Question

multiple choice question
what is tissue thromboplastin?

a precursor to prothrombin

a compound that keeps platelets from sticking to the endothelium

a compound released by healed tissues that initiates clot dissolution

a compound released by damaged tissue that initiates the extrinsic clotting pathway

Explanation:

To determine the correct answer, we analyze each option:

• "A precursor to prothrombin" is incorrect. Prothrombin's precursor is not tissue thromboplastin.
• "A compound that keeps platelets from sticking to the endothelium" describes an anti - adhesive compound, not tissue thromboplastin.
• "A compound released by healed tissues that initiates clot dissolution" is wrong as tissue thromboplastin is related to clot formation, not dissolution, and is released by damaged, not healed, tissue.
• "A compound released by damaged tissue that initiates the extrinsic clotting pathway" is correct. Tissue thromboplastin (also called tissue factor) is released by damaged tissue and starts the extrinsic coagulation pathway.

Answer:

D. A compound released by damaged tissue that initiates the extrinsic clotting pathway