The Human Skeletal system is made up of bones, cartilage, ligaments, and tendons. Its primary functions are to provide support and protection for the body, enable movement, store minerals and lipids, and produce blood cells.

The skeletal system mainly provides a structural framework and supports the body. It is made up of 206 bones in an adult human. It comprises bones, cartilage, ligaments and tendons that connect bones and bones to muscles. The human skeletal system provides definite shape to the body and protection to internal organs.

The branch of Biology that concerns with the scientific study of the structure and function of the skeleton and bony structures, known as Osteology, is studied due to the fact that at birth, infants have ~300 bones, which fuse together as the body matures, leaving 206 bones in an adult human.

Table of Contents:

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Functions of Human Skeletal System

Functions of Bones

[Axial Skeleton](#Axial Skeleton)

‘+ Vertebral Column '

‘[Appendicular Skeleton](#Appendicular Skeleton)’

Diseases of the Skeletal System

Frequently Asked Questions

Functions of the Human Skeletal System

Functions of Different Parts of the Skeletal System

In this article, we will explore the various functions and roles of the human skeletal system.

Functions of Bones

Bones provide structure and mobility to the body, protect internal organs, store minerals, produce red and white blood cells, and help regulate calcium levels in the body.

The 206 bones in the human body perform the following functions:

Bones give structure to the body.

Bones provide a protective covering for internal organs such as the brain, heart, lungs, etc.

Supports the body and anchors muscles.

Bones serve as a reservoir for minerals such as calcium and phosphate.

Bones aid in enabling body movements.

Bones serve as the place where red blood cells are created.

Axial Skeleton

The two major divisions of the human skeletal system are the axial skeleton and the appendicular skeleton.

Axial Skeleton

Appendicular Skeleton

Axial Skeleton

The axial skeleton is made up of 80 bones and it constitutes the middle axis. It includes the following regions:

Skull

Hyoid

Auditory Ossicles

Vertebral Column

Ribs

Sternum

Appendicular Skeleton

The adult human body contains a total of 206 bones, of which 126 make up the appendicular skeleton. This skeleton is composed of the pelvic and pectoral girdles, as well as the bones of the hands, feet, upper and lower extremities, shoulder girdle, and pelvic bones.

Skull

The human skull consists of the cranium and facial bones. The cranium is formed of 8 plate-shaped bones joined together at meeting points called sutures and its function is to protect the brain. The remaining 14 bones make up the facial bones and the mandible is the only movable bone in the human skull.

The main function of the skull is to render protection and support. It does so along with the surrounding meninges. Protection is provided to the different parts of the brain – Cerebellum, Cerebrum and brainstem in addition to the orbits of the eyes. Structural support is provided for attachments of the muscles of the face and scalp. Additionally, it protects different vessels and nerves innervating the facial muscles, brain and other related parts. The skull hardens and fuses as it develops to safeguard its internal contents.

Hyoid

The hyoid bone is a U-shaped bone located in the anterior neck. It acts as an intermediary between the skull and post cranial skeleton, aiding tongue movement and swallowing. It does not articulate with any other bones.

Auditory Ossicles

The auditory ossicles, namely malleus, incus, and stapes, are the three smallest bones in the human body located in the middle ear. These ossicles serve to transmit sound from the air to the cochlea.

Ribs

Ribs are the long curved bones which form the rib cage. This cage consists of 24 bones in 12 pairs which provide protection to the thoracic internal organs. The ribs are connected posteriorly to the vertebral column and terminate anteriorly as cartilage.

Sternum

The Sternum, or breastbone, is a long bone located at the center of the chest. The Sternum and ribs form the rib cage. The Sternum is connected to the first seven ribs, as well as the Clavicle, or collarbone.

Vertebral Column

The vertebral column is a part of the axial skeletal system. It is composed of approximately 33 bones, known as vertebrae, which are separated by intervertebral discs. The vertebral column is divided into five categories: Cervical, Thoracic, Lumbar, Sacrum, and Coccyx.

