Chapter 7 part 1- chat study guide

5 main functions of skeletal system

Support, movement, protection, blood cell formation, mineral storage

What makes up skeletal system

Bones, tendons, ligaments, cartilage

Bone is a type of ?

connective tissue made of cells and extracellular matrix

2 components to bone matrix

Collagen fibers and calcium phosphate salts

Collagen fibers

provide flexibility and tensile strength, resisting pulling forces

Calcium phosphate salts

make bone hard and resistant to crushing

Osteoblast

builds new bone

Osteoclasts

breaks down bone

Osteocyte

mature bone cell that maintains bone tissue

Parts of osteon

osteon, central canal, lamellae, lacunae, canaliculi

Osteon

functional unit of compact bone

Central canal

contains blood vessels and nerves

Lamellae

circular layers of bone matrix

Lacunae

Small spaces containing osteocytes

Canaliculi

tiny channels allowing osteocytes to exchange nutrients, oxygen, and wastes because the hard bone matrix limits direct movement

Perforating canals

run perpendicular to osteons and carry blood vessels and nerves that connect with central canals

Main difference between central canal and perforating canals

central canal run lengthwise while perforating canals run across

Compact bone osteons generally run along?

diaphysis (shaft) of long bones, helping resist stress and compression

Spongy bone

lighter and has many open spaces; does NOT contain osteons; instead made of small trabeculae

Trabeculae in spongy bone

small pieces of bone that form a supportive network

Lamellae in spongy bone

layers of bone matrix inside trabeculae

Lacunae in spongy bone

spaces containing osteocytes

Canaliculi in sponge bone

tiny channels connecting osteocytes to one another and toward bone surface

Compact bone features

dense and solid; contains osteons; has central canals; mainly forms the outer bone and shaft of long bones; provides strength

Spongy bone features

Porous and lightweight; does not contain osteons; has trabeculae; found inside the ends of long bones and between compact bone layers in other bones; provides support while reducing weight

2 important membranes associated with bone

Periosteum and endosteum

Periosteum

covers outside of bone, except surfaces covered by articular cartilage

Periosteum outer layer

dense CT for protection and attachment of tendons and ligaments

Periosteum inner layer

contains cells involved in bone growth and repair

Endosteum

lines the medullary cavity and surfaces of trabeculae (inside)

Features of endosteum

thin membrane associated with blood supply and bone surfaces; contains cells involved in bone formation and breakdown

Both periosteum and endosteum are involved in?

bone remodeling which is the ongoing process of building and breaking down bone

Diaphysis

shaft or middle of lone bone

Epiphysis

ends of long bone

Medullary cavity

hollow space inside the shaft

Articular cartilage

covers joint surfaces to reduce friction