Impairment of the blood clotting mechanism
Explanation
Blood is a specialized connective tissue consisting of a fluid matrix (plasma) and formed elements: Erythrocytes (RBCs), Leukocytes (WBCs), and Thrombocytes (Platelets). Each formed element has a specific physiological role.
- Cessation of oxygen transport to tissues is incorrect: The transport of oxygen to tissues is the primary function of Red Blood Cells (RBCs), facilitated by the iron-containing pigment hemoglobin. Platelets do not participate in gas transport.
- Impairment of the blood clotting mechanism is correct: Platelets (thrombocytes) are cell fragments produced from megakaryocytes in the bone marrow. They release a variety of substances, most notably clotting factors like thromboplastin, which initiate the coagulation cascade. A deficiency in platelets (thrombocytopenia) prevents blood from clotting effectively, leading to excessive bleeding from minor injuries.
- Loss of immunity against bacterial infections is incorrect: Immunity and defense against pathogens (bacteria, viruses) are the functions of White Blood Cells (WBCs), specifically neutrophils, lymphocytes, and monocytes.
- Discoloration of the blood plasma is incorrect: The straw color of blood plasma is primarily due to the presence of bilirubin and dissolved proteins. A change in platelet count does not affect the coloration of the plasma.
Key Takeaway: Platelets are essential for hemostasis (blood clotting); their deficiency compromises the body's ability to stop bleeding.