Skeleton Anatomy

The human skeleton is the foundation of our body. It enables movement, stores minerals, produces red blood cells, bears our weight, and provides support and protection for our internal organs, such as our brain, lungs, and heart. The skeletal system consists of the bones, ligaments, and cartilage that make up our internal framework.

To gain a deeper understanding of skeleton anatomy, our extensive collection of anatomical charts and posters offers clear, detailed illustrations that will enhance your learning experience. Whether you’re a student, lecturer, or healthcare professional, these visual aids are perfect for simplifying complex concepts and improving retention.

The human skeleton is a system of bones that holds the body together. The adult human skeleton is made up of 206 bones. Infants are born with about 300 bones, mostly made of cartilage, which turns into bone during a process called ossification.

The outer surface of bones is called the periosteum, a dense membrane of vascular connective tissue that nourishes the bone. Next is a hard layer called compact bone (also known as cortical bone). This is the smooth surface that you see when you look at the skeleton. The next layer is cancellous bone (often referred to as spongy bone due to its spongy appearance), which is made up of groupings of trabeculae that provide structural support and strength. Bone marrow is a thick, jelly-like substance found in the centre of most bones that contains stem cells, which can turn into red blood cells, white blood cells, and platelets.

Our highly detailed anatomical skeleton models provide an accurate visual representation of the human skeleton. These models are ideal for exploring the bones of the body in three dimensions, allowing you to better understand their structure, function, and movement. Perfect for students, educators, and healthcare professionals alike, these models are invaluable tools for both learning and teaching.

The different types of bones include flat, long, short, irregular, sesamoid, and sutural bones.

• Flat bones are made up of cancellous bone sandwiched between two layers of compact bone and are flat, as their name suggests. Some examples of these bones include several of the bones of the skull, the sternum, ribs, pelvis, and scapula. These bones protect internal organs.
• Long bones are typically found in the appendicular skeleton, and their name speaks to their appearance, with a shaft and two ends. Some examples of these bones include the femur, tibia, and fibula, metatarsals and phalanges, the humerus, ulna, and radius. Long bones provide structure, mobility, and strength.
• The irregular bones vary in shape and consist of thin layers of compact bone surrounding cancellous bone. The vertebrae consist of 33 irregular bones, which protect the spinal cord. The sacrum, coccyx, sphenoid, zygomatic, maxilla, and hyoid bones are more examples of irregular bones.
• Sesamoid bones are round bones embedded in the tendons of the hands, knees, and feet that function to protect tendons from wear and stress. The patella of the knee is an example of a sesamoid bone.
• Sutural bones (also known as Wormian bones and intra-sutural bones) are the accessory bones (extra bone pieces) that occur within the sutural joint of the skull.

The bones are grouped into two divisions called the axial skeleton and the appendicular skeleton.

• The axial skeleton is made up of 80 bones and forms the vertical axis of our body. This includes the bones of the skull, vertebral column, and rib cage.
• The appendicular skeleton is made up of the remaining 126 bones of the body and appends to the axial skeleton. This part of the skeleton facilitates movement, and it consists of the bones of the shoulder girdle, the upper limbs, the pelvic girdle, and the lower limbs.

A joint is where two or more bones of the skeleton meet and allow movement. They can be classified by their structure or by their function.

Functional classification is based on the type of joint movement: 

• Synarthrosis - immovable
• Amphiarthrosis - partly movable
• Diarthrosis - movable joints. 

Structural classification is based on the three tissue types that make up the joint: 

• Fibrous
• Cartilaginous
• Synovial 

Synarthrosis joints include fibrous joints; an example of this is the sutures of the skull, such as the coronal suture. Amphiarthrosis joints include cartilaginous joints; an example of this is the pubic symphysis, a slightly mobile joint that unites the bones of the hip with fibrocartilage. Diarthrosis joints include synovial joints; examples of these joints include the shoulder and elbow joints.

Synovial joints can be broken into more categories based on the shape and structures of the joints. These include:

• Pivot joints - such as the atlas and axis of the neck
• Hinge joints - such as interphalangeal joints, the knee, and elbow
• Saddle joints - such as the carpometacarpal joint of the thumb
• Plane joints - such as the carpals of the hands and tarsals of the feet
• Condyloid joints - such as the radiocarpal joint
• Ball and Socket joints - such as the shoulder and hip joints.

The skeletal system consists of more than just bones. The skeleton includes approximately 900 ligaments. Ligaments are fibrous, tough, flexible, rope-like connective tissues that connect and stabilise joints, often named from the bones to which they attach.

The ligaments of the skeleton can be broken down into two types: white ligaments and yellow ligaments. White ligaments are made up of inelastic collagenous fibres, while yellow ligaments are made up of tough elastic fibres.

Cartilage is resilient, rubber-like connective tissue that covers the surface of our joints and acts as a shock absorber, creating a low-friction environment at the end of our bones. Although cartilage is stiff and inflexible, it is not quite as hard and rigid as bone. It is, however, significantly less flexible than ligaments and muscles.

Cartilage is found at the ends of the bones where joints form. It is also found at the ends of our ribs, in our bronchial tubes and airways, between the vertebrae and spine, and in our nose and ears.

The three types of cartilage include hyaline, fibrous, and elastic cartilage.

• Hyaline cartilage exists around our joints and in the nose, rings of the trachea, and the tips of our ribs.
• Fibrous cartilage is found in the pubic symphysis and in vertebral discs.
• Elastic cartilage can be found in non-load-bearing parts of the body, such as the external ear.

Our anatomical models and charts are designed to provide comprehensive insights into the human skeleton, enhancing your study of bone structure, function, and joint movement. These tools aid in developing a deeper understanding of human anatomy and support effective study and retention.