Blood

Question 1

what is the percentage composition of the following:
1. Blood plasma
2. RBCs
3. WBCs
4. Platelets

Answer 1

Blood Plasma: 55%
RBCs: 45%
WBCs: <1%
Platelets: <1%

Question 2

what is the function of RBCs?

Answer 2

transport oxygen from the lungs to respiring tissue cells in the other parts of the body

Question 3

what are the structural adaptations of RBCs? (4)

Answer 3

1. biconcave disc shape (due to absence of nucleus), increase SA:V, increase rate of absorption
2. absence of nucleus, increase no. of Hb, increase carrying capacity
3. flexible and elastic cell surface membrane, change shape, squeeze thru narrow blood capillaries
4. contains haemoblobin, allows reversible binding of oxygen

Question 4

what are the two types of cells that are under WBCs

Answer 4

phagocytes and lymphocytes

Question 5

what is the structure of phagocytes?
what is phagocytosis?

Answer 5

1. highly granular cytoplasm and lobed nucleus
2. phagocytes engulf, ingest and digest foreign particles/pathogens

Question 6

what is the structure of lymphocytes?
what is its function?

Answer 6

1. non-granular cytoplasm and spherical nucleus
2. produces antibodies to kill pathogens and bacteria

Question 7

human ABO blood groups
list down the antigens and antibodies produced by blood type A, B, AB and O and which types they agglutinate with

Answer 7

1. type A:
   - antigen A, antibody B, agglutinate with B and AB
2. type B:
   - antigen B, antibody A, agglutinate with A and AB
3. type AB (universal recipient):
   - antigen A & B, no antibodies, no agglutination
4. type O (universal donor)
   - no antigens, antibodies A &B, agglutinate with all

Question 8

what is the consequence of wrong donation of blood? (5)

Answer 8

1. antibodies can recognize and bind to their specific antigens
2. results in agglutination
3. block up small blood vessels, reduce blood flow
4. reduce rate of supply of oxygen and nutrients to respiring tissues
5. fatal, respiring tissues die, body unable to function

Question 9

platelets/ thrombocytes: release materials necessary for clotting
- what is the importance of clotting?

Answer 9

1. prevents excessive blood loss
2. prevents pathogens from entering and harming body

Question 10

describe what happens during clotting (4)

Answer 10

1. thrombokinase produced by platelets & damaged tissue
   2.thrombokinase converts inactive prothrombin to active thrombin in presence of calcium ions
2. thrombin converts soluble fibrinogen to insoluble fibrin in presence of Vitamin K
3. fibrin traps blood cells and forms blood clot