Rest of Chapter 14 Flashcards
1
Q
Give the formula for oxyhaemoglobin that forms from oxygen and haemoglobin.
A
Hb + 4O2 = HbO8
2
Q
Name the adaptations of a red blood cell and why.
A
- smallest cells in the body. ( to be squeezed through capillaries )
- Contains haemoglobin that easily bonds with oxygen.
- have elastic walls to make it flexible to squeeze through capillaries.
- No nucleus. ( more space for haemoglobin )
- no mitochondria (obviously)
- Biconcave ( To increase surface area : volume ratio )
3
Q
Explain the transport of oxygen by red blood cells.
A
- oxygen diffuses from the alveoli in the lungs into the blood of the capollaries.
- this happens because of the higher concentration of oxygen in the alveoli than in the blood capillaries.
- oxygen is taken by haemoglobin in the red blood cell and forms oxyhaemoglobin with it.
- this is trasported from regions with high oxygen tension to regions of low oxygen tension in the blood.
4
Q
Name the components of blood.
A
- Platelets
- Neutrophil
- plasma
- lymphocyte
- red blood cell
5
Q
Describe the oxygen dissociation curve
A
- Verticle axis = percentage saturation of haemoglobin with O2
- Horizontal axis = amount of oxygen available in the surrounding medium.
- curve shape is called a sigmoid.
- the saturation of haemoglobin with oxygen depends on the partial pressure of oxygen in the alveoli and blood.
- haemoglobin has a high affinity for oxygen when oxygen tensions are high, therefore it combines with the oxygen in the lungs.
- haemoglobin has a low affinity for oxygen where the oxygen tensions is low therefore it dissociates among the body tissues releasing oxygen.
- the lower the partial pressure of oxygen, the more oxygen is released.
- the release of oxygen from the haemoglobin is called oxygen dissociation.
6
Q
Describe the Bohr Effect.
A
- The Bohr Effect is that carbon dioxide’s presence in respiring tissues increases the dissociation of oxygen from haemoglobin.
- The bohr effect is the effect of the carbon dioxide on the dissociation curve.
- it moves the curve to the right.
- more oxygen is unloaded.
7
Q
What is the significance of the Bohr Effect?
A
- It is that oxyhaemoglobin releases more oxygen to the tissues which need oxygen the most.
8
Q
Describe the process of blood clotting.
A
- a blood vessel is damaged.
- blood plasma, blood cells and platelets flow from the cut vessel.
- platelets in the blood are activated by Vitamin K and calcium ions.
- Platelets release an emzyme called thromboplastin.
- this enzyme cause soluble prothrombin to change in thrombin.
- thrombrin acts on soluble fibrinogen in the blood plasma.
- soluble fibrinogen becomes insoluble fibrin.
- red blood cells get trapped in mesh of fibres and dries out.
- this causes a clot.
9
Q
Describe Blood plasma.
A
- It is water with a large number of substances dissolved into it.
- IONS of sodium, chloride, calcium, etc
- PROTEINS such as, fibrinogen
- Varying FOOD SUBSTANCES like amino acids, glucose, fatty acids, glycerol and vitamins.
- HORMONES
- UREA
- CARBON DIOXIDE
10
Q
Describe the transport of digested food.
A
- soluble products of digestion ( amino acids, glucose ) and ions and vitamins pass into the blood stream through the villi to the liver via hepatic portal vein.
11
Q
Explain the transport of urea.
A
- Urea travels from the liver in the blood plasma in solution until it reaches the kidneys, where it is removed and excreted from the body in urine.
12
Q
Transport of hormones. Describe it.
A
- Hormones are chemical substances transported in the blood plasma from endocrine glands to target organs.
13
Q
Explain how oxygen, carbon dioxide and nutrients are echanged between tissues and caplliaries.
A
- Oxygen and small soluble molecules diffuse form a high concentration to a low concentration down their concentration gradient from the blood to the capillaries across the capillary walls to the ttissue fluid which bath the cells.
- Carbon dioxide and other waste products produced by the body tissues diffuse out of the cells to the tissue fluid, across the capillary walls into the blood in the capillaries.
14
Q
Describe the formation of tissue fluid.
A
- Blood plasma : the liquid part of blood inside blood vessels.
- Tissue fluid : Blood plasma leaks out of and escapes from capillaries to surround and bath the cells by filling the spaces between the cells.
- Lymph: The tissue fluid return to the circulation as lymph in the lympatic vessels.
15
Q
Describe the function of tissue fluid.
A
- contains amino acids, glucose, minerals, vitamins and oxygen.
- This fluid gets ou of capillaries because of the tiny gaps between the cells of the wall of the capillaries.
- this fluid is the medium through which substances are exchanged between the blood and the cells.
- the gaps allow small melcules to pass through, but keep back red blood cells and large plasma proteins.
- some tissue fluid returns directly to the capillaries because the pressure in the capillaries is lower than in the fluid. It contains carbon dioxide and other waste products from cells which are carried away in the bloodstream.
- Capillaries are tiny, have thin walls and also come in contact with almost every cell. this diffusion distance is very short.
- Tissue fluid maintains a relatively constant environment around body cell, helping them to function efficiently.
