What are the red pulp and white pulp of the spleen?
White pulp is lymphatic tissue that mainly consists of B-lymphocytes and T-lymphocytes that surround arteries. Red pulp consists of venous sinuses and splenic cords.
300
What mediates type IV hypersensitivity and how long after contact does the reaction occur?
Mediated by T cells and macrophages (antibody independent), and occurs hours to days after contact with antigen.
300
What is an ‘M-spike’?
On serum protein electrophoresis you get a large spike in the gamma region. It represents a high concentration of monoclonal immunoglobulin.
300
What are the four stages in the Ann Arbor staging system?
Stage I = one lymph node site (group)
Stage II = more than one group of lymph nodes, but on the same side of the diaphragm
Stage III = Lymph node groups on both sides of the diaphragm
Stage IV = Extra-nodal involvement (organs etc.)
300
What is the difference between absolute and relative polycythemia? What are some causes of each?
Absolute = increased number of red cells with a normal total plasma volume. E.g. polycythemia vera, high altitude living, cyanotic heart disease
Relative = decreased total plasma volume and normal total red cell volume. E.g. prolonged vomiting or diarrhea, excessive use of diuretics, deprivation of water.
300
What are the two parts of the orbicularis oculi, and what is the function of each part?
Palpebral = closes the eye gently
Orbital = closes more forcefully - scrunches up the eye
400
How does adrenaline help in anaphylactic shock?
Tightens junctions between endothelial cells, relaxes bronchial smooth muscle and stimulates the heart.
400
What causes renal failure in MM patients?
Renal impairment is caused by the accumulation and precipitation of light chains – obstruction of tubules and toxic to proximal tubules
400
Reed Sternberg cells are CD15+, CD30+ and CD45-. True or false?
True
400
What is the pathophysiology of anaemia of chronic disease?
Increased cytokine release (IL-6) → increased hepcidin →decreased serum iron → decreased RBC production.
[Could also be kidney disease, bone marrow infiltration or increased erythrophagocytosis]
400
What bones make up the pterion, and what artery runs behind it?
The frontal, temporal, parietal and greater wing of sphenoid make up the pterion. The middle meningeal artery runs behind it.
500
Name two common bacterial and two common viral infections of the skin?