Haemodynamic Disorders

Question 1

define ‘extravasation’

Answer 1

where increased BP causes vessel walls to become leaky

Question 2

What does hydrostatic pressure cause?

Answer 2

Fluid to be driven OUT of capillary into tissues

Question 3

What is colloid osmotic pressure/oncotic pressure?

Answer 3

Pressure that pulls fluid back into vessels. linked with protein concentrations (e.g. albumin concs)

Question 4

define ‘oedema’

Answer 4

abnormal increased fluid in interstitial tissue space

Question 5

What would increased hydrostatic pressure cause and name a reason for it occuring.

Answer 5

It would cause oedema. Caused by heart failure or localised in limbs by something such as a DVT

Question 6

What is anasarca?

Answer 6

Oedema caused by malnutrition - not enough protein content in plasma so causes oedema.

Question 7

define haemorrhage

Answer 7

extravasation of blood (not just fluid) due to vessel rupture

Question 8

What percentage of blood does someone need to lose to be classified as haveing hypovolemic shock

Answer 8

More than 20%

Question 9

What is petechiae and what causes it?

Answer 9

minute haemorrhages (1-2mm) of skin and mucosa. 
caused by thrombocytopenia, clotting factor deficiency or increased pressure in capillaries

Question 10

What is pupura and what causes it?

Answer 10

small haemorrhage (3-5mm) usually due to trauma or vasculitis

Question 11

define ecchymosis/bruises

Answer 11

subcutaneous haematoma

Question 12

Define thrombosis

Answer 12

formation of blood clot on vessel wall.

Question 13

Define embolism

Answer 13

solid, liquid or gaseous mass carried in the blood to a site distant from the point of origin. Most of time clinically you see thromboembolisms

Question 14

What do you call an arterial thrombi that does not occlude a vessel?

Answer 14

Mural thrombi

Question 15

what do you call a thrombi that blocks a vessel?

Answer 15

Occlusive thrombi

Question 16

Thrombi that form in arteries are driven by what?

Answer 16

Platelets

Question 17

Thrombi that form in veins are driven by what?

Answer 17

Fibrin due to hypercoagulation from blood stasis

Question 18

When will giving anti-platelet drugs not work for a thrombus?

Answer 18

When it’s in veins because the clot is due to stasis in veins, not due to coagulation

Question 19

define hyperaemia

Answer 19

increased blood flow in tissue

Question 20

What is the difference between reactive and active hyperaemia?

Answer 20

Reactive - vasodilation caused by oxygen debt or accumulation of metabolic waste.
Active - vasodilation in response to period of activation (e.g during exercise)

Question 21

Name a possible cause of venous congestion

Answer 21

1) venous pressure increased
2) obstruction inside vein
3) obstruction outside vein (e.g. tumour)

Question 22

Define Shock

Answer 22

organs not receiving enough o2 and nutrients to function properly

Question 23

Define cardiogenic shock and name a cause

Answer 23

failure of heart to pump enough blood.

causes: myocardia damage

Question 24

define hypovolemic shock

Answer 24

loss of blood or plasma (e.g. haemorrhage or severe burns)

Question 25

What is neurogenic shock and what causes it?

Answer 25

sympathetic NS adrenergic stimulation causing wide spread vasodilation, pooling of blood in extremeties and hypotention. caused by severe damage to CNS

Question 26

What happens in anaphylactic shock?

Answer 26

Severe allergic reaction causes release of inflammatory mediators and cytokines which triggers widespread vasodilation and hypoperfusion.

Question 27

define sepsis

Answer 27

uncontrolled systemic reaction to bacteraemia