Skeletal System Functions

Functions of the Skeletal System

• Provides support through rigid bones and cartilage, contributing to overall body structure.
• Protects vital organs; for example, cranial bones shield the brain from injury.
• Facilitates movement by serving as attachment points for skeletal muscles via tendons.
• Acts as a storage reservoir for fat, minerals like calcium and phosphorus, helping maintain mineral homeostasis in the blood.
• Responsible for hematopoiesis, with many bones housing bone marrow that produces blood cells and platelets.

Osteology

• Defined as the study of bone structure and disorders affecting the skeletal system.

Bone Ossification

• Bone formation occurs through osteoblasts.
• Intramembranous Ossification: Bone development from fibrous membranes; primarily forms flat bones of the skull, mandible, and clavicles.
• Endochondral Ossification: Bone development from hyaline cartilage, forming most bones except those mentioned above.

Bone Growth

• Appositional Growth: Expands bone width by new bone formation on existing surfaces by osteoblasts.
• Endochondral Growth: Involves cartilage growth at the epiphyseal plate, eventually replaced by bone, increasing bone length until early childhood.

Bone Remodeling

• An ongoing process of old bone resorption by osteoclasts and new bone deposition by osteoblasts.
• Responsible for bone growth, shape changes, adjustment to stress, repair, and calcium ion regulation.
• Consists of three phases: resorption, reversal, and formation.

Bone Repair

• The healing process includes forming a clot at the fracture site and creating a callus for tissue repair.
• Osteoblasts form cancellous bone in the callus, which is later remodeled into compact bone.

Bone and Calcium Homeostasis

• Bones serve as the primary storage for calcium; the balance of calcium in blood is controlled by osteoblast and osteoclast activity.
• Parathyroid hormone and calcitonin maintain calcium homeostasis.

Bone and Joint Disorders

• Achondroplasia: Genetic disorder causing short-limbed dwarfism due to defective conversion of cartilage to bone.
• Osteogenesis Imperfecta: Also known as brittle bone disease, characterized by fragile bones due to collagen deficiency.
• Rickets: Inadequately mineralized bones in children, leading to deformities, often caused by vitamin D deficiency.
• Osteomalacia: Return of weak bones in adults with similar causes as rickets.
• Osteomyelitis: Bone infection primarily caused by Staphylococcus bacteria.
• Osteoporosis: Condition where bone resorption exceeds formation, particularly affecting postmenopausal women, making bones fragile.
• Scoliosis: Lateral curvature of the spine caused by congenital issues, muscle paralysis, or poor posture.
• Fractures: Breaks in bones categorized as simple, compound, compression, comminuted, or greenstick.

Types of Arthritis

• Arthritis: Inflammation of joints leading to pain, stiffness, and swelling.
• Osteoarthritis: Degenerative joint disease with cartilage deterioration, causing pain and restricted movement.
• Rheumatoid Arthritis: Chronic inflammatory autoimmune disorder affecting synovial membranes.
• Gouty Arthritis: Caused by abnormal uric acid metabolism leading to joint inflammation.
• Bursitis: Inflammation of the bursa, a fluid-filled sac at friction points, can result from acute or chronic stress.

Explore the key functions of the skeletal system, including its role in support, protection, and movement. This quiz will test your understanding of how bones, cartilage, and ligaments contribute to the body's structure. Dive into the essential components that keep us upright and agile.