B4 -Organising Animals & Plants Flashcards
What is blood mostly made of?
Plasma (55%)
What does plasma do in blood?
It transports all blood cells and other substances around your body
Where is does waste carbon from the cells go?
To the lungs
What is the most common blood cell in the body
Red blood cell (5 million in every square mm of blood)
What do red blood cells do?
They carry oxygen (from the lungs) around the body to cells that need it
Why are red blood cells biconcave discs (pushed in on the sides)?
To increase surface area for diffusion as it increases surface area to volume ratio.
Why are red blood cells packed with haemoglobin?
So they can bind to oxygen.
Why do they not have a nucleus?
To make more space for haemoglobin.
What are white blood cells?
Bigger than red blood cells and fewer as well. But do not carry oxygen, in fact, fight harmful micro organisms and defend the body.
How do lymphocytes fight harmful micro organisms?
This type of white blood cell forms antibodies to kill harmful micro organisms.
How do others (not phagocytes or lymphocytes) fight harmful micro organisms?
Form antitoxins to fight poisons from micro organisms
How do phagocytes fight micro organisms?
Engulf and digest invading pathogens and harmful micro organisms
What do platelets do?
They form blood clots at the site of a wound. This helps stop bleeding which stops you bleeding to death.
What are the three blood vessels?
- Arteries
- Veins
- Capillaries
Where do arteries go from?
Heart to organs
Describe the arteries walls?
Arteries have a small lumen and have thick walls which are made of muscle and elastic fibres.
What happens to arteries every time the heart beats? What could happen if cut?
Arteries expand when blood squeezes through, this happens every heart beat.
If an artery is cut, blood will spurt out uncontrollably every time the heart beats.
Where do the veins go?
Carry blood away from the organs towards the heart
Describe the veins walls?
They have thinner walls and a large lumen compared to capillaries and have skeletal muscles to stop back flow in the blood.
What do capillaries do?
Connect the arteries and veins through a network of tiny vessels.
Describe the capillaries walls?
Walls one cell wide and a lumen which is very narrow. This helps diffusion.
How are our vessels arranged?
In a double circulatory system. This means some vessels carry blood from the heart to the lungs and back and others carry blood from the heart, again, to the other organs and back again.
All Heart Notes are in Good Notes
Go Onto Good Notes for Notes on the Heart
How are lungs adapted to make gas exchange more efficient?
Lungs are made of clusters of alveoli that create a large surface area which increases the rate of diffusion. Capillaries in the alveoli keep a concentration gradient.
How does the immune system respond to pathogens
- Reproduce rapidly
* Reproduce anti-toxins rapidly
What is Plasma?
Transports all blood cells and other substances around the body
What is in plasma?
• Waste carbon dioxide
• Urea formed in the liver
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