Open fracture

Fell onto right brachial region while running

bone fragments in wound

Broken right elbow

bone protruding from upper right brachial region

Not enough calcium in diet due to lactose intolerance

Long Bones

Diaphysis (tubular shaft that forms long axis of bone)

Distal epiphysis (end of long bone that consists of compact bone externally and spongy bone internally)

Proximal epiphysis (end of long bone that consists of compact bone externally and spongy bone internally)

The proximal epiphysis contains the epiphyseal plate/line, which is responsible for longitudinal growth

Compact bone surrounding medullary cavity which is filled with yellow bone marrow

Anatomy of bones

osteogenic cells- active stem cells in periosteum and endosteum

osteoblasts- bone building cells that secrete osteoid

epiphysis- end of bone

osteocytes- mature cells that maintain bone matrix

diaphysis- long axis of bone

osteoclasts- break down bone

red/yellow bone marrow- creates blood

osteon- structural unit of compact bone

endosteum- membrane that covers trabeculae

lamellae-rings of bone matrix

periosteum- membrane outside of compact bone

canals/canaliculi- communication and relay of nutrients and wastes

hydroxyapatites- responsible for strength and resistance

Spongy bone- made up of tiny holes called trabeculae which are filled with bone marrow

osteoid- collagen+hydroxyapatite

Compact bone- dense outer layer on all bones

Ossification

Endochondral Ossification

Intramembranous Ossification

Central cartilage in diaphysis calcifies, dies, and develops cavities

Periosteal buds invade cavities, forms spongy bone

Bone collar forms around diaphysis of cartilage

diaphysis elongates, medullary cavity forms

Epiphyses ossify

Osteoid is secreted and calcified

Osteoid around blood vessels forms trabeculae and woven bone

Mesenchymal cells cluster and become osteoblasts

Compact and spongy bone form, bone marrow appears

Hyaline cartilage remains only in epiphyseal plates and articular cartilages

Bone growth

Growth hormone stimulates epiphyseal plate

Thyroid hormones modulate growth hormone

Bones increase in thickness though apppositional growth

Sex hormone promotes growth spurt

Long bones grow lengthwise by interstitial growth of epiphyseal plate

Bone remodeling

Bone resorption

Bone deposit

Vitamin C forms collagen

Calcium + phosphate = calcification

Vitamin D enhances calcium absorption

Osteoclasts undergo apoptosis

Digested products are released into the blood

enzymes are secreted that digest matrix

Osteoclast activation involves parathyroid hormone and T cell proteins

Classification of Fractures

Complete-broken all the way through

Incomplete- not completely broken

Displaced- ends out of normal alignment

Open- skin is penetrated

Nondisplaced- ends retain normal position

Closed- skin is not penetrated

Fracture repair

Fibrocartilegenous callus formation

Bony Callus formation

Hematoma formation

Bone remodeling

Cast or splint needed to immobilize arm, possible surgery to reset fracture with additional metal plates or screws to hold the bone in proper position while it heals, along with a calcium supplement and more nutritious diet to decrease the risk of further injury.