1. The Circulatory System

2. To survive what do cells need? Food and Oxygen A single celled animal like the amoeba, gets its food and oxygen by allowing materials to move across its cell membrane. In large animals most cells are not close to the surface of the body so they would not get supplies quick enough. So how does the food and oxygen get as far down as your Big toe?

3. Hence they need a transport System! Circulatory System Open- in insects Open- in insects Fluid which flows over the cells Closed- Humans (vertebrates) Closed- Humans (vertebrates) Kept in special tubes, from which nutrients can diffuse.

4. Circulatory System

6. Our Circulatory System Consists of: 1. Fluid (blood) 2. Pump (heart) 3. Tubes to carry the liquid (Arteries & Veins) Walls of the smallest blood vessels (capillaries) are thin enough to allow diffusion of: Gases,Nutrients, and Wastes between the blood & cells

7. Blood

8. Blood Blood is made up of 4 different substances: 1.Plasma – this is the liquid part of the blood and is about 90% water it carries around the Red & white blood cells, Platelets & Materials (e.g. CO2, O2, nutrients, waste and heat) 2.Red Blood Cells – these contain haemoglobin and carries oxygen around the body. 3.White Blood Cells – these cells fight infection. 4.Platelets – these cells are involved in clotting the blood to keep blood in & germs out

9. 3 Types of Blood Cell

10. Red Blood Cells Produced in red bone marrow Produced in red bone marrow 5 million per drop of blood 5 million per drop of blood Live for about 4 months Live for about 4 months Flexible biconcave disc (doughnut shaped) Flexible biconcave disc (doughnut shaped) Contains protein called haemoglobin, oxygen binds to the haem (iron) part and gets carried around the body Contains protein called haemoglobin, oxygen binds to the haem (iron) part and gets carried around the body Oxygenated blood is Red Oxygenated blood is Red Deoxygenated blood is darker red but looks blue under skin Deoxygenated blood is darker red but looks blue under skin

11. White Blood Cells Made in bone marrow. Made in bone marrow. 8,000 per drop of blood 8,000 per drop of blood Twice as large as red blood cell Twice as large as red blood cell Each has nucleus and lives for a few hours or a few days before being replaced. Each has nucleus and lives for a few hours or a few days before being replaced. Monocytes- eat germs Monocytes- eat germs Lymphocytes- produce antibodies that attack & neutralise germs Lymphocytes- produce antibodies that attack & neutralise germs

13. Antibodies These are proteins our white blood cells make which stick to the foreign chemical (antigen) and mark it for destruction by other defence cells. An Antigen is any chemical that triggers our body to make antibodies against it.

14. Platelets Tiny, round bits of cytoplasm with no nucleus. Tiny, round bits of cytoplasm with no nucleus. Made in bone marrow Made in bone marrow Live for a week Live for a week 300,000 per drop of blood 300,000 per drop of blood Haemophiliacs are unable to produce the clotting chemicals and may suffer excessive bleeding. Haemophiliacs are unable to produce the clotting chemicals and may suffer excessive bleeding. Thrombosis occurs if a clot blocks a blood vessel (in brain=stroke, heart=heart attack) Thrombosis occurs if a clot blocks a blood vessel (in brain=stroke, heart=heart attack)

15. Functions of Blood Transport food waste products & hormones Transport food waste products & hormones Transport heat, maintain constant temp. Transport heat, maintain constant temp. Transport oxygen Transport oxygen Defence against disease Defence against disease

16. Karl Landsteiner Discovered that most red blood cells contain a complex carbohydrate and protein chemical on the surface membrane. Red Blood Cell’s can be placed into blood groups depending on the types chemicals attached to their cell membrane.

17. Blood Type 4 major blood groups O = 55% of Irish population O = 55% of Irish population A = 31% A = 31% B = 11% B = 11% AB = 3% AB = 3% Important when giving blood transfusions to match the blood group Blood group O is the universal donor as it can be given to all the 4 blood groups

19. Rhesus Factor Apart from the ABO blood groups there are about 400 other blood types. Apart from the ABO blood groups there are about 400 other blood types. Best known of these is the Rhesus factor. Best known of these is the Rhesus factor. 85% of Irish people have rhesus chemical on surface of red blood cell. 15% don’t. 85% of Irish people have rhesus chemical on surface of red blood cell. 15% don’t. People who have it are Rhesus positive (Rh+) People who have it are Rhesus positive (Rh+) People without are Rhesus negative (Rh-) People without are Rhesus negative (Rh-)

21. Further detail of blood cells Red blood cells (erythrocytes) Red blood cells (erythrocytes) 1.Have no nucleus or mitochondria 2.Bioconcave shape give greater surface area. 3.Haemoglobin forms loose bond with oxygen, in the lungs haemoglobin combines with 4 oxygen molecules to form oxyhaemoglobin White blood cells (Leucocytes) White blood cells (Leucocytes) 1.2 main types Lymphocytes and monocytes 2.Lymphocytes - Stored in lymphatic system (spleen, lymph nodes, tonsils, adenoids & thymus gland), have large nucleus and make antibodies. (25% of white cells) 3.Monocytes – called marcophages, digest bacteria, have kidney shaped nucleus & live for 6-9 days (5% of white cells)