Anatomy of Bones

Structure of Bones

• Bones are composed of:
  • Compact bone: dense, compact tissue that forms the outer layer of bones
  • Cancellous bone: spongy, porous tissue that forms the inner layer of bones
  • Bone marrow: soft, fatty tissue that fills the cavities of bones
  • Periosteum: a layer of connective tissue that covers the surface of bones
  • Endosteum: a layer of connective tissue that lines the inner surface of bones

Functions of Bones

• Support: provide a framework for the body
• Protection: protect internal organs and tissues
• Movement: act as levers for muscles to move the body
• Blood cell production: produce blood cells in the bone marrow
• Storage: store minerals such as calcium and phosphorus
• Endocrine functions: regulate hormones and maintain homeostasis

Types of Bones

• Long bones: longer than they are wide, e.g. femur, humerus
• Short bones: approximately equal in length and width, e.g. carpals, tarsals
• Flat bones: thin and flat, e.g. ribs, sternum
• Irregular bones: complex shapes, e.g. vertebrae, pelvis
• Sesamoid bones: small, embedded in tendons, e.g. patella

Bone Development and Growth

• Ossification: the process of bone formation
• Endochondral ossification: bone formation from cartilage models
• Intramembranous ossification: bone formation from mesenchymal tissue
• Bone growth: occurs through the process of appositional growth, where new bone tissue is added to the surface of existing bone

Bone Remodeling and Repair

• Bone remodeling: the process of resorbing and replacing existing bone tissue
• Bone resorption: the breakdown of bone tissue by osteoclasts
• Bone formation: the buildup of new bone tissue by osteoblasts
• Bone repair: the process of repairing damaged bone tissue, involving inflammation, repair, and remodeling

Structure of Bones

• Bones are composed of four main components: compact bone, cancellous bone, bone marrow, periosteum, and endosteum.
• Compact bone forms the outer layer of bones and is dense and compact.
• Cancellous bone forms the inner layer of bones and is spongy and porous.
• Bone marrow is a soft, fatty tissue that fills the cavities of bones.
• Periosteum is a layer of connective tissue that covers the surface of bones.
• Endosteum is a layer of connective tissue that lines the inner surface of bones.

Functions of Bones

• Bones provide a framework for the body through their support function.
• They protect internal organs and tissues through their protective function.
• Bones act as levers for muscles to move the body through their movement function.
• They produce blood cells in the bone marrow through their blood cell production function.
• Bones store minerals such as calcium and phosphorus through their storage function.
• They regulate hormones and maintain homeostasis through their endocrine functions.

Types of Bones

• Long bones are longer than they are wide, examples include the femur and humerus.
• Short bones are approximately equal in length and width, examples include the carpals and tarsals.
• Flat bones are thin and flat, examples include the ribs and sternum.
• Irregular bones have complex shapes, examples include the vertebrae and pelvis.
• Sesamoid bones are small and embedded in tendons, an example is the patella.

Bone Development and Growth

• Ossification is the process of bone formation.
• Endochondral ossification is a type of bone formation that occurs from cartilage models.
• Intramembranous ossification is a type of bone formation that occurs from mesenchymal tissue.
• Bone growth occurs through the process of appositional growth, where new bone tissue is added to the surface of existing bone.

Bone Remodeling and Repair

• Bone remodeling is the process of resorbing and replacing existing bone tissue.
• Bone resorption is the breakdown of bone tissue by osteoclasts.
• Bone formation is the buildup of new bone tissue by osteoblasts.
• Bone repair involves the processes of inflammation, repair, and remodeling to repair damaged bone tissue.

Skeletal System

• The skeletal system consists of 206 bones that provide support, protection, and movement for the body.
• It also produces blood cells, stores minerals, and maintains pH balance.

Functions of the Skeletal System

• Provides a framework for the body's muscles, organs, and tissues.
• Protects internal organs, such as the heart, lungs, and brain.
• Acts as a system of levers and joints to facilitate movement.
• Produces blood cells, including red and white blood cells and platelets.
• Stores minerals, such as calcium and phosphorus, and releases them as needed.
• Helps maintain the body's acid-base balance by storing and releasing alkaline minerals.

Bone Structure

Types of Bones

• Long bones are characterized by a shaft (diaphysis) and two ends (epiphyses), and examples include the femur and humerus.
• Short bones are cubical in shape and provide support and stability, and examples include the carpals and tarsals.
• Flat bones are thin and flat, often providing protection, and examples include the ribs and sternum.
• Irregular bones do not fit into any of the above categories, and examples include the vertebrae and pelvis.

Bone Tissue

• Compact bone is dense, compact tissue that forms the outer layer of bones.
• Cancellous bone is spongy, porous tissue that forms the inner layer of bones.
• Bone marrow is the spongy tissue that fills the cavities of bones and produces blood cells.

Bone Components

• Periosteum is a layer of connective tissue that covers the surface of bones.
• Endosteum is a layer of connective tissue that lines the marrow cavity.
• Cortical bone is the compact bone that forms the outer layer of bones.
• Trabeculae are the bony struts that make up cancellous bone.