Skeletal System

Mandible

The lower jawbone.

Vertebrae

Comprises the spine; categorized into cervical (7), thoracic (12), lumbar (5), sacral, and coccygeal regions.

Sacrum

The triangular bone at the base of the spine, formed from fused vertebrae.

Coccyx

The tailbone, located at the end of the vertebral column.

Ribs

Protects the thoracic cavity; includes true ribs, false ribs, and floating ribs.

Sternum

Located in the center of the chest, connects to the ribs.

Humerus

Upper arm bone; extends from shoulder to elbow.

Radius

Forearm bone located on the same side as the thumb.

Ulna

Forearm bone located on the side of the pinky.

Femur

Thigh bone; the longest bone in the body.

Patella

Knee cap; protects the knee joint.

Tibia

Shin bone; larger bone of the lower leg.

Fibula

Smaller bone of the lower leg, next to the tibia.

Pelvis

Supports the spinal column and protects organs in the lower abdomen.

Ilium

The largest bone of the pelvis.

Clavicle

The collarbone, connecting the arm to the body.

Carpals

The eight bones of the wrist.

Ball and Socket

(e.g., shoulder, hip) allows rotation and movement in multiple directions.

Hinge

(e.g., elbow, knee) permits flexion and extension.

Pivot

(e.g., neck) allows rotational movement.

Saddle

(e.g., thumb) allows grasping and rotation.

Plane

(e.g., intercarpal joints) allows sliding movements.

Condyloid

(e.g., wrist) permits movement in two planes.

Greenstick Fracture

An incomplete fracture; bends like a green twig.

Transverse Fracture

A horizontal fracture across the bone.

Comminuted Fracture

The bone shatters into several pieces.

Spiral Fracture

A fracture that twists around the bone.

Stress Fracture

A hairline fracture from overuse or repetitive force.

Oblique Fracture

A diagonal fracture across the bone.

Avulsion Fracture

A fracture occurring when a fragment of bone is separated by the pull of a tendon or ligament.

Diaphysis

The long shaft of the bone.

Epiphysis

The ends of the bone, often covered with articular cartilage.

Medullary Cavity

The central cavity where marrow is stored.

Periosteum

A fibrous membrane covering the bone surface.

Compact Bone

Dense and forms the outer layer of the bone.

Spongy Bone

Lighter, less dense bone found at the ends of long bones and in the interior of others.

Epiphyseal Line

The remnant of the growth plate in adults.

Articular Cartilage

Smooth tissue covering the ends of bones at joints.

Support

Provides structure and shape to the body.

Protection

Shields vital organs (e.g., brain, heart).

Movement

Serves as levers for muscles to create movement.

Mineral Storage

Stores minerals like calcium and phosphorus.

Blood Cell Production

Produces blood cells in the bone marrow.

Long Bones

Longer than they are wide (e.g., femur).

Short Bones

As wide as they are long (e.g., carpals).

Flat Bones

Thin and flat (e.g., skull, ribs).

Irregular Bones

Complicated shapes (e.g., vertebrae).

Sesamoid Bones

Embedded in tendons (e.g., patella).

Crest

A narrow ridge of bone (e.g., iliac crest).

Foramen

An opening through a bone (e.g., optic foramen).

Fossa

A shallow basin-like depression in a bone (e.g., glenoid fossa).

Cranium

Protects the brain

Sinus

Hollow spaces and channels in skull and facial bones

Tuberosity

Rounded prominence on a bone that serves as an attachment point for muscles and ligaments

Condyle

Rounded prominence at the end of a bone that is part of a joint and provides structural support