7.1 Flashcards
Besides supporting the other tissues of the body, what else do bones do?
Bones protect many delicate vital organs and tissues by surrounding them
They act as levers for skeletal muscles, enabling body movement.
Bones store minerals, especially calcium.
Some bones are sites for blood cell formation (hematopoiesis) in bone marrow.
What happens to bones when the level of calcium in the blood falls too low? What happens when it rises too high?
level of calcium in the blood falls too low, osteoclast activity is increased to withdraw calcium from the bones and raise the blood calcium level.
level of calcium in the blood rises too high, osteoblast activity is increased to deposit the excess calcium in the bones.
What are the three kinds of bone cell? What role does each play in the life of a bone?
osteoblasts (create bone), osteocytes (maintain bone), osteoclasts (dissolve bone)
What is the matrix of bone made of? What makes it so hard?
Matrix is the intercellular substance in which bone cells are embedded. It is hard because calcium and phosphate crystals are deposited in it.
What are the main differences between the structures of cancellous bone and compact bone? Why does the body need these two different types of bone?
Cancellous bone is lighter and porous, found inside bones, red bone marrow, and spicules while Compact bone is dense and forms the bones outer layer
Both important bc cancellous bone keeps an animal’s body weight lower, being lighter than compact bone and both are needed to stand up to the stresses encountered by an animal’s skeleton.
