Prac write ups

Skeletal system

Prawn, worm, cuttlefish, humans


Describe its skeletal system. What are some key features of it?
The skeletal system of a prawn is external and covers nearly the whole body expect the legs and some of the head. The key feature of it is the tail which is nearly all bone and the top of the head where the bone gets thicker.

What are some of the roles of the skeleton for the prawn?
The main role is to protect the prawn from any predators or environmental pressures. It is also used to keep the prawn in shape because without it the prawn would be very floppy and move shapes.

What other kinds of animals have this kind of skeletal system?
Lobsters, Crabs and insects also have this skeletal system

What are some benefits of this kind of skeletal system?
It is different because it is an exo-skeleton and is on the outside

What are the benefits of this kind of skeletal system?
The benefit is that the prawn has a layer of protection

What are some disadvantages of this kind of skeletal system?
The disadvantage is that the shell could break easil and they can grow out of their shells and are venerable while they are growing their new one

How might it grow?
It grows by making a new shell

What is this kind of skeletal system called?
The type of skeleton is the exo-skeleton

What is the skeletal system called?
The skeleton is made of Chitlin

Worm and cuttlefish

What kind of skeletal system does the worm have?
The worm has a hydrostatic skeletons

How does this work?
The Hydrostatic skeleton

Describe the cuttlebone
The cuttlebone is white and chalky. It has a smooth shiny surface.

What would its main role be?
The main role would be to keep the structure and to help the animal float

Is this an internal or external skeleton?
It has an internal skeleton


Describe the Structure of our skeletal system?
The structure of the human skeletal system is a Endo-skeleton

What is our skeletal system made of?
Our skeletal system is made of 300 bones for a baby and 206 for an adult.

What is the role of our skeletal system?
The role of our skeletal system is to keep our body up and to protect us.

What is the role of bone marrow marrow? Where is this found?
Bone marrow is the tissue in the middle of the large bones. Bone marrow produces cells like red blood cells, white blood cells and platelets

What materials are our bones made of?
The human bone is principally made of collagen and calcium phosphate

How does our skeletal system change as we develop ( from baby to adult)?
As we develop our bones change from cartilage to bones. some of the smaller bones also join together to make bigger bones.

What is this kind of skeletal system called?
This is a internal skeleton

What other kind of animals have this kind of skeletal system?
Apes, cats and dogs have this skeletal system

Muscular system
Chicken Wing dissection

1. What structures do these correspond to in humans?
Upper wing= deltoid , Lower wing=bicep+triceps, lower wing= Ulnaris

2. What happens when you tug on these muscles?
When you tug the top of the wing you see the lower half contract.

3. What muscles do they correspond to in humans?
Their muscles are similar and they have the bicep, tricep, radialis longus and the Olnarius

4. Which muscle is an extensor? (ie. causes the limb to extend when it contracts)
The extensor in the chicken wing is the tricep

5. Which muscle is a flexor? (ie. causes the limb to flex when it contract)
The flexor in the chicken wing is the bicep

6.What happens when you tug on these muscles?
When you push the tricep forward, the bicep with contract

7. what is this tissue called?
It is called a Tendon

8.Describe what it looks like?
It's white and quite tough

9. What is the tissue that connects the bones at the joint called?
It is a Tendon

10. What kind of joint is this?
It is a hinge joint

11. What kind of joint connects the wing at the shoulder?
It is called a Ligaments

12. Describe the cartilage the lines the joint ( appearance,texture, how much is there?)
It's white and shinny. It covers the ends of the bones

13. Name the bones fond in the chicken wing?
In the upper wing there is the ulnar and radius then in the lower part of the wing there is the humerus.


Circulatory system

Heart dissection

1. Describe the appearance of the heart. What does it look like? How does it feel? Are there any features you can describe?
The heart feels very squishy in most parts. It has a triangular look and has a deep dark red colour.

3. Find the blood vessels on the surface of the heart muscle. These are the coronary arteries. They carry nutrients and oxygen to the heart muscle.

Describe what this artery looks like.
They are long, thin and branchy.

What do you think would happen if this artery was blocked by a clot?
The Heart might not be able pump blood around the body and you could potentially die.

4. How do you know which is the left and right ride of the heart?
You would know because the left side of the heart should have a thicker muscle wall. You can also tell because when you put your finger down the Aorta and push out, it should push out on the left side and be on the top.

