Haemopoesis and the Lymphoid System

Question 1

all precursor cells come from?

Answer 1

haemopoietic progenitor cell which themselves derive from haemopoietic stem cells (HSC)

Question 2

what are the sites of haemopoiesis from embryo to adult?

Answer 2

Embryo- HSC in mesoderm

Wk 5- circulating committed progenitors

Wk 6- liver starts

Wk 10- erythroid acvtivity in yolk sac stops

Wk 16- bone marrow

Adults- marrow within axial skeleton

Question 3

what is polychromasia?

Answer 3

abnormally high number of reticulocytes

Question 4

what is the name of platlet precursor cells?

Answer 4

megakaryocytes

Question 5

what marrow is active red or yellow?

Answer 5

red- haemopoietically active

yellow- fatty inactive

Question 6

what are the three things regulating haemopoesis?

Answer 6

intrinsic properties of cells (stem cells vs progenitor cells vs mature cells)

signals from immediate surroundings and periphery

speciifc anatomical area (niche) fro optimal developmental signals

Question 7

how is haemopoesis assessed?

Answer 7

routinely undertaken blood count

morphology

bone marrow aaspirate- specialist test

Question 8

which type of cells cannot be assessed using FBC?

Answer 8

non-lymphoid cells

Question 9

what test is used to identify non-lyphoid cells?

Answer 9

immunophenotyping

Question 10

what are the central (primary) lymphoid tissues?

Answer 10

boen marrow

thymus

Question 11

what are the peripheral (secondary) lyphoid tissues?

Answer 11

lymoh nodes

spleen

tonsils (waldeyers ring)

epithelio-lymphoid tissues

bone marrow

Question 12

what is chylous ascties?

Answer 12

accumulation of lipid rich lymph in the peritoneal cavity- due to disruption of lymphatic system secondary to trauma or obstruction

Question 13

how is lymph drained from nodes?

Answer 13

affernet channels drain lymph through capsule

efferent vessel leaves hilum and drains to cristerna chyli or L/R jugular, subcalvian or bronchomediasteinal trunks

Question 14

what is the marker for B cells?

Answer 14

CD20

Question 15

what is the marker for T cells?

Answer 15

CD3

Question 16

what are causes of lymphadenopathy?

Answer 16

inflammation due to infection

maligancy

Question 17

what is castlemans disease?

Answer 17

benign enlargement of lymphnodes

Question 18

superficial and generalised lymphadeopathy is suggestive of what?

Answer 18

superficial → underlyng malignancy

generalised → systemic inflammatory process or widespread malignancy

Question 19

what causes a predominant B cell repsonse in lymph nodes?

Answer 19

auto-immune conditions

infections

Question 20

what causes a predominatn phagocytic response in lymph nodes?

Answer 20

draining a tumour site

Question 21

what causes a predominant T cell repsonse in lymph nodes?

Answer 21

viral infections

drugs i.e. phenytoin

Question 22

what are the two surfaces of the spleen?

Answer 22

diphragmatic surface

visceral surface: left kidney, gastric fundus, tail of pancreasm splenic felxure of colon

Question 23

desccribe red pulp in teh spleen parenchyma?

Answer 23

sinusoids and cords

Question 24

cords in the red pulp contain what?

Answer 24

macrophages, firoblasts and cells in transit RBC, WBC, PC, CD8+T)

Question 25

sinusoids in the red pulp are lined by what?

Answer 25

endothelial celss

Question 26

white pulp in the spleen parenchyma comprises what?

Answer 26

peri-arteriolar lymphoid sheath (PALS)

Question 27

describe the immune response that occurs in the white pulp of the spleen parenchyma?

Answer 27

antigens reach white pulp via the blood before APCs present the antigen to immune reactive cells

Question 28

what are howell jolly bodies?

Answer 28

left over nuclear remnants usually cleared when blood cells are in the spleen- occur if no spleen or non functioning spleen

Question 29

splenic vein with the SMV forms what?

Answer 29

portal vein