Bottom line: The planets in our solar system orbit (revolve) around the sun, and the sun orbits (revolves) around the center of the Milky Way galaxy. We take about 225-250 million years to revolve once around the galaxy's center. This length of time is called a cosmic year.

Explanation:

3 0

3 years ago

Clotting begins when a __(1)__ occurs in a blood vessel wall. Almost immediately, __(2)__ cling to the blood vessel wall and rel

Wittaler [7]

Question is incomplete, the complete question is as follows :

Clotting begins when a _________ occurs in a blood vessel wall. Almost immediately, _______ cling to the blood vessel wall and release _____________ which helps to decrease blood loss by constricting the vessel. __________ is also released by damaged cells in the area. This chemical substance causes ________to be converted to ____________. Once present, thrombin acts as an enzyme to atatch ___________molecules together to form long, threadlike strands of _________, which then traps ____________ flowing by in the blood.

Answer:

Clotting begins when a BREAK occurs in a blood vessel wall. Almost immediately, PLATELETS cling to the blood vessel wall and release SEROTONIN, which helps to decrease blood loss by constricting the vessel. THROMBOPLASTIN is also released by damaged cells in the area. This chemical substance causes PROTHROMBIN to be converted to THROMBIN. Once present, thrombin acts as an enzyme to attach FIBRINOGEN molecules together to form long, threadlike strands of FIBRIN, which then traps ERYTHROCYTES flowing by in the blood.

8 0

3 years ago