5. Have a feel of the thickness of the heart muscle at the top and bottom of the heart. Describe the following features;

a. The thickness of the muscles at the top of the heart.
It is hard, quite thick and contains lots of blood

b. The thickness of the muscles at the bottom of the heart.
It feels hard and quite small and pointy

c. The amount of fat surrounding the heart.
The fat seems to be extremely hard and hard to break though

d. Any major vessels entering and exiting the heart.
They are squishy and soft

6. Circle the correct answer;
Oxygenated / Deoxygenated blood leaves the right ventricle / right atrium in an artery / vein and travels to the lungs / rest of the body. Here, the blood collects oxygen / drops off oxygen, so it is now oxygenated/ deoxygenated. The blood travels back to the heart via an artery / vein.

a. Describe the thickness of this vessel. Why do you think it needs to be so thick?
The Aorta is massive so it can carry lots of oxygenated blood

b. Where is it taking blood to?
The aorta it taking oxygenated blood around the body.

8. Find the vena cava. This is the vein that returns blood from the body.
a. Compare the thickness of the vena cava to the aorta. Why do you think it is different?

They both carry different bloods, and the Aorta carries oxygenated blood so it should be thicker

b. What part of the heart does the vena cava go back in to?

The Vena Carta should travel into the right atrium to deliver deoxygenated blood

c. Remember what you observed when you observed the water flowing through the heart.

The water went into the vena cava and into the heart. Which blood vessel did the water come out of the heart from?
The water should come out of the Primary artery and into the lungs to be oxygenated if it was blood.

9. When the water was flowing into the pulmonary vein, which vessel did it come out of?
The pulmonary vein should take the water straight to the heart and into the left ventricle and Atrium. The vessel it should come out of is the Aorta.

We then cut into the Left Ventricle

    1. Describe what you see inside the left side of the heart.
    It looks thick with a darker red colour than the outside. You can see the main veins.

    2. Observe any valves you see. What do you think their job would be?
    The values are used to open and lose the atrium and Ventricle. They look and white.

    3. Cut the aorta. Describe how it appears and how it feels and any other features

    It is big, thick, tough and very pink.

Walking the Heart

Pluck Dem

1. Explain how the diaphragm muscle helps you to breathe?
The diaphragm contracts and expands to help you breathe

2. What is breathing?
Breathing is inhaling oxygen to oxygenated your blood and exhaling carbon dioxide

3. Name the 2 stages involved with each breath.
inhaling and exhaling

4. What are 3 things that happen when you inhale?
When you inhale, your diaphragm contracts, you let in air through the windpipe and your lungs expand

5. What are 3 things that happen when you exhale?
When you exhale, your diaphragm relaxes, your lungs contract and you realise carbon dioxide.

6. How is your breathing rate controlled?
The Medulla in the centre of your brain automatically receives information from sensors in your body and tell you your levels of carbon dioxide and if they are too high, the medulla will make you rate of breathing increase.

7. Table:
My heart rate at rest is:72
My heart rate at exercise is: 130
My breathing rate at rest is:28
My breathing rate at exercise is: 31

8. How much air can your lungs hold? What would be expected for someone at your age?
Your lungs should be able to hold around 6 litres of air but for someone the age of 12-15 it is around 4 litres but it also depends on your size and gender.

9. During exercise the rate of breathing increases. How does this happen and why is this?
The rate of breathing increases because you need to pump more oxygen around the body. Breathing is a voluntary action so you can easily change the amount of air you take in and how often you breathe.

10. Why is it best to breathe in through your nose?
Its best to breathe through your nose because your nose fill filter out the dust and dirt well your mouth will suck it all in.

11. What is the function of the Epiglottis?
The epiglottis is a small flap in your oesophagus and it closes and opens at certain times to make sure you air goes to your lungs and your food goes to your stomach.

12. How are gasses exchanged in your lungs? Use a diagram to help explain your answer.

13. How does the air your breathe out differ from the air you breathe in.
When you breathe in you are breathing in oxygen. The oxygen will go to your lungs and will oxygenated your red blood cells which will carry the oxygen around your body. The red blood cells will then drop off the oxygen and collect waste and carbon dioxide. We will breathe out the carbon dioxide and then the whole process will start again.

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