Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Bio 153 midterm lecture > hemostasis > Flashcards

hemostasis Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What is hemostasis?

A

stoppage of bleeding in response to blood vessel damage

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

what is hemostasis triggered by

A

chemicals released/ activated by damaged cells & platelets

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

what is the purpose of hemostasis

A

to prevent blood loss

build a framework for tissue repair

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

What are the 3 major phases of hemostasis

A

1) Vascular phase
2) platelet phase
3) coagulation phase

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

What are the 4 major events in hemostasis

A

1) Vascular spasm
2) platelet plug
3) Activation of platelets
4) Coagulation

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

What is the major event that happens in the vascular phase?

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

What is a vascular spasm

A

vessel spasms in damaged blood vessel.

the smooth muscle contracts to reduce blood flow to injured site

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

what do the endothelial cells (lining of the vessel) do during the vascular phase?

A

release endothelins

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

what are endothelins?

A

Peptide hormones that:

  • Stimulate contraction of smooth muscle
  • make endothelium sticky
  • stimulate division/repair
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 2 major events of the platelet phase?

A

1) Formation of platelet plug

2) activation of platelets

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

What do the platelets begin by doing in the platelet phase?

A

they adhere to the collagen fibres that are exposed when the endothelium is damaged

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

what is the von willebrand factor purpose?

A

it stabilized the bound platelets when they begin to adhere to the collagen

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

what happens when the platelets begin to aggregate

A

as the become sticky, they become activated by aggregating to each other and this forms a PLATELET PLUG !!

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

What do the activated platelets release?

A

granules of:

  • Sereotinin
  • thromboxane, A2+ ADP
  • PDGF
  • Ca2+
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does serotonin do?

A

Stimulates more vascular spasm & platelet aggregation

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

what does the thromboxane A2+ ADP do?

A

stimulates platelet aggregation

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

What does the platelet derived growth factor do?

A

promotes vessel repair

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

what does the ca2+ do?

A

it promotes coagulation

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

is formation of platelet plug positive or negative feedback mechanism ?

A

Positive! +++

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

what is coagulation?

A 
Blood clotting (liquid to gel) 
the result of this will be a clot
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is clot?

A

a tangle of fibrin & cells

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

what are clotting factors?

A

proteins in the blood (many are enzymes)
the circulate as inactivated procoagulants
they must be activated for coagulation to occur (by an enzyme)
they are numbered I - XIII (in the order they were discovered)

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

Where are clotting factors made?

A

the liver

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

what do clotting factors require to be made?

A

VITAMIN K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the 2 clotting pathways

A

1) intrinsic
2) Extrinsic
* Both go into common path tho

26
Q

where is the intrinsic pathway initiated

A

within the blood

27
Q

what triggers the intrinsic pathway?

A

when clotting factor XII and platelets are activated by COLLAGEN

28
Q

what does intrinsic pathway require?

A

Platelet phospholipid (PF3) expressed when platelets are exposed to collagen

29
Q

where is collagen?

A

In the C.T and walls of the torn vessel

30
Q

Why does the intrinsic pathway occur in test tube?

A

they are a negatively charged surface…

It has the same effect as collagen

31
Q

Is the intrinsic pathway slow or fast?

A

SLOW :-(

32
Q

what initiates the extrinsic pathway?

A

chemical external to the blood

33
Q

what triggers the extrinsic pathway?

A

chemical released by damaged cells

TISSUE FACTOR

34
Q

what does tissue factor do?

A

activates platelets

35
Q

What is tissue factor also known as?

A

thromboplastin

36
Q

is the extrinsic pathway slow or fast?

A

Faster! under 2 mins

37
Q

What do both pathways do?

A

activate factor X

38
Q

what does clotting factor X do

A

Initiates the common pathway.. which will result in a network of fibrin

39
Q

do both extrinsic and intrinsic pathways usually occur simultaneously or just usually one or the other?

A

simultaneously activated in most cases

40
Q

What is hemophilia

A

a genetic defect in 1+ genes that code for clotting factors
affected individuals have blood that won’t clot normally
( its usually VIII factor…)

41
Q

What is a a thrombus

A

clot that forms in blood vessels of the heart and partially or completely obstructs flow

42
Q

what is an embolus

A

any detached, intravascular mass that is carried by circulation, which is capable of clogging blood vessel

43
Q

what is meant by clot retraction

A

shrinking of a clot

44
Q

what is meant by fibrinolysis

A

breaking down of fibrin

45
Q

What ion is needed for clot formation

A

calciummm

46
Q

[ activated factor X] & [Ca2+] & [activated factor V] =

A

prothrombinase - a complex of Xa & Va

it is now a FUNCTIONAL enzyme

47
Q

what does prothrombinase activate?

A

Prothrombin (II)

48
Q

What is the activated form of prothrombin called?

A

thrombin (IIa)

49
Q

What does thrombin activate?

A

fibrinogen (I)

50
Q

what is the activated form of fibrinogen?

A

fibrin (Ia)

51
Q

what happens when fibrin is activated?

A

insoluble cross-linked fibrin mesh and trapped cells AKA A CLOT !!

52
Q

what do the platelets do first to break down a clot?

A

release PDGF: promotes healing of the vessel wall

53
Q

what do the endothelial cells do to break down the clot?

A

they release TPA (tissue plasminogen activator)

54
Q

What does TPA do?

A

it activates plasminogen (plasma protein that is trapped in the clot)

55
Q

what is the activated form of plasminogen

A

plasmin

56
Q

what does plasmin do?

A

it is a fibrin digesting enzyme

it is the cause of fibrinolysis

57
Q

what is fibrinolysis

A

retracted clot is dissolved as fibrin is digested by plasmin over several days

58
Q

what else is happening within the clot during breakdown?

A

Clot retraction

59
Q

what is clot retraction?

A

The platelets contract and pull torn edges of the damaged vessel closer together to make repair easier

60
Q

how are the platelets able to contract??

A

because they contain actin & myosin like a muscle

61
Q

What happens to the serum during clot breakdown

A

it is squeezed out of the clot

62
Q

what is serum?

A

plasma without any clotting proteins in it

Bio 153 midterm lecture (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions