Chapter 6: Bones and Bone Tissue

What are the functions of the skeletal system?

support, protection, muscle attachment, mineral and fat storage, blood cell formation, and hormone production

What are the structures of a bone ?

diaphysis, epiphysis, metaphysis, articular cartilage, and medullary cavity

Where is there articular cartilage?

coverings the ends of bones

What is “dipole”?

the end of a long bone that contains both compact and spongey bone

What are the 4 cells of bone tissue and what do they do?

osteogenic cells: stem cells, osteoblasts: cells that build bone tissue, osteocytes: mature cells that maintain tissue, osteoclasts: cells that decompose bone tissue

What is an osteon and what are the parts?

unit of compact bone and it includes the central canal with layers of lamellae, and canaliculi connecting the lacunae

What is the structure of spongy bone?

trabeculae with cavities that contain red bone marrow

Why doesn’t spongy bone have osteons?

because it has trabeculae

What are trabeculae?

pieces of spongy bone

What is the periosteum? What is the endosteum?

it has two layers, the outer (fibrous) and inner (cellular) layers

it only has one layer

What is the composition of bone matrix?

fibers and ground substance

What are the important mineral (calcium) salts?

calcium, and potassium

What is osteogenesis/ossification and when/where does it occur?

formation of bone tissue

as an embryo, during growth, repairing fractures/breaks, remodeling

What is calcification?

when there is a build up of calcium

What is endochondral ossification and what types of bones does it create?

1. bone collar forms diaphysis

2. cartilage in diaphysis calcifies

3. periosteal bud invades and spongy bone forms

4. diaphysis elongates and medullary cavity forms

5. epiphyses ossify

Long bones

What are growth in length vs. appositional growth and where do they occur?

length: continuous remodeling of epiphyseal ends to maintain proper proportions between diaphysis and epiphysis and this occurs in long bones

appositional: growth in width and this occurs in all bone

What is intramembranous ossification and what types of bones does it create?

1. ossification center develops in fibrous CT

2. osteoid is secreted and calcifies

3. immature spongy bone and periosteum form

4. compact bone replaces immature bone. red marrow develops

flat bones, mandible, and clavicle

What is bone remodeling?

bone architecture continually changes

Why would we resorb bone? Which cells are involved?

to get the correct shape and to release minerals stored in the bone, osteoclasts

Why would we deposit bone? Which cells are involved?

to make bone and to store minerals in bone, osteoblasts