FOUND-SOM-HAEM

Question 1

what are the 3 components of blood and their % makeup?

Answer 1

• plasma-55%
• (buffy coat) WBCs and platelets <1%
• RBCs 45%

Question 2

what are the components of plasma?

Answer 2

>95% water
6-8% dissolved proteins
glucose
electrolytes
-hormones
-co2

Question 3

what is the difference between plasma and serum?

Answer 3

If you take the clotting factors out of plasma, then you have serum. This occurs in blood centrifugation

Question 4

describe embryonic stem cell differentiation related to haematopoiesis?

Answer 4

Blastocyte—>pluripotent cells (stem)—->endoderm/germ cells/mesoderm——>forms precursor cells-haemangioblasts

Question 5

what do haemangioblasts form?

Answer 5

vascular cells

blood cells

Question 6

what are the sites of fetal haematopoiesis?

Answer 6

• yolk sac
• liver
• spleen

Question 7

what are the sites of postnatal haematopoiesis?

Answer 7

• —>red bone marrow
• pelvis
• vertebral column
• —>extramedullary regions: thymus

Question 8

what is haematopoesis?

Answer 8

differentiation of cells to form different blood cells

Question 9

how many blood cells does each haematopoetic stem cell have the potential to produce after 20 divisions?

Answer 9

10^6

Question 10

what is the significance of RBCs being anucleate?

Answer 10

no transcription of unnecessary genes

Question 11

what is the role of RBCs?

Answer 11

-carry O2 from the lungs and return CO2

Question 12

what is the shape of RBCs and what is it significance?

Answer 12

discoid shape

-increases SA allowing gas exchange to take place over largest possible SA

Question 13

what are the main functions of thrombocytes (platelets)?

Answer 13

• form platelet plug in order to stop bleeding following injury
• initiates wound healing/ innate immune function

Question 14

what are the blood cells associated with adaptive immunity?

Answer 14

• all lymphocytes
• B cell
• CD4+ T-cell (Helper)
• CD8+ T-cell (killer)

Question 15

what is the site of maturation of B-cells ?

Answer 15

bone marrow but once mature, resides in the blood stream and lymph nodes

Question 16

What is the site of maturation of CD4+/ CD8+ T-cells?

Answer 16

thymus-but once mature, reside in lymph nodes

Question 17

what are the functions of B-cells?

Answer 17

• primary cell type of humoral immunity
• will differentiate into antibody-producing plasma cells
• also use CD4+ cells to help produce antibodies which are complimentary to the antigen

Question 18

what are the functions of CD4+ T-cell?

Answer 18

• work with MHC Class II molecules to exogenously process pathogens, and then present the antigens to B-cells
• this causes B cells to produces antibodies complimentary to antigen

Question 19

what is the role of CD8+ T cells?

Answer 19

work with MHC Class I molecules to endogenously process pathogens-killing them

Question 20

Which 7 blood cells are associated with innate immunity?

Answer 20

• macrophage
• dendritic cells
• natural killer cells
• mast cells
• neutrophils
• basophils
• eosinophil

Question 21

which blood cells, associated with innate immune system, are granulocytes?

Answer 21

• mast cells
• basophils
• neutrophils
• eosinophil

Question 22

which blood cells associated with innate immune system are phagocytes, sentinel and APC?

Answer 22

• macrophage

- dendritic cells

Question 23

what type of cell are natural killer cells?

Answer 23

lymphocytes

Question 24

what is the appearance of macrophages?

Answer 24

central round nucleus with a vacuole

Question 25

what is the appearance of dendritic cells?

Answer 25

large branchlike projections coming off the body

Question 26

what is the appearance of natural killer cells?

Answer 26

- single-lobed nucleus | - very little cytoplasm

Question 27

what is the appearance of mast cells?

Answer 27

- 'fried egg' appearance of nucleus and cytoplasm | - granules

Question 28

what is the appearance of neutrophils?

Answer 28

- multilobed nucleus | - granules

Question 29

what is the appearance of basophils?

Answer 29

- 2-lobed nucleus - purple-staining - granules

Question 30

what is the appearance of eosinophils?

Answer 30

- 2-lobed nucleus - orange-staining - granules

Question 31

what does a monocyte develop into?

Answer 31

macrophage

Question 32

what is the shape of the nucleus of monocytes?

Answer 32

horse-shoe shaped

Question 33

what are the roles of macrophages?

Answer 33

- phagocytose pathogens | - may present the digested antibodies to stimulate the rest of the immune system

Question 34

what are the roles of dendritic cells?

Answer 34

- phagocytose pathogens | - presents digested antibodies to trigger adaptive immune response

Question 35

what is the role of natural killer cells?

Answer 35

-kills tumour and virus infected cells by releasing perforin

Question 36

what are the roles of mast cells?

Answer 36

- causes vasodilation and inflammation - degranulation to release heparin and histamines - can phagocytose and present antigens too

Question 37

what are the most abundant granulocyte cells?

