A & P Test

Diaphysis

The long, cylindric shaft of a bone, composed mainly of compact bone.

Epiphysis

The enlarged end of a long bone that articulates with another bone.

Epiphyseal Disc

A band of hyaline cartilage between diaphysis and epiphysis where longitudinal growth occurs.

Medullary Cavity

The hollow central space located inside the diaphysis.

Bone Marrow

Tissue occupying medullary cavities and spongy bone spaces, existing as red or yellow.

Red vs. Yellow Bone Marrow (Adults)

Yellow marrow stores fat in adults; red marrow produces blood cells and concentrates at ends.

Endosteum

Connective tissue membrane lining the medullary cavity of long bones.

Periosteum

Tough fibrous membrane covering the outside of the diaphysis, essential for repair and nutrition.

Two Layers of Periosteum

Consists of a dense fibrous membrane layer and an osteoblast layer.

Functions of Periosteum

Protects bone, attaches muscles/tendons, and carries blood vessels and nerves.

Articular Cartilage

Smooth cartilage on the outer epiphysis surface that reduces friction in joints.

Fissure

A cleft or deep groove in a bone.

Foramen

An opening through a bone serving as a passageway for nerves and vessels.

Fossa

A depression or groove space in a bone.

Fovea

A small pit or depression.

Meatus

A tunnel or tube-like passageway running within a bone.

Groove

A shallow linear channel in a bone.

Notch

An indentation into the border of a bone.

Fistula

A suppurating channel in soft tissues.

Sinus

An air cavity in bone or hollow space/channel for venous blood.

Sulcus

A furrow, trench, or fissure-like depression.

Condyle

A large rounded knob that usually articulates with another bone.

Coracoid or Coronoid

A beaklike process on a bone.

Cornu

A hornlike process.

Crest

A ridge on a bone.

Epicondyle

An enlargement near or above a condyle.

Facet

A small, flattened smooth surface process for articulation.

Hamulus

A hook-shaped process.

Head

An enlarged or expanded and rounded end of a bone.

Line

A less prominent ridge than a crest; a linear elevation.

Malleolus

A club-shaped process.

Process

A prominent projection on a bone.

Protuberance

A projecting part or prominence.

Spine

A sharp projection on a bone.

Styloid

A long, pointed process.

Tubercle

A small rounded knob-like projection and elevated process.

Tuberosity

A large, rounded, and elevated process.

Trochanter

A large rounded and elevated tubercle found only on the femur.

Synarthrosis

An immovable joint, such as the sutures in the skull.

Structure of Skull Sutures

Interlocking bone edges bound together by fibrous connective tissue.

Amphiarthrosis

A slightly movable joint connected by a cartilaginous disc.

Examples of Amphiarthroses

Intervertebral discs in the spinal column and the symphysis pubis.

Diarthrosis

A freely movable joint providing maximum flexibility and movement.

Diarthroses and Synovial Joints

All freely movable joints are classified as synovial joints.

Basis of Structural Joint Classification

Type of tissue separating bone ends or binding articular bones together.

Key Characteristics of Fibrous Joints

Lack a joint cavity, held by fibrous tissue, and are virtually immovable.

Three Types of Fibrous Joints

Syndesmosis, suture, and gomphosis.

Syndesmosis Definition & Functional Class

Joint united by fibrous sheets; amphiarthrodial (slightly movable) or synarthrodial.

Sutures Location & Characteristics

Found only in the skull, featuring interlocking bone edges joined by fibrous tissue.

Functional Classification of Adult Sutures

Synarthrodial (immovable joints).

Cartilaginous Joints Key Features

Lack a joint cavity, held tightly by cartilage, and allow little or no movement.

Functional Classification of Cartilaginous Joints

Either synarthrodial (immovable) or amphiarthrodial (slightly movable).

Two Types of Cartilaginous Joints

Symphyses and synchondroses.

Symphysis Definition

Joint characterized by a broad, flattened disc of fibrocartilage between bony surfaces.

