Blood L2-4 Flashcards
1
Q
blood functions
A
gas transport/ exchange
solute distribution
immunity
body temp
blood clot regulation
acid-base homeostasis preservation
BP stability
2
Q
blood constituents
A
erythrocytes
leukocytes
thrombocytes
soluble materials
plasma
cellular elements
3
Q
plasma constituents and functions
A
water/ plasma proteins/ globulins/ fibrinogen
thermoregulation
transport
4
Q
plasma proteins
A
serum albumin > large protein
liver-synthesised
osmotic pressure/ lipid and steroid hormone transport
5
Q
globulins
A
bind/ transport ions/ hormones/ lipids
immune proteins
6
Q
electrophoresis function
A
identifies plasma proteins for diagnostics
7
Q
erythrocytes
A
~35% Hb
primary oxygen transport
80-96 femtolitre volume
8
Q
microcytic
A
small RBC
found in Fe-deficiency anaemia
9
Q
macrocytic
A
large RBC
folate-deficiency anaemia
10
Q
erythropoiesis
A
RBC formation
26 day feedback loop
starts in bone marrow, ends in vessels
11
Q
cirrhosis
disorder
causes?
A
progressive decrease in plasma production proteins
causes: viral hepatitis, cancer, alcoholism
12
Q
number oxygen per Hb
A
4
13
Q
haemoglobin components/ structure
A
4 subunits> 2 alpha, 2 beta
4 Fe-containing haem to reversibly bind O2 molecules
14
Q
haem
A
iron-containing pigment
porphyrin ring w 1 Fe central atom
15
Q
4 types of globin
A
alpha (2 genes on ch16)
beta (1 gene on ch11)
delta
gamma
16
Q
HbA
A
97%
2a 2b
17
Q
HbA2
A
~2.5%
2a 2delta
18
Q
HbF
A
foetal
2a 2gamma
19
Q
Hb binding factors
A
oxygen partial pressure
no. free oxygen binding sites in molecule
20
Q
2 forms of Hb
A
taut
relaxed
21
Q
taut Hb
A
decreasing oxygen affinity/ partial pressure
releases oxygen
22
Q
relaxed Hb
A
increasing oxygen affin/ partial pressure
firm oxygen binding
23
Q
what does Hb bind to?
A
O2, CO2, H+ of carbonic acid, CO, NO
24
Q
haemoglobinopathies
A
abnormal globin chain production
25
thalassemia types
minor
intermediate
major
26
thalassemia
decreased production / absence of normal globin chains
defect at gene expression/ recessive
gross deletion of >1 globin genes
27
sickle cell anaemia
Glut-6-val mutation in B sub-unit
therefore polymerises at low partial pressure
causes ischaemia/ infarction
RBC life-span reduction
28
sickle cell trait
heterozygotes
rarely symptomatic
29
Glucose-6-phosphate
rate-limiting enzyme in pentose phosphate pathway required for energy and glutathione production
lacking in sickle cell RBCs
30
a-thalassemia
from India
a-globin deficiency
excess beta chains/ unstable b tetramers
31
B-thalassemia
mediterranean
b-globin deficiency
a chain excess/ no tetramers
RBC membrane damage therefore toxic aggregates at high conc
Fe overload
32
electrophoresis a-thalassemia
decreasing HbA
HbH presence
33
electrophoresis b-thalassemia
decreasing HbB
34
haemostasis
arrest of bleeding from a broken blood vessel
35
platelets
anuclear cell fragments
budded off of megakaryocytes
36
megakaryocyte
large bone marrow cell
37
thrombopoietin
hormone produced in liver/ kidney regualting megakryocyte/ platelet production
stimulates megakaryocytic extended arm via bone marrow sinusoids to vessels
38
no. platelets per megakaryocyte
1000-3000
39
platelet storage/ activation
stored in spleen
activated by sympathetic nervous system
40
platelet life span and end
~7-10 day life span prior to apoptosis/ phagocytosis in spleen/ liver
41
dense tubular system
regulates platelet activation by calcium release
thromboxane A2 synthesis site
42
platelet granule types
alpha > clotting mediators
delta > platelet activators/ clotting agent/ contain ADP/ Ca2+/ serotonin
43
vascular spasm
vessel damage releases vasoconstrictors, slowing blood flow and therefore minimising blood loss
endothelial surfaces adhere via platelets sticking to exposed collagen
44
platelet plug formation
von willebrand's factor aid sticking
plug seals break in vessel lining fro compaction/ vasoconstriction/ clotting cascade stimulation
45
prostacyclin PG12
Normal blood vessel lining release
inhibits platelet aggregation
restricts platelet plug to damaged region
46
final step of blood clotting
fibrinogen conversion to fibrin (soluble> insoluble)
fibrin plug enmeshes RBC's
47
cascade of reactions in clotting
fibrinogen > (thrombin)> fibrin monomers> (factor VIII)> fibrin polymer
48
2 thrombin stimulating pathways
intrinsic > initial stimuli exposed to collagen
extrinsic > initial stimuli blood contact exposing tissue factor
49
anti-clotting systems
anti-thrombin
thrombomodulin
tissue factor pathway inhibitor
thrombin receptor
50
anti-thrombin
inhibits clotting factors
enhanced by heparin
51
thrombomodulin
expressed by endothelial cells
binds thrombin
decreases coagulant effects/ inactivates factors V / VIII
52
tissue factor pathway inhibitor
binds to factor III/VII, prevents activation
binds factor X directly
53
thrombin reeptor
stimulates PGI/ NO/ ADP to inhibit aggregation
