21 Which of the following is the largest component in a skel

21. Which of the following is the largest component in a skeletal?

A.       Sarcomere               C.       Myofibril

B.       Myosin                   D.       Myofiber

22. Where is erythropoietin produced?

A.       Bone marrow C.       Spleen

B.       Lungs                     D.       Kidneys

23. Which of the following best describes normal plasma:

A.       About 70% of blood composition, contains thrombin

B.       About 30% of blood composition, contains prothrombin

C.       About 70% of blood composition, contains prothrombin

D.       About 70% of blood composition, contains fibrin

24. Which of the following most accurately approximates the normal amount of blood in an animal?

A.       2.5% of body weight                    C.       15.5% of body weight

B.       7.5% of body weight                    D.       45.0% of body weight

Solution

21. D. Myofiber

Muscle fibers or myofibers are in turn composed of myofibrils. The myofibrils are composed of actin and myosin filaments, repeated in units called sarcomeres, which are the basic functional units of the muscle fiber.

22. Kidneys

Erythropoietin (EPO) is a hormone produced by the kidney that promotes the formation of red blood cells by the bone marrow.

23. C. About 70% of blood composition, contains prothrombin

24.  C. 15.5% of body weight