1. Blood
1.1. Corpuscles
1.1.1. Red Blood Cells: carry O2
1.1.2. White Blood Cells: fight infection
1.1.3. Platelets: clotting
1.2. Plasma
1.2.1. Transport of food, CO2 and metabolic waste
2. Blood Pressure
2.1. What is it?
2.1.1. The force that blood exerts against the walls of a vessel
2.1.2. Pressure during contraction of cardiac muscles is called systolic and pressure during relaxation of cardiac muscles is called diastolic
2.2. How is it measured?
2.2.1. It is measured by an instrument called a sphygmomanometer
2.3. Normal range
2.3.1. 120,80 mm of Hg is normal where 120 refers to systolic pressure and 80 refers to diastolic pressure
3. Platelets and Lymph
3.1. Why are platelets necessary?
3.1.1. They plug leaks and tears in vessels by helping to clot the blood at the points of rupture
3.1.2. If they were not present, every small tear in a vessel or in the skin would lead to excessive loos of blood and blood pressure
3.1.3. This would mean higher risk of infection and reduced efficiency in pumping blood
3.2. How is lymph useful?
3.2.1. Also known as tissue fluid or interstitial fluid when outside the lymph vessels
3.2.2. It is similar to plasma but is colourless and contains less protein; it also has different functions
3.2.3. It carries excess fat and interstitial fluid from the blood capillary bed
4. Components
4.1. A pump (heart)
4.2. Tubes to push blood (blood vessels)
4.3. System of repairs (platelets)
5. Heart
5.1. Blood flow
5.1.1. Deoxygenated blood from body enters right atrium then moves to right ventricle
5.1.2. The blood moves to lungs through pulmonary artery and exchange of gases occurs
5.1.3. The now oxygenated blood enters the left atrium through pulmonary veins and moves to left ventricle
5.1.4. It then moves through the arteries to all parts of body
5.2. Double circulation
5.2.1. Commonly observed in birds and mammals
5.2.2. 1st circulation is between heart and body and is called systemic while 2nd circulation is between heart and lungs and is called pulmonary
5.2.3. Separation of left and right side of heart is useful to keep oxygenated and deoxygenated blood from mixing
5.2.4. This creates a very efficient supply of oxygen and is useful in high energy, warm blooded animals
6. Blood Vessels
6.1. Arteries
6.1.1. Carry oxygenated blood to body (except pulmonary artery)
6.1.2. Thick and elastic walls
6.1.3. Valves not present (except pulmonary artery)
6.2. Veins
6.2.1. Carry deoxygenated blood from body (except pulmonary veins)
6.2.2. Thinner, more rigid walls
6.2.3. Valves present (except pulmonary veins)
6.3. Capillaries
6.3.1. Connect the arteries and veins at body tissues
6.3.2. Exchange of materials between blood vessels and tissue cells occurs
6.3.3. Only one cell thick