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.