• 22 bones
  • Checked October 2026

Bone Classification Quiz

A bone lights up on the skeleton: choose long, short, flat, irregular or sesamoid.

Bone Classification Quiz

Name Date

Which class of bone is lit?

1 of 8

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
More options

Write the name of each numbered bone.Answer key

  1. Long bone
  2. Long bone
  3. Flat bone
  4. Short bone
  5. Irregular bone
  6. Sesamoid bone
  7. Long bone
  8. Long bone
  9. Flat bone
  10. Short bone
  11. Irregular bone
  12. Long bone
  13. Long bone
  14. Flat bone
  15. Flat bone
  16. Irregular bone
  17. Long bone
  18. Flat bone
  19. Long bone
  20. Long bone
  21. Irregular bone
  22. Long bone

Drawn for this site, 2026-09-20. Licence: own work.

Each numbered ring is a button. Use the arrow keys to move between them and Enter to choose. Names are read out in Study, and once a bone is answered.

Next step Inside a long bone: shaft and endsInside a flat bone

All 22 bones on the diagram

Show the list

Shoulder and arm 8

  1. Long bone The humerus of the upper arm: a shaft with two ends.
  2. Short bone The carpals of the wrist: about as wide as they are long.
  3. Long bone The radius of the forearm: a shaft with two ends.
  4. Long bone The ulna of the forearm: a shaft with two ends.
  5. Flat bone The scapula, the shoulder blade: a broad plate where muscles attach.
  6. Long bone The clavicle, the collarbone: short, but a shaft with two ends.
  7. Long bone A metacarpal in the palm: small, but a shaft with two ends.
  8. Long bone A finger bone, or phalanx: tiny, but a shaft with two ends.

Leg and foot 6

  1. Long bone The femur, the thigh bone: a shaft with two ends.
  2. Sesamoid bone The patella, the kneecap: a bone that lies inside a tendon.
  3. Long bone The tibia, the shinbone: a shaft with two ends.
  4. Short bone The tarsals of the ankle: about as wide as they are long.
  5. Long bone The fibula: thin, but still a shaft with two ends.
  6. Long bone A metatarsal in the foot: small, but a shaft with two ends.

Spine and rib cage 4

  1. Irregular bone A vertebra: its shape fits none of the other classes.
  2. Flat bone The sternum, the breastbone: a flat plate in the chest.
  3. Flat bone A rib: long and curved, but a thin plate of bone.
  4. Irregular bone The sacrum, below the lumbar vertebrae: irregular, like the vertebrae.

Skull 4

  1. Flat bone The frontal bone of the forehead: a broad, thin plate.
  2. Irregular bone The mandible, the lower jaw: its shape fits no other class.
  3. Flat bone The parietal bone: a broad, thin plate of the skull.
  4. Irregular bone The zygomatic bone, the cheekbone: its shape fits no other class.

How this list was compiled: Which bones are long, short, flat and irregular: Henry Gray, Anatomy of the Human Body, 20th edition, 1918 (public domain), II. Osteology, the opening section ("Bones are divisible into four classes: Long, Short, Flat, and Irregular", with the members of each), https://www.bartleby.com/107/17.html, read 2026-10-01. The same lists, the fifth class and what defines each class: the English Wikipedia articles Long bone, Short bone, Flat bone, Irregular bone and Sesamoid bone, read 2026-10-01. A bone is asked only where the two agree. Ring positions and shape ids are those of the site's skeleton drawing (data/bones-of-the-body-quiz.json); the names were read against the two sources above and no line of that dataset is carried over. Licence: own work

The drawing: Drawn for this site, 2026-09-20. Proportions and bone shapes were checked by eye against three public-domain pictures on Wikimedia Commons: Gray188.png (side view of the skull from Gray, Anatomy of the Human Body, 1918), Human_skeleton_front_-_no_labels.svg and Human_skeleton_back_en.svg (Mariana Ruiz Villarreal, released into the public domain), and against the descriptions of the wrist and ankle bones in the English Wikipedia articles Carpal bones and Tarsus (skeleton). Nothing was traced or copied, and the numbers and labels are our own. Licence: own work

How it works

This bone classification quiz lights up one bone on a skeleton and asks for its class by shape: long, short, flat, irregular or sesamoid. It asks 22 bones, from the humerus to the kneecap.

Read the full guide

The five classes in this bone shape quiz

A long bone has a shaft and two ends, whatever its size, so a finger bone counts. A short bone is about as wide as it is long. A flat bone is a thin, broad plate. An irregular bone fits none of these. A sesamoid bone lies inside a tendon.

One part of the skeleton at a time

Start from has four sets: shoulder and arm, leg and foot, spine and rib cage, and skull. The sets are regions, not classes, so choosing one does not give the answers away. Study shows the class on every ring.

  • Long is the build, not the size: the collarbone, the palm bones and the finger bones are all long bones.
  • The short bones are in the wrist and the ankle: carpals and tarsals.

Questions and answers

What are the classes of bones by shape?

Five: long, short, flat, irregular and sesamoid. Older textbooks give four and treat sesamoid bones, such as the kneecap, as short or flat bones.

Is the patella a short bone or a sesamoid bone?

A sesamoid bone. It lies inside the tendon at the front of the knee, and it is the largest sesamoid bone in the body.

Are the ribs long bones or flat bones?

Flat bones. A rib is long and curved, but it is a thin plate. Gray's Anatomy lists the ribs with the sternum and the shoulder blade among the flat bones.

Why is the hip bone not asked?

Textbooks do not agree on its class, so the quiz leaves it out. Every bone that is asked has the same class in both of the page's sources.

More quizzes

Show 8 more

Browse Human Body Quizzes