Question

Blood does not clot inside the blood vessels due to the presence of
A. Heparin
B. Fibrinogen
C. Vitamin K
D. Thrombin

Answer 1

Hint: Blood is the fluid connective tissue that is present in the body and flows all over the body to transport oxygen, nutrients, drugs and other minerals all over the body. It is mainly formed of two components that are plasma and cellular components like RBC, WBC and Platelets.

Complete Answer:
Blood is the major connective fluid that acts as a transporter of oxygen, nutrients, minerals drugs and other substances all over the body. It is also responsible for transporting metabolic products away from the cells.
- The blood constituents of plasma i.e. about 55% and cellular components i.e. about 45%. The cellular components include:
- RBC (red blood cells): It is also called as erythrocytes responsible mainly for the transportation of the substances all over the body. The formation of RBC (erythropoiesis) takes place in bone marrow.
- WBC (white blood cells): Iit is also called leukocytes. It helps in defense mechanisms and kill the foreign particles entering the body.
- Platelets: it is also called thrombocytes. It is responsible for clotting the blood if any cut or injuries happen.
- Heparin is the anticoagulant that is a highly sulfated form of heparan sulfate. It is mainly made by connective tissue mast cells as a large heparin proteoglycan. It is having an anticoagulant property due to which the blood does not clot in the blood vessels.

The correct option is A i.e. Heparin.

Additional information: Thrombin, fibrinogen, vitamin K are the clotting factors that are present in blood and the blood to clot when any injury takes place externally over the body.

Note: Heparin is also used as an anticoagulant in the blood collection vials so that the clotting does not take place in the blood and the blood is viable for diagnosis. It is also used in kidney dialyzing machines.
Due to the anticoagulant(blood thinner) property of heparin, it is used in various clinical conditions like atrial fibrillation, acute coronary syndrome, unstable angina, heart attack etc.