Histology Flashcards
7 cards from real NBME practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Histology flashcards as text
Which capillary type, found in the kidney glomerulus and small intestine, has pores in its endothelium that enhance permeability?
Answer: Fenestrated capillaries
Fenestrated capillaries have transcellular pores (fenestrae) that allow rapid passage of water, ions, and small molecules, critical for filtration and absorption.
Elastic arteries (e.g., the aorta) differ from muscular arteries primarily by having a tunica media dominated by which component?
Answer: Elastic lamellae
The aortic media contains numerous concentric elastic lamellae that store systolic energy and maintain diastolic pressure via the Windkessel effect.
The white pulp of the spleen is organized around central arterioles and is primarily composed of which cell type?
Answer: T and B lymphocytes
White pulp consists of periarteriolar lymphatic sheaths (T cells) and lymphoid follicles (B cells), forming the immune compartment of the spleen.
On a peripheral blood smear, which white blood cell is identified by its bilobed nucleus and large red-orange cytoplasmic granules?
Answer: Eosinophil
Eosinophils have a characteristic bilobed nucleus and prominent eosinophilic (red-orange) granules containing major basic protein and enzymes.
Megakaryocytes in the bone marrow produce platelets by which mechanism?
Answer: Budding off of cytoplasmic fragments (thrombopoiesis)
Megakaryocytes extend long cytoplasmic projections (proplatelets) through sinus walls, which fragment into individual platelets in the circulation.
In a lymph node, primary lymphoid follicles are converted to secondary follicles (with germinal centers) upon exposure to antigen. Germinal centers are the site of which process?
Answer: B cell somatic hypermutation and affinity maturation
Germinal centers within secondary follicles are where B cells undergo somatic hypermutation, class switching, and selection for high-affinity antibodies.
The endothelium lining blood vessels is classified as which epithelial type?
Answer: Simple squamous
Vascular endothelium is simple squamous epithelium (mesothelial origin), forming a smooth, low-friction lining that minimizes turbulence.