Parts of a Long Bone

One long bone, cut open lengthwise: 13 parts to name, labeled or blank.

Parts of a Long Bone

Name Date

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1 2 3 4 5 6 7 8 9 10 11 12 13
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Write the name of each numbered part.Answer key

  1. Proximal epiphysis
  2. Metaphysis
  3. Diaphysis
  4. Distal epiphysis
  5. Articular cartilage
  6. Spongy bone
  7. Red marrow
  8. Epiphyseal line
  9. Compact bone
  10. Medullary cavity (yellow marrow)
  11. Endosteum
  12. Periosteum
  13. Nutrient foramen

Drawn for this site by script, 2026-09-26. 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 part is answered.

Next step Next: 35 bones of the whole body, front and back

All 13 parts on the diagram

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Start here: 9 main parts 8

  1. Proximal epiphysis The wide end nearest the body, filled with spongy bone. The other end is the distal epiphysis.
  2. Diaphysis The tubular shaft between the two ends. Its walls are compact bone round the medullary cavity.
  3. Articular cartilage Reduces friction and absorbs shock. A thin layer of cartilage where the bone meets another at a joint.
  4. Spongy bone Bone full of spaces that fills the epiphyses. Red marrow fills its spaces.
  5. Epiphyseal line What is left of the growth plate. Once growth stops, around 18 to 21 years, the cartilage plate turns to bone and leaves this line.
  6. Compact bone Dense, hard bone that makes the walls of the diaphysis. It also makes a thin shell round each end.
  7. Medullary cavity (yellow marrow) The hollow inside the diaphysis, filled with yellow marrow.
  8. Periosteum A fibrous membrane over the outer surface, except at the joints. It carries blood vessels and nerves, and tendons and ligaments attach to it.

Regions of the bone: 4 2

  1. Metaphysis Where each epiphysis meets the diaphysis. It holds the epiphyseal plate in a growing