lecture test 2 ch 6.txt

• Support – framework
• Protection – Bone marrow and organs. (axial skel has cranial bones & thoracic cage.)
• Leverage – long bones esp. Long bones give more power for effort
• Storage – Minerals and lipids.
• Minerals - calcium and phosphate.
• Lipids – energy reserves in areas filled with yellow marrow.

• Long Bones – femur
• Short Bones – talus
• Irregular Bones – sphenoid
• Sesamoid Bones – patella
• Flat Bones – occipital bone
• Sutural Bones – often found within the sutures of flat bones in skull

• Compact or dense bone is
• organized in osteons and is stronger and heavier than spongy bone.
• Stronger so it can withstand more stress than spongy bone.
• found on the surface of all bones.
• slower to form.

• Osteoprogenator Cells – Stem cells which can divide quickly. Important for growing and healing.
• Osteoblast Cells – produce bone matrix – collagen and other organic bone components (osteoid)
• Osteocyte – Mature bone cells that sit in lacunae. They maintain the bone matrix
• Osteoclast – Macrophages (a monocyte (mononuclear phagocytic WBC) that has left circulation and settled and matured in tissue. There are a variety of macrophages found throughout the body.) These are the “cleanup” cells.

• bone developes directly from mesenchyme or fibrous connective tissue.
• happens in ossification center
• bone grows from center outward forming spicules.
• Blood vessels grow into area and become trapped as bone develops.
• Osteons and periosteum forms

prebone; resembles bone

• CT cells,
• Osteoprogenator
• Osteoblasts

• most common process of bone formation.
• bone is formed within hyaline cartilage
• gradual process that continues as long as cartilage remains.
• As long as growth plate has cartilage, bone can lengthen.

• 1. Chondrocytes enlarge near ctr of shaft, calcium is added to the matrix and chondrocytes cant get nutrients so they start dying
• 2. increased blood vessel growth in perichondrium, perichondrium cells chg to osteoblast producing a periosteum
• 3. Primary ossification ctr develops near middle of model - capillaries and fibroblast move into ctr of cartilage
• 4. Remodeling begins - osteoclasts carve out a marrow cavity, spongy remodels to compact, epiphyseal cartilage growth continues
• 5. Development of bone in epiphysis - blood vessels enter epiphysis allowing 2nd ossification ctr to begin forming. Same process as primary EXCEPT spongy bone is left in epiphyses.

the amount of cartilage at the growth plate could be reduced thus will be converted to bone sooner than normal.

• 1. Blood clot forms to stabilize break
• 2. fibroblasts move in from periosteum forming external callus, fibroblast from endosteum form internal callus, fibroblasts produce collagen to knit bone together
• 3. Callus convert to bone - osteoblast replace cartilage w/ bone, external and internal callus tissues connect
• 4. osteoblasts and clasts remodel area, attempting to regain orig shape.

by osteoprogenators and osteoblasts. Marrow cavity is enlarged by osteoclasts

part of normal bone maintenance where the organic and mineral components of the bone matrix are being recycled. Also takes place to reshape after injury.

• Mandible
• Maxillae
• Palatine bones
• Nasal bones
• zygomatic bones
• lacrimal bones
• inferior nasal concha

mandibular fossae of temporal bones

lighten skull and resinate sound

• Cervical curve - Anterior Curve
• Thoracic Curve - posterior curve
• Lumbar Curve - anterior curve
• Sacral Curve - posterior curve

• kyphosis- hump back
• lordosis - bending backwards
• scoliosis - side to side curving

pairs 1 - 7

prs 11 and 12. they are called floating ribs

sacroiliac joint

• Tibia and the medial malleolus
• Fibula and the lateral malleolus

Calcaneus

• Osteoclast - clean-up
• Osteoblast - build
• osteocytes - maintain

• Vit C (needed for collagen) - deficiency = scurvy (brittle bones)
• Vit D (needed for calcium absorption) - deficiency = rickets (soft bones
• Calcium (needed to harden bones)

• blood clotting
• muscle contraction
• neural signaling
• co-enzyme use

• Calcitonin - used to lower calcium in blood by decreasing absorption in GI tract, kidneys allow more loss, keep bones from releasing store calcium into system.
• Parathyroid hormone - stimulates osteoclasts to release calcium from bone, decrease rate of excretion at kidneys, increase rate of absorption in GI tract
• calcitriol - Active form of Vit. D - allows for greater absorption in GI tract and in kidneys

All types of blood cells are produced in red bone marrow

Shattered

Cracking in bone due to repeated stress

projection or bump

small, articular surface

hole

shallow depression

passage or opening

smooth rounded articular process

open area within a bone

expanded articular end of an epiphysis

prominent ridge

lg rough projection

small rounded projection

narrow grove

extension of bone that makes an angle with the rest of the structure