Vascular Disturbances Flashcards
Describe the difference between an Exudate and a Transudate
- What is Oedema/Effusion
- What is the difference beween Oedema and Effusion
- excess of extracellular fluid
- oedema = fluid in tissues, effusion = fluid in body cavaities.
Generalised Oedema is called ?
Anasarca
What is pulmonary oedema ?
Fluid in the lungs.
What is this ?
- Pulmonary oedema
What are the primary causes of oedema?
increase intravascular pressure
lymphatic obstruction
decreased blood oncotic pressure (aka colloid osmotic pressure)
increased interstitial osmotic pressure
increased vascular permeability
Right sided heart failure, sequale
liver congestion causes increased hydrostaticpressure in periacinar regions
leads to fluid into space of disse
leads to fluid into lymphatics, beneath and through the liver capsule, leads fluid into abdo cavity = ascites.
Left sided heart failure sequale
Lung congestion leads to increased hydrostatic pressure septal capailiaries.
Fluid is forced ionto the alveoli (soft cough) = pulmonary oedema.
RBC leak into alveoli - phagocytosed.
- what is hyperaemia?
- Defined the two types of hyperaemia
- Increased blood within tissue organ vascular bed
- passive hyperaemia (reduced venous drainage, cap bed is engorged with blood). Everything is black Active (increased cap supply , cap bed is engorged with blood ) everything is red .
What is ischaemia?
What are the two types ?
too little blood in the circulation
Generalised - hypovolameia -blood loss/ dehydration
Generalied - anaemia
Localised - obstruction to blood flow ( intraluminal / extraluminal)
What are the physical responses to hypovolaemia due to blood loss ?
- Venous return falls
- cardiac output is reduced
- aterial blood pressure falls
- carotid & aortic bodies = stimulate the vasomotor centres = strong sympathetic stimulation.
- blood supply to the vital organs only - brain and resp muscles is maintained
- tachycardia occurs
- adrenalin & noradrenalin are released leading to general vasoconstriction and coronary artery dilation (NAdr)
- decrease in blood pressure - renin - angiotensin production (potent vasodilator) & aldosterone production (Na & h20 reabsorption).
Phase 2 - restoration of blood volume
- blood pressure decreases , despite phase 1
- fluid moves from extrvascular spaces into circulation (osmotic forces) to replace lost fluid.
Phase 3 Eryhtropoiesis
Number of RBC and the haemoglobin content of the blood is restored to normal
there is enhaced manufacture of plasma proteins within the liver
reticulocytes and metarubicytes will be circulating in the blood , takes abnout 4 days
What is shock ?
inadequate perfusion of an organ / microcirculation
inability of the body to compensate through stages 2 & 3
Shock leads to multi organ failure
What are the types of shock
Hypovolaemic shock
Cardiogenic shock
Septic Shock
Anaphylactic Shock
Neruogenic - systemic microcirculation prefusion failure
What are the functions of hemostatis ?
What are there failures called ?
- maintain blood & fluid state =thrombosis
- arrest bleeding follow trauma = heamorraghe
- remove platlet plug when healing complete = thrombosis
What are the 7 steps in the hemostatic process?
- Vascular spasm
- Primary platlet response
- Initiation of thrombin generation
- Amplification of thrombin generation
- Propogation of thrombin generation
- Fibrin formation
- Fibrinolysis
What are the consequences of endothelial injury?
Vascular spasm
vWF release (from endothelial cells & platelets)
exposure of sub-endothelial matrix proteins ( collagen, fibrinogen etc )
What are the 4 steps of hemostatic processes?
- Injury
- Adhesion (platelets bind to sub-endothelial matrix proteins)
- Activation
- Aggregation (fibrinogen-platelet plug)