Symphysis Function & Movement

Amphiarthrodial (slightly movable); designed for strength and shock absorbency.

Examples of Symphyses Joints

Intervertebral discs and the symphysis pubis.

Synchondrosis Definition

Temporary joint where rigid hyaline cartilage connects bones and converts to bone in adulthood.

Functional Classification of Synchondroses

Synarthrodial (immovable).

Examples of Synchondroses Joints

Epiphyseal plates of long bones and the three-part pelvic union forming the acetabulum.

General Movement Class of Synovial Joints

Generally diarthrodial (freely movable).

Exception to Diarthrodial Synovial Joints

Sacroiliac joints of the pelvis, which are amphiarthrodial (slightly movable).

Articular Cartilage Composition & Function

Hyaline cartilage layer lining bone surfaces, replacing periosteum to form a smooth surface.

Joint Cavity Definition

The potential space within the fibrous capsule containing viscous synovial fluid.

Function of Synovial Fluid

Lubricates the bones in the joint to decrease friction.

Bursae Definition & Function

Small sacs of synovial fluid between joints and tendons that permit tendons to slide smoothly.

Supporting Ligaments Function

Surround the joint, connect articulating bones, stabilize the joint, and reduce friction during movement.

Six Types of Freely Movable Synovial Joints

Gliding (plane), Hinge (ginglymus), Pivot (trochoid), Ellipsoid (condyloid), Saddle (sellar), Ball-and-socket (spheroid).

Gliding (Plane) Joint Movement & Examples

Uniaxial sliding/gliding motion; found in intermetacarpal, intercarpal, and CMC wrist/hand joints.

Hinge (Ginglymus) Joint Movement & Examples

Uniaxial joint allowing flexion and extension only; examples include elbow, knee, ankle, and IP joints.

Pivot (Trochoid) Joint Movement & Examples

Uniaxial rotational movement; examples include atlas pivoting on axis and radioulnar joints.

Ellipsoid (Condyloid) Joint Movement & Examples

Biaxial joint allowing flexion, extension, abduction, adduction, circumduction; found in MCP and wrist joints.

Saddle (Sellar) Joint Characteristics & Example

Biaxial concave-convex joint allowing biaxial movement; the only sellar joint is the 1st CMC joint of thumb.

Ball-and-Socket (Spheroid) Joint Movement & Examples

Multiaxial joint with maximum motion freedom; examples are the shoulder and hip joints.

Flexion

The bending of a joint that decreases the angle between the bones.

Extension

The straightening of a joint so that the angle between the bones increases.

Plantar Flexion

Bending the foot down, as in toe dancing.

Dorsiflexion

Bending the foot up toward the leg.

Hyperextension

Overextending the joint beyond its normally straightened position.

Abduction

Movement away from the midline of the body.

Adduction

Movement toward the midline of the body.

Inversion

Turning the sole of the foot inward so that it faces the opposite foot.

Eversion

Turning the sole of the foot outward.

Supination

Turning the hand so that the palm faces upward.

Pronation

Turning the hand so that the palm faces downward.

Circumduction

A combination of movements, as in the circular arm movement.

Os

A bone; pl. Ossa; adj. Osseous

Ossicle

A little bone, e.g., ossicles of ear

Ossify

To form bone

Ossification

Formation of bone

Calcification

A deposit of calcium, not the formation of bone

Articulation

A joint; adj. Articular; (l. Articulatio)

Arthron

A joint (g)

Arthrosis

A joint; adj. Arthrodial; pl. Arthroses

Junctura

A joint

Lacunae

Pit, space, groove or cavity

Openings

Aperture, foramen, hiatus, orifice, os (pl. ora), ostium, lumen, porus

Depressions

Fissure, fossa, hilum, sulcus, sinus

Compound (Open) Fracture

A broken bone that pierces the skin, with bone protruding through disrupted skin.

Concerns with Compound Fractures

Extensive tissue damage and a significant risk of infection.

Greenstick Fracture

An incomplete break in a bone, typically occurring in infants and children.