Skeletal System Anatomy

The Skeletal System

The skeletal system is a complex and essential part of the human body, composed of bones, cartilages, ligaments, tendons, and muscles. It plays a vital role in providing support, protection, and structure to the body.

Bones and Cartilages

The adult human skeleton consists of 206 bones, which are supported by ligaments, tendons, bursae, and muscles. Bones are rigid structures made of calcified dense connective tissue, with bone tissue composed of a mineralized bone matrix that consists of type 1 collagen fibers dispersed throughout the matrix. The cellular component of the bones is represented by three types of specialized bone cells: osteocytes, osteoblasts, and osteoclasts.

Bones are grouped into two distinct divisions: the axial skeleton and the appendicular skeleton. The axial skeleton includes the vertebral column, bones of the head, and bones of the thoracic cage, while the appendicular skeleton involves the bones of the shoulder and pelvic girdle, as well as the bones of the upper and lower extremities.

Muscles, Tendons, and Ligaments

Skeletal muscle is the only type of muscle that we can control voluntarily and is innervated by the somatic part of the nervous system. These muscles attach to the bones and provide voluntary movement. Muscles have a significant role in heat production, as they are one of the most metabolically active tissues in the body, accounting for approximately 85 percent of the heat produced in the body.

Tendons, which connect muscles to bones, are strong and flexible, preventing muscles from extending too much. Ligaments, which connect bones to other bones, serve as an extra protection, preventing bones from moving too far apart or twisting dangerously.

Connective Tissues

Connective tissues are found throughout the body and help keep parts separate from each other while connecting them together. There are three main types of connective tissue: loose connective tissue, dense connective tissue, and specialized connective tissue. Loose connective tissue holds organs in place and connects the skin to the tissues under it. Dense connective tissue helps attach muscles to bone and links bones together at joints. Specialized connective tissues include tissues with specialized cells that connect parts together, such as bone, cartilage, blood, and lymph.

The Role of the Skeletal System

The skeletal system plays a crucial role in providing support and protection to the body, allowing for movement with the help of muscles, and maintaining a stable body temperature through the production of heat by muscle tissue. It also stores essential minerals, such as calcium, which can be released when other body functions require them.

In summary, the skeletal system is a complex and vital part of the human body, comprised of bones, cartilages, ligaments, tendons, and muscles. It provides support, protection, and structure to the body, allows for movement, maintains body temperature, and stores essential minerals.