The  _______ is the smallest contractile unit of the muscle fiber. 

Once an organism dies,  _______ sets in about 3 to 4 hours after death which causes the carcass to become ridged. Peak rigidity occurs around 12 hours postmortem. 

What is it called when a muscle receives two stimuli in rapid succession? 

What is the energy supplied by ATP not used for by the muscle fiber during contraction. 

Osteoblasts, Osteocytes, and Osteoclasts are all derived from a bone cell lineage. 

Muscle contraction ends once the enzyme  _______ breaks down acetylcholine. 

The skin has limited excretory capabilities, it can secrete limited amounts of nitrogenous waste, such as ammonia, urea, and uric acid. 

Bone tissue is half as strong as steel in resisting compression and as strong as steel in resisting tension. 

In newborns and adults, the medullary cavities of long bones and all spongy bone, contain red bone marrow. 

_______ are the bone forming cells which secrete the unmineralized bone matrix.