Hard skeleton on the outside of the body, made of chitin.

Examples - insects.

Hard skeleton inside of the body, made of cartilage or bone.

Examples - humans, fish, frogs, birds.

> Softer and more flexible than bone.

> Absorbs shock.

> Helps bones to slide over each other in joints.

> Forms framework for body.

> Grows with the body.

> Allows muscles to be easily attached.

> Has many joints to give flexibility.

> Is made from living tissue such as bone cells, cartilage and blood cells.

> Hollow - strong, lighter, less likely to break than if solid.

> Has a main shaft - inside is bone marrow which contains blood vessels.

> Each end called the head - covered with cartilage.

> Bones begin made entirely from cartilage.

> As person ages, calcium salts and phosphates are deposited in the bones - making them hard.

 > No cartilage between head and main shaft = stopped growing.

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Joint where the bone cannot move.

e.g. skull.

Connects bones to each other.

Prevents dislocations.

> A condition in which the bones become brittle.

> Lack of calcium and phosphorus.

> Any fall can easily break bones.

Joints that contain synovial fluid.

Synovial membrane keeps synovial fluid within the joint, preventing any leakage.

Cartilage on the end of bones - prevents shock.

A pair of muscles that bend or straighten the arm (biceps and triceps).

Forearm is raised = biceps contract, triceps relax.

Forearm is lowered = biceps relax, triceps contract.

Arm movement is an example of a lever.

Elbow acts as a fulcrum (pivot).

As the bicep muscles contract - exerts an upward force on the arm bones.

> Blood does not travel in blood vessels.

> Flows slowly round the body cavity.

> Blood does not carry oxygen.

> e.g. insects.

> Blood flows in blood vessels - arteries, capillaries and veins.

> Blood carries oxygen and nutrients all around the body.

> e.g. humans.

> Closed circulatory system in fish.

> Blood picks up oxygen from the gills.

> Blood goes around a single circuit from the heart.

> The fish heart has two chambers - one to receive blood, one to push it round the body.

> Closed circulatory system in humans.

> Blood goes round two circuits - from the heart to the lungs, from the heart to the rest of the body.

> Human heart has four chambers - two to receive blood, two to push it to the lungs/body.

> Blood flows from arteries to arterioles, capillaries and veins - pressure decreases.

> High blood pressure in arteries is cause by the heart muscles contracting to force blood around the body.

> A hormone.

> Affects the heart rate.

> Prepares the body for 'flight or fight'.

> Increasing heart rate = more energy supplied to muscles.

> Two chambers - one to receive blood, one to pump it out.

> Blood pressure is not high - has to flow through a lot of capillaries in the gills before reaching the muscles.

> Four chambers, blood travels through two circuits.

> Blood pressure in the circuit around the body is maintained at a high level - much quicker transport of materials.

> Right side of the heart - deoxygenated blood.

> Left side of the heart - oxygenated blood.

> Valves prevent backward flow of blood.

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> A. Heart relaxes, blood enters both atria.

> B. Atria contract at same time - forces blood into both ventricles.

> C. Ventricles contract from bottom upwards - forces blood into pulmonary artery or aorta.

> Special type of muscle that contracts and relaxes without tiring.

> Uses a lot of energy.

> Oxygen and food (including glucose) is carried in the blood.

> Glucose and oxygen - needed for respiration.

> Exercise = heart rate increases.

> Increased heart rate = more blood containing oxygen and food to muscles.

> Heart rate controlled automatically.

> Small group of cells (pacemaker) - produces a small electric current, stimulates heart muscle = contracts.

> Used to record the nerve impulses in a heart.

> Shows the changes in electrical impulses in the heart muscles.

> Electrodes attached to the patient's chest sense the changes.

> Problems with the parts of the heart can be identified.

> Uses ultrasound to produce pictures of the working heart.

> Video of an echocardiogram shows if any parts of the heart e.g. valves, are not working properly.

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> 'P' waves - impulses from SAN.

> 'R' waves - impulses from ventricles.

> 'T' waves - as ventricles contract.

> 2nd century.

> First doctor to realise the importance of the pulse in medicine.

> However, he believed that the liver made blood, which was then pumped around the body by the heart in a backwards and forwards movement.

> His theory on blood circulation was published in the 17th century.

> Explained the heart had four chambers.

> Blood travelled through arteries and veins.

> Believed that they were joined by tiny blood vessels, microscopes were not good enough for him to see capillaries.

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> Sino-atrial nodes (SAN) generates electrical impulses.

> Impulses spread across the atria - causes both atria to contract.

> Impulses reach the atrio-ventricular node (AVN) - more impulses spread across the ventricles, causing them to contract.

> Impulses from the vagus and sympathetic nerve - modify the action of the pacemaker cells.

> Plasma - liquid that contains the blood cells.

> Red blood cells and white blood cells, there are more red than white.

> Platelets - small fragments of cells.

> Irregular heart beat - when the heart doesn't beat properly.

> Hole in the heart - caused by a hole in the heart wall between its left and right sides.

> Damaged or weak heart valves between the atria and ventricles.

> Coronary heart disease - caused by a blockage in the coronary artery, can lead to a heart attack.

> Provides a constant supply of food and oxygen to the heart.

> Seen on the outside of the heart.

> Heart develops before birth - division between atria and ventricles is not complete.

> Baby's blood is oxygenated by mother's blood in placenta, baby's lungs are not developed enough - hole allows blood to bypass lungs.

> Sometime a hole can be left at birth.

> Allows oxygenated blood and deoxygenated blood from the left and right sides of the heart to mix.

> Blood leaving the aorta carries a lower amount of oxygen.

> Open-heart surgery can repair the heart wall.

> Coronary artery supplies the heart muscle with oxygen and food.

> Artery is blocked = heart muscles are not supplied with energy.

> This can result in a heart attack.

> During surgery, the artery can be by-passed using veins transplanted from other parts of the body.

> The new veins take blood from the aorta, avoiding the blocked coronary artery.

> Reduce the work done by heart muscles.

> Help to pump blood.

> Allows the heart muscles to recover, then the device can be removed.

> Valves in the heart prevent the backflow of blood.

> Weak or damaged valves affect the blood circulation - slowing down the supply of food and oxygen, affecting heat distribution.

> Can be replaced by artificial valves in open-heart surgery.

> Added to the collected blood to stop it from clotting as it is being stored.

> Blood is labelled and stored in a temperature-controlled environment.

> New blood is checked to ensure it does not react with the patient's blood.

> Blood is slowly introduced into the patient via a vein.

> Important that no air bubbles get into the blood - can cause a blockage.

> Blood clots in order to seal wounds - prevents entry of pathogens, reduces blood loss.

> Alcohol slows down the clotting of blood.

> Vitamin K is important for blood to clot.

> Drugs such as warfarin, heparin and aspirin prevent clotting.

> Clots could - block coronary artery = heart attack, block blood vessels in brain = stroke.

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> Skin is cut - platelets are exposed to air.

> Thromboplastin is created.

> Prothrombin from the liver.

> Calcium ion are added to make thrombin.

> Fibrinogen in plasma is added to thrombin.

> Fibrin clot.

> Agglutination was solved by Karl Landsteiner in 1901 - discovered four main blood groups, depended on the presence/absence of agglutinins = two proteins (Antigen A/Antigen B) on the surface of red blood cells and two antibodies (Anti-A/Anti-B) in blood plasma.

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