Intro to Haem

Question 1

what is blood

Answer 1

specialised fluid composed of cells suspended in liquid (plasma)

Question 2

what are the 3 types of blood cells

Answer 2

red blood cells
- transport oxygen

white blood cells
- fight infection

platelets
- prevent bleeding

Question 3

what is haematopoiesis

Answer 3

production of blood cells

Question 4

where does haematopoiesis occur in different stages of life

Answer 4

Embryo
-yolk sac then liver marrow

At birth
-bone marrow, liver and spleen when needed

birth to maturity
-number of active sites in bone marrow decrease

adult

• not all bones contain bone marrow
• restricted to skull, ribs, sternum, pelvis and proximal ends of the femur (axial skeleton)

Question 5

what are haemopoeitic stem cells

Answer 5

precursor to all blood cells - can generate into a wide array of cell types

Question 6

what happens to a stem cell to make blood

Answer 6

Proliferation and differentiation

goes from stem cell to:

• multipotent progenitors
• oligolineage progenitors
• mature cells

Question 7

what are the cell stages of erythropoiesis

Answer 7

pronormoblast

early normoblast

intermediate normoblast

late normoblast

reticulocyte - found in blood

mature red cell/erythrocyte

Question 8

what do RBCs duo

Answer 8

carry oxygen
buffer CO2
other roles

Question 9

what do platelets do

Answer 9

prevent bleeding

Question 10

what do white cells do

Answer 10

fight infection
cancer prevention
others

Question 11

what are the different types of white cells in the blood

Answer 11

Granulocytes 
Macrophages 
Dendritic cells 
T cells 
NK cells 
B cells

Question 12

what are granulocytes

Answer 12

cells which contain granules and are easily visible of light microscopy

eosinophils
basophils
neutrophils

Question 13

what is the structure and function of neurtrophils

Answer 13

segmented nucleus - neutral staining granules

short life in circulation
phagocytose invaders
kill with their granule contents so die in the process

attract other cells

increased by body stress - infection, trauma, infarction

Question 14

what is the structure and function of eosinophils

Answer 14

bilobed nucleus
bright orange/red granules

fight PARASITIC infections (ew a parasite)
involved in type 1 hypersensitivity reactions (allergies)
often elevated in patients with allergic conditions (asthma, atopic rhinitis)

Question 15

what is the structure and function of basophils

Answer 15

infrequent in circulation
large deep purple granules obscuring the nucleus

circulating version of tissue mast cell

mediates hypersensitivity reactions
bine to IgE
granules contain histamine

Question 16

what are monocytes

Answer 16

circulating macrophages - become macrophages once they enter the cells

phagocytose invaders, kill them and also PRESENT the antigen to lymphocytes

attract other cells

live longer than neutrophils

Question 17

structure and function of lymphocytes

Answer 17

mature -cells with small condensed nucleus and rim of cytoplasm

activated - large with plentiful blue cytoplasm extending around neighbouring red cells

numerous types and functions
cognate response to infection
brains of the immune system

Question 18

what are the lymphocytes

Answer 18

T cells
B cells
NK cells

Question 19

how can you examine the haematopoietic system

Answer 19

look at peripheral blood
look at bone marrow
specialised tests of marrow
other relevant sites - spleen, liver, lymph nodes

Question 20

what is the most common site for bone marrow aspiration/biopsy

Answer 20

posterior iliac crests