Psio 201 Exam 2

1) Support

2) Protection

3) Mineral Storage

4) Triglyceride storage (yellow marrow)

5) red/white blood cell formation

6) leverage (assistance in movement)

Axial: skull, spine, thoracic cage

Appendicular: legs and arms

Epiphysis

Metaphysis

Diaphysis

Edosteum: inner surface lining of bone marrow cavity, traveculae of spongey bone, canals of compact bone. Contains osteogenic cells.

Periosteum: Connective membrane tissue covering external, attached to bone matrix via perforating fibers, 1) outer fibrous, 2) inner osteogenic

stem cells formed from mesenchyme.

Mitosis > daughter cells Differentiation > osteoblasts

build bone, synthesize organic components, initiate calcification (taking calcium from blood and deposit into matrix)

Mature cells involved in maintenance of bone. Senses micro damage and mechanical forces on bone then sends signals for repair. Housed in lacuna.

Breaks down bone, release proteolytic enzymes and acids to degrade collagen and release minerals into blood. Derived from myeloid cells.

Osteoblasts secretion

Ground substance: glycoproteins-GAG

Type 1 Collagen: fibrous protein arranges in helical form. Resistant to pulling forces, provides flexibility and framework

25% water (attracted to ground substance)

Hydroxyapatite (calcium minerals and ions)

Forms mineral plates that fill spaces within collagen fibers, provides firmness.

Osteoblasts > Tropocollagen (triple helix) > microfibril > fibril > fiber > lamella > osteon/tribecullae > compact bone/spongey bone > bone

Bones form through osteoblasts without prior bone resorption.

Occurs during growth, produces change in bone size/shape

Bone is resorbed by osteoclasts and then new Bone is built. Maintenance of bone strength.

Irregular lattice of trabeculae

Epiphysis of Long bones, surrounding marrow cavities

Flat, short, irregular bones

Withstand forces in many directions (trabeculae arrangement), lightens skeleton, red marrow for hemopoesis

More metabolically active than compact

Network of Bone organized into concentric rings (osteons), alternating twisting of collagen between layers

External layer of all bones, diaphysis of Long bones

Gives Long bones ability to withstand forces along longitudinal axis

More length than width

Humerus, femur

Square/trapezoidal

Carpals

Sternum, ribs

Vertebrae

Seed shaped in mostly in soft tissue

Patella

Preosteoclasts are stimulated and differentiate under the influence of cytokines and growth factors into mature osteoclasts

Osteoclasts digest mineral Matrix (old bone)

End of resorption; recruitment of osteoblasts

Osteoblasts synthesize new bone matrix

Osteoblasts become resting bone lining cells on new surface

Mesenchyme to Bone

Cranial bones, mandible, sternum, and clavicle

Heterotropic bone formation

Osteoblasts form bone on the outer surface of the model

Osteoblasts create primary Ossification center

Bone replaced Cartilage

Osteoclasts create marrow cavity

Spongey bone remodeled to compact bone

Around birth, a secondary Ossification center forms

Spongey bone replaces Cartilage at the epiphysis with the exception of epiphyseal plates and articulate Cartilage

Replacement of connective tissue with bone

Deposition of calcium

Marrow cavity formed, replaces Cartilage with bone, located in the diaphysis, occurs before birth

No marrow cavity, Cartilage is left for epiphyseal plates and articular cartilage, located in epiphysis, occurs around time of birth

Occurs where bone doesn’t naturally occur (sesamoid bones)

Occurs within the cartilage of the epiphyseal plate and increases length

1) Chondrocytes build matrix and differentiate into cytes

2) chondrocytes divide

3) chondrocytes build matrix and spread apart

4) Cartilage grows from within

Diaphyseal osteoclasts break down cartilage

Osteoclasts lay down spongey bone

Chondrocytes continue to form cartilage

Growth in length stops when the osteoclasts/blasts work faster than the chondrocytes in the proliferating zone

Epiphyseal plate closes

Growth at the outer surface, increase in width

1) periosteal osteogenic cells differentiate into blasts (ridges in periosteum create groove for vessel)

2) blasts build bone on outer surface of diameter of marrow cavity (ridges fuse, endosteum lined tunnel)

3) bone diameter, cortical width, and medullary cavity increases (osteoblasts in endosteum build new concentric lamellae)

Development of ossification center.

