MDS PREP
What is the primary mechanism of action of antihistamines in the management of anaphylaxis?
1) Blocking the release of mediators from mast cells
2) Directly counteracting the effects of histamine on H1 receptors
3) Acting on beta-2 adrenergic receptors to dilate bronchioles
4) Inhibiting the production of leukotrienes and prostaglandins
Antihistamines, particularly H1 blockers, are used to counteract the vasodilatory and bronchoconstrictive effects of histamine in anaphylaxis.
The most frequent source of pulmonary embolism is
1) Leg veins
2) Heart
3) Arm veins
4) Splenic vein
General Medicine
Answer: 1
The most frequent source of pulmonary embolism is leg veins
Which of the following is NOT a primary glomerular disease that can cause nephrotic syndrome?
1) Membranous nephropathy
2) Minimal change disease
3) Focal segmental glomerulosclerosis
4) Systemic lupus erythematosus
Systemic lupus erythematosus is a systemic disease with renal manifestations that can cause nephrotic syndrome, but it is not a primary glomerular disease. The primary glomerular diseases listed that can lead to nephrotic syndrome are membranous nephropathy, minimal-change disease, and focal segmental glomerulosclerosis.
In which of the following conditions is nephrotic syndrome characterized by the presence of fibrin in the glomerulus?
1) Membranoproliferative glomerulonephritis
2) Minimal-change disease
3) Focal segmental glomerulosclerosis
4) Membranous nephropathy
Membranoproliferative glomerulonephritis is characterized by the deposition of immune complexes in the glomerular basement membrane and mesangium, leading to proliferation of mesangial cells and the formation of a dense, double-contour appearance. This can result in the deposition of fibrin in the glomerulus.
Commonest type of lung carcinoma in non-smokers
1) Squamous cell carcinoma
2) Adenocarcinoma
3) Alveolar cell carcinoma
4) Small cell carcinoma
General Medicine
Answer: 2
Adenocarcinoma is the most prevalent lung carcinoma type among non-smokers, often linked to genetic mutations and environmental factors rather than smoking.
What is the first step in the activation of vitamin D3 in the body?
1) Liver hydroxylation to calcidiol
2) Kidney hydroxylation to calcitriol
3) Skin synthesis from 7-dehydrocholesterol
4) Intestinal absorption with bile salts
The initial activation of vitamin D3 begins with its synthesis from 7-dehydrocholesterol in the skin when exposed to UV light.
What is the primary source of vitamin D3 in humans?
1) Diet
2) Skin synthesis from sunlight
3) Intestinal bacteria
4) Supplementation
The precursor of vitamin D3, 7-dehydrocholesterol, is present in the keratinocytes of the skin's stratum corneum. Upon exposure to UV light, it is converted into cholecalciferol (vitamin D3).
Which of the following is NOT a function of albumin?
1) Osmotic regulation
2) Transport of thyroid hormones
3) Binding and transport of fatty acids
4) Carrier protein for bilirubin
Albumin is mainly involved in osmotic regulation and serves as a carrier protein for various substances, including bilirubin and fatty acids. However, it is not a primary carrier for thyroid hormones, which are mainly transported by thyroxine-binding globulin.