Check out: Bones of the Spine

Functions of the Vertebral Column

The vertebral column protects the spinal cord.

Adds rigidity to the body.

Provides structural support by balancing the bodyweight

Attaches pectoral and pelvic girdles and other muscles.

Cervical Vertebrae

The cervical is the most delicate and the thinnest bones of the vertebral column. The cervical vertebrae are formed of 7 vertebrae. The seven cervical vertebrae are arranged along the length of the neck. They are named according to its position from the skull to the chest. The superior C1 or first cervical vertebrae to C7 or the seventh cervical vertebrae constitute the cervical vertebrae. The C1 vertebrae are named as Atlas whose function is to hold up the skull. Also, C2 is named as Axis since it serves as the axis for the skull and atlas to rotate while turning head from one side to another.

Thoracic Vertebrae

The Thoracic Vertebrae is located in the mid-back of the human body. Its primary purpose is to support the rib cage, protect the heart and lungs, and differentiate itself from the other vertebrae. It is designated as T1 to T12.

Lumbar Vertebrae

The Lumbar Vertebrae are the largest in the vertebral column and comprise of 5 vertebrae bones between the rib cage and pelvis. These vertebrae are named from L1 to L5, with L1 being closest to the thoracic vertebrae and L5 adjacent to the pelvis. The lumbar vertebrae serve as the load-bearing structure.

Sacral Vertebrae

The sacral vertebrae consist of 5 vertebrae bones which fuse together to form Sacrum. The Sacrum is a long wedge-shaped vertebra at the inferior end of the spine. It is a very strong bone which supports the weight of the upper body as it spread across the pelvis into the legs.

Coccyx Vertebrae

The coccyx vertebrae are formed by the fusion of three to five rudimentary bones to form a small, triangular bone at the bottom of the vertebral column. This bone is also referred to as the tail bone. The coccyx serves as an attachment site for ligaments, tendons, and muscles. It can be fractured if a person falls abruptly.

Appendicular Skeleton

The appendicular skeleton is the part of the human skeletal system that supports the appendages. It consists of 186 bones, including the bones of the limbs as well as supporting the pelvic and pectoral girdles.

The appendicular skeleton is divided into 6 regions.

1. Shoulder Girdle

2. Arms and Forearms

1. Feet
2. Knees
3. Hands

4. Pelvis

5. Thighs and Legs

6. Feet and Ankles

Shoulder Girdle

The pectoral girdle or shoulder girdle is a set of four bones which connects to the arm on each side. It is part of the appendicular skeleton which are for the upper limbs. In human beings, the pectoral girdle consists of the scapula and the clavicle.

Learn more about Glenoid Cavity.

Arms and Forearms

The large bones of the arm include:

• Humerus
• Radius
• Ulna

The Humerus runs from the shoulder socket and joins the radius and ulna at the elbow.

Radius - The radius is a bone in the forearm that runs from the elbow to the thumb side of the wrist.

The Ulna - The ulna is a bone in the forearm that runs from the elbow to the pinky side of the wrist.

Hands

The hands consist of 54 bones which provide support and flexibility to the soft tissues. These bones are categorized into three groups:

1. Carpals - A set of 8 irregularly shaped bones located in the wrist area.

2. Metacarpals – Metacarpals are bones which are related to each digit, with five metacarpal bones in total.

1. Phalanges - Phalanges are the bones of the fingers.
2. Each finger has three phalanges, except for the thumb which has two phalanges only.

Pelvic Girdle

The pelvic girdle is located in the lower part of the trunk and is a ring-like bony structure. It consists of two bones, the sacrum and the coccyx. Each hip bone is made up of three parts: the ilium, the ischium, and the pubis.

Functions of Pelvic Girdle

It transfers the weight of the body from the axial skeleton to the appendicular components, particularly when in motion.

Attachment from multiple muscles and ligaments facilitates movement.

