1. MUSCULOSKELETAL SYSTEM
The musculoskeletal system (known also as the locomotor system) provides the body with structure, support, stability, and movement. It is composed of bones, muscles, cartilage, tendons, ligaments, and other connective tissues.
| Bones and skeleton: | The human skeleton is the framework of the body, consisting of 206 bones in an adult. These bones can be classified into different categories, such as long bones (e.g., femur), short bones (e.g., carpals), flat bones (e.g., skull), and irregular bones (e.g., vertebrae). The skeleton serves multiple functions: it supports the body’s structure, protects vital organs (such as the brain and heart), and facilitates movement by providing attachment points for muscles. Bones are dynamic tissues that undergo constant remodeling throughout life, which involves bone formation and resorption. |
| Muscles: | Muscles are tissues that contract to produce movement. The human body has over 600 muscles, which are categorized into three types: skeletal, smooth, and cardiac muscles. Skeletal muscles are under voluntary control and are responsible for body movements, posture, and balance. Smooth muscles, found in the walls of internal organs like the stomach and intestines, are involuntary and control movements within these organs. Cardiac muscle, also involuntary, forms the heart’s walls and is responsible for pumping blood throughout the body. |
| Joints and Connective Tissues: | Joints are the areas where bones meet and allow for movement. They are classified into several types based on their structure and function, such as hinge joints (e.g., elbows), ball-and-socket joints (e.g., hips), and pivot joints (e.g., neck). Connective tissues, including cartilage, tendons, and ligaments, play a crucial role in the musculoskeletal system. Cartilage cushions joints and supports soft tissues, tendons connect muscles to bones, and ligaments connect bones to other bones, providing joint stability. |