Blood Cells And Haemopoesis

Question 0

Describe the control of erythropoiesis

Answer 0

Detect fall in partial pressure of oxygen

Increase erythropoetin which stimukates maturation and release of red cells from marrow

Question 1

Outline the process of haemopoesis

Answer 1

1) stem cell divides into two - one to replace original and one that will differentiate
2) haemopoetic progenitor will first differentiate into myeloid blast or lymphoid blast
3) the progenitor will differentiate jnto a certain cell type jnter the influence of a particular cytokine
E.g. Erythropoetin cause differentiation into a RBC

Question 2

Describe the structure of nuetrophil

Answer 2

Multilobed nucleus

Specialised for working in anaerobic (useful for damaged)

Question 3

Describe the function of a neutrophil

Answer 3

Migrate out of circulation to site of infection
Phagocytosis
Imcreased production by G-CSF

Question 4

Describe structure of eosinophil

Answer 4

Bi-lobed nucleus

Question 5

Describe the function of eosinophil

Answer 5

Phagocytosis

Release cytotoxic particles to damage larger particles

Question 6

Describe the function of basophil

Answer 6

Mediate acute inflmatory reactions using heparin and histamine

Question 7

Describe the function of monocytes

Answer 7

Migrate to become macrophages in many organs

Capable of phagocytosis and interact with t cells

Question 8

Describe function of B lymphocytes

Answer 8

Humorsl immunity. Stimulated by antigens, transform into plasma cells which secrete immunoglobulins

Question 9

Describe the function of t lymphocytes

Answer 9

Express CD4 on surface (helper)
Can be killer
Permit transformation of b cells into plasma cells

Question 10

Describe the structure of erythrocytes

Answer 10

Biconcave disc
4 globin chains (2alpha and 2 beta)
Each molecule carries haem
Flexible - to fit through small capillaries

Question 11

Describe the function of erythrocytes

Answer 11

Carries O2 to tissues and CO2 to lungs
Maintain haemoglobin in its reduced (ferrous) state
Maintain osmotic equilibrium

Question 12

Describe the structure of reticular cells

Answer 12

Synthesise reticular fibres and surround them with cytoplasm

Question 13

Describe the function of reticular cells

Answer 13

Direct t and b lymphocytes to specefic regions with lymphatic tissues

Question 14

Describe the structure of platelets

Answer 14

Small round blue particles
Produced by megakaryocytes
Complex surface membrane
Cytoplasm contains alpha and dense granules
Alpha contains fibrinogen and von willebands factor
Dense contains ADP and Ca2+

Question 15

Describe the function of platelets

Answer 15

Clotting cascade

Adhere to damaged cell walls and aggregate together

Question 16

Describe haemoglobin synthesis

Answer 16

Globin gene clusters on chromosome II and Ib
Globin chains synthesised indipendently and combine to form Hb
Switch from fetal to adult at age 3-6 months

Question 17

Describe the process of red cell destruction and Hb catabolism

Answer 17

RBC broken down into haem, globin and iron
The haem is converted to billirubin snd transported to the liver bound to albumin
It travels down the bile duct to the intestine where is is converted to urobilinogen
Then travels to kidney and is excreted