Skeletal Anatomy, Histology, Markings, and Pathology

Comprehensive vocabulary flashcards covering skeletal markings, bone anatomy, histology, marrow functions, classifications, ossification, bone disorders, and fracture types.

Groove

A furrow depression on a bone.

Groove (Example)

Intertubercular groove of the humerus.

Fissure

A narrow, slit-like opening in a bone.

Fissure (Example)

Superior orbital fissure of the sphenoid.

Foramen

A round or oval opening through a bone.

Foramen (Examples)

Optic foramen of the sphenoid and foramen magnum.

Notch

An indentation at the edge of a bone or structure.

Notch (Example)

Radial notch of the ulna.

Meatus

A canal-like passageway through a bone.

Meatus (Example)

External acoustic meatus.

Sinus

A cavity or hollow space within a bone.

Sinus (Example)

Sphenoid sinuses.

Fossa

A shallow, basin-like depression on a bone.

Fossa (Examples)

Coronoid fossa of the humerus and mandibular fossa.

Sulcus

A furrow or trench along a bone surface.

Sulcus (Example)

Intertubercular sulcus of the humerus.

Head (Bone Marking)

A bony expansion carried on a narrow neck that forms a joint.

Head (Bone Marking Example)

Head of the femur.

Facet

A smooth, nearly flat articular surface that forms a joint.

Facet (Example)

Superior articular facet of vertebrae.

Condyle

A rounded articular projection that forms a joint.

Condyle (Examples)

Lateral condyle of the femur and occipital condyles.

Ramus

An arm-like, angular bar of bone.

Ramus (Example)

Ischium of the pelvis.

Tuberosity

A large, rough, rounded projection serving as a site for muscle or ligament attachment.

Tuberosity (Examples)

Ischial tuberosity and tibial tuberosity.

Crest

A prominent, narrow ridge of bone.

Crest (Examples)

Medial sacral crest and iliac crest.

Trochanter

A very large, blunt, irregularly shaped process found exclusively on the femur.

Trochanter (Example)

Greater trochanter of the femur.

Line (Bone Marking)

A narrow ridge of bone that is less prominent than a crest.

Line (Bone Marking Example)

Linea aspera of the femur.

Tubercle

A small, rounded projection or process.

Tubercle (Example)

Greater tubercle of the humerus.

Epicondyle

A raised area situated on or above a condyle.

Epicondyle (Example)

Medial epicondyle of the femur.

Spine (Bone Marking)

A sharp, slender, pointed projection.

Spine (Bone Marking Examples)

Spinous process of vertebrae and spine of the scapula.

Process (Bone Marking)

Any bony prominence or projection.

Process (Bone Marking Example)

Transverse process of vertebrae.

Orthopedist

A doctor who diagnoses and treats disorders and injuries of the musculoskeletal system, including bones, joints, ligaments, tendons, and muscles, using medication, physical therapy, or surgery.

Hematopoiesis

The production of blood cells—specifically red blood cells, most white blood cells, and platelets—which takes place in red bone marrow.

Red Bone Marrow

Marrow tissue that produces blood cells (red blood cells, most white blood cells, and platelets) and is found in the spaces of spongy bone.

Yellow Bone Marrow

Marrow that consists mostly of fat cells and stores energy; it occupies the medullary cavity of many adult long bones and can convert back to red marrow during severe blood loss.

Long Bones

Bones that are longer than they are wide.

Long Bones (Examples)

Femur, humerus, and phalanges.

Short Bones

Roughly cube-shaped bones.

Short Bones (Examples)

Carpals and tarsals.

Flat Bones

Thin, often curved or slightly rounded bones.

Flat Bones (Examples)

Sternum, ribs, and many skull bones.

Irregular Bones

Bones with complex shapes that do not fit into other shape categories.

Irregular Bones (Examples)

Vertebrae and hip bones.

Sesamoid Bones

Small, rounded bones embedded within tendons.

Sesamoid Bones (Example)

Patella.

Diaphysis

The central tubular shaft of a typical long bone surrounding the medullary cavity.

Epiphyses

The two expanded ends of a long bone, composed mainly of spongy bone surrounded by a thin outer layer of compact bone.

Metaphysis

The transitional region of a long bone located between the diaphysis and each epiphysis.

Epiphyseal Plate

A layer of cartilage located in the metaphysis of a growing bone where lengthwise growth takes place.

Epiphyseal Line

The remnant structure that forms in the metaphysis after bone lengthwise growth concludes and the epiphyseal plate closes.

Medullary Cavity

The hollow internal chamber within the diaphysis of a long bone containing yellow marrow in many adults.

Periosteum

A tough, vascular connective-tissue membrane covering the outer bone surface that supports bone growth and repair, anchors tendons and ligaments, and is secured by perforating fibers.

Perforating (Sharpey's) Fibers

Connective-tissue fibers that firmly anchor the periosteum to the underlying bone matrix.

Endosteum

A thin membrane lining the internal surfaces of bone involved in bone growth, remodeling, and repair.

Articular Cartilage

Cartilage covering the joint surfaces of epiphyses that cushions bone ends and reduces friction during joint movement.

Compact Bone

Dense bone tissue forming the hard outer layer of bones and the shaft of long bones, organized structurally into units called osteons.

Osteons

The cylindrical structural units of compact bone arranged around central canals carrying blood vessels and nerves.

Lamellae

Concentric rings of bone matrix surrounding each central canal inside an osteon.

Lacunae

Small spaces within the bone matrix that house osteocytes.

Canaliculi

Tiny channels that radiate between lacunae to connect osteocytes to one another.

Spongy Bone

A lightweight type of bone constructed of a lattice of trabeculae aligned along lines of stress with spaces containing red bone marrow.

Trabeculae

Thin plates or struts forming the lattice network of spongy bone, oriented along stress lines to withstand force while minimizing weight.

Paget's Disease

A chronic disorder in which bone is broken down and rebuilt abnormally—often faster than normal—resulting in enlarged, misshapen, but weakened bones at risk of pain and fractures.

Intramembranous Ossification

Bone formation directly from sheets of connective tissue without a prior cartilage model.

Intramembranous Ossification (Bones Formed)

Many flat skull bones and part of the clavicle.

Endochondral Ossification

Bone formation that gradually replaces a preexisting cartilage model.

Endochondral Ossification (Bones Formed)

Most bones of the human body, including long bones.

Closed (Simple) Fracture

A fracture in which the broken bone does not pierce through the skin.

Open (Compound) Fracture

A fracture where the broken bone or fracture site communicates with the outside body environment through a wound.

Complete Fracture

A fracture where the break extends entirely through the cross-section of the bone.

Incomplete Fracture

A fracture where the break does not extend through the entire bone.

Incomplete Fracture (Example)

Greenstick fracture.

Comminuted Fracture

A fracture in which the bone shatters or breaks into three or more pieces.

Transverse Fracture

A fracture where the break line runs roughly straight across the bone axis.

Oblique Fracture

A fracture where the break line runs diagonally across the bone.

Spiral Fracture

A fracture that twists around the bone, commonly caused by a twisting force.

Impacted Fracture

A fracture in which the broken ends of the bone are forcibly driven into one another.

Compression Fracture

A fracture where the bone is crushed.

Compression Fracture (Common Site)

Vertebrae.

Depressed Fracture

A fracture where a broken bone segment is pushed inward.

Depressed Fracture (Typical Site)

Skull.

Stress Fracture

A small crack in a bone that develops from repeated loading or overuse.