Bio Exam 2 Part 4

Skeletal System PT 1

BONESS

Functions of Skeletal System

Support Protection Movement Electrolyte - Acid-Base Balance Storage Blood Cell Production (Hematopoiesis)

Bone Shapes

Flat bone - Parietal bone Long bone - Humerus Sesamoid bone - Patella Short bone - Carpal bone Irregular bone - Vertebra Sutural bone - Sutures

Bone Markings

Every bump, groove, and hole has a name on your bones Two types Projections (Processes) - that grow out from the bone Depressions (cavities) - that indent the bone

Joint Projections

Condyle - Rounded articular projection Head - Bony expansion on a narrow neck Facet - smooth, nearly flat, articular surface

Ligament and Tendon Projections

Crest - Narrow ridge of bone Epicondyle - Raised area on or above condyle Tubercle - Small rounded projection Tuberosity - large rounded or roughened projection Trochanter - very large, blunt projection Spine - Sharp, pointed projection

Depressions

Allow blood vessels or nerves to pass through Meatus - Canal or Tube Fossa - shallow basin Fissure - narrow, slit like opening Sinus - cavity within a bone; filled with air and lined with mucous membranes Foramen - round or oval opening Fovea - small pit for ligament attachment Sulcus, Groove or Furrow - a shallow depression

Review

Projections - 10 of them Depression - 6 of them

Structures of Long Bone

Epiphysis (Proximal and Distal) Diaphysis Articular Cartilage Periosteum Medullary cavity Endosteum Marrow (Red Bone Marrow and Yellow Bone Marrow) Nutrient Artery Metaphysis (Epiphyseal plate, disc, line)

Characteristics of Bone Tissue

Dense Matrix Contains Protein fibers Mineral deposits Cell populations Canaliculi Periosteum

Bone Matrix

Mineral component:  Calcium phosphate - Ca3(PO4)2 + Calcium hydroxide - Ca(OH)2 = Hydroxyapatite Protein Fibers:  Collagen

Osteoblasts

Immature bone cells Osteogenesis Produce osteoid Will become osteocytes

Osteocytes

Mature Bone cells Reside in lacunae Are between layers of matrix (lamellae) Canaliculi

Osteoprogenitor Cells

Mesenchymal cells Located in the endosteum Aid in repair of fractures

Origin of bone cells

Mesenchymal cells > Osteoprogenitor cells > Osteoblasts > Produce matrix > Osteocytes

Osteoclasts

Secrete protein digesting enzymes and acids Multinucleate cells Osteolysis Different origin than other bone cells

Homeostasis

Bone build up and recycling must occur at equal rates More breakdown = bone weakens More buildup = bone mass increases

Compact Bone

Osteons Concentric lamellae Interstitial lamella Lacunae Canaliculi Central canals