Histology of Connective Tissues Flashcards

Which feature distinguishes a myofibroblast from a fibroblast histologically?

Answer: Expression of alpha-smooth muscle actin (α-SMA)

Myofibroblasts express α-smooth muscle actin, assembling stress fibers that give them contractile properties absent in typical fibroblasts.

Scurvy results from impaired collagen synthesis because vitamin C is required for:

Answer: Hydroxylation of proline and lysine residues

Vitamin C (ascorbate) is an essential cofactor for prolyl and lysyl hydroxylases, enzymes that modify collagen precursors in the rER.

Brown adipose tissue differs from white adipose tissue primarily in that it:

Answer: Has abundant mitochondria for thermogenesis

Brown adipose tissue contains numerous mitochondria with uncoupling protein-1 (UCP-1), enabling heat generation through non-shivering thermogenesis.

Which connective tissue component is detected by Alcian blue staining?

Answer: Glycosaminoglycans and proteoglycans

Alcian blue selectively stains acidic polysaccharides including glycosaminoglycans and proteoglycans in the extracellular matrix.

Tendon is an example of which type of connective tissue?

Answer: Dense regular connective tissue

Tendons consist of dense regular connective tissue with parallel bundles of type I collagen aligned along the axis of tensile stress.

During wound healing, granulation tissue is characterized by:

Answer: New capillaries, fibroblasts, and macrophages in loose matrix

Granulation tissue contains newly formed capillaries (angiogenesis), activated fibroblasts/myofibroblasts, and macrophages in a provisional loose ECM.

The ground substance of connective tissue achieves its gel-like consistency primarily through:

Answer: Water bound by negatively charged proteoglycan aggregates

Proteoglycan aggregates in the ECM bind enormous amounts of water via their negatively charged GAG chains, creating a hydrated gel.