Mesenchyme cells differentiate into osteogenic cells, then into osteoblasts, osteoblasts secrete Bone Matrix.

Calcification

Osteoblasts deposit calcium into the matrix and differentiate into osteocytes

Formation of trabeculae (spongey bone)

Development of periosteum

Remodeling of spongey bone into compact bone

Mesenchyme to Cartilage to bone

Most bones in the body

Primary and secondary Ossification

Cartilage model forms

Mesenchyme cells into chondroblasts

Growth of Cartilage model

Interstitial = length

Appositional = width

Blood vessels penetrate model and stimulate differentiation of osteogenic cells into osteoblasts

Normal bone with abnormal fractures

1: nearby bone cells die which leads to swelling and inflammation, phagocytes/osteoclasts remove damaged tissue

2: blood vessels grow into hematoma, mesenchyme differentiates, growth of Cartilage and collagen, to produce spongey bone

3. Bone remodeling

Surgical rods

Natural healing with splinting and setting

Minerals: Calcium and phosphorous

Vitamins: A(stimulated osteoblast activity), C (needed for collagen synthesis), D (stimulates calcium absorption), K B12 (synthesis of proteins)

Stimulus: high blood calcium

Source: thyroid gland

Target Tissue: bone, kidney, intestine

Actions: inhibits osteoclast activity, increase excretion of calcium at kidney, inhibits absorption at intestine

Stimulus: low blood calcium

Source: parathyroid

Target tissue: bone, kidney, intestine

Actions: stimulates osteoclast activity, decreases excretion of calcium at kidney, stimulate intestinal absorption of calcium

Active form of vitamin D. Stimulates osteoclast activity, decreases calcium excretion at kidney, increase absorption at intestine

Steroid hormone derived from cholesterol

1000 mg

Stimulates cell growth and protein synthesis

Stimulates the formation of insulin which stimulates osteoblast activity which stimulates bone formation

Children with low levels of growth hormone meanings slow epiphyseal growth and short stature

Abnormal bone with normal fractures

Hyper-secretion of growth hormone in childhood leading to accelerated epiphyseal growth and tall stature

Hypersecretion of growth hormone after puberty meaning appositional growth in skulls, hands and feet.

Stimulate osteoblast activity

Increased levels at puberty means growth spurts until epiphyseal plate closes

Bone is partially broken

Loss of continuity

Incomplete: one side broken, the other bent

Complete with no separation

Complete with separation

Piece of bone does not brake skin

Complete with skin break

Transverse

Oblique

Spiral

Communicated

Impounded

1) muscles pulling on joint > joint reaction forces

2) impact > ground reaction forces

Mono-Axial

Trochlea - ulna

Capitulum - radius

Tri-axial

Special ligament inside acetabulum and femoral head

Mono-Axial

Meniscus cushion

Intracapsular and extracapsular ligaments

Sensed by osteocytes > proliferation of osteoblasts (influx of calcium) > gap junctions > bone cell response bone formation greater than bone resorption

Proportion of collagen and minerals is normal but a decrease in mass. Porous trabeculae.

Immovable joint

Situation bones, alveolar process with teeth, epiphyseal plates

Slightly movable joint

Between tibia/fibula, pubic symphysis

Freely movable joint

Covered in protective connective tissue

Shoulder, elbow, hip

1) osteoarthritis (oa) - degenerative (thinned articular Cartilage)

2) rheumatoid - inflammatory (swelling in synovial membrane)

Only movable joint of the skill

Mandibulat chondyle and the mandibular fossa

TJM- pulling mandible out of joint

1- facets

The rest have demi facets

Try-Axial - more prone to injury

Stabilized by coracohumeral ligament, glenohumeral ligament, transverse humoral ligament

Upward rotation of scapula and lateral rotation of humerus