The majority of women have a gynaecoid pelvis and males have an android pelvis. The differences in the structure creates a great pelvic outlet enabling the process of childbirth.

Thighs and Legs

The appendicular skeletal system is composed of the bones of the legs and thighs. These bones provide support to the muscles of the lower limbs which are essential for activities such as walking, running, standing and jumping. It is important that these bones are strong enough to support the weight of the body.

The Femur, or thigh bone, is the largest and heaviest bone in the human body. At the proximal end of the Femur, there is a rounded prominence known as the Head of the Femur.

The Tibia and Fibula are two separate bones located in the lower leg. They are closely connected at both the knee and ankle joints.

The Tibia connects to the knee joint at the top and to the ankle joint at the bottom. Despite bearing all the body weight, it relies on the Fibula for support.

Feet and Ankles

The foot is a strong, stable base that can bear the weight of the body. It is composed of several bones, including the tarsals, metatarsals, and phalanges.

Tarsals: A set of 8 irregular bones located near the ankle at the top of the foot.

Metatarsals: A set of 5 bones, each one connecting the tarsals with the phalanges and corresponding to a single digit.

Each toe has 3 phalanges: Proximal, Intermediate and Distal.

Tendons are fibrous cords of tissue that connect muscles to bones.

Tendons are made up of connective tissue and joint bones to skeletal muscles.

Ligaments are fibrous tissues that connect bones to other bones and are crucial for joint stability.

Ligaments join two bones together and are a type of connective tissue.

Cartilage

Cartilage provides protection of bones at the joints from wear and tear. They are firm yet softer and flexible than bones.

The skeleton provides a structural framework for many parts of the body, such as the ear, nose, ribs, bronchial tubes, etc.

Diseases of the Skeletal System

1. Osteoporosis: A condition in which the density of bones is reduced, increasing the risk of fracture, Osteoporosis is a bone-related disease.

2. Paget’s Disease: It is a chronic bone disorder that causes the affected bones to become enlarged and misshapen.

3. Arthritis: It is an inflammatory condition that affects the joints, causing pain and difficulty with movement, and limiting mobility.

Frequently Asked Questions

What are the Major Divisions of the 206 Bones in the Human Body?

The adult human skeletal system typically has 206 bones, divided into two major divisions – the axial skeleton (80 bones) and the appendicular skeleton (126 bones).

The Function of the Skull

The skull is the bony structure that makes up the head of a vertebrate. It supports the structures of the face and provides a protective cavity for the brain. The skull also plays an important role in the body’s sensory functions, such as hearing, balance, and vision.

The human skull consists of the cranium and facial bones. Its function is to protect the brain and its inner contents, as well as to support them. Additionally, the skull fixes the position of the ears and the distance between the eyes, thus helping with sound localization and stereoscopic vision in humans.

The study of bones and joints is called Orthopedics.

The study of bones is called Osteology while the branch of biology dealing with the study of joints is called Arthrology.

What is Osteology?

Osteology is the scientific study of bones and the structures of the skeletal system. It is a sub-field of anatomy, which is the study of the structure and organization of living things. Osteology focuses on the skeletal system, including the bones, cartilage, ligaments, and other connective tissues that make up the skeleton.

Osteology is the scientific study of bones which involves a detailed study of the skeletal elements, their structure, function, pathology, disease, etc. It is a subdiscipline of palaeontology, anatomy and anthropology.

The appendicular skeleton consists of the bones of the upper and lower limbs, as well as the bones that attach them to the axial skeleton.

The human foot consists of the heel, ankle, arch, toes, metatarsals, and phalanges.

The foot is composed of three sections: the forefoot, midfoot, and hindfoot. The forefoot is made up of the phalanges (five toes) and metatarsals (five long bones). The midfoot section forms an arch in the feet, resembling a pyramid of bones; it includes the cuboid, navicular, and cuneiform bones. The hindfoot connects to the ankle and heel.

Also check:

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