Body Systems

By Helena Phimister

Skeletal System

Prawn Skeletal System

The prawn unlike humans has an exoskeleton made of Chitin (sugar-like), which is where the skeleton is on the outside. Although it may sound disgusting it has its benefits. The skeleton acts like a fragile shell, protecting the insides and keeping them safe, and it is bendy which allows the prawn to swim and have freedom. The disadvantages are; when it sheds the skin for a new one it means that the prawn is completely vulnerable. When the prawn sheds it's skin the prawn grows in size and then another skin is grown. Other animals that have the same skeletal system are; Yabbies, Lobsters and Crayfish.

Worm Skeletal System

The worms skeletal system is called a hydro-skeleton which is; a layer of skin protecting the fluid inside. The worm is able to move by the fluid and muscles moving it stretches and contracts. Other animals that have this skeletal system are; starfish, sea urchins and jellyfish.

Cuttlefish Skeletal System

The skeletal system of a cuttlefish is internal, unlike the worm and prawn. The cuttlebone is made of calcium carbonate which helps the cuttlefish to float. The cuttlebone is light, fragile and a bit crumbly, that is why it is used to make powder for polishing and fed to pet birds to help their diet.

Human Skeletal System

Humans skeletal system is internal, like the cuttlefish, but it is called an endoskeleton and it grows with our body. Our skeletal system is made up of bones which support us and keep us standing upright. Bone marrow is inside of all our bones its role is to produce red blood cells and lymphocytes that help our immune system. Bones are living tissues, the contain living cells that are surrounded by calcium phosphate, which makes the bones hard. they also contain collagen, which provides elasticity, blood vessels that supply the bone with the nutrients it requires. As they are living, they can repair themselves, like when the break. Other animals that have this skeletal system are; dogs, cats, bears, tigers, horses, kangaroos...

Muscular Systems

Chicken Wing

Corresponding to humans the structure of a chicken wing is; the upper wing is like the upper arm, the lower wing is like the lower arm and the wing tip is like the hand, so technically a chicken wing is an arm for humans.

When you tug on the extensor (for humans it is a triceps) the chicken wing extends and if you tug on the flexor (for humans it is bicep) the chicken wing flexes.

The tissue that connects the muscle to the bone is called tendons and it is; white, stringy and long. The tissue that connects the bones to the joints are called the ligaments. the type of joint that is the elbow would be a hinge joint. The shoulder joint (connects the wing to the shoulder) is a ball and socket joint. The cartilage lines in the joint are; white, shiny, hard and slippery.

The bones that are found in the chicken wing are; the humorous, ulna, radius, metacarpals and carpels.

Heart and Circulatory System

The human heart is around the size of your fist, it sits in the middle of your chest, tilted slightly to the left and protected by your ribcage. It is a pinky-red colour as of the blood circulation and it feels slimy, squishy and a bit rough.

The coronary arteries is like a thin tunnel connected to the heart, it is thin and a bit squishy. If this artery was blocked by a clot it would prevent nutrients and oxygen from travelling to the heart. if this happens the heart could fail, resulting in death or a stroke.

The left and right side of the heart is in accordance to the left and right side of your body. The left side of your body is the left side of your heart.

Deoxygenated blood leaves the right ventricle in an artery and travels to the lungs. Here, the blood collects oxygen, so it is now oxygenated. The blood travels back to the heart via a vein.

The aorta is thick because it has to carry a lot of blood out of the heart, it is around about the size of you pinkie.

Respiratory System

The texture of the trachea is rubbery, tough and a bit squishy. The importance of the rings of cartilage is that it holds open and up the trachea so we are able to breathe.

The lungs are a light red colour and when blown up there is a layer of white. the texture of the lungs are squishy. The difference the lungs would have if the animal was still alive would be that there would be blood which would make the colour of the lungs a darker red.

The heart connects to the lungs by the pulmonary artery, which leads out of the right ventricle into the lungs.

The role of the diaphragm is that is contracts (gets smaller) when we breathe in to give room for the lungs to expand (get bigger). When we breathe out the lungs contract and the diaphragm expands.

Some of the roles of the liver are; producing bile which helps carry away waste and break down fats in the small intestine during digestion, producing certain proteins for blood plasma, producing cholesterol and special proteins to help carry fats through the body, converting glucose into glycogen for storage, regulating blood levels of amino acids, processing haemoglobin for iron content, converting poisonous ammonia to urea, clearing the blood of drugs and alcohol, regulating blood clotting and resisting infections by producing immune factors and removing bacteria from the blood stream.


The links between the skeletal system and the muscular system are; muscles cover various bones and allow our body to perform functions like lifting, bending, grasping... The combination of the skeletal and muscular system makes the working of involuntary and voluntary actions possible.

The links between the circulatory system and the respiratory system are; that they keep each other alive in the way that they oxygenate and deoxygenate blood for each other. Deoxygenated blood flows from the heart to the lungs through an artery (high pressure), it goes through the lungs and becomes oxygenated blood. This oxygenated blood flows back to the heart through a vein (low pressure).

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