Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

M103 T2 > M103 T2 L2 > Flashcards

M103 T2 L2 Flashcards

(97 cards)

Start Studying
1
Q

How is haemostasis prevented from spontaneously occuring in the body?

A

the endothelium secretes anticoagulants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What happens in the endothelium when it is injured?

A

it stops secreting anticoagulants and instead secretes VWF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the three platelet-based pathways to repair blood vessels? (PMV)

A 
PHG, meshwork, vasoconstriction
--
the formation of a primary haemostatic plug 
a meshwork on the clot via coagulation  
vasoconstriction to slow down blood flow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What three activities can platelets use to form a primary haemostatic plug?

A

(3As - dcg)
adhesion to the wall - exposed collagen in the basement membrane
activation - exocytose their dense granules
aggregation - the platelets stick together to start forming a plug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a clot made up of?

A

lots of little tiny fibres in every direction with cells stuck between them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What types of substances are released for vasoconstriction to occur?

A

the release of vasoconstrictors and coagulants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How many platelets is produced by one megakaryocyte?

A

on average 4000 platelets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What do platelets do when they’re activated?

A

exocytose - excrete various chemicals and vasoconstrictors
they change shape
increase in the amout of o2 they consume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What two terms are used to describe the two states of platelets?

A

quiescence - inactive / at rest - have smooth surfaces

pseudopodia - irregular shape / activated - have irregular surfaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What three compounds are contained in the dense granules of platelets?

A

(SAC)
serotonin
ADP
calcium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the relationship between ADP and platelets?

A

ADP triggers platelet activation and stimulates aggregation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are examples of blood thinners?

A

Prasugrel and Ticagrelor (antiplatelet agents)

Aspirin and Clopidogrel (anticoagulants)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the role of fibrinogen in clotting?

A

help the platelets bind to eachother and to the collagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What substances are secreted during platelet activation?

A

ADP (activates the P2Y receptor)

TXA2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does ADP use positive feedback to trigger platelet activation?

A

the ADP secretion will activate one platelet
when other platelets detect the ATP, they also activate
leads to positive feedback where more and more platelets activate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Are factors activated in the blood?

A

no, they mostly circulate in the form of inactive precursors so that reactions only happen when they need to rather than all the time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What special about factors 5 & 8?

A

they are co-factors not enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does tissue factor work?

A

when an individual cell is damaged, TF in the basement membrane underneath is exposed
it activates inactive clotting factors in the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How can atrial fibrillation cause a stroke?

A

the atrium is unable to pump successfully so blood just sits there
can form a thrombus which can travel to the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What two chemicals are added to blood to stop it from clotting in the lab?

A

citrate

heparin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the stages involved in coagulation?

A

fibrinogen (+ thrombin) > fibrin + factor 13 + Ca2+
causes cross links in the fibrin
forms a stable clot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which two coagulation cascades are there?

A

the tissue factor pathway (ex)

the contact activation pathway (in)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is thrombin activated by and how?

A

Factor Xa and Factor Va as a co-factor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How is Factor X activated?

