Haemodynamic disorders

Question 1

Haemodynamics

Answer 1

the movement of blood, the study of blood circulation

Question 2

What does homeostasis require?

Answer 2

vessel wall integrity
osmolarity
maintenance of intravascular pressure

Question 3

Hydrostatic pressure

Answer 3

pressure exerted by a fluid at equilibrium at a given point within the fluid

Question 4

What does a high hydrostatic pressure do to fluid

Answer 4

drives it out of the vessel and into the tissues

Question 5

What is colloid osmotic pressure

Answer 5

a form of osmotic pressure exerted by proteins (albumin)

Question 6

What does high colloid osmotic pressure do to fluid

Answer 6

drives fluid into the vessel from the interstitial space

Question 7

Hydrothorax

Answer 7

oedema in the thoracic cavity

Question 8

Hydropericardium

Answer 8

oedema in the pericardial cavity

Question 9

General causes of oedema

Answer 9

increased hydrostatic pressure
decreased colloid osmotic pressure
lymphatic obstruction 
sodium retention 
inflammation

Question 10

example of oedema due to increased hydrostatic pressure

Answer 10

generalised heart failure

localised in limbs in DVT

Question 11

example of oedema due to decreased colloid osmotic pressure

Answer 11

reduction in general plasma proteins (e.g. liver cirrhosis and malnutrition).

Question 12

Anasarca

Answer 12

widespread swelling of the skin due to effusion of fluid into extracellular space

Question 13

what conditions can cause anasarca

Answer 13

cirrhosis, renal failure, right-sided heart failure, severe malnutrition

Question 14

example of oedema due to lymphatic obstruction

Answer 14

elephantiasis (lymph nodes blocked by parasitic worm)
malignancy
following surgery and radiation therapy

Question 15

example of oedema due to sodium retention

Answer 15

excessive salt intake in renal insufficiency

increased renin-angiotensin-aldosterone system –> these increase hydrostatic pressure

Question 16

3 phases of the circulatory haemostats process

Answer 16

1- haemorrhage (process of bleeding)
2- thrombosis (process of clotting)
3- fibrinolysis (process of close dissolution)

Question 17

what is a haemorrhage?

Answer 17

the extravasation of blood due to rupture of blood vessel. can be internal or external.

Question 18

what happens if you have above 20% blood loss

Answer 18

hypovolemic shock (severe fluid loss makes it impossible for heart to pump sufficient blood around the body, can lead to organ failure)

Question 19

name 4 causes of haemorrhage

Answer 19

trauma
atherosclerosis
inflammation
erosion by tumour

Question 20

name 3 types of bleeding into skin in size order

Answer 20

petechiae
purpura
ecchymosis

Question 21

petechiae

Answer 21

minute haemorrhage (1-2 mm) of skin and mucosa
occurs during thrombocytopenia, clotting factor deficiency or increased pressure in capillaries

Question 22

purpura

Answer 22

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

Question 23

ecchymosis

Answer 23

subcutaneous hepatoma. changes in colour from red –> blue-green –> yellow —> brown

Question 24

what is a blood clot made up of

Answer 24

platelets, red blood cells, neutrophils, lymphocytes held together by fibrin

Question 25

what 3 main factors can form a thrombus

Answer 25

endothelial injury, abnormal blood flow, hyper-coagulability

Question 26

what are arterial thrombi usually made up of

Answer 26

platelets

Question 27

why are arterial thrombi made up of platelets

Answer 27

blood is flowing under higher pressure. form around ruptured atherosclerotic plaques or damaged endothelium.

Question 28

what is the name of the arterial thrombi that don't occlude vessel

Answer 28

mural thrombi

Question 29

occlusive thrombi

Answer 29

occludes vessel

Question 30

what are venous thrombi rich in

Answer 30

fibrin

Question 31

how is a venous thrombi formed

Answer 31

changes in blood flow (stasis due to immobility) --> activates coagulation system --> hyper coagulation --> fibrin driven response

Question 32

what is an embolism?

Answer 32

solid, liquid or gaseous mass carried in the blood to a site distant from the point of origin, clinical significance is related to where they lodge rather than origin

Question 33

what are nearly all emboli the result of

Answer 33

a dislodged thrombus (a thromboembolism)

Question 34

what is are hyperaemia and congestion characterised by

Answer 34

a local increase of blood volume in a particular tissue

Question 35

hyperaemia

Answer 35

increased blood flow in to a tissue in response to a change in the environment

Question 36

2 types of hyperaemia

Answer 36

reactive --> local vasodilation in response to oxygen debt or accumulation of metabolic waste active --> increased blood flow/vasodilation is response to a period of activation (e.g exercise)

Question 37

congestion

Answer 37

reduced blood flow out caused by impaired venous return from the affected area (passive process)

Question 38

what can cause congestion

Answer 38

physical obstruction of veins or failure of heart to pump blood away from affected area

Question 39

what is circulatory shock

Answer 39

life-threatening medical condition that occurs due to the provision of inadequate substrates for cellular respiration

Question 40

typical symptoms of shock

Answer 40

``` weak heart rate low blood pressure poor organ function confusion low urine output loss of consciousness ```

Question 41

causes of shock

Answer 41

reduced cardiac output or ineffective circulation

Question 42

types of shock

Answer 42

``` cariogenic shock hypovolemic shock septic shock neurogenic shock anaphylactic shock ```

Question 43

cardiogenic shock

Answer 43

failure of the heart to pump sufficient blood due to myocardial damage (e.g. myocardial infarction, arrhythmia, pulmonary embolism with outflow obstruction)

Question 44

hypovolemic shock

Answer 44

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

Question 45

septic shock

Answer 45

systemic infection, primary cause is bacteria (bacteria in the bloodstream).

Question 46

sepsis vs septic shock

Answer 46

sepsis --> uncontrolled systemic reaction to the infection leading to life threatening organ dysfunction septic shock --> subset of patients with sepsis in which particularly profound circulatory, cellular and metabolic abnormalities substantially increase mortality infection --> bacteremia --> sepsis --> septic shock

Question 47

neurogenic shock

Answer 47

caused by severe damage to the CNS. loss of systemic stimulation of blood vessels (via sympathetic adrenergic stimulation). leads to widespread vasodilation, pooling of blood in extremities and hypotension

Question 48

anaphylactic shock

Answer 48

severe allergic reaction causes release of inflammatory mediators cytokines (triggers widespread vasodilation and hypo perfusion).