KMU Past Paper Practice

Question:

A 23-year-old man develops an acutely inflamed wound. Shortly after the vascular response begins, the affected area becomes red and warm and subsequently develops edema. Which sequence best explains these findings?

Options:

Correct Answer: Vasodilation → hyperemia → increased permeability → exudation

Explanation: Vasodilation produces hyperemia and therefore redness and warmth; increased permeability then allows protein-rich fluid to escape and produce inflammatory edema.

Question:

Fluid collected from an inflamed pleural surface is rich in protein. In another patient, edema caused by altered hydrostatic forces produces protein-poor fluid. Which feature most reliably identifies the first fluid as inflammatory?

Options:

Correct Answer: Escape of plasma proteins through a permeable endothelium

Explanation: An inflammatory exudate forms because endothelial permeability increases, allowing plasma proteins and fluid to enter tissues; a transudate is comparatively protein-poor.

Question:

A researcher exposes macrophages to bacterial products. The cells recognize the stimulus even though they have never encountered that bacterial strain previously. Which characteristic of the recognition system best accounts for this response?

Options:

Correct Answer: Recognition of conserved structures through innate receptors

Explanation: Pattern-recognition receptors recognize conserved microbial molecular patterns without requiring previous exposure, allowing rapid initiation of innate inflammation.

Question:

Two tissue samples activate the same innate inflammatory cell. One contains bacterial cell-wall material and the other contains products released from necrotic host cells. How should the activating signals be classified?

Options:

Correct Answer: The bacterial signal is a PAMP and the host signal a DAMP

Explanation: PAMPs originate from microbes, whereas DAMPs are endogenous molecules released or exposed by injured and necrotic host cells.

Question:

A patient sustains a deep traumatic injury without microbial contamination. The damaged tissue nevertheless develops a rapid inflammatory reaction. Which principle best explains why infection is not required for this response?

Options:

Correct Answer: Host-derived danger signals can activate innate receptors

Explanation: Sterile tissue injury releases DAMPs that are recognized by pattern-recognition receptors, allowing acute inflammation to occur without microorganisms.

Question:

Histological examination of an inflamed tissue shows many neutrophils close to the endothelial surface rather than in the central column of flowing blood. Which preceding vascular event is most important in producing this arrangement?

Options:

Correct Answer: Slowing of flow after loss of intravascular fluid

Explanation: Plasma leakage produces hemoconcentration and stasis. Slower flow permits leukocytes to leave the axial stream and approach the endothelium.

Question:

Neutrophils in an inflamed venule are seen making transient endothelial contacts, followed by stable attachment and passage through the vessel wall. Which pairing correctly matches the interaction with its major adhesion molecule?

Options:

Correct Answer: Rolling — selectins; firm attachment — integrins

Explanation: Selectins produce weak transient interactions responsible for rolling, whereas activated leukocyte integrins mediate stable endothelial adhesion.

Question:

In an experimental model, neutrophils roll normally along activated endothelium but cannot progress to migration across the vessel wall. The cells remain loosely associated with the endothelial surface. Which step must fail before transmigration can occur?

Options:

Correct Answer: Development of stable endothelial adhesion

Explanation: Leukocytes must progress from selectin-mediated rolling to integrin-mediated firm adhesion before they can pass through endothelial junctions.

Question:

A neutrophil has crossed the wall of a post-capillary venule during an acute bacterial infection. It must now reach bacteria located several millimeters away in the tissue. Which mechanism provides directional guidance for this movement?

Options:

Correct Answer: Movement along a concentration gradient of attractants

Explanation: Chemotaxis is directed leukocyte movement along a chemical gradient and guides extravascular neutrophils toward microbes or injured tissue.

Question:

Neutrophils at an infected wound engulf bacteria much more efficiently after the organisms become coated with host-derived recognition molecules. At which stage of phagocytosis is this coating most beneficial?

Options:

Correct Answer: Attachment of the target to the phagocyte

Explanation: Opsonins coat microbes and improve their recognition and attachment to phagocytic receptors, thereby facilitating subsequent engulfment.

