composition/features of blood - L21

Question 1

innate vs adaptive immune

Answer 1

innate are rapid, not specific to pathogens (includes external 1st line and internal 2nd line defence)
adaptive are slower, specific to pathogens (only 3rd line of defence), has memory

Question 2

complement pathway activation

Answer 2

3 arms (ways of activation) - classical (antibodies), lectin (carbohydrates), alternative (senses bacteria surface)

Question 3

complement pathway summary

Answer 3

complement components break down proteolytic cascade –> anaphylotoxins (e.g. c3a c3b) attract and activate phagocytes in opsonisation when convertases permanently bind in bacterial membrane–> lytic pores form MAC after c5 for lytic digestion

Question 4

coagulation pathway activation and their factors

Answer 4

two arms (ways of activation):
intrinsic (contact w surfaces) or extrinsic (tissue damage)

intrinsic has factors 8,9,10,11,12
extrinsic has factors 5,7,10

Question 4

coagulation pathway summary

Answer 4

both pathways have factor X –> factor Xa turns prothrombin into thrombin –> cleaves fibrinogen into many fibrins –> fibrins forms clot

Question 5

declot pathway and TPA

Answer 5

plasminogen activation turns into plasmin which breaks down fibrin molecules

Tissue Plasminogen Activator can be injected to break down clots (treats myocardial infarction)

Question 6

how haemoglobin works in gas exchange?

Answer 6

4 heme proteins have Fe (II) in middle

Iron binds O2

in venous blood O2 pressure is low so O2 dissociates into tissues, CO2 pressure high so CO2 associates to heme

in lung alveoli O2 pressure high so binds to heme, CO2 low so CO2 dissociates from heme

Question 7

major blood proteins

Answer 7

albumin - nearly 50% of blood proteins, maintains colloidal osmotic pressure (buffer against water movement), binds /transports small molecules (hormones)

fibrinogen - 7% of blood proteins, forms cross-linked fibrin clot via coagulation

Question 8

blood cell differentiation

Answer 8

all from multipotent CD23 stem cell –> myeloid: erythrocytes, megakaryocytes, monocytes, mast cells, eosinophil, basophil, neutrophil
lymphoid: B cells, T cells

Question 9

immunoglobins and multiple myeloma

Answer 9

antibodies produced by B cells

multiple myeloma - form of leukemia where malignant B cells overproduce one antibody. Diagnosed by serum electrophoresis by sharp peak in gamma band

Question 10

functions of electrolytes

Answer 10

HCO3-, creatine, creatinine act as buffers to changes in pH

Na+, Cl- water movement, channels

Mg+, Ca ++(essential for clotting), K+ control tissue function

Question 11

antibodies study

Answer 11

serology studies antibodies to see whether someone is infected, past infections, how long immunity lasts etc

Question 12

antigen structure

Answer 12

antigens make pathogens immunogenic and are reactive to antibodies and cells

have several epitopes (small parts of antigen that receptor binds to)

Question 13

2 functions of blood pressure

Answer 13

1.) even blood flow through capillaries which require high pressure to force through because thin

2.) high enough to prevent coagulation but low enough that vessels don’t rupture

Question 14

hypotension vs hypertension

Answer 14

hyper=high blood pressure > 130

hypo=low blood pressure <100

default esp in aorta is 120/80 (when left ventricle contracts/when heart relaxed)

Question 15

Circulatory system overview

Answer 15

5L of blood average, 14000L pumped per 24 hrs, can lose up to 1L before significant reduction in bp

muscular arteries and valves provide directional pressure

Question 16

major components of blood

Answer 16

cells (myeloid, erythroid, lymphoid), proteins, lipids, electrolytes, vitamins/hormones, glucose, complements, coagulation factors

Question 17

proteins in blood

Answer 17

major:
albumin - binds/transports small molecules, maintains colloidal osmolarity (buffer to H2O movement), nearly 50%

fibrinogen - clotting, 7%

others:
haemoglobin
immunoglobin - diverse repertoire, produce by B cells, for humoral (soluble) immunity

Question 18

lipids in blood

Answer 18

lipoproteins: HDL (high density lipoprotein), LDL, VLDL bind lipids from food or produced by tissues; named by relative densities seen in centrifugation

Question 19

electrolytes

Answer 19

Ca++(essential to coagulation factors), K+, Mg+ control muscle/nerve tissue function by regulation of channels & pumps

HCO3-, creatine, creatinine - isotonicity, buffers of pH, maintained at 7.4

NaCl - gradients/channels

Question 20

complements

Answer 20

9 proteins which coat pathogens to identify them for phagocytosis - opsonisation

major complement is C3

Question 21

coagulation factors

Answer 21

13 proteins cleaved in proteolytic cascade resulting in breakdown of fibrinogen to fibrin

haemophilia caused by missing factor, usually factor VIII

Ca++ essential to coagulation

Question 22

cells in blood

Answer 22

erythroid - RBC
myeloid - WBC innate
lymphoid - adaptive B/T cells