What are the five functions of the skeletal system?
1. Support 2. Protection 3. Hematoposesis (production of blood cells) - red bone marrow 4. Movement 5. Storage
What is bone tissue also known as?
What are the five types of bone?
1. Long 2. Short 3. Flat 4. Irregular 5. Sesamoid
What is the Diaphysis?
The long, central shaft of a long bone.
What is the Epiphysis?
Ends of the bone
Describe the periosteum.
1. Dense connective tissue. 2. Covers outer bone surface, except joints. 3. Continuous with ligaments and tendons 4. Contains blood cells and osteoblasts.
Describe compact bone tissue.
Strong, resistant to bending. WALLS OF DIAPHYSIS.
Describe spongy bone tissue.
Tiny plates of bone with spaces inbetween. Filled with red marrow. Most in epiphysis (Ends of the bone)
What is the medullary cavity?
Hollow space with yellow bone marrow inside
What is the endosteum?
Lining on the inside of the medullary cavity.
What is an Osteoblast?
"Youthful" bone cell. Builds bone tissue.
What is an Osteocyte?
"Older" bone cell, trapped in lacunae, decrease in the output of bone tissue
What is an Osteoclast?
Crushes/Destroys bone tissue.
Bone Cells start off as?
What is an osteon?
Functional unit of the bone. (AKA is Haverison System).
What does the osteonic canal do?
It connects to the medullary cavity. (contains blood vessels)
Perforating (aka Volkman's) Canal
Go horizontally, rest of osteon goes vertically.
What are the lacunae?
Chambers for the osteocytes.
What are the canaliculi?
Tiny canals that allow osteocytes to pass waste and nutrients.
What are the lamellae?
Layers of bone tissue that are arranged in concentric rings.
Circumferntial Lamellae are...?
Layers of bone tissue that wrap around the circumferance of the bone.
What is intramembranous ossification?
Forms the mandible clavicle, calvaria. (Finishes are Week 5) Osteoblasts gather and then secrete mesenchyme. Osteoblasts become osteocytes. Vessels in developing periosteum bring osteoblasts- lay down thin layer of compact over sponge bone.
What is Endocrhondral Ossification?
Finishes at Week 8. Forms all other types of bone. Chondroblast produe hyaline cartilage in the same shapes as bones. Many chrondrocytes die, some change into osteoblasts.
Where is compaact bone formed?
Center of the diaphysis. AKA primary ossification center.
Where is the secondary ossifictaion center?
What is the thing layer of cartilages that remains at the corder of the epipysis and diaphysis?