Tag: blood circulatory system of human

The ornithine cycle (urea cycle) is a metabolic pathway that converts toxic ammonia into urea, which is then excreted by the kidneys.

Platelets, also called thrombocytes, are blood cells whose function is to stop bleeding. The average life span of circulating platelets is 7 to 10 days.

Platelets, also called thrombocytes, are blood cells whose function is to stop bleeding. Platelets have no nucleus: they are fragments of cytoplasm, which are derived from the megakaryocytes of the bone marrow, and then enter the circulation. These unactivated platelets are biconvex discoid structures. They are smallest of the three major blood types. They make up a tiny portion of the blood volume.

Life span of platelets is 8 - 9 days. Platelets, also called thrombocytes, are blood cells, whose function is to stop bleeding. Platelets have no nucleus: they are fragments of cytoplasm, which are derived from the megakaryocytes of the bone marrow, and then enter the circulation. These unactivated platelets are biconvex discoid structures. Life span of individual platelets is controlled by the internal apoptotic regulating pathway. Old platelets are destroyed by phagocytosis in the spleen and liver.

Blood platelets are found in mammals. Platelets, also called thrombocytes, are blood cells, whose function is to stop bleeding. Platelets have no nucleus: they are fragments of cytoplasm, which are derived from the megakaryocytes of the bone marrow, and then enter the circulation. These unactivated platelets are biconvex discoid structures.

Megakaryocytes cells is thrombocyte producer. A megakaryocyte is a large bone marrow cell with a lobulated nucleus responsible for the production of blood thrombocytes, which are necessary for normal blood clotting. Megakaryocytes normally account for 1 out of 10,000 bone marrow cells but can increase in number nearly 10- fold during the course of certain diseases.

Platelets are a source of thromboplastin. Thromboplastin is a plasma protein aiding blood coagulation through catalyzing the conversion of prothrombin to thrombin. It is a complex enzyme that is found in the brain, lung, and other tissues and especially in blood platelets and that functions in the conversion of prothrombin to thrombin in the clotting of blood, called as thrombokinase.

Structure absent from fresh frozen blood plasma are platelets. Platelets have no nucleus: they are fragments of cytoplasm which are derived from the megakaryocytes. The main function of platelets is to contribute to hemostasis: the process of stopping bleeding at the site of interrupted endothelium. They gather at the site and unless the interruption is physically too large, they plug the hole. In the fresh frozen blood plasma, there will be an absence of blood cells. So, in frozen plasma platelets are also absent.

Platelet also known as thrombocyte is a colourless, nonnucleated blood cell that is important in the formation of blood clots (coagulation). Platelets are found only in the blood of mammals. Platelets are formed when cytoplasmic fragments of megakaryocytes, which are very large cells in the bone marrow, pinch off into the circulation as they age. They are stored in the spleen. Hence, option C is the correct answer. 

A megakaryocyte is a large bone marrow cell with a lobulated nucleus, responsible for the production of blood thrombocytes (platelets), which are necessary for normal blood clotting. Megakaryocytes normally account for 1 out of 10,000 bone marrow cells but can increase in number nearly 10-fold during the course of certain diseases.