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Blood
There are several components in human blood that we need to know in I/GCSE Biology.👇🏻 👇🏻 👇🏻
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_auto/4936730/756074_105822.png)
Red blood cell
- Contain haemoglobin which carries oxygen
- Made in the bone marrow. The more you train the more red blood cells are made.
- Have no nucleus to allow more space for oxygen
- Biconcave disc shape - greater surface area and allows cell to move through small spaces
White blood cells
- Protect the body by fighting disease
Plasma
- Fluid part of blood
- Carries carbon dioxide, hormones and waste
Platelets
- Clump together to form clots
- Protect the body by stopping bleeding
Blood Vessels
There are various types of blood vessels that we need to know in I/GCSE Biology. 👇🏻 👇🏻 👇🏻
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_auto/4936730/763633_507546.png)
Artery
- Carry blood away from the heart (always oxygenated apart from the pulmonary artery which goes to the lungs)
- Have thick muscular walls - to withstand pressure
- Have small passageways for blood (internal lumen)
- Contain blood under high pressure
Vein
- Carry blood to the heart (always de-oxygenated apart from the pulmonary vein which goes from the lungs to the heart)
- Have thin walls
- Have larger internal lumen
- Contain blood under low pressure
- Have valves to prevent blood flowing backwards
Capillaries
- Found in the muscles and lungs
- Microscopic – one cell thick
- Very low blood pressure
- Where gas exchange takes place. Oxygen passes through the capillary wall and into the tissues, carbon dioxide passes from the tissues into the blood
That's the end of the topic!
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_60/4936730/13924_543177.gif)
Drafted by Joey (Biology)
Reference:
https://getrevising.co.uk/revision-notes/biology_b3_the_circulatory_system_and_blood_4
https://cdn.kastatic.org/ka-perseus-images/8b58582c697c7bc7cc83755edbb599218f8164fe.png