Bone

BONE

Them Not-So-Dry Bones

[Schoolhouse Rock]

by: Jack Sheldon Lyrics by: George Newall

Bones of heard of, but seldom seen `Cept each year `round Hallowe`en But I`ve got a shock-a-roo Right now there`s a skeleton locked up inside of you!

Two Types of bone Compact-makes up the shaft of the bone

Spongy-fills ends of bone and fills flat bones

Parts of a long bone Epiphysis-end of the bone Diaphysis-shaft of the bone Periosteum-”skin” of the bone Articular cartilage-smooth surface for joint

Types of Bone Marrow Red Marrow-found within the hollow spaces of the spongy bonemakes red blood cells Yellow Marrow-found withing the large hollow medullary cavity in long bones, stores fat

Bone Microanatomy

Osteon-round building block of compct bone Central canal-large passageway in center of osteon, blood vessels run through them lamellae-rings of bony marix within the osteon Canaliculi-tiny channels that allow “interaction” between osteocytes

lose up look at osteocy

Remember, an osteocyte resides in an empty place called a lacuna. An osteocyte is a unspecialized, mature bone cell, found in a lacuna. Osteocytes have small cytoplasmic extensions that run through the canaliculi.

Osteoblasts and Osteoclasts

Osteoblasts build new bone cells, turn into osteocytes when surrounded by new bone. Osteoclasts break down bone.

Skeletal remodeling-new bone is made as fast as old bone is broken down Osteporosis-bone is broken down too fast for osteoblasts to keep up

That’s all for now soon we’ll start on the