Feel the firm outline of your collarbone. It belongs to a framework that supports the whole body. Divide that framework into its central axis and attached limbs.
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Axial / appendicular
The axial skeleton is the central framework. The appendicular skeleton consists of the limbs and the groups of bones that attach them to the trunk.
For example
Ribs belong to the axial skeleton. The collarbone and arm bone belong to the appendicular skeleton.
Read all notes for this section
Axial / appendicular
The axial skeleton is the central framework. The appendicular skeleton consists of the limbs and the groups of bones that attach them to the trunk. Ribs belong to the axial skeleton. The collarbone and arm bone belong to the appendicular skeleton.
Girdle
A group of bones that connects a limb to the trunk. The shoulder girdle consists of clavicle and scapula.
Vertebra / disc
A vertebra is one bone of the spine. A disc is a tough, flexible cushion between the main parts of most neighbouring vertebrae. The stacked vertebrae surround a canal that protects the spinal cord and the roots of nerves leaving it.
Joint / suture
A joint is a connection between bones. A suture is a fibrous joint between skull bones. The knee permits large movement; adult skull sutures allow very little.
Start with the centre and the limbs
The axial skeleton is the central framework: skull, spine, ribs and breastbone. The appendicular skeleton includes the limbs and the bones that attach them to the trunk. These attachment groups are called girdles: the shoulder girdles and pelvic girdle.
Follow the spine from top to bottom
The spine is a stack of bones called vertebrae. There are usually 7 cervical vertebrae in the neck, 12 thoracic vertebrae in the chest region and 5 lumbar vertebrae in the lower back. Below them are the sacrum and coccyx, formed from fused segments. A central canal protects the spinal cord and nerve roots.
Learn a few limb bones first
The humerus runs from shoulder to elbow. The forearm contains the radius on the thumb side and the ulna on the little-finger side in anatomical position. In the lower limb, the femur is the thigh bone, the patella is the kneecap, and the tibia and fibula lie between knee and ankle.
Explore the illustration
Look at the whole view first. Then select one label and connect it to the idea you just read.
Axial and appendicular skeleton
Identify the bones from head to foot. The skull, vertebral column and thoracic cage form the axial skeleton; the girdles and limbs form the appendicular skeleton.
More controls
01 / 9 Skull
Guided anatomy tour: each step identifies one structure and explains its relationship to the next. The highlight moves; the anatomy stays still. Reduced motion is enabled. Use the arrows to study one step at a time, or choose Play.
Skull
The skull protects the brain and supports the face. It belongs to the axial skeleton.
Adapted for this lesson: labels removed, artwork cropped or recoloured, and interactive teaching overlays added. Adapted artwork retains its source licence.
Go deeper
In-depth reading
Follow this example step by step, then try explaining it yourself. The extra reading is optional: you can return to it after exploring the illustration.
Worked example: locating a forearm bone
Begin with the region. In anatomy, the arm runs from shoulder to elbow; the forearm runs from elbow to wrist. Everyday speech sometimes calls both the “arm”, but anatomical descriptions separate them.
Return the hand to anatomical position, with the palm forward. Find the thumb side: the forearm bone on this side is the radius. It is lateral, meaning farther from the body’s midline.
The other forearm bone is the ulna, on the medial side. Both belong to the appendicular skeleton because they are part of a limb. You have connected region, direction, name and skeletal division.
Explain it yourself
Does the femur belong to the axial or appendicular skeleton?
Show the explanation
Appendicular. The femur is the thigh bone, so it belongs to a limb. The spine is part of the axial skeleton.
More detail — when you are ready
These notes expand the mechanisms and vocabulary. Read one topic at a time and find the structures in the illustration.
Axial protection and the vertebral column
The skull has cranial and facial components. The cranium encloses the brain; facial bones support openings and structures of the face.
Frontal, parietal, temporal and occipital bones form major visible parts of the cranial wall; sphenoid and ethmoid contribute to its base. Sutures join many skull bones.
The mandible moves at the jaw joints. Below the skull, seven cervical, twelve thoracic and five lumbar vertebrae precede the fused sacrum and the variable coccyx.
C1 is the atlas, which articulates with the skull.
Cage, girdles and limb bones
The sternum, twelve pairs of ribs and thoracic vertebrae form the thoracic cage. It protects thoracic organs and provides attachments for breathing muscles.
Each shoulder girdle includes a clavicle and scapula. The upper limb has a humerus, radius and ulna, followed by eight carpals, five metacarpals and fourteen phalanges.
Each lower limb has a femur, patella, tibia and fibula, followed by seven tarsals, five metatarsals and fourteen phalanges. The pelvic girdle consists of two hip bones; the bony pelvis also includes the sacrum and coccyx.
Worked comparison: arm, forearm, thigh and leg
In anatomical language, the arm is between shoulder and elbow, and the forearm between elbow and wrist. The thigh is between hip and knee, while the leg is between knee and ankle.
Thus a femoral injury concerns the thigh, not the leg in this precise usage. The radius is lateral in anatomical position, the ulna medial; the tibia is medial and the fibula lateral.
Distinguish the vertebral canal, which houses neural structures, from intervertebral openings through which spinal nerves pass. Discs cushion between most adjacent vertebral bodies.
Further reading — optional
Free external resources in English. Internet connection required to open the links. Choose the topic you want to explore; these readings are not required to complete the section.
Use the whole-skeleton figure to separate the central framework from the limbs and their attachments.
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Sources and illustration notes
Bilingual teaching notes organised from your supplied anatomy reference pages. Medical SVG artwork is credited beneath each illustration; guided sequences and process overlays support slow, step-by-step study. Anatomy and translation await expert review.