Question:

Microscopy of a neutrophil shows an engulfed bacterium enclosed within a membrane-bound intracellular compartment. The organism has not yet been exposed to the full contents of lysosomes. Which event should occur next?

Options:

Correct Answer: Fusion of the phagosome with lysosomes

Explanation: After engulfment forms a phagosome, fusion with lysosomes creates the compartment in which antimicrobial substances kill and degrade the organism.

Question:

A patient with an acute bacterial infection has effective recruitment and activation of neutrophils. Microbes are destroyed, but nearby normal tissue also shows inflammatory injury. Which mechanism best explains this unintended damage?

Options:

Correct Answer: Leukocyte enzymes and reactive products escape extracellularly

Explanation: Antimicrobial products protect the host when directed at microbes, but extracellular release of lysosomal enzymes and reactive products can damage adjacent normal tissue.

Question:

A 48-year-old man has an inflammatory lesion in which neutrophils dominate initially. On later examination, many monocyte-derived cells are removing dead cells and coordinating tissue repair. Which change best explains the later cellular pattern?

Options:

Correct Answer: Circulating monocytes enter tissue and become macrophages

Explanation: Blood monocytes migrate into inflamed tissues and differentiate into macrophages, which phagocytose debris and contribute to regulation and repair.

Question:

A 29-year-old woman develops an inflammatory reaction dominated by cells that participate in adaptive immunity rather than rapid phagocytic killing. Which functional combination best identifies these cells?

Options:

Correct Answer: Immune regulation and antibody-producing cell formation

Explanation: T lymphocytes regulate immune responses, while B lymphocytes can differentiate into plasma cells that produce antibodies.

Question:

A blood film from a patient with an inflammatory disorder shows an increase in granulocytes whose mediators are particularly relevant to hypersensitivity reactions. Which leukocyte pattern is most consistent with this setting?

Options:

Correct Answer: Basophilia

Explanation: Basophils contain inflammatory mediators including histamine and may increase in hypersensitivity states; related tissue mast cells have a similar mediator-rich phenotype.

Question:

A patient experiencing marked physiological stress has a reduction in circulating eosinophils. The remainder of the leukocyte count does not suggest generalized bone marrow failure. Which explanation best fits this isolated change?

Options:

Correct Answer: A stress response associated with corticosteroid activity

Explanation: Eosinopenia may accompany physiological stress and increased corticosteroid activity, whereas allergy and parasitic disease characteristically favor eosinophilia.

Question:

A patient has a prolonged infectious-inflammatory illness. His differential leukocyte count shows a persistent rise in a cell population that can enter tissues, become strongly phagocytic and participate in later inflammatory responses. Which change is most likely?

Options:

Correct Answer: Monocytosis

Explanation: Monocytosis may accompany prolonged inflammatory or infectious states; circulating monocytes subsequently enter tissues and differentiate into macrophages.

Question:

A patient with severe suppression of bone marrow function has reduced circulating neutrophils, monocytes and other leukocyte populations. Which general mechanism can account for these different forms of leukopenia?

Options:

Correct Answer: Decreased production of leukocytes

Explanation: Bone marrow suppression reduces production of multiple leukocyte lineages and can therefore produce several forms of leukopenia simultaneously.

Question:

A bacterial stimulus is recognized by resident inflammatory cells in tissue. Several hours later, circulating neutrophils are actively engulfing bacteria at the affected site. Which sequence best connects initial recognition with this final cellular response?

Options:

Correct Answer: Recognition → mediator release → vascular change → neutrophil recruitment → phagocytosis

Explanation: Innate recognition activates inflammatory cells, mediator release produces vascular changes, recruited neutrophils then reach the tissue and remove microbes by phagocytosis.

Question:

A pathologist reconstructs the events occurring in an acutely inflamed tissue. The initiating stimulus has already been recognized, and leukocytes ultimately reach and destroy the offending agent. Which sequence most accurately represents the overall progression?

Options:

Correct Answer: Vasodilation → permeability increase → stasis → recruitment → phagocytosis

Explanation: Acute inflammation progresses from vascular dilation and leakage to stasis, organized leukocyte recruitment and finally phagocytic removal of the offending stimulus.