Skeletal System Overview

Study Notes

Skeletal System Overview

Axial Skeleton: Forms the central axis of the body, including the head, neck, and trunk.
Appendicular Skeleton: Comprises bones of the shoulders, pelvis, and upper and lower limbs.
Bone Types:
- Compact Bone: Dense, strong outer layer of bones.
- Spongy Bone: Porous inner layer, stores minerals and marrow.
- Long Bones: Longer than wide (e.g., femur).
- Short Bones: Cube-shaped (e.g., wrist and ankle bones).
- Flat Bones: Thin, flattened, and usually curved (e.g., skull bones).
- Irregular Bones: Complex shapes (e.g., vertebrae, facial bones).
Long Bone Structure:
- Diaphysis: The shaft of a long bone.
- Epiphysis: The end of a long bone.
- Periosteum: Connective tissue covering the outer surface of the bone.
- Medullary Cavity: Space within the diaphysis filled with bone marrow.
- Epiphyseal Plate: Growth plate (present in growing bones); replaced by epiphyseal line in adults.
Bone Projections and Depressions:
- Projections: Bone outgrowths (e.g., tuberosity, spine, trochanter, crest, head, facet, condyle, ramus).
- Depressions and Openings: Bone indentations (e.g., fossa, foramen, meatus).
Joints:
- Fibrous Joints: Immovable; connected by fibrous tissue (e.g., skull sutures).
- Cartilaginous Joints: Slightly movable; connected by cartilage (e.g., vertebrae).
- Synovial Joints: Freely movable; enclosed in a joint capsule.
  - Types of Synovial Joints: Ball and socket (shoulder and hip), hinge (elbow and knee), pivot (atlantoaxial joint), condyloid (wrist), plane (intercarpal joints), saddle (carpometacarpal joint of thumb).
Supporting Tissues:
- Ligaments: Connect bone to bone.
- Tendons: Connect muscle to bone.
- Synovial Fluid: Lubricates synovial joints.
- Hyaline Cartilage: Covers ends of bones in synovial joints; important for smooth movement.
Bone Injuries and Diseases:
- Bursitis: Inflammation of a bursa (fluid-filled sac).
- Sprain: Injury to a ligament.
- Arthritis: Inflammation of joints.
  - Osteoarthritis: Degenerative joint disease.
  - Rheumatoid Arthritis: Autoimmune disorder attacking joint cartilage.
  - Gout: Arthritis caused by uric acid buildup.
- Osteoporosis: Bone loss leading to fragility.
- Rickets: Vitamin D deficiency in children causing bone deformities.
- Bone Fractures: Broken bones categorized by type (simple, compound, comminuted, compression, depressed, impacted, spiral, greenstick).

Description

Explore the key components and structure of the skeletal system in this informative quiz. Gain insights into the axial and appendicular skeletons, different types of bones, and the detailed anatomy of long bones. Ideal for students studying human anatomy.