haemostasis, hemorrage and shock

Question 1

what effect does a decrease in blood vol have on BP and delivery of nutrients to cells?

Answer 1

decreased BP and delivery

Question 2

what causes shock?

Answer 2

lack of blood flow to tissues

Question 3

what are the effects of shock?

Answer 3

decreased BP and delivery of nutrient to cells

Question 4

what are the 4 physiological responses to blood loss?

Answer 4

immediate - stop bleeding
short term - restore BP
medium term - restore fluid vol
long term - replace blood constituents

Question 5

the immediate response to shock is to stop blood flow, what is this called?

Answer 5

hemostasis

Question 6

what responses are involved in hemostasis?

Answer 6

• vascular response
• platelet response
• plasma response (coagulation)

Question 7

what role does smooth muscle play in the vascular response go hemostasis?

Answer 7

vascular spasms - vasoconstriction

Question 8

what role does endothelium play in the vascular response go hemostasis?

Answer 8

• platelet adhesion and aggregation

- anticlotting and fibrinolysis

Question 9

describe the platelet response in Hemostasis

Answer 9

• damage to BV causes turbulent blood flow, platelets come into contact with collagen vessel wall
• platelets clump together (aggregation) forming platelet plug

Question 10

during hemostatic coagulation, plasma proteins and tissue components combine to convert what into what?

Answer 10

fibrinogen into fibrin

Question 11

which fibrous molecule forms a blood clot?

Answer 11

fibrin

Question 12

where are the majority of clotting factors made?

Answer 12

liver

Question 13

synthesis of several clotting factors requires which vitamin?

Answer 13

vit k

Question 14

describe the enzyme cascade that results in the production of insoluble fibrin

Answer 14

• prothrombin is converted to thrombin in the presence of factor Xa, Ca, factor V and phospholipid
• prothrombin converts fibrinogen to soluble fibrin
• soluble fibrin is converted to insoluble fibrin by factor XIIIa

Question 15

what is bloodclotting factor I?

Answer 15

fibrinogen

Question 16

what is bloodclotting factor II?

Answer 16

prothrombin

Question 17

what is bloodclotting factor III?

Answer 17

tissue factor (thromboplastin)

Question 18

what is bloodclotting factor IV?

Answer 18

calcium

Question 19

how many bloodclotting factors are there?

Answer 19

12

Question 20

both the extrinsic and extrinsic coagulation pathways work on factor X to form what?

Answer 20

factor Xa

Question 21

what activates the intrinsic coagulation pathway?

Answer 21

• vascular damage

Question 22

what activates the extrinsic coagulation pathway?

Answer 22

• tissue damage

Question 23

what factors does the intrinsic coagulation pathway involve ?

Answer 23

factors VIII, IX, XI, XII

Question 24

what factor does the extrinsic coagulation pathway involve ?

Answer 24

factor VII

Question 25

both coagulation pathways work in the presence of what?

Answer 25

calcium and phospholipid

Question 26

which coagulation pathway is more important in initiated the clot after injury ?

Answer 26

extrinsic

Question 27

which coagulation pathway is more important at maintaining the blood clot once it has started ?

Answer 27

intrinsic

Question 28

which coagulation pathway has a role in thrombosis?

Answer 28

intrinsic

Question 29

after the blood clot has served its function it dissolves, what is this known as?

Answer 29

fibrinolysis

Question 30

what is fibrinolysis?

Answer 30

after the blood clot has served its function it dissolves

Question 31

fibrinolysis is undertaken by which enzyme?

Answer 31

plasmin

Question 32

the describe the steps in the process of fibrinolysis?

Answer 32

- plasminogen is converted to plasmin in the presence of plasminogen activator - plasmin converts fibrin to soluble fibrinogen fragments

Question 33

a fall in BP during hemostasis activates a compensatory mechanism triggered by which receptor?

Answer 33

arterial baroreceptors

Question 34

baroreceptor reflexes are mediated by what?

Answer 34

- sympathetic nerves | - hormones (adrenaline, angiotensin II, vasopressin [ADH])

Question 35

the medium term response of hemostasis aims to restore blood vol, how does it do this?

Answer 35

- shift interstitial fluid back into BVs - decreasing fluid loss in kidneys - increasing fluid intake

Question 36

during the medium term response to blood loss, interstitial fluid is shifted back into BVs, how is this done?

Answer 36

- baroreceptors react to decreased BP by vasoconstriction of arterioles - this decreases hydrostatic pressure pushing fluid out capillaries - oncotic pressure draws more fluid back into capillaries

Question 37

during the medium term response to blood loss, there is a decreased loss of fluid kith kidneys, how is this achieved?

Answer 37

- decreased glomerular filtration | - increased reabsorption of sodium and water (by release of ADH and renin-angiotensin-aldosterone)

Question 38

during the medium term response to blood loss, there is an increase in thirst, where is the bodies thirst centre?

Answer 38

hypothalamus

Question 39

the long term response to blood loss aims to replace plasma proteins and blood cells, what is the name of the process used to produce RBCs?

Answer 39

erythropoiesis

Question 40

which hormone regulates erythropeisis?

Answer 40

erythropoietin

Question 41

where is erythropoietin released?

Answer 41

kidney

Question 42

describe the process of erythropoiesis?

Answer 42

- decreases in RBCs - decreased oxygen delivery - kidney produce erythropoietin - erythropoietin stimulates red bone marrow to increase RBC production

Question 43

name the 3 types of shock

Answer 43

- hypovolaemic shock - law resistance (distributive) shock - cariogenic shock

Question 44

describe hypovaelemic shock

Answer 44

- decreased ECF due to haemorrhage, sweating, diarrhoea etc

Question 45

describe law resistance shock

Answer 45

- decreased peripheral resistance, wide spread vasodilation

Question 46

give an example of law resistance shock

Answer 46

anaphylactic shock

Question 47

describe cardiogenic shock

Answer 47

heart fails as pump