A

by Xase from either the extrinsic or intrinsic pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How does positive feedback occur in coagulation?
thrombin activates Factor V & VIII into Factor Va and VIIIa factor VIII contributes to Intrinsic Xase and factor V contributes to the thrombinase essentially, it will activate thrombin itself, so thrombin activates upstream cofactors IOT activate itself
26
Which factors belong to the prothrombin group?
factors II, VII, IX and X | 279,10
27
Which factors belong to the thrombin group?
Factors I, V and VIII | 1, 5, 8
28
When will the amount of thrombin in circulation increase?
inflammation pregnancy with oral contraceptives
29
Where are clotting factors in the body?
made in the kidney | secreted into the blood
30
What is vitamin K's function?
helps blot clot | required to synthesise various enzyme coagulation factors, in particular prothrombin
31
Which prothrombins require vitamin K to be synthesized?
2, 4, 5, 7
32
What happens if anticoagulant factors go into overdrive?
the inhibition of coagulation, fibrinolysis, accumulating blood vessel damage and eventual haemorrhaging
33
Where does plasmin come from and how does it activate?
inactive plasminogen, made as a plasma protein by the liver, activated by tPa
34
Where does protein C come from? and what is its function?
starts an inactive enzyme made by the liver | it is activated on surface of endothelial cells
35
What substance does antithrombin III work with and why?
always works with heparin | by itself, is very inactive / with heparin, powerful
36
What three substances does antithrombin III and heparin block from working?
thrombin Factor Xa Factor IXa
37
How can the effects of heparin be reversed in the lab?
protamine sulfate
38
What are the effects of an antithrombin III deficiency?
risk of thrombotic disease
39
What is the recombiant form of antithrombin III used for medically?
thrombotic disorders
40
What are the effects of a vitamin K deficiency?
reduced coagulation
41
What is a vitamin K deficiency usually caused by and how?
liver disease - it affects the production of bile salts so fat absorption can't occur AAR vitamin K can't be produced by bacteria in the LI
42
What is haemophilia A caused by?
a congenital lack of factor VIII
43
Is haemophilia A more common in males or females?
Males - the condition is X-linked so with the exception of females who are homozygous for the mutated gene, only males show symptoms
44
How is haemophilia A treated?
injected forms of purified factor VIII - purified from an animal or blood products it's an expensive and rare medication
45
Why are the symptoms for haemophilia B the same as those for A?
haemophilia B involves a genetic defect in factor 9 | Factors 8 & 9 are both part of the intrinsic pathway and work together to activate factor 10
46
How can purified factor VIII be generated in a cheaper way?
genetically modified animals' milk
47
What is the positive feedback mechanism caused by atherogenesis?
monocytes / WBCs become foam cells they can die and release their contents (cytokines and chemo-attractants - more signalling) which attract more monocytes positive feedback mechanism
48
How does atherogenesis cause the reactivity of cholesterol esters?
lipids are deposited in lesions by LDL the deposits can be made to be solid or hard by cholesterol esters in the lesion the deposits can also be oxidized, making oxygen radicals the cholesterol esters become so reactive that they can destroy any immune cells that try to regulate them
49
What three things is atherogenesis a disease of? (LIE)
lipids inflammation endothelium
50
What happens during atherogenesis to cause inflammation?
the endothelium expresses chemoattractants - they attract WBCs which allow monocytes to find and enter lesion when the endothelium is lost, exposing the collagen basement layer, it stimulates coagulation Endothelium normally covers collagen and basement membrane when the endothelium is lost, the vessel can't control its dilation - can't control haemostasis
51
When are anti-platelet agents used instead of anticoagulants?
in acute coronary syndromes to prevent clotting in arteries where anticoagulants have limited effects
52
What are the uses of aspirin?
they are commonly used to reduce the risk of heart attack | acts as a blood thinner - is an antiplatelet agent
53
What are the medical uses of anti-coagulants?
prevent clotting in veins so it is prophylactic for DVT and PE's
54
What are three examples of thrombolytics?
tPA Streptokinase Urokinase
55
What are three common anti-coagulants?
heparins NOACs Warfarin
56
What are the features of prothrombin Factors?
enzymes that need vitamin K for their synthesis and calcium for their activation are stable they all ultimately contribute to prothrombin synthesis
57
Why is platelet activation required for some coagulation steps of haemostasis?
bc the PPLPDs on the membrane are essential for driving some parts of the rest of haemostasis forward
58
How is vitamin K found in the body?
vitamin K has to be taken into the diet
59
What are the features of factors in the thrombin group?
activated by thrombin V & VIII are co-factors - 5 works with 10 and 8 works with 9 Factor I is fibrinogen
60
What is the extrinsic pathway activated by?
external trauma
61
What is the overall effect of the extrinsic pathway?
it causes blood to escape from the vascular system
62
What is the difference between the extrinsic and intrinsic pathways?
extrinsic is quicker than intrinsic | intrinsic is more important than extrinsic
63
Why is it called extrinsic pathway?
because it is activated by TF, a protein extrinsic to the blood
64
What is the intrinsic pathway activated by?
by trauma inside the vascular system | by platelets, exposed endothelium or collagen
65
How does the intrinsic pathway work?
it amplifies the coagulation cascade via positive feedback
66
What is Extrinsic Xase a combination of?
tissue factor and factor 7a
67
What is Intrinsic Xase a combination of?
Factors 8a and 9a
68
Which factor is fibrinogen?
Factor I
69
What is the role of plasmin?
it dissolves the fibrin of blood clots
70
Where is Antithrombin III made?
in the liver
71
What is haemophilia B caused by?
a genetic defect in factor 9 | causes a factor IX deficiency
72
What are antiplatelets otherwise known as?
anti coagulants
73
What is the use of fibrinolytics?
they dissolve fibrin in arterial disease - break clots
74
What are Fibrinolytics otherwise known as?
clot-busting drugs | thrombolytic agents
75
What key substance is produced by COX catalysation?
thromboxane
76
What is the physiological role of aspirin?
it blocks the formation of TXA2 in platelets
77
What substance do heparins work in co-operation with?
AT III
78
How are heparins administered?
injection into a vein or under the skin
79
What is the role of heparins?
they inhibit coagulation by inhibiting Factor Xa
80
What does NOAC stand for?
Novel Oral Anti-Coagulant
81
What are NOACs alternatives to?
warfarin | for high-risk patients who have atrial fibrillation
82
When is rivaroxaban used specifically?
DVT PE to prevent blood clots in atrial fibrillation to prevent blood clots following hip or knee surgery
83
What substance does Rivaroxaban inhibit?
factor Xa
84
What terms are associated with warfarin?
anticoagulant | vitamin K antagonist
85
What is the onset of warfarin?
has a slow onset of 2 days and requires monitoring
86
How is warfarin administered?
injection iv orally - pills
87
What is the role of warfarin?
it prevents the recycling of vitamin K | to reduce clotting
88
What three substances are responsible for vasoconstriction?
Serotonin, ADP and TXA2
89
What are the two main types of blood thinners and how do they work?
anticoagulants - slow down the coagulation process of the body antiplatelet agents - prevents platelet aggregation so they can't develop into a clot
90
What is another term for warfarin?
Coumadin
91
How does Prasugrel work as an antiplatelet agent?
it inhibits ADP receptors | AAR, it inhibits the ADP-mediated platelet activation and aggregation occurs
92
How do Aspirin and Clopidogrel work as anticoagulants?
they slow the blood's clotting action by making platelets less sticky
93
How does Ticagrelor work as an antiplatelet agent?
it blocks the P2Y12 receptor responsible for promoting platelets and blood clots
94
What is the function of protein C?
it inactivates Factor Va & Factor VIIIa | it works with a co-factor Protein S to inactivate Va
95
Why are vitamin K deficiencies rare?
bc vitamin K is made by bacteria in the LI | it's also found in leafy green vegetables
96
How do WBCs become foam cells?
they enter a lesion and consume local cholesterol esters
97
What is nitrogen oxide's relationship with inflammation?
in normal conditions it is anti-inflammatory | in abnormal conditions it is pro-inflammatory

M103 T2 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions