ANAPHY Skeletal

Skeletal System

The framework of bones, joints, cartilages, and ligaments that provides support, protection, movement, storage of minerals and fats, and blood cell formation in the body.

Axial Skeleton

The division of the skeletal system that includes the bones of the skull, vertebral column, and rib cage.

Appendicular Skeleton

The division of the skeletal system that includes the bones of the upper and lower limbs, shoulder, and hip.

Compact Bone

Homogenous bone tissue that is dense and strong.

Spongy Bone

Bone tissue composed of small needle-like pieces with many open spaces.

Long Bones

Bones that are typically longer than they are wide, with a shaft and heads at both ends, such as the femur and humerus.

Diaphysis

The shaft or middle part of a long bone, composed of compact bone.

Epiphysis

The ends of a long bone, composed mostly of spongy bone.

Periosteum

The outside covering of the diaphysis, a fibrous connective tissue membrane.

Articular Cartilage

The hyaline cartilage that covers the external surface of the epiphyses, decreasing friction at joint surfaces.

Medullary Cavity

The cavity of the shaft that contains yellow marrow (mostly fat) in adults and red marrow (for blood cell formation) in infants.

Short Bones

Bones that are generally cube-shaped and contain mostly spongy bone, such as the carpals and tarsals.

Flat Bones

Thin and flattened bones that usually have thin layers of compact bone surrounding a layer of spongy bone, such as the skull, ribs, and sternum.

Irregular Bones

Bones with an irregular shape that do not fit into other bone classification categories, such as the vertebrae and hip.

Osteocytes

Mature bone cells.

Osteoblasts

Bone-forming cells.

Osteoclasts

Bone-destroying cells that break down bone matrix for remodeling and release of calcium.

Bone Fractures

A break in a bone.

Closed (Simple) Fracture

A break that does not penetrate the skin.

Open (Compound) Fracture

A broken bone that penetrates through the skin.

Reduction and Immobilization

The treatment for bone fractures that involves realignment of the bone and immobilizing it.

Hematoma

A blood-filled swelling that forms during the repair of a bone fracture.

Callus

Fibrocartilage or bony tissue that splints the broken bone during the repair process.

Fontanelles

Fibrous membranes connecting the cranial bones in the fetal skull, allowing the brain to grow and converting to bone within 24 months after birth.

Paranasal Sinuses

Hollow portions of bones surrounding the nasal cavity that lighten the skull and give resonance and amplification to the voice.

Hyoid Bone

The only bone that does not articulate (move) with another bone, serving as a movable base for the tongue.

Vertebral Column

The series of vertebrae separated by intervertebral discs that form the spine and provide support and protection for the spinal cord.

Bony Thorax

The cage-like structure formed by the sternum, ribs, and thoracic vertebrae that protects major organs.

Pectoral (Shoulder) Girdle

The bones of the clavicle and scapula that connect the upper limbs to the axial skeleton and allow for free movement of the upper limb.

Pelvic Girdle

The hip bones composed of three pairs of fused bones (ilium, ischium, and pubic bone) that support the weight of the upper body and protect reproductive and urinary organs.

Joints

Articulations of bones that hold bones together and allow for mobility.

Synarthroses

Immovable joints.

Amphiarthroses

Slightly movable joints.

Diarthroses

Freely movable joints.

Fibrous Joints

Joints where bones are united by fibrous tissue and are generally immovable or synarthrotic.

Cartilaginous Joints

Joints where bones are connected by cartilage and are mostly amphiarthrotic.

Synovial Joints

Freely movable joints where articulating bones are separated by a joint cavity filled with synovial fluid.

Bursae

Flattened fibrous sacs lined with synovial membranes and filled with synovial fluid, providing cushioning and reducing friction between structures.

Tendon Sheath

An elongated bursa that wraps around a tendon, reducing friction during tendon movement.

Inflammatory Conditions Associated with Joints

Bursitis (inflammation of a bursa), Tendonitis (inflammation of tendon sheaths), and Arthritis (inflammatory or degenerative diseases of joints).