hemolymph returns to the heart through pores.
• The heart is a tubular structure.

8. CLOSED CIRCULATORY SYSTEM

9. CIRCULATORY SYSTEM IN ANIMALS
• CLOSED-
• Circulate blood entirely within vessels.
• So the blood is distinct from the interstitial
fluid.
• Chemical exchange occurs between the
blood and interstitial fluid as well as
between interstitial fluid and body cells.

10. DOUBLE CIRCULATION

11. DOUBLE CIRCULATION
• The circulatory systems with two distinct circuits.
• The pumps of the two circuits serve different tissues but
are combined into a single organ, the heart.
• The two circuits are called:
• 1. Pulmonary circuit
• 2. Systemic circuit

12. DOUBLE CIRCULATION
• 1. Pulmonary circuit
• The heart pumps deoxygenated blood to the lungs and oxygenated blood
back to the heart.
• 2. Systemic circuit
• The heart pumps oxygenated blood to the body cells and the
deoxygenated blood back to the heart

13. DIFFERENT BLOOD VESSELS:
ARTERIES, VEINS AND CAPILLARIES

14. FUNCTION OF CAPILLARIES

15. CAPILLARIES
• Capillaries: Connect arteries and veins – are structurally suited to facilitate
the exchange of substances
between the blood in the
capillaries and the interstitial
tissue fluid

16. FUNCTIONS OF ARTERIES
• Arteries: transports oxygenated blood except for the pulmonary artery.
Main artery is called the Aorta – pumping oxygenated blood from heart to
rest of body.
• Other arteries:
• Renal artery (kidney)
• Hepatic artery (liver)

17. FUNCTIONS OF VEINS
• Veins : transports deoxygenated blood except for the pulmonary vein. Main
vein is called the vena cava – pumping deoxygenated blood towards the
heart from the rest of the body.
• Other veins:
• Renal vein (kidney)
• Hepatic vein (liver)