The skeletal system, or the musculoskeletal system, is the body’s internal framework and support structure. It is composed of bones, cartilage, and connective tissues. The skeletal system is divided into two parts: the axial skeleton and the appendicular skeleton. Its primary functions include providing structural support, protecting vital organs, and enabling bodily movements through joints.

The skeletal system also plays an important role in mineral storage, blood cell production, and maintaining overall stability and integrity in physiological processes. In this article, we will study the functions of the skeletal system in detail.

What is the Skeletal System?

Definition of Skeletal System: Skeletal system consists of a framework of bones and a few cartilages that support bodily functions and provide protection to internal organs.

The human skeletal system is made up of bones, cartilage, ligaments, and tendons. It is composed of around 270 bones at birth, but this total decreases to around 206 bones by adulthood after some bones fuse together. The bone mass in the skeleton makes up about 14% of the total body weight and reaches maximum mass between the ages of 25 and 30. The human skeleton can be divided into two parts: the axial skeleton and the appendicular skeleton. 

• The axial skeleton is formed by the vertebral column, the rib cage, the skull, and other associated bones. 
• The appendicular skeleton is attached to the axial skeleton and is formed by the shoulder girdle, the pelvic girdle, and the bones of the upper and lower limbs.

The human skeleton performs six major functions: support, movement, protection, production of blood cells, storage of minerals, and endocrine regulation. The human skeletal system diagram is given below:

Human Skeletal System

Also Read: Human Body-Anatomy and Physiology of Human Body

Five Major Functions of Skeletal System

The skeletal system performs various functions that contribute to the overall structure, support, and functioning of the human body. The five major skeletal system functions are:

Support and Framework

The skeletal system provides a rigid framework that supports the body’s weight against gravity. It also maintains the body’s shape.

• Bone Structure: Bones provide a rigid framework that supports the entire body. The skeletal system consists of 206 bones in adults. It offers structural support and maintains the shape of the body.
• Axial and Appendicular Skeleton: The axial skeleton, including the skull, vertebral column, and ribcage, supports and protects the central nervous system and vital organs. The appendicular skeleton, comprising the limbs and girdles, facilitates movement and provides support.

Protects Vital Organs

The skeletal system protects the body’s internal organs.

• Cranium and Vertebrae: The skull protects the brain from external injuries and the vertebral column protects the spinal cord.
• Ribcage: Ribs protect the heart, lungs, and major blood vessels within the thoracic cavity and minimizes the risk of damage.

Facilitation of Movement

The skeletal system works with muscles to produce movement.

• Joint Function: Joints, where bones meet, allow for movement. Various types of joints enable diverse motions, such as hinge joints in the knee and ball-and-socket joints in the hip.
• Muscle Attachment: Muscles attach to bones via tendons. When muscles contract, they pull on bones, generating movement at the joints and facilitating bodily motions.

Also Read: Mechanism of Muscle Contraction

Mineral Storage

The skeletal system stores minerals like calcium and phosphorus.

• Calcium and Phosphorus: Bones serve as a reservoir for essential minerals, particularly calcium and phosphorus. Calcium is crucial for muscle contraction, nerve transmission, and bone strength. Phosphorus is essential for energy metabolism.
• Dynamic Balance: The skeletal system continually exchanges minerals with the bloodstream, maintaining a dynamic balance that supports various physiological functions.

Blood Cell Formation (Hematopoiesis)

The skeletal system contains bone marrow, which produces red blood cells, white blood cells, and platelet.

• Bone Marrow: Red bone marrow present in some bones, is involved in hematopoiesis—the formation of blood cells. It produces red blood cells (which carry oxygen), white blood cells (immune response), and platelets (blood clotting).
• Hematopoietic Role: This function ensures a steady supply of blood cells which contributes to the body’s immune system, oxygen transport, and clotting mechanisms.

Components of a Skeletal System

The skeletal system is composed of several components, including bones, joints, cartilage, ligaments, and tendons. An overview of the different components of the skeletal system and their functions are given below:

Bones

Bones are mineralized connective tissues that are found in vertebrates. They are made of calcium, connective tissue, and specialized bone cells. It is covered by a thin layer of tissue called the periosteum, which helps to protect them and provide a place for muscles, ligaments, and tendons to attach.

