Blood system Flashcards Preview

HUBS192 Blood > Blood system > Flashcards

Flashcards in Blood system Deck (37)
Loading flashcards...
1

function of blood

transport, immune response, coagulation

2

composition of blood plasma

  • 90% water
  • 10% solutes including plasma proteins, nutrients, waste products etc

3

3 groups of plasma proteins

  1. albumins - maintain osmotic pressure; hormones, coagulation factors
  2. globulins - antibodies
  3. fibrinogen - blood clotting

4

cells in blood

  • erythrocytes (RBCs)
  • leukocytes (WBCs)
  • Thrombocytes (platelets)

5

types of WBCs

  1. granulocytes
  2. monocytes
  3. lymphocytes

6

types of granulocytes

  1. neutrophils
  2. basophils
  3. eosinophils

7

what does blood transport

O2, nutrients, CO2, hormones, phagocytic cells, antibodies, coagulation factors

8

function of neutrophils

cellular defence - phagocytosis 

9

function of basophils

anticoagulation and inflammatory response

10

function of eosinophils

cellular defence and anti-inflammatory

11

function of monocytes

aggressive phagocytosis of bacteria, debris etc

12

function of lymphocytes

humoral defence - secrete antibodies

13

features of neutrophils

  • 65% of blood cells
  • multilobed nucleus
  • small pink staining granules

14

features of basophils

  • <1% of blood cells
  • 2-lobed nucleus
  • large purple stained granules

15

16

features of eosinophils

  • 2-5% of blood cells
  • 2-lobed nucleus
  • large orange stained granules

17

features of monocytes

  • 3-8% of blood cells
  • horse-shoe shaped nucleus
  • steel blue colour

18

features of lymphocytes

  • 25% of blood cells
  • round nucleus
  • little cytoplasm

19

features of RBC

  • Biconcave disc shape for large surface area: volume ratio

  • Flexibility for movement though narrow capillaries

  • Contain large amounts of Hb- 1/3 of weight of RBC

20

features of RBC production (erythropoiesis)

  • stimulated  by erythropoietin (EPO) 
  • requires folic acid, vit B12, thymine, iron
  • controlled by homeostatic mechanism with EPO
  • helped by testosterone
  • decrease in RBC sensed by kidneys

21

destruction of RBCs

  • life span = 120 days
  • break apart in capillaries
  • fragments removed by macrophages
  • iron recycled in bone marrow, amino acids to produce more proteins, bilirubin pigment transported to liver and excreted in bile

22

anaemia definition and causes

  • A reduction in the concentration of Hb (reduced O2 carrying capacity of blood- insufficient to supply tissues)

causes:

  • decreased production of RBCs
  • increased destruction of RBCs
  • severe bleeding

23

3 components of haemostatic response to injury

  • Blood vessels vasoconstrict (stage I haemostasis) 
  • Platelets form the platelet plug (stage I haemostasis) 
  • Coagulation cascade: sequential series of chemical reactions of clotting factors, resulting in the formation of a fibrin clot (stage II and III haemostasis) 

24

stage 1 haemostasis

  1. Vessel damage  
  2. altered endothelial surface
  3. exposure of sub-endothelium
  4. platelets get activated and begin to aggregate (form platelet plug)
  5. activated platelet release mediators (e.g. ADP, thromboxane A2) that activate more platelets (platelet plug gets bigger) and constrict blood vessels 

25

stage 2 of haemostasis

  • Prothrombin, prothrombin activator and calcium to be released, which produces thrombin which combines with fibrinogen to make fibrin (the spider-web like mesh stuff that holds all platelets together)
  • intrinsic or extrinsic pathways

 

26

intrinsic pathway

  • Intrinsic pathway already has everything (clotting factors) in blood 
  • clotting factors XII, XI and IX

27

extrinsic pathway

  • Extrinsic pathway requires tissue factor (from sub-endothelium) to be activated 
  • clotting factor VII

28

common pathway

  • Pathways join to form a common pathway at production of "Activated factor X"

  • factor X converts prothrombin to thrombin, which then converts fibrinogen to fibrin (forming a clot) 

  • Ca2+ is essential for the common pathway 

29

haemophilia A

absence of factor VIII

30

haemophilia B

absence of factor IX