54
fibrinolysis
clot breakdown
55
fibrinolysis process
clots secrete PDGF beta, recruiting fibroblasts from surrounding tissue
forms scar tissue surrounding
plasmin fibrolytic enzyme dissolves
56
plasmin
tissue plasminogen factor activated > needs to bind to fibrin for activity
endothelial cell activated
57
clotting factors
proteases activating downstream factors
III, V, VIII glycoproteins
XIII transglutaminase
58
quantitative platelet defects
thrombocytopaenia
59
qualitative platelet defects
thrombopathy
60
coagulopathy
dysfunction/ deficiency of coagulation factors
61
acquired haemostasis disorders
renal disease
hepatic disease
vitamin K deficiency
drug-induced disorders
62
inherited haemostasis disorders
structural defects of vascular system
thrombotic disorder
thrombocytopaenia
thrombopathy
coagulopathy
63
thrombotic disorder
haemostasis alteration impairing clot formation combatting capacity
64
coagulopathy
deficiency of coagulation factors
65
haemorrhage
bruising/ contusion caused by Hb degradation to biliverdin/ bilizubin/ haemosiderin
66
biliverdin removal
plasmin and phagocytosis
67
thrombosis
excessive / unwanted clotting
68
thrombus
clot in vessel/ heart
69
embolus
detached mass able to travel in vessel
70
embolism
lodging of embolus
71
thrombo-embolism
blockage by thrombus
72
stenosis
abnormal narrowing of body passage
73
virchow's triad
3 risk factors for thrombosis
1. blood stasis
2. vessel wall changes
3. thrombosis changes to blood
74
anticoagulants example
warfarin
heparin
75
warfarin
oral anticoagulant
inhibits vit K
76
heparin
injection
activates antithrombin III
77
when are anticoagulants used?
atrial fibrillation
aortic valve replacement
recent surgery
autoimmune diseases
78
thrombocytopaenia
low platelet count
79
thrombocytopaenia causes
autoimmune disease
drug-induced > platelet synthesis interference and immunologic destruction of platelets
80
clinical characteristics of thrombocytopaenia
easy bruising
petechial rash
excessive bleeding
mucous membrane bleeding
81
petchiae
pin-point haemorrhages w blood leakage from capillaries, ^vascular permeability/ platelet function failure
82
inherited coagulopathies
von willebrand's disease
haemofilia A
haemofilia B
83
von willebrand's disease
autosomal dominant
lack of VW factor
poor platelet aggregation
excessive gum bleeding
84
haemofilia A
x-linked recessive
factor VIII deficiency
85
haemofilia B
factor IX deficiency
86
haemofilia treatment
replacement of missing factor
87
blood groups
blood classification based on inherited antigenic substances on RBC surface and presence/ absence of rhesus D antigen
88
blood group discovery
karl landsteiner in vienna 1901 as A/B/C blood groups
89
RBC antigen substance
protein/ glycoprotein/ glycolipid mixture
90
why may someone's complete blood group change in their life time?
infection
malignancy
bone marrow transplant
autoimmune disease
91
5 sugars in ABO system and most common 3?
fucose*
Galactose*
N-acetylglucosamine*
sialic acid
92
3 enzymes in ABO system
fucosyl transferase (FUT1)
N-acetylgalactosamine transferase (A transferase)
galactose transferase (B transferase)
93
2 genes in blood groups
ABO
H
94
ABO determination
terminal sugar structure on galactose of H substance on RBC surface
95
function of glycosyl transferases
transfer monosaccharides to polysaccharides
96
O allele encodes
truncated/ non-functional proteins
97
H gene
encodes fucosyl transferase/ FUT1
located on Ch19
dominant to h
98
bombay phenotype
hh
v rare/ no symptoms
transfuse w other hh
99
ABO gene
7 exon gene on Ch19
100
O-allele
deletioin on exon 6 > frameshift> inactive protein
101
A/B alleles
7 nuc substitutions
4 translate into amino acid differences in gene product
102
hh phenotype
no functional FUT1
May have A/B transferases
no sub. H / ABO antigens
103
blood type O
no A/B transferase
only H substance
104
blood type AB
both A/B transferase
add galactose/ N-acetylglucosamine to terminal galactose on H substance
105
antibodies belonging to A/B/O
A> beta
B> alpha
O> alpha/beta
106
agglutinogens
blood group antigens
107
agglutinins
antibodies against blood groups
108
adverse agglutinin reaction
cause RBC clumping
RBC lysis> kidney failure/ uncontrolled clotting/ circulatory shock
109
Rh+ genotypes
DD/ Dd
110
Rh- genotypes
dd
111
anti-Rh(D) antibodies
exposure required
destroy Rh(D)+ cells > RBC bound by IgG, engulfed by macrophages/ transported to liver/ spleen for removal
112
universal donor
O-
113
universal acceptor
AB+
114
newborn haemolytic disease process
Rh- mother has Rh + baby, causing anti-Rh antibody production, damaged foetal RBC w next Rh+ baby
115
newborn haemolytic disease symptoms
anaemia
jaundice
fatality
116
newborn haemolytic disease treatment
mother given anti-D immunoglobulin
117
class of ABO antibodies
IgM therefore don't cross placenta
