I believe the answer is heart rate
Answer:
[Updates on rickets and osteomalacia: mechanism and regulation of bone mineralization]. ... Bone is mineralized when hydroxyapatite crystals derived from calcium ions and inorganic phosphate (Pi) grow along collagen fibrils in the extracellular matrix. Mineralization is initiated by nucleation of those crystals.
Explanation:
Poor posture can cause back problems
Doing one pull-up followed by a second pull-up would be an example of two reps
Answer:
When the penis is erect, the flow of urine is blocked from the urethra, allowing only semen to be ejaculated at orgasm. The scrotum is the loose pouch-like sac of skin that hangs behind the penis. It holds the testicles (also called testes), as well as many nerves and blood vessels.
Explanation:
