Musculoskeletal System

The musculoskeletal system includes the bones, joints, muscles, fascia, tendons, ligaments, and connective tissues that provide structure, support, protection, movement, mineral storage, and posture. It is a dynamic, constantly remodeling system influenced by circulation, inflammation, hormones, nutrition, and nervous system signaling.
- Support + structural framework of the body
- Movement through skeletal muscle contraction
- Protection of vital organs (rib cage, pelvis, skull)
- Mineral storage (calcium, phosphorus)
- Blood formation (hematopoiesis in red marrow)
- Posture + stability
- Shock absorption (cartilage, fascia, synovial fluid)
- Repair + remodeling (constant turnover influenced by hormones + nutrition)
- Heat generation through muscle metabolism
Bones
- Osseous connective tissue
- Compact bone (diaphysis)
- Spongy bone (epiphysis)
- Bone marrow (red & yellow)
- Osteoblasts (build), osteoclasts (break down), osteocytes (maintain)
Joints
- Synovial joints (knees, shoulders, hips)
- Cartilage (hyaline, fibrocartilage)
- Synovial cavity + fluid
- Ligaments (dense connective tissue)
- Joint capsule + bursa
Muscles
- Skeletal muscle fibers
- Myofibrils (actin + myosin)
- Sarcomeres (contractile units)
- Tendons
- Fascia (continuous connective tissue matrix)
Connective Tissue
- Collagen + elastin networks
- Fibroblasts
- Ground substance
- Fascia, ligaments, periosteum, aponeuroses
Nerves + Vessels
- Motor neurons
- Neuromuscular junction
- Sensory receptors (spindles, Golgi tendon organs)
- Vascular supply for oxygen, minerals, and repair