THE SKELETAL SYSTEM
Functions of bones
Support- Bones are the "steel grinders" and "reinforced concrete" of the body, that form the internal framework that supports the body and cradles its soft organs
Protection- Protect the soft body organs. Examples: The vertebrae surround the spinal cord, and the rib cage helps protect the vital organs of the thorax
Movement- Skeletal muscles, attached to bones by tendons, use the bones as levers to move the body and its parts.
Storage- Fat is stored in the internal (marrow) cavities of bones. It also can be a storehouse for minerals, calcium, and phosphorus.
Blood cell formation- Occurs within the marrow cavities of certain bones.
Protection- Protect the soft body organs. Examples: The vertebrae surround the spinal cord, and the rib cage helps protect the vital organs of the thorax
Movement- Skeletal muscles, attached to bones by tendons, use the bones as levers to move the body and its parts.
Storage- Fat is stored in the internal (marrow) cavities of bones. It also can be a storehouse for minerals, calcium, and phosphorus.
Blood cell formation- Occurs within the marrow cavities of certain bones.
Classifications of bones
Compact bone- dense and looks smooth
Spongy bone- composed of small needlelike pieces of bone and lots of open space Long bones- They are longer than wide. Have a shaft with heads at both ends. Mostly compact. All of the bones of the limbs, except the patella and the wrist and ankle bones, are long bones Short bones- Usually cube-shaped and contain mostly spongy bone. Bones of the wrist and ankle are short bones. Flat bones- They are thin, flattened, and usually curved. There are two thin layers of compact bone sandwiching a layer of spongy bone between them. Irregular bones- Bones that do not fit one of the preceding categories |
Bone Markings
Muscle and ligament attachment
- Tuberosity: Large, rounded projection; may be roughened
- Crest: Narrow ridge of bone; usually prominent
- Trochanter: Very large, blunt, irregularly shaped process
- Line: Narrow ridge of bone; less prominent than a crest
- Tubercle: Small, rounded projection or process
- Epicondyle: Raised area on or above a condyle
- Spine: Sharp, slender, often pointed projection
- Process: Any bone prominence
Form joints
- Head: Bony expansion carried on a narrow neck
- Facet: Smooth, nearly flat articular surface
- Condyle: Rounded articular projection
- Ramus: armlike bar of bone
Depressions and Openings
For passage of blood vessels and nerves
- Groove: Furrow
- Fissure: Narrow, slitlike opening
- Foramen: Round or oval opening through a bone
- Notch: Indentation at the edge of a structure
- Meatus: Canal-like passageway
- Sinus: Cavity within a bone, filled with air and lined with mucous membrane
-Fossa: Shallow, basinlike depression in a bone, often serving as an articular surface
- Tuberosity: Large, rounded projection; may be roughened
- Crest: Narrow ridge of bone; usually prominent
- Trochanter: Very large, blunt, irregularly shaped process
- Line: Narrow ridge of bone; less prominent than a crest
- Tubercle: Small, rounded projection or process
- Epicondyle: Raised area on or above a condyle
- Spine: Sharp, slender, often pointed projection
- Process: Any bone prominence
Form joints
- Head: Bony expansion carried on a narrow neck
- Facet: Smooth, nearly flat articular surface
- Condyle: Rounded articular projection
- Ramus: armlike bar of bone
Depressions and Openings
For passage of blood vessels and nerves
- Groove: Furrow
- Fissure: Narrow, slitlike opening
- Foramen: Round or oval opening through a bone
- Notch: Indentation at the edge of a structure
- Meatus: Canal-like passageway
- Sinus: Cavity within a bone, filled with air and lined with mucous membrane
-Fossa: Shallow, basinlike depression in a bone, often serving as an articular surface
Common fractures
Skull
Vertebrae
Thoracic cage & upper limbs
Pelvic Girdle & Lower Limb
Joints
Fibrous: Bone ends/parts united by collagenic fibers (Immobile)
Cartilanginous: Bone ends/ parts united by cartilage (Immobile)
Synovial: Bone ends/ parts covered with articular cartilage and enclosed within an articular capsule lined with synovial membrane (Moveable)
Cartilanginous: Bone ends/ parts united by cartilage (Immobile)
Synovial: Bone ends/ parts covered with articular cartilage and enclosed within an articular capsule lined with synovial membrane (Moveable)