The Skeletal System
Skeletal System of a prawn-
The prawns skeletal system is an exoskeleton, meaning it has a skeleton on the outside of it's body. The skeleton is fragile and bendy to help it move around. The skeleton is made of chitin (sugar) and calcium carbonate (strength). Some other animals with this kind of skeleton are Lobsters, Crayfish and yabbys. Some advantages of this skeleton are that it is bandy and allows freedom. Some disadvantages are when the shell comes of (To allow it to grow) it is completely vulnerable. A prawn grows by it's shell/skeleton falls off and then it has a big growth spurt, then when it is time the prawn will grow another skeleton. It is different to a human skeleton because it on the outside of the body unlike ours which is inside.
Skeletal system of a worm-
The worm has a hydro-skeleton, this means it just has liquid inside it. The worm moves by stretching out and then contracting over and over again. Some advantages of this is that they can squish around and change shape to fit through small gaps. Some disadvantages is that they do not move extremely fast, this makes it easier for their predators to catch them.
Skeletal system of a cuttlefish-
The skeleton of a cuttlefish is very light for floating, It is also fragile and crumbly. The main role of it is to help the cuttlefish to float. The skeleton of a cuttlefish is made of bone and cartilage. The cuttlefish has an internal skeleton making it have a endoskeleton.
Skeletal system of a human-
The human skeleton is made up of two structures these are called the axial skeleton which protects the brain, spinal chord, heart and other important organs. Then there is the appendicular skeleton which allows movement. The skeletal system is made of bone, cartilage and ligaments, did you know that when you are born you have over 300 bones in your body, but when you are fully grown you only have 206 bones in your body. Our bones are made of calcium, which provides strength, and calligan, which provides flexibility. Unlike the prawn our skeletal system grows with us. Humans have an endoskeleton. Other types of animals with and endoskeleton are dogs, cats, bears, tigers, kangaroos and lions.
The Muscular System-Chicken wing disection
1. We looked at a chicken wing, and the parts that corresponded with the human is The upper wing with the upper arm, the lower wing with the lower arm and the wing tip and the hand.
2. We played around with the wing and when we pulled on certain muscles the wing extended.
3.The muscles that we pulled on correspond to the biceps and the triceps in a human.
4.The triceps is the extensor.
5.The biceps are the flexor.
6.When we tug on the biceps the wing contracts and when we tug on the triceps the wing extends.
below there is a diagram that shows us the flexor and the extendor.
Next we cut away the muscle tissue and found the tissue that connect the muscle to the bone.
7.The tissue that connects the muscle to the bone is called a tendon.
8.The tendon is a white bouncy/stretchy tissue.
Next we observed the elbow joint.
9. The tissue that connects the bones at this joint is called cartilage.
10. This kind of joint is a this is a ball socket joint.
11. The joint that connects the wing to the shoulder is also a ball socket joint.
12.The cartilage is stuck to the joint it is a light pinky colour.
Next we cut away all of the muscle from around the bone
13. The bones found in this chicken wing are the humorous, the radius, the ulna, the carpals the the phalanges (basically the same as the human.)
The Circulatory System
First we examine the outside of the heart.
1. The heart was a pinkish colour. I was slimy and gooey. The heart was heavier than I expected it to be and it had lots of fat surrounding the outside.
Next we looked for the blood vessels on the outside of the heart muscle. These are called the coronary arteries. They carry nutrients and oxygen to the heart muscle.
3.The coronary arteries are thin and small.They travel from the top of the heart down to the bottom.
If there was a blood clot in this artery it would not be able to supply blood to the hear muscle, there for the heart muscle would not be able to pump blood around the body properly.
4. The left side of the heart is thicker and fatter than the right because it has to pump blood from the left throughout the body, the right side only has to pump blood to the lungs.
5. we had a feel of the thickness of the heart muscles and observed.
a)The thickness of the muscle at the top of the heart it was tin compared to the top but it was still thick. It was made of a material that was very strong and very hard to cut through.
b) The muscles at the bottom of the heart are probably the thickest of all of them, as it has one of the most important jobs, which is to pump.
c) The amount of fat surrounding the heart was a lot more then i expected. I thought there was just going to be a little bit here and a little bit there, but there was actually fat all around the top and sides of the heart.
d) The major vessels entering the heart such as the aorta has a thick wall because it has to be more resilient. When blood is pumped into it from your heart it expands putting it under more pressure than the rest of your arteries. Your veins have thinner walls because there is not as much pressure in them they just trickle backinto the heart.
6. Deoxygenated blood leaves the right atrium in an artery and travels to the lungs. Here, the blood collects oxygen, so now it is oxygenated. The blood travels back to the heart via a vein.
7. Next we found the aorta and, the artery that carries blood away from the heart.
a) The vessel needs to be thick because there is more pressure in the blood. If it was thinner is would be more likely to burst or pop.
b) The aorta takes blood to the rest of the body.
8. Next we looked at the vena cava. This is the vein that returns blood from the body.
a) The vena cava is much thinner than the aorta because there is not as much pressure, the blood basically just trickles in
b)The vena cava goes back into the right ventricle.
c) We put water into the vena cava and it came out of the pulmonary artery.
9. When we put water into the pulmonary vein it came out of the aorta.
Now it is finally the time when we made our first incision into the left ventricle.
1.Describe the inside of the heart .
The inside of the heart is much the same colour as the outside, a deep red-ish colour. There are many valves which stop the back flow. The inside has a lot more liquid.
2.Observe the valves what do you think there job would be?
The valves are very thin and easy to cut through they are like little stringy white-ish coloured things. Their job is to the blood from flowing backwards.
3. Cut the aorta. Describe how it appears and how it feels and any other features.
The aorta is a thick muscular artery, it is sticky and gooey to touch, It appears to be much stronger that the other veins and arteries.
The Respiratory system
1. Describe the texture of the trachea. Why are the cartilage rings important?
The trachea is very bumpy from the rings of cartilage. They are important because they are needed to keep the trachea open to let air through.
2.Describe the texture of the lungs. Do you think it could have differed when the animal was functioning?
The lungs were are deep red colour with white bits of fat on them. The texture was smooth and slimy. It definitely could have differed if the animal was alive, maybe it could have been a brighter red.
3.Explain how the heart connects to the lungs.
The heart sends deoxygenated blood to out the pulmonary artery and to the capillaries in the lungs. The lungs then give oxygen to the blood through the alveoli. The now oxygenated blood then travels back to the heart through the pulmonary vein ready to be pumped around the body.
4.What is the role of the diaphragm? How does it control our breathing?
The role of the diaphragm is to control our breathing. It does this by contracting and relaxing as we breath in and out.
In conclusion this unit has been a great success. It has included many great learning experiences and i had a great time.
One of the things I learnt is that even though each system works by its self to do it's own job, all they systems cross over to work together and that explains a lot about how we are today. For example the skeletal system and the muscular system work together as the muscles move the skeleton. Skeletal system is the supporting system. Muscular system is the system that provides movement in the skeletal system. Skeletal system protects the body organs like the brain. Muscular system does not perform this function. Muscular system is required for the flexibility speed and endurance. Skeletal system assists the muscular system in these function. Skeletal system produce red blood cells and some white blood cells. Muscular system produce lactic acid during anaerobic conditions. These are just a few comparisons.
Another example is the respiratory system and the circulatory system. The respiratory system has more to do with breathing and CO2 and O2. Where as the circulatory system delivers the oxygen around the body. They have a lot to do with each other though, as i have explained before.
This sums up my unit on the body Systems. I hope you have enjoyed reading about all that I have learnt.