Question

During menstrual phase, the blood released from uterus does not clot due to the presence of:

• A. Fibrinogen
• B. Fibrinolysin
• C. Prostaglandin
• D. Inhibin

Hint:

{Quick Memory Trick:}

• {Fibrinogen} → Helps in clot formation
• {Fibrinolysin} → Breaks fibrin and prevents clotting

Thus, menstrual blood generally {does not clot} because of {fibrinolysin}.

Answer 1

The Correct Option is B

Concept:
The menstrual phase is the first stage of the menstrual cycle and occurs when the endometrial lining of the uterus is shed. This results in the release of blood, mucus, and uterine tissue through the vagina. Normally, blood clots when fibrin threads are formed. However, during menstruation the blood usually does not clot. This is because the uterine fluid contains an enzyme called fibrinolysin. Fibrinolysin breaks down fibrin and prevents clot formation, ensuring smooth menstrual flow.
Step 1: Understanding menstrual bleeding.
During menstruation, the endometrial lining breaks down and blood is released from uterine blood vessels.
Step 2: Identifying the factor preventing clotting.
The enzyme responsible for preventing clot formation is: \[ Fibrinolysin \] It dissolves fibrin and keeps menstrual blood fluid.
Step 3: Eliminating incorrect options.

• (A) Fibrinogen $\rightarrow$ Protein involved in clot formation
• (B) Fibrinolysin $\rightarrow$ Dissolves fibrin and prevents clotting (Correct)
• (C) Prostaglandin $\rightarrow$ Causes uterine contractions
• (D) Inhibin $\rightarrow$ Hormone regulating FSH secretion

Final Answer: \(\boxed{\text{Fibrinolysin}}\)