Skeletal System Lecture Flashcards

Vocabulary flashcards covering the structural characteristics, bone types, landmarks, and common pathologies from the PHT1121 Skeletal System lecture notes.

Axial Skeleton

The central part of the body consisting of the bones of the head, neck, thorax, and trunk, which includes the skull, hyoid bone, inner ear ossicles, vertebral column, and rib cage.

Appendicular Skeleton

The portion of the skeleton that attaches to the axial skeleton and consists of the bones of the upper and lower extremities, including the shoulder girdle and pelvis.

Organic Bone Material

Living component that makes up $\frac{1}{3}$ of bone composition and provides elasticity.

Inorganic Bone Material

Non-living component that makes up $\frac{2}{3}$ of bone composition and provides hardness and strength.

Compact Bone

The hard, dense outer layer of all bone that appears opaque upon x-ray.

Cancellous Bone

The less dense, porous, or spongy inner portion of bone containing a latticework trabecular system that appears less opaque upon x-ray.

Wolff's Law

The principle stating that bone density increases in response to increased forces imposed and decreases in response to decreased forces imposed.

Epiphysis

The end of each bone that provides joint surfaces and contains the epiphyseal plate.

Epiphyseal Plate

The specific area within the epiphysis of a bone where growth occurs.

Metaphysis

The transition section of a bone located between the epiphysis and the diaphysis.

Diaphysis

The main shaft of a bone.

Periosteum

The outer membrane layer of bone containing nerves, pain receptors, and blood vessels for nourishment and growth in diameter; serves as an attachment site for tendons and ligaments.

Endosteum

The membrane lining of the medullary canal that contains osteoclasts for bone resorption.

Medullary Canal

The hollow center of a bone containing marrow and blood vessels.

Long Bones

Bones with length greater than width that make up most of the appendicular skeleton, grow at the epiphyseal plate, and have articular surfaces covered by hyaline cartilage.

Short Bones

Bones found in the wrist and ankle with relatively equal dimensions of height, width, and length that have multiple articular surfaces to articulate with more than one bone.

Flat Bones

Broad, non-thick, curved bones that serve as main sites of blood formation, including the cranium, scapula, sternum, and ribs.

Irregular Bones

Bones with a variety of unique shapes that do not fit into other categories, where their shape provides specific functions such as protecting the spinal cord.

Sesamoid Bone

Small accessory bones resembling sesame seeds located where tendons cross the ends of long bones; they protect tendons from wear and alter attachment angles for mechanical advantage.

Foramen

A hole in a bone structure.

Fossa

A hollow or depression in a bone.

Groove

A narrow channel in a bone.

Meatus

A canal or tube-like opening in a bone.

Sinus

An air or fluid cavity within a bone.

Condyle

A rounded, knuckle-like projection related to joints.

Eminence

A projecting, prominent part of a bone related to joints.

Facet

A flat or shallow articular surface on a bone.

Head (Bone Structure)

A rounded articular projection on a bone.

Crest

A sharp ridge or border on a bone.

Epicondyle

A prominence located above or below a condyle.

Line (Bone Structure)

A bony ridge that is less prominent than a crest.

Spine (Bone Structure)

A thin projection on a bone.

Tubercle

A small rounded projection on a bone.

Tuberosity

A large rounded projection on a bone.

Trochanter

A large prominence on a bone.

Avulsion Fracture

A fracture defined by the separation of a tendon or ligament from the bone.

Comminuted Fracture

A fracture resulting in multiple bone fragments.

Greenstick Fracture

A fracture where the bone is bent on one side and separated on the other side, common in children.

Osteoporosis

Pathology marked by loss of normal bone density and overall bone weakening, common in the thoracic vertebrae of the elderly.

Osteopenia

A condition of reduced bone mass that acts as a precursor to osteoporosis.

Osteomyelitis

A bacterial infection of the bone.

Legg-Calvé-Perthes Disease

A condition occurring in children usually aged $4$ to $10$ where blood supply interruption to the femoral head causes avascular necrosis at the pressure epiphysis.

Apophysitis

Irritation and inflammation occurring at the traction epiphysis where tendons attach to bone.

Osgood-Schlatter Disease

Apophysitis occurring at the tibial tuberosity during bone growth years.

Sever's Disease

Apophysitis occurring at the calcaneus during bone growth years.