Haematopoiesis

Question 1

Haematopoiesis what

Answer 1

Process by which mature blood cells are generated from precursor cells

Question 2

Conc and % for RBC, platelet, WBC

Answer 2

RBC-4-6x106/microlitre 45%
Platelet-~1.5-4x105/microlitre
WBC=~4-11x103/microlitre

Question 3

Prenatal and post natal haematopoesis location

Answer 3

Prenatal=yolk sac, liver, spleen, bone marrow, lympth nodes

Postnatal=tibial,femur, lymph nodes, ribs, sternum, vertebral+pelvis

Question 4

Define: totipotent, pluripotent, multipotent, unipotent/progenitor

Answer 4

Totipotent=stem cell that is able to produce all the differentiated organisms
Pluripotent=stem cell that can divide into either the endoderm, mesoderm, ectoderm
Multipotent=stem cell that has the ability to divide into multiple but restricted cell types
Unipotent/progenitor: restricted to single lineage. Multiplification is lineage-specific growth factors. Does not have potential for self renewal

Question 5

Draw flow chart of stem cell, progenitor cells, precursor cells and blood tissue

Answer 5

ref. notes

Question 6

Draw macrostructure bone marrow

Answer 6

ref. notes. Haematopoesis occur between sinuses

Question 7

Blood cell differentiation draw out

Answer 7

ref. notes

Question 8

erythrocyte precursor where. RBC removedwhere

Answer 8

erythrocyte precursor=cells in bone marrow

Old RBC=spleen and liver

Question 9

RBC how produced

Answer 9

Normoblast (prenultimate precursor) eject nucleus and form reticulocyte. Takes 1-2 days for remaining RNA and organelles to be lost

Question 10

Platelet where produced, describe shape, function

Answer 10

where-BM (limited de novo) from megakaryocyte precursors via thrombopoeitin
shape-anuclear, discoid, 2-4micrometre diameter 8-12 days
function-haemostasis nad maintenance of blood vessels. Attach to fibrin filaments and damaged endothelial surfaces

Question 11

Megakaryocyte what

Answer 11

responsible for platelet production.The cytoplasm in giant cells partitioned into packages by vesicles of ER. Vesicles of ER fuse ejecting platelets

Question 12

Neutrophil traits

Answer 12

predominant circulating leukocyte 60%, 10^11 produced and released from bone marrow. polymorphonuclear=no ability to multiply, little capacity for protein synth. Highly motile, respond rapidly to chemotactic substances. First cell type recruited to site of inflammation

Question 13

what gives traction for neutrophil motility

Answer 13

uropod

Question 14

Eosinophil traits

Answer 14

rare circulating leukocyte under basal conditions, bi lobed nucleus, motile to various chemoattractants, extracellular killing of parasites, eosinophil associated gut diseases, hypereosinophilic syndromes

Question 15

Eosinophil morphology

Answer 15

major basic protein: very highly cationic, toxic towards helminthic parasites, tissue damage to host
eosinophil cationic protein: bacteriocidal, promotes mast cell degranulation
eosinophil derived neurotoxin: antiviral activity in respiratory infection
Eosinophil peroxidase: catalyses teh peroxidation of halides and hydrogen peroxide. Bacteriocidal tissue damage to host

Question 16

Eosinophil how long last for

Answer 16

leave circulation after 8-12 hours of release from bone marrow. Lifespan in tissues~several days. Number increase greatly in parasitic infections and some allergic states.

Question 17

Monocytes trait

Answer 17

largest leukocyte, nucleus - horseshoe or kidney shape, highly phagocytic and motile

Question 18

Functions of macrophages

Answer 18

1. Defence against microorganisms
2. Refuse collection
3. antigen presentation
4. cytokine secretion (important in regulation of haemopoiesis)

Question 19

Lymphocytes types and traits

Answer 19

small lymphocytes: 6-9 micrometre in diameter, condensed nucleus 90% of cell, thin rim of cytoplasm
large lymphocyte: 9-15 micrometre diameter, mostly activated B cells in transit to tissues to become plasma cells
NK cells: thesecan kill some virus infected or tumour cells by mechanism not involving specific antigens

Question 20

What do B and T lymphocytes have on the surface and give function

Answer 20

B lymphocytes: have surface immunoglobulin (receptor), respond to antigen by proliferating and maturing into plasma cells which then secrete the same immunoglobulin (antibody)
T cells have receptors for antigen
Helper=express the CD4 marker on surface, respond to antigen by secreting cytokines that help other lymphocytes
Cytotoxic=express CD8 markers on surface, kill virus infected cells