Vascular Disturbances Flashcards
What is pathology?
The study of structural and functional abnormalities in cells, tissues, organs and body systems = disease
Lesion
Any abnormality
What determines if a lesion is clinical vs subclinical?
The organs functional reserve capacity
Aetiology
Cause of disease
Pathogenesis
How a disease/lesion develops
Sequelae
Consequences of lesion/ disease
Mechanisms/ processes of disease
Vascular disturbances Inflammation Healing and repair Adaptive tissue response Pigments, infiltrates and storage disease Necrosis, cell degeneration and death Neoplasia Teratology
Oedema/ transudate
Excess extracellular fluid
Low protein, few cells, salty, watery fluid
Exudate
Inflammatory effusion
High protein, many cells, fibrin present
Primary causes of oedema
Increased intravascular pressure Lymphatic obstruction Low blood oncotic pressure High interstitial osmotic pressure High vascular permeability
Right sided heart failure
Congestion of liver –> increased hydrostatic pressure in sinusoids –> fluid forced into spaces of disse –> drains to lymphatics –> leaks into abdominal cavity = ascites
Left sided heart failure
Congestion of lungs
Increased hydrostatic pressure septal capillaries
Pulmonary oedema
Hyperaemia
Too much blood within circulation
Active - increased arterial supply
Passive - reduced venous drainage
Active hyperaemia
Increased arterial pressure = pink tissues
Physiological process - exercise etc
Pathological process - inflammation
Passive hyperaemia
Decreased drainage of blood through veins = increased blood = dull red tissue (blood poorly oxygenated)
Capillary bed engorged with blood
Always pathological process
Accumulation of metabolic waste products due to decreased drainage
Blood volume expansion
Increase in arterial stretch and/or pressure
Stimulates cardiomyocytes to release natriuretic peptides to decrease extracellular fluid volume and blood pressure
Effects of natiuretic peptides
Vasodilation (ANP, BNP)
Increased glomerular filtration rate (ANP)
Increased sodium excretion (ANP, BNP)
Inhibit renin-angiotensin- aldosterone system (ANP, BNP)
Inhibit endothelium release (ANP)
Increase vascular permeability (ANP)
Inhibit vascular smooth muscle, endothelial cells, cardiac myocyte proliferation
Ischemia
Too little blood within circulatory bed
Generalised - blood loss, dehydration, anaemia
Localised - obstruction to blood flow
Ischemic necrosis - if rapid and cannot adapt quickly = tissue dies
Physiological response to dehydration
Decreases blood vol. and pressure + increases osmolarity
- leads to vasoconstriction to increase osmolarity –> increase ADH –> renal reabsorption and thirst
Shock
Inadequate perfusion of an organs micro circulation
Give an example of what increases intravascular pressure
Hyperaemia
Active - exercise
Passive - portal hypertension (RSHF) or pulmonary hypertension (LSHF)
Give an example of lymphatic obstruction
Blockage by tumour in lymph nodes
Give an example of what decreases blood oncotic pressure
Whipped disease (malabsorption of amino acids from gut)
Excessive loss of albumin (renal damage to glomerulus)
Give an example of what increases interstitial osmotic pressure
Excess ion intake
Kidney insufficiency
Give an example of what increases vascular permeability
Allergy
Virus/ bacteria
Endotoxins
Clotting abnormalities
