S2 Biology Madras College

When you exercise, your heart beats faster and you breathe quicker and more deeply. This provides your muscles with more oxygen and sugar from your blood.

The Oxygen and Sugar are needed by your muscle cells for RESPIRATION.

The main jobs of the blood are: –Transport Oxygen and Food to your body cells. –Removal of Carbon Dioxide and Waste Chemicals from your cells. –Protection from Disease.

Plasma – Liquid part of blood. Contains cells and dissolved substances. Red Blood Cell – Contain Haemoglobin and carry Oxygen. Platelets – Help blood to clot. White Blood Cell – Helps destroy infecting germs.

There are 4 Blood Groups A,B,AB and O. People from different parts of the world may have different blood groups to us. Global distribution of Blood Groups

The heart is made of muscle and pumps blood around your body. There are 2 chambers on each side of the heart (4 in total). Oxygenated Blood Deoxygenated Blood Body cellsLungs Right Atrium Right Ventricle Left Atrium Left Ventricle Aorta Vena Cava Pulmonary Vein Pulmonary Artery Oxygen enters cells. Carbon Dioxide enters blood. Carbon Dioxide enters lungs. Oxygen enters blood

Semi-Lunar Valves Atrioventricular Valve Right Atrium Left Atrium Right Ventricle Left Ventricle Aorta Pulmonary Artery Vena Cava Pulmonary Vein Cardiac Muscle – Left Ventricle more muscular. Pumps blood to whole body.

Right Atrium Left Atrium Right Ventricle Left Ventricle Oxygenated blood Deoxygenated Blood Atria fill with blood from Veins. Atria contract and pump blood down into Ventricles Ventricles contract and pump blood into Arteries

You can listen to your heart beat with a stethoscope.

There are 3 types of blood vessel. These are Arteries, Veins and Capillaries. Thick muscular wall. Carry blood AWAY from heart. Blood under HIGH PRESSURE. Thin walls. Carry blood TO the heart. Blood under LOW PRESSURE. Have VALVES. Walls ONE CELL thick. Substances exchanged between BLOOD and CELLS. Deliver blood to ALL BODY CELLS.

The Coronary Arteries deliver blood to your heart muscle. They can sometimes become blocked by fatty substances (eg. Cholesterol). The blockage is sometimes called a Plaque. They can cause heart attacks. A healthy diet and regular exercise can reduce the risk of these plaques appearing.

Causes of heart attacks are written inside the heart. Good advice is written outside. Remember:

Carpals Sternum Clavicle Jawbone Backbone Rib Humerus Ulna Radius Pelvis Tarsals Femur Phalanges Metacarpals Fibula Tibia Knee cap Skull Metatarsals Phalanges The human Skeleton does 3 main jobs: 1.Provides support. 2.Provides a place for muscles to attach and so allows movement. 3.Protects vital inner organs.

Joints allow our bodies to move. They are found where bones meet. There are several types of joint in the body. The two we learn about are: 1.HINGE JOINT. 2.BALL AND SOCKET JOINT.

Hinge joints (eg. Finger, knee, elbow) only move in 1 direction

These joints (eg. Hip, Shoulder joint) can move in many directions

Bone Cartilage – allows smooth movement of bones and acts as a shock absorber. Synovial Membrane – produces synovial fluid. Ligament – holds the joint together. Synovial Fluid – lubricates the synovial joint.

Your muscles are attached to your bones by TENDONS. Your muscles provide the force to move your bones at the joints. This allows your body to move.

Muscles can only.. CONTRACT – Become shorter. RELAX – Become longer. CONTRACT RELAX

Muscles work in pairs. Eg. BICEPS and TRICEPS in the upper arm. When one contracts, the other relaxes. Muscles which work this way are ANTAGONISTIC. BICEPS TRICEPS Biceps contract. Triceps relax. Arm raised. TRICEPS BICEPS Biceps relax. Triceps contract. Arm lowered.

LOAD EFFORT PIVOT Muscles and Bones work like LEVERS. 1 Kg BICEPS

TENDONS join MUSCLE to BONE. LIGAMENTS join BONE to BONE. BONE LIGAMENTS BONE TENDONS MUSCLE