Bones and joints are essential components of the musculoskeletal system that provide structure, support, and movement to the body. 

In human infants, the typical count of bones is approximately 270. However, as they mature, these bones gradually fuse together resulting in a range of 206 to 213 bones in adults. The specific number may vary due to individual differences in the count of ribs, vertebrae, and digits. 

Anatomy of Bones

Bone is a dynamic and living tissue comprising the body’s skeletal system. Each bone in the body is made up of three main types of tissues.

1. Compact tissue: The harder outer layer of bone.
2. Spongy Bone: The sponge-like tissue inside bones.
3. Subchondral tissue:  The smooth tissue at the end of the bones is covered with a specialized type of tissue called cartilage. Cartilage is a unique connective tissue found in adults.

Bones are made up of four main types of bone cells.

• Osteoblasts are responsible for new bone formation
• Osteocytes are inactive osteoblasts
• Osteoclasts are involved in bone resorption
• Hematopoietic cells are found in the bone marrow, and it is responsible for producing red blood cells, white blood cells, and platelets

The femur is the longest bone of the human body, while the stapes in the middle ear is the smallest bone.

Anatomy of Joints

Joints serve as the meeting points where two or more bones come together. An adult human body has 360 joints. Joints consist of various components, including:

• Cartilage: A specialized tissue that covers the surface of bones at a joint, reducing friction during movement within the joint.
• Synovial membrane: This tissue lines and encloses the joint within a joint capsule. It secretes synovial fluid, a clear and sticky fluid that lubricates the joint, facilitating smooth movement.
• Ligaments: Strong and elastic bands of connective tissue that surround the joint, providing support and limiting excessive movement.
• Tendons: Located on both sides of a joint, they control joint movement.
• Bursas: Fluid-filled sacs between bones, ligaments, or adjacent structures. Bursas act as cushions, reducing friction within the joint.

The Function of Bones and Joints

In addition to providing our body with its distinctive shape and characteristics, bones and joints perform the following roles:

• Facilitates movement: The skeletal system, through the collaboration of joints, connective tissues, and muscles, supports our body weight, allowing us to stand and engage in various movements. This coordinated effort enables the mobility of different body parts.
• Produces blood cells: The production of red and white blood cells occurs within the bones, specifically in the bone marrow. This vital process contributes to maintaining a healthy blood supply within the body.
• Protects and supports organs: Our skeletal system acts as a protective shield for vital organs. The skull safeguards the brain, while the ribs provide a protective covering for the heart and lungs. Additionally, the backbone plays a crucial role in protecting the spinal cord.
• Stores minerals: Bones serve as a reservoir for essential minerals like calcium and vitamin D.