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 cellsLungsRight 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

AortaPulmonary 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

RadiusPelvis

Tarsals

Femur

Phalanges

Metacarpals

Fibula

Tibia

Knee cap

Skull

MetatarsalsPhalanges

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

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.

CONTRACTRELAX

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.B

ICE

PS

TR

ICE

PS

Biceps contract.

Triceps relax.

Arm raised. TR

ICE

PS

BIC

EP

S

Biceps relax.

Triceps contract.

Arm lowered.

LOAD EFFORT

PIVOT

• Muscles and Bones work like LEVERS.

1 Kg

BIC

EP

S

TENDONS join MUSCLE to BONE.

LIGAMENTS join BONE to BONE.

BO

NE

BO

NE

LIGAMENTS

BONE

TENDONS MU

SC

LE