Comprehensive Human Skeletal System: Bones, Joints, and Disorders

Framework

Gives our body shape and support, similar to the frame of a building.

Protection

Bones protect vital organs, such as the skull protecting the brain and ribs protecting the heart and lungs.

Levers

Bones act as levers to help us move; muscles attach to bones and pull on them when they contract.

Production of blood cells

Blood cells are produced inside certain bones in a tissue called bone marrow.

Hematopoiesis

The process of blood cell production in red bone marrow.

Storage

Bones store minerals such as calcium and phosphorus and fat in yellow bone marrow.

Skeletal system

Made up of bones along with other connective tissues, including ligaments and cartilage.

Ligaments

Connect bone to bone and help stabilize joints.

Cartilage

Provides cushioning and reduces friction where bones meet.

Living tissue

Bones are living tissue that contain blood vessels and nerves.

Ossification

The process of bone hardening as calcium deposits form in the bone structure.

Osteogenic cells

Stem cells found in bone marrow and periosteum that develop into osteoblasts.

Osteoblasts

Cells that build bone and produce new bone matrix.

Osteocytes

Mature bone cells that maintain bone tissue.

Osteoclasts

Cells that break down bone and help with bone remodeling.

Diaphysis

The long shaft of the bone containing yellow marrow.

Epiphysis

The expanded ends of the bone covered with articular cartilage.

Periosteum

The tough outer covering of the bone that contains blood vessels and nerves.

Endosteum

Thin membrane that lines the inside of the medullary cavity.

Red bone marrow

Responsible for blood cell production, including red blood cells, white blood cells, and platelets.

Yellow bone marrow

Stores fat and serves as an energy reserve.

Compact bone

Forms the strong outer layer of the bone.

Spongy bone

Located near the epiphysis and contains marrow.

Axial skeleton

Forms the central axis of the body and includes 80 bones.

Appendicular skeleton

Includes bones that allow movement and consists of 126 bones.

True ribs

7 pairs of ribs that attach directly to the sternum.

False ribs

3 pairs of ribs that attach indirectly to the sternum.

Floating ribs

2 pairs of ribs that do not attach to the sternum.

Vertebral column

Supports the body and protects the spinal cord, divided into regions.

Pelvic girdle

Supports body weight, protects pelvic organs, and provides attachment for the legs.

Ischium

Forms the lower, back portion of the pelvis.

Pubis

Forms the front, lower part of the pelvis.

Acetabulum

The socket formed where the ilium, ischium and pubis meet.

Lower extremities

Support body weight and allow walking and movement.

Femur

Thigh (longest bone in the body).

Patella

Kneecap.

Tibia and fibula

Lower leg.

Tarsals, metatarsals, phalanges

Ankle, foot and toes.

Long bones

Bones of the extremities - humerus, radius, ulna, tibia, fibula, clavicle.

Short bones

Length and width are near equal - wrist, hand, ankle, feet.

Flat bones

2 layers of bones divided by a narrow space - Skull, sternum, ribs, shoulder blade.

Irregular bones

Bones that do not fit the shapes of the other groups - face, spine, hip.

Kneecap

Sesamoid bone - called the patella.

Fontanels

Spaces that allow for the enlargement of the skull as brain growth occurs.

Sutures

Areas where the cranial bones have joined together.

Sinuses

Air spaces in the bones of the skull that act as resonating chambers for the voice.

Synarthrosis

Immovable joints that protect the brain.

Amphiarthrosis

Slightly movable joints that provide stability.

Diarthrosis

Freely movable joints that are the most common in the body.

Ball-and-socket joint

Found in the hip and shoulder, allowing movement in many directions.

Hinge joint

Found in the elbow and knee, moving like a door hinge.

Pivot joint

Found in the neck, allowing rotation.

Arthritis

Inflammation of a joint causing pain, stiffness, swelling and decreased movement.

Osteoarthritis

Most common type of arthritis, often due to aging or overuse.

Rheumatoid arthritis

An autoimmune disease that attacks the joints.

Bursitis

Inflammation of bursa, causing painful movement.

Fractures

Breaks in bones due to falls, accidents or trauma.

Dislocation

Occurs when a bone is forced out of its normal position in a joint.

Sprain

Injury to a ligament caused by twisting or stretching too far.

Osteomyelitis

Infection of the bone, often requiring antibiotics.

Osteoporosis

Metabolic condition causing bones to become thin and brittle.

Ruptured disc

Occurs when the soft center of an intervertebral disk pushes out.

Kyphosis

An exaggerated outward curve of the upper spine.

Lordosis

Exaggerated inward curve of the lower spine.

Scoliosis

An S-shaped curve of the spine.

Open Fracture

Bone breaks and the skin is open or the bone is sticking out.

Closed Fracture

Bone is broken but the skin is intact.

Pathologic Fracture

Bone breaks due to being weakened by disease.

Greenstick fracture

An incomplete break where the bone bends and cracks but doesn't break all the way through.

Transverse fracture

The break goes straight across the bone at a 90 degree angle.

Oblique fracture

The break runs at an angle across the bone often from twisting injury combined with a strong force.

Spiral fracture

Happens when a twisting force is applied to the bone, causing a spiral-shaped break.

Comminuted fracture

When the bone breaks into 3 or more pieces.

Depressed fracture

Occurs when a bone is pushed inward, commonly seen in skull fractures.

Compression fracture

The bone is crushed or collapses, most common in the vertebrae.

Avulsion fracture

A small piece of bone is pulled off by a tendon or ligament.

Impacted fracture

Occurs when the broken ends of the bone are driven into each other.

Colles fracture

A specific fracture of the distal radius near the wrist where the broken piece tilts upward.

Signs and symptoms of fractures

Fractures are painful, movement is limited, skin may appear deformed, edema is common, ecchymosis may occur.

Control pain

Pain control helps the patient relax and prevents more injury.

Reduce edema

Swelling happens because blood vessels are damaged, fluid leaks into the tissues.

Keep the bone aligned

Bones need to heal in the correct position to avoid crooked healing.

Keep the bone immobile

Bones heal best when they are not moving.

Typical healing times for fractures

Children: 3-6 weeks; Teens/adults: 6-12 weeks; Older adults or complex fractures: 3-6 months or more.

Healing stages of fractures

1) Blood clot forms at the break 2) Soft callus forms 3) Hard bone replaces the callus 4) Bone reshapes.

ORIF

Open Reduction Internal Fixation - the surgeon realigns broken bone pieces and holds them in place using hardware.

Immobilization

Keeping the bone completely still so it can heal.

Pins

Thin metal rods placed through the bone to hold pieces together.

Screws

Used to hold bones tightly in place, often part of ORIF.

Splints

Support and protect the injured area but do not fully surround the limb.

Bone plates

Flat metal plates attached to the bone with screws to keep the bone aligned.

Casts

A hard shell made of plaster or fiberglass that completely immobilizes the bone.

Traction

Uses weights, pulleys, and ropes to gently pull on the bone or limb.

Skin traction

Pulling force applied to the skin, used short term.

Skeletal traction

Pins or wires inserted into bone, weights apply steady pulling force.

Prevent complications during immobilization

Engage other muscles to prevent weakness and maintain circulation.

Cough and deep breathe

Helps open the lungs, clear mucus, and keep oxygen levels healthy.

Increasing fluid intake

Helps prevent complications like constipation and urinary tract infections.

Trapeze

A triangle-shaped bar over the bed that helps patients reposition themselves.

Total Hip Replacement (THR)

Surgery to replace damaged parts of the hip joint.