Haematopoiesis

Question 1

extra medullary haematopoiesis is?

Answer 1

haematopoiesis that occurs outside the bone marrow

Question 2

What are the primary lymphoid organs?

Answer 2

thymus and bone marrow

Question 3

What are the secondary lymphoid organs?

Answer 3

adenoid tonsils
lymphatics
spleen
peyers patches

Question 4

What is the primary lymphoid organs the site of?

Answer 4

immune cell production and development

Question 5

Regarding bone marrow where are the sites of haematopoiesis?

Answer 5

pelvis
sternum
vertebrae
heads of femur

Question 6

What is bone marrow

Answer 6

spongy tissue inside bones that produces blood cells. includes immature blood cells and stromal cells. Stromal cells form extracellular matrix and secrete growth factors. include macrophages, fibroblasts adipocytes and endothelial cells

Question 7

where can red marrow be found?

Answer 7

flat bones and heads of long bones, produces most blood cells

Question 8

Where can yellow marrow be found?

Answer 8

in long bones, produces some white cells

Question 9

What are immature t cells called?

Answer 9

thymocytes

Question 10

the thymus has a _____ and a ______

Answer 10

cortex and a medulla

Question 11

what occurs in the cortex?

Answer 11

Positive selection

Question 12

What occurs in the cortex-medulla border?

Answer 12

Negative selection

Question 13

what occurs in the medulla?

Answer 13

differentiation

Question 14

where are most of the thymocytes?

Answer 14

in the medulla

Question 15

What is the function of the thymus?

Answer 15

generate and select a repertoire of T-cells that protect the body from infection

Question 16

T cell receptors recognise antigen ____ ______

Answer 16

MHC complexes

Question 17

What does the cortex-medulla remove in negative selection?

Answer 17

T cells that have receptors that recognise self antigen MHC complexes

Question 18

What is the collective name for positive and negative selection in the thymus?

Answer 18

Central tolerance

Question 19

___% of the thymocytes die before reaching maturity

Answer 19

95

Question 20

what is meant by thymic involution

Answer 20

The thymus decreases in size with age which contributes to a decline in immune function with old age

Question 21

by what age is the thymus often completely replaced by fatty tissue?

Answer 21

70 years

Question 22

What is the site of secondary lymphoid organs?

Answer 22

lymphocyte maturation, antigen entrapment and blood cell destruction

Question 23

List the types of MALT

Answer 23

peters patches
adenoid tonsils
appendix
lymphoid follicles in intestine
lymphoid follicles in mucous membranes lining he airways and genital tracts

Question 24

What does MALT stand for?

Answer 24

Mucosal associated lymphoid tissue

Question 25

about who much fluid is lost by the capillaries a day?

Answer 25

4L

Question 26

Where does the fluid from capillaries go?

Answer 26

travels in the lymphatic vessels and collects in thoracic duct and drains in subclavian vein

Question 27

When foreign antigens enter the lymph system where do they become trapped?

Answer 27

Lymph nodes

Question 28

what are the lymph nodes a site of?

Answer 28

activation and division of antigen activated B and T cells

Question 29

Only a few activated B cells find their way into the _________ ______ to meet activated __ cells that provide ____ help

Answer 29

germinal centres T cells B cell

Question 30

What do the B cells in germinal centres do?

Answer 30

divide to become plasma cells and secrete Ab to fight infection

Question 31

What is the lymph node packed with?

Answer 31

lymphocytes macrophages dendritic cells

Question 32

What are the three zones of the lymph node?

Answer 32

Cortex Paracortex Medulla

Question 33

what is in the cortex?

Answer 33

primary follicles containing B lymphocytes | after antigenic challenge these enlarge to form secondary follicles containing a germinal centre

Question 34

What is in the Paracortex?

Answer 34

T lymphocytes

Question 35

What is in the medulla?

Answer 35

macrophages

Question 36

Where can you find the spleen?

Answer 36

upper left abdominal cavity

Question 37

the spleen is the ______ _______ of blood int he body

Answer 37

largest filter

Question 38

the spleen plays a major role in what?

Answer 38

mounting an immune response to antigens in blood | storage of RBCs, neutrophils and platelets

Question 39

in the spleen the blood passes from what pulp to what pulp?

Answer 39

White pulp to red pulp, and re-enters circulation by passing across the endothelium into venous sinuses passing into the splenic vein

Question 40

Blood enters the spleen via?

Answer 40

the splenic artery giving rise to arterioles which end up in CORDS

Question 41

What is in the red pulp?

Answer 41

surrounds the artery forming a periarteriolar lymphoid sheath (PALS) containing mainly t-lymphocytes.

Question 42

What occurs in Germinal centres?

Answer 42

B cell memory response

Question 43

What is in the marginal zone?

Answer 43

mainly B-cells and macrophages

Question 44

The cords in the red pulp are?

Answer 44

packed with macrophages and Ab-secreting plasma cells. Sinus walls act as a filter where only healthy deformable blood cells can squeeze out.

Question 45

MALT are what for pathogens?

Answer 45

major sites of entry

Question 46

MALT contains more _______ than the spleen lymph nodes, bone marrow combined.

Answer 46

Ab producing plasma cells

Question 47

Tonsils are located where?

Answer 47

within lingual, paladin and pharyngeal

Question 48

What is the structure of tonsils?

Answer 48

meshwork of reticular cells, fibres interspersed with lymphocytes, macrophages, granulocytes and mast cells

Question 49

what is the function of the tonsils?

Answer 49

defend against antigens entering through nasal and epithelial routes

Question 50

What is haematopoiesis?

Answer 50

process of the production of blood cells

Question 51

blood cells are derived from what type of stem cell?

Answer 51

pluripotent/multipotent

Question 52

the stem cell undergoes a commitment division to either a...

Answer 52

myeloid or a lymphoid progenitor

Question 53

Myeloid cells differentiate to:

Answer 53

granulocytes, macrophages, megakaryocytic (platelets), eythrocytes

Question 54

Lymphoid cells in the bone marrow differentiate to:

Answer 54

T cells, B cells, NK cells

Question 55

Commitment of the stem cell to a myeloid/lymphoid progenitor depends on:

Answer 55

Gf and cytokines

Question 56

Stem cells grow on a mesh of..

Answer 56

STROMAL CELLS

Question 57

stroll cells provide:

Answer 57

haemopoietic growth factor

Question 58

What does haemopioietic growth factor not provide?

Answer 58

erythropoietin and thrombopoietin

Question 59

Where are erythropoietin and thrombopoietin synthesised?

Answer 59

erythropoietin - kidney | thrombopoietin - liver