Lecture 6 Flashcards
Thrombosis
the formation of a solid or semi-solid mass from the constituents of the blood while moving within the vascular system during life
Lines of Zahn
alternate layers of platelet and erythrocytes causing a layered structure.
Virchow’s triad
Factors that promote thrombosis
Abnormalities of the vessel wall
Abnormalities of blood flow
Abnormalities of the blood’s constituents
Sclerosants
Irritant chemicals injected to obliterate varicose veins
Polycycythaemia
High RBC count
Chronic hypoxia
16-20Hb
12-14 is normal
Polycythaemia rubra vera
Thick blood- can cause reduced flow
Fate of thrombi
Resolution- Fibrinolysis (common)
Organisation- Incorporation into a scar (mural nodule or web) by macrophages and fibroblasts. Vessel limen remains narrow/occluded. Intimal cell proliferation, capillary invasion and recanalisation. Vessel again becomes patent.
Detachment- thromboembolism
Embolism
The transport of abnormal material (solid, liquid, gas) by the blood stream and its impacting in a vessel.
Shock
A physiological state characterised by a significant, systemic reduction in tissue perfusion, resulting in decreased tissue oxygen delivery and insufficient removal of cellular metabolic products, resulting in injury. CO2, lactic acid.
Hypovolaemic shock
Haemorrhage-internal or external
Severe burns- fluid loss
Cariogenic shock
Large acute MI
Other acute disease
Septic shock
Endotoxins from gram -ve or +ve bacteria
Both lead to dilation of blood vessels
Anaphylactic shock
Immune related
Severe form of allergic reaction
Neurogenic shock
Spinal chord trauma
regional anaesthesia
