Human Skeletal System: Parts, Functions, Diagram, Facts

Definition of Skeletal System

In humans, the skeletal system forms one of the most complex structures or frameworks of bones and connective tissues functioning for structuring, protection, and mobility. The human adult skeleton is composed of 206 bones connected by a system of joints, yet held together with cardiovascular, cartilaginous, ligamentary, and tendinous parts.

It supports the body to take shape and maintain posture, protects vital organs like the brain, heart, and lungs and provides for movement via the articulation of bones and the associated action of bones and muscles. It is also relevant to the foremost physiological processes of human beings, offering storage for minerals and producing blood cells inside the bone marrow.

Skeletal System Anatomy

The structure is discussed below-

Number of Bones in the Human Body

Adult vs. Newborn Skeletal System: Whereas an adult has 206 bones, in a newborn it is about 270 bones. With increasing maturity, some of the bones fuse and hence the number decreases.

Simple Classification of Bones: The bones can be simply classified into four major groups by their shapes, long bones, for example, femur, and short bones, for example. carpals, flat bones, for example. skull, and irregular bones, for example. vertebrae.

Major Components of the Skeletal System

The components are discussed below-

Axial Skeleton

The components of the axial skeleton are:

Skull

This is made up of 22 bones, all together, protecting the brain, and generally forming the structure of the face.

Vertebral column

This is composed of 33 vertebrae, each of which supports the spinal cord a provides protection. These could be grouped into cervical-7, thoracic-12, lumbar-5, sacral-5 fused into the, and coccygeal-4 fused into the coccyx.

Rib cage

This structure is composed of 24 ribs in 12 pairs and the sternum, protects the heart and lungs and supports respiration or breathing.

Appendicular Skeleton

The components of the appendicular skeleton are:

Pectoral girdle

This is made of the clavicles and scapulae. These bones serve to support the limbs of the upper part of the body, hence making wide-ranging movements at the shoulder possible.

Pelvic girdle

The hip bones are created by the ilium, ischium, and pubis. These bones convey the weight from the upper body to the lower extremities while on the same note serving to protect the pelvic organs.

Limbs

The upper limbs consisting of arms, forearms, wrists and hands and the lower limbs consisting of thighs, legs, ankles, and feet are made up of long and short bones that offer locomotion and contact with the environment

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Skeletal System Physiology

The functions are discussed below-

Support and Shape

The skeleton provides a great framework that helps to support the shape and structure of the body. Since the bones are the chief constituent structure of the body, they are easily able to provide support against the force of gravity and bear other external forces upon it.

Protection of Vital Organs

• The skull covers, overlays, and protects one of the most important organs in the human body, the brain, against damage.

• The protective function of the rib cage shields from direct physical trauma heart and lungs—key molecular structures to cardiovascular and respiratory functions.

Movement and Locomotion

The skeletal system makes movements and locomotions possible through its interaction with the muscular system. More precisely, bones are attachment sites for muscles; when these muscles contract, they will pull on the bones, generating movement at joints.

Mineral Storage

Bones act as a storage site for several crucial minerals, primarily calcium and phosphorus, both of which are critical to many bodily functions in general. This mineral content might then be resorbed back into the bloodstream when required and therefore help in the maintenance of mineral balance and metabolism.

Blood Cell Production

The process of hematopoiesis occurs within the red bone marrow in some bones. It is the area where blood cells are formed. Every day, millions of red blood cells are produced by this process for carrying oxygen, many white blood cells for immune defence, and thousands of platelets required for blood clotting

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