Bones come in various shapes and sizes and are classified into two main types: compact bone (dense and hard) and spongy bone (porous and contains bone marrow). Functions of Bone are:

• Support and movement: Bones support the body and help it move. Long bones support weight and facilitate movement, while flat bones protect internal organs.
• Protection: Bones protect internal organs, like the brain, heart, and lungs..
• Blood cell production: The bone marrow, a soft, spongy material in the center of bones, produces about 95% of the body’s blood cells.
• Storage and Shape: Bones store and release fat and minerals like calcium and phosphate. It provide shape to the body.

Also Read: Difference Between Compact And Spongy Bones

Joints

Joints are the points where two or more bones meet. They allow for movement and flexibility. There are different types of joints, including:

• Hinge joints: Allow movement in one direction, like the knee.
• Ball-and-socket joints: Allow a wide range of movement, like the hip joint.
• Pivot joints: Allow rotational movement, like the joint between the radius and ulna in the forearm.

Also Read: Types Of Joints – Classification of Joints in the Human Body

Cartilage

Cartilage is a flexible connective tissue that covers the ends of bones at joints. There are different types of cartilage, including hyaline cartilage, elastic cartilage, and fibrocartilage. Various functions of the cartilage are:

• Structural Support: Cartilage provides support to bony areas that need flexibility.
• Shock Absorption: Cartilage acts as a shock absorber throughout the body.
• Reduced Friction: Cartilage at the end of bones reduces friction and prevents them from rubbing together when joints are used.
• Structural Component: Cartilage is an important structural component of the body.
• Different Types: Cartilage exists in different types throughout the body’s joints, bones, spine, lungs, ears, and nose.

Also Read: Areolar Connective Tissue

Ligaments

Ligaments are tough, fibrous tissues that connect bones to bones, providing stability to joints. They play a crucial role in preventing excessive movement and helping to maintain the integrity of the skeletal structure.

Tendons

Tendons are strong, fibrous tissues that connect muscles to bones. When muscles contract, they pull on tendons, which in turn pull on the bones, causing movement at the joints. Tendons transmit the force generated by muscles to the bones.

Also Read: Difference Between Ligaments and Tendons

Bone Marrow

Bone marrow is the soft, spongy tissue found within certain bones. It is responsible for the production of blood cells through a process called hematopoiesis. There are two types of bone marrow: red bone marrow, which produces blood cells, and yellow bone marrow, which stores fat.

Also Read: Difference between Epiphysis and Diaphysis

Conclusion – Five Major Functions of Skeletal System

The skeletal system has five major functions: support, movement, protection, blood cell production, and storage of minerals. It provides the framework that supports the body and maintains its shape. The joints between bones allow movement, with some joints allowing a wider range of movement than others. The skeleton helps to protect many internal organs from external injury. The inside of bones contains a soft substance, called bone marrow, where the blood cells are made. Bones are a reservoir of minerals like phosphorus and calcium.

Also Read:

• Locomotion and movement
• Disorders of the Muscular and Skeletal System
• What is the difference between B and T cells?
• Difference Between Red and White Muscle
• List of 206 Bones in Human Body

FAQs on Five Major Functions of the Skeletal System

What are Joints?

A joint is a place where two or more bones meet to allow movement. Joints make the skeleton flexible and allow the body to move in many directions.

What is a Tendon?

A tendon is a strong, flexible cord of tissue that connects muscles to bones. Tendons are made of dense connective tissue, primarily composed of tendon cells, also known as tenocytes. They are strong and durable, but also flexible.

What are the Functions of Bones?

Bones provide structural support, protect internal organs, facilitate movement, store minerals, and contribute to blood cell formation.

What is a Rib Cage?

The rib cage is a skeletal structure that protects the heart and lungs. It’s made up of 24 ribs, which are attached to the sternum and the vertebral column. The ribs are connected to the sternum by cartilage, a strong yet flexible material.

What are the 5 Major Functions of Skeletal System?

The skeletal system provides structural support, protects vital organs, enables movement through joints and muscles, stores essential minerals, and facilitates blood cell formation in the bone marrow.

What is Skeletal System Parts and Functions?

The skeletal system is made up of bones, cartilage, ligaments, and tendons. It provides structure and support for the body and protects internal organs.

Where are 206 Bones in Our Body?

The human skeleton has 206 bones, which are divided into the axial skeleton and the appendicular skeleton. Axial skeleton includes the head, spine, and chest, and contains 80 bones whereas appendicular skeleton includes the arms and legs and contains 126 bones.