L.48. Haemorrhage & Shock

Question 1

What does decreased blood volume lead to?

What does this result it?

Answer 1

Decreased blood volume

• > decreased blood pressure
• > shock

Question 2

Describe how a healing “aggregate” is formed.

Answer 2

Platelets form an aggregate by adhering to a lesion and clumping together. Positive feedback causes further aggregation.

Question 3

Where are many clotting factors made?

Answer 3

Kidneys

Question 4

Which vitamin do many clotting factors require?

Answer 4

Vitamin K

Question 5

Give an example of a clotting factor, and what it is broken down to.

Answer 5

Fibrinogen -> Fibrin.

Question 6

Which enzyme is required for fibrinolysis?

Answer 6

Plasmin

Question 7

What is fibrinolysis?

Answer 7

Fibrinolysis is the process of dissolving a clot which has served its purpose.

Question 8

Arterial baroreceptors try to restore blood pressure. What is this process mediated by and which hormones does it involve?

Answer 8

Mediated by : sympathetic nerves
Involves hormones : adrenaline
angiotensin
ADH

Question 9

Give an exampleof a medium term response to blood loss

Answer 9

Decreased fluid loss via kidneys

Question 10

What does the mechanism of “Starling’s Forces” ensure?

Answer 10

A constant balance between filtration and reabsorption to maintain hydrostatic and oncotic pressure.

Question 11

What is hydrostatic pressure?

Answer 11

Blood pressure

Question 12

What is oncotic pressure?

Answer 12

Plasma protein induced pressure

Question 13

Due to baroreceptor reflexes, decreased blood pressure causes _______________ of arterioles.

Answer 13

Vasoconstriction

Question 14

During haemorrhage, what do “Starling’s forces” ensure?

Answer 14

Reabsorption is greater than filtration.

Question 15

Renin-angiotensin-aldosterone and ADH are both examples of what?

Answer 15

Vasoconstrictors.

Question 16

With decreased fluid loss in the kidney, what happens to the glomerular filtration rate?

Answer 16

Decreased glomerular filtration rate

Question 17

When glomerular filtration decreases, there is increased reabsorption of Na+ and H20 by stimulating the release of ____________ and _____________ [hormones}

Answer 17

Renin-angiotensin-aldosterone

ADH

Question 18

Plasma volume decrease
->
Baroreceptor distension _________ (Increase/decrease)
->
_____________ (Increased/decreased) ADH release

Answer 18

Plasma volume decrease
-> 
Baroreceptor distension decrease
->
Increased ADH release

Question 19

Which part of the body controls thirst?

Answer 19

Hypothalamus

Question 20

Give an example of a change in the body which stimulates thirst.

Answer 20

Increased plasma osmolarity stimulates thirst.

Question 21

What action can help replace red blood cells?

Answer 21

Drinking water

Question 22

What is erythropoiesis?

Answer 22

The process of creating mature red blood cells from stem cells.

Question 23

What causes shock?

Answer 23

Inadequate blood flow to a tissue

Question 24

What is a common cause of shock?

Answer 24

Lack of blood

Question 25

Name the 2 forms of shock.

Answer 25

Reversible

Irreversible (fatal)

Question 26

Name 3 types of shock which can occur.

Answer 26

1. Hypovolaemic
2. Low resistance
3. Cardiogenic

Question 27

Describe the causes of a hypovolaemic shock.

Answer 27

Decreased ECF from haemorrhage, sweating, diarrhoea etc

Question 28

Describe the causes of a low resistance shock.

Answer 28

Widespread vasodilation, eg anaphylactic shock

Question 29

Describe the cause of a cardiogenic shock.

Answer 29

The heart fails as a pump.