Chapter 6: Skeletal System Flashcards
how many bones are you born with
270
how many bones are in the adult body
206
why do we start with more bones than we end with
because as we grow they fuse together
what are the two categories of the skeletal system
axial and appendicular
what are the functions of the skeletal system
support
movement
protection
blood formation
storage
detoxification
how does the skeletal system support
framework the body is built on. hold softer tissues in place
how does the skeletal system help with movement
muscles are attached to bone to move and bones act as levers around joints
how does the skeletal system help with storage
fat and minerals are stored in the bones
how does the skeletal system help with blood formation
red bone marrow is involved in blood cell protection
how does the skeletal system help with detoxification
bones can store metal and other foreign materials so they don’t circulate in the blood
what are the two types of bone
compact and spongy
compact bone
very dense and hard, homogenous to the naked eye, surrounds entire surface of the bone, arranged in osteons
spongy bone
empty spaces contain red bone marrow, contains trabeculae
trabeculae
small pieces of bone surrounded by spaces
osteons
elongated cylindrical structures found in compact bones
lamellae
ring like layers around the osteons, collagen fibers run parallel and in one direction, fibers of adjacent ones run at 90 degrees to each other
canals
found in osteons
have blood vessels and nerves
supply nutrients and get rid of waste
central canal
opening in middle of osteon
perforating canal
runs at right angles to the central canal
helps with blood supply b/t osteons by connecting the blood and nerve supply of the periosteum to the central canal
osteocytes
mature bone cells responsible for maintaining the extracellular matrix