The Skeletal System
The Skeletal System is the system that controls the bones in our bodies. It is a very important system in human bodies as it allows us to stand up, gives us strength and protects and holds in our important organs.
Prawns
We did a prac on dissecting a pawn. In the prac we pulled apart the layers of a prawn's skeleton. As you can see in the photo on the left.
The prawn has an exoskeleton, meaning its skeleton is on the outside of its body. It has a few different layers overlapping giving it protection and allowing it to move easily. Crabs, lobsters and shrimp have the same type of skeleton, give or take a layer. Prawns must also shed their skeleton to grow, leaving them unsafe while they are growing without the protection.
Their skeleton is made up of a substance called chitin (ky-ton) a type of sugar and calcium carbonate to give them strength.
It is different to our skeleton as for one we don't have an exoskeleton, we have a endoskeleton, on the inside of our bodies. We don't have to shed our skeleton to grow. We have different substances used to make them. The advantages to having an exoskeleton are that you have a strong hard protective layer. Some disadvantages are that when you grow from that time you have no protective layer and therefore no protection to predators.
We did a prac on dissecting a pawn. In the prac we pulled apart the layers of a prawn's skeleton. As you can see in the photo on the left.
The prawn has an exoskeleton, meaning its skeleton is on the outside of its body. It has a few different layers overlapping giving it protection and allowing it to move easily. Crabs, lobsters and shrimp have the same type of skeleton, give or take a layer. Prawns must also shed their skeleton to grow, leaving them unsafe while they are growing without the protection.
Their skeleton is made up of a substance called chitin (ky-ton) a type of sugar and calcium carbonate to give them strength.
It is different to our skeleton as for one we don't have an exoskeleton, we have a endoskeleton, on the inside of our bodies. We don't have to shed our skeleton to grow. We have different substances used to make them. The advantages to having an exoskeleton are that you have a strong hard protective layer. Some disadvantages are that when you grow from that time you have no protective layer and therefore no protection to predators.
Worm
Another type of skeleton is a hydroskeleton. A hydroskeleton is a type of skeleton that is made of water. It is a fluid filled cavity. The pressure of the fluid and action of the muscles are used to move. We looked at worm and how they move around using a hydroskeleton. Animals like starfish, jellyfish, snails and worms have this type of skeleton.
You can see a photo of some worms on the left.
Another type of skeleton is a hydroskeleton. A hydroskeleton is a type of skeleton that is made of water. It is a fluid filled cavity. The pressure of the fluid and action of the muscles are used to move. We looked at worm and how they move around using a hydroskeleton. Animals like starfish, jellyfish, snails and worms have this type of skeleton.
You can see a photo of some worms on the left.
Cuttlefish
We looked at the bone of a cuttlefish. It is a long thin oval-shaped bone that is very light and has a chalky texture. The cuttlefish uses this bone for buoyancy and protection. It is made up of a substance called aragonite. It is a gas-filled shell used for buoyancy control. It is an internal or an endoskeleton.
You can see a photo of a cuttlefish bone on the left.
We looked at the bone of a cuttlefish. It is a long thin oval-shaped bone that is very light and has a chalky texture. The cuttlefish uses this bone for buoyancy and protection. It is made up of a substance called aragonite. It is a gas-filled shell used for buoyancy control. It is an internal or an endoskeleton.
You can see a photo of a cuttlefish bone on the left.
Humans
The human skeletal system is made up of 206 bones all working together to allow us to move. It is a endoskeleton meaning it is on the inside of our bodies.
Our bones are made up of an outer surface of the bone called the periosteum. It's a thin, dense membrane that contains nerves and blood vessels that nourish the bone. The next layer is made up of compact bone. This part is smooth and very hard. It's the part you see when you look at a skeleton. Within the compact bone are many layers of cancellous bone, which looks a bit like a sponge. The cancellous bone is not
quite as hard as compact bone, but it is still very strong. In many bones, the cancellous bone protects the innermost part of the bone, the bone marrow. Bone marrow is bit like a thick jelly, and its job is to make blood cells.
Our bones change from when we are babies to adults. In a baby they have 300 bones. They then fuse together and by the time we are an adult we have 206 bones in our body. All mammals have the same type of bones as us.
In the diagram below there is a picture of a human skeleton naming some of our main bones in our body.
The human skeletal system is made up of 206 bones all working together to allow us to move. It is a endoskeleton meaning it is on the inside of our bodies.
Our bones are made up of an outer surface of the bone called the periosteum. It's a thin, dense membrane that contains nerves and blood vessels that nourish the bone. The next layer is made up of compact bone. This part is smooth and very hard. It's the part you see when you look at a skeleton. Within the compact bone are many layers of cancellous bone, which looks a bit like a sponge. The cancellous bone is not
quite as hard as compact bone, but it is still very strong. In many bones, the cancellous bone protects the innermost part of the bone, the bone marrow. Bone marrow is bit like a thick jelly, and its job is to make blood cells.
Our bones change from when we are babies to adults. In a baby they have 300 bones. They then fuse together and by the time we are an adult we have 206 bones in our body. All mammals have the same type of bones as us.
In the diagram below there is a picture of a human skeleton naming some of our main bones in our body.