A patient is suffered from vitamin K deficiency. Which of the coagulation factors will not be affected?

Correct Answer: C

Rationale: The correct answer is C, Factor VIII. Vitamin K is crucial for the activation of Factors II, VII, IX, and X in the coagulation cascade. Factor VIII is not dependent on vitamin K for its synthesis or activation, so it will not be affected by vitamin K deficiency. Factors II, VII, and IX will be affected as they require vitamin K for their activation. Therefore, Factor VIII is the only factor that will not be impacted by vitamin K deficiency.

Correct Answer: B

Rationale: The correct answer is B: Basophilic stippling. Basophilic stippling is a common finding in the peripheral blood smear of patients infected with hookworms due to lead poisoning, which can occur as a result of hookworm infection. Basophilic stippling is seen as the presence of small, dark blue granules within red blood cells and is indicative of impaired heme synthesis. Howell-Jolly bodies (A) are remnants of nuclear material in red blood cells and are typically seen in patients with functional asplenia. Target cells (C) are seen in conditions such as liver disease and hemoglobinopathies. Spherocytes (D) are seen in conditions like hereditary spherocytosis or autoimmune hemolytic anemia, but not specifically in hookworm infection.

Correct Answer: D

Rationale: The correct answer is D: Aplastic anemia. This condition is characterized by pancytopenia, which includes low hemoglobin (anemia), low platelets (manifested as petechiae), and low white blood cells (frequent infections). Dry tap marrow is a classic finding in aplastic anemia due to bone marrow failure. Iron deficiency anemia (choice A) typically presents with microcytic hypochromic anemia without pancytopenia. Megaloblastic anemia (choice B) is characterized by macrocytic anemia with hypersegmented neutrophils and is usually caused by deficiencies in vitamin B12 or folate. Hemolytic anemia (choice C) presents with anemia due to increased destruction of red blood cells, which does not explain the low platelets and white blood cells seen in this patient.

Correct Answer: C

Rationale: The correct answer is C: Microangiopathic hemolytic anemia. Schistocytes are fragmented red blood cells seen in conditions where RBCs are physically sheared or damaged as they pass through small blood vessels. In microangiopathic hemolytic anemia, abnormal or damaged blood vessels cause mechanical destruction of RBCs, leading to the formation of schistocytes. Sickle cell trait (A) and Thalassemia (B) are genetic disorders that do not typically cause schistocytes. Idiopathic thrombocytopenic purpura (D) is a condition characterized by low platelet count, not associated with schistocytes.

Correct Answer: C

Rationale: Platelets change their shape during platelet aggregation to form a plug at the site of vascular injury. This process involves platelets adhering to the injured blood vessel wall, becoming activated, and then changing shape to form a clot. Vasodilation is not an initial response, as vasoconstriction occurs to reduce blood loss. Clotting factors are essential for clot formation and play a significant role. Serotonin is released from platelets during aggregation but does not directly stimulate aggregation. The correct choice, C, directly correlates with the physiological process of platelet aggregation in response to vascular injury.