The tunica adventitia is relatively thin and consists chiefly of:

Correct Answer: C

Rationale: The tunica adventitia, the outermost layer of blood vessels, is primarily connective tissue (including collagen and some elastic fibers) anchoring the vessel to surrounding structures. Epithelium is not present here.

Correct Answer: B

Rationale: Lymphocytes lack visible granules in their cytoplasm under a microscope, unlike neutrophils, eosinophils, and basophils, which are granulocytes with specific staining granules (neutrophils: neutral, eosinophils: red, basophils: blue).

Correct Answer: D

Rationale: Albumin, globulins, and fibrinogen are plasma proteins synthesized by the liver. Platelets are cellular fragments, not proteins, involved in clotting.

Correct Answer: A

Rationale: Albumins (~60% of plasma proteins) are the most abundant, maintaining osmotic pressure. Globulins (~35%) and fibrinogen (~4%) are less plentiful. ‘Hemogen’ is not a recognized term.

Correct Answer: D

Rationale: Both pulmonary and systemic circulations handle the same cardiac output (volume per minute, ~5 L/min at rest), as blood flows continuously through both. Capacity, pulse pressure, and resistance differ due to distinct vessel properties and pressures.