Weeks 4 and 5 The Skeletal System SB
Objective 1: Bone Classification Classification by shape: Long bones are longer than they are wide phalanges metacarpals humerus
Short bones are roughly cubical carpals Sesamoid bones are a type of short bone that form in tendons patella
Flat bones are thin with parallel surfaces and usually a little curved parietal bone sternum rib
Irregular bones do not fit into the other categories vertebra/vertebrae pelvic bone
Projections that help form joints: Objective 2: Bone Markings Bone markings are bumps, projections, openings and ridges on the surfaces of bones. They function as passageways for nerves and blood vessels, as points of muscle and ligament attachment, and as joint surfaces. Projections that help form joints: Head: a bony expansion carried on a narrow neck Facet: smooth, nearly flat articular surface
Projections that help form joints Condyle: rounded articular projection Ramus: armlike projection of bone
Projections that serve as sites for muscle and ligament attachment Crest: a narrow prominent ridge of bone Sacrum Line: Narrow ridge of bone; less prominent than a crest
Projections that serve as sites for muscle and ligament attachment Spine: sharp, slender, pointed projection Process: prominence or projection
Projections for muscle and ligament attachment Trochanter: very large, blunt, irregularly shaped process Tuberosity: large, rounded projection which may be roughened Femur Fibula and Tibia
Projections for muscle and ligament attachment Tubercle: small, rounded projection or process Epicondyle: raised area on or above a condyle Humerus
Depressions and openings to allow passage of nerves and vessels Meatus: canal-like passageway Foramen: rounded or oval opening through a bone
Depressions and openings to allow passage of nerves and vessels Foramen: rounded or oval opening through a bone Meatus: canal-like passageway
Depressions and openings Fissure: narrow, slit-like opening Sinus: cavity within a bone filled with air Ethmoid bone
Depressions and openings Groove: furrow Fossa: shallow, basin-like depression in a bone, often serving as an articular surface Humerus
Objective 3: Gross Anatomy of a Long Bone
Objective 4: Chemical Composition of Bone Bone matrix has two components: Organic ground substance (osteoid) which consists of soluble proteins and collagen fibers (1/3 of matrix) osteoid gives bone its tensile strength (flexibility) in lab you will observe bone treated with heat to denature proteins What effect do you think heating bone will have? Inorganic materials (hydroxyapatite) which consist of a variety of mineral salts, primarily calcium and phosphorus (2/3 of matrix) hydroxyapatite gives bone its compressional strength (hardness) in lab you will observe bone that has been treated with acid to remove minerals What effect do you think treating bone with acid will have?
Objective 5: Microscopic Structure of Compact Bone
Human bone is primarily arranged in a ringed pattern and is called lamellar bone:
Osteon (Haversian System) The structural unit of compact bone Central (Haversian) canal
Interstitial lamella/lamellae concentric lamella
Mature bone cells are called osteocytes They are embedded in spaces called lacuna/lacunae
Canaliculi Lacuna (containing an osteocyte)
Perforating (Volkman’s) canal Haversian canal Perforating (Volkman’s) canal