Answer 37

neutrophils (70%)

Question 38

what are the roles of neutrophils?

Answer 38

first responder at the site of infection - degranulates releasing toxins which kill pathogens - can also phagocytose

Question 39

what are the roles of basophils?

Answer 39

- defends against parasites | - causes allergic inflammation by degranulation to release histamine and heparin

Question 40

what are the roles of eosinophils?

Answer 40

- defends against parasites | - causes allergic inflammation by degranulation to release histamine and heparin

Question 41

how does cell differentiation of blood cells occur?

Answer 41

- gene expression - cellular environment - cellular signalling from transcription/ growth factors

Question 42

how are erythropoietins (EPO) produced?

Answer 42

produced by interstitial fibroblasts of the juxtaglomerular apparatus in the kidney

Question 43

what do EPOs do?

Answer 43

stimulate production of RBCs

Question 44

where are thrombopoietin (TPOs) produced?

Answer 44

in the liver

Question 45

what is the function of TPOs?

Answer 45

aids production of platelets

Question 46

how are granulocyte-colony stimulating factor (G-CSF) produced?

Answer 46

produced by macrophages and endothelial cells

Question 47

what is the role of G-CSF?

Answer 47

stimulates production and maturation of neutrophils

Question 48

what are interleukins?

Answer 48

proteins that mediate communication between cells

Question 49

which cell type is most involved in the cutaneous immunosurveillance?

Answer 49

-langerhans cells

Question 50

which transcription factor is involved in the production of neutrophils?

Answer 50

G-CSF

Question 51

which WBC type bridges innate and adaptive immunity?

Answer 51

monocytes-as they can engulf and destroy foreign organisms and particles through phagocytosis (innate) and then stimulate T and B cells through presentation of digested peptides on their cell surface (adaptive)

Question 52

describe the basic structure of immunoglobulin molecule

Answer 52

- heavy and light chains encoded by different genes - constant region functions to bind specific receptors Fc receptors - variable region functions to bind antigen

Question 53

what are the 5 types of immunoglobulins?

Answer 53

- IgM - IgG - IgA - IgE - IgD

Question 54

which immunoglobulins are involved in innate immune cell activation?

Answer 54

IgA | IgE

Question 55

what are the roles of IgG?

Answer 55

- opsonisation - activation of complement - immune cell activation

Question 56

what is the role of IgM?

Answer 56

activation of serum complement

Question 57

which cytokines are important for adaptive immunity?

Answer 57

- IFN-induces IgG class switch and promotes development of effector CD8+ T cells - IL4/ IL21-induces IgG class switch, aids affinity maturation of B cells for production of plasma and memory cells - IL17-involved in mucosal immunity - IL10-immune response inhibition

Question 58

describe B-cell maturation.

Answer 58

- germinal cell reaction - B cells enter LN to encounter antigen and cognate help from CD4+ T-cells - affinity maturation occurs to enhance antibody-antigen interaction - generation of immune memory - -memory B cells - -plasma cells

Question 59

what is the role of mature RBCs?

Answer 59

o2 transportation

Question 60

in which process are RBCs synthesised?

Answer 60

erythropoiesis

Question 61

what are the steps involved in erythropoiesis?

Answer 61

IN BONE MARROW: stem cell---->proerythroblast---->early erythroblast (ribosome synthesis)---->late erythroblast (Hb acculmulation)---->normoblast------>reticulocyte (remains in BM for 3 days) CIRCULATION: reticulocyte-----(24-48hrs)---->erythrocyte

Question 62

what is the average lifespan of an erythrocyte?

Answer 62

120 days

Question 63

which 3 organs are involved in erythrocyte removal?

Answer 63

- spleen - liver - bone marrow

Question 64

which cells are involved in erythrocyte removal?

Answer 64

macrophages

Question 65

describe how macrophages remove erythrocytes.

Answer 65

- macrophages engulf and break down old RBCs - left with lots of Hb - Hb broken down into globin and haem - globulin broken down into amino acids - haem broken down into Fe2+ and bilirubin

Question 66

what are the amino acids from globin used for?

Answer 66

used in haematopoiesis in bone marrow

Question 67

what are the Fe2+ ions from haem used for?

Answer 67

- obtains a Fe2+ transporter-transferin in liver | - travels to bone marrow for erythropoiesis

Question 68

what happens to the bilirubin from haem?

Answer 68

-enters bile -secreted into duodeum via the bile duct -excreted in faeces OR -reabsorbed and excreted in urine

Question 69

what hormone is important in influencing erythropoiesis and what does it do?

Answer 69

erythropoietin-stimulates erythropoietin

Question 70

which organ secretes hormone erythropoietin?

Answer 70

kidney

Question 71

what is a potential consequence of kidney failure due to its resulting inability to secrete erythropoetin?

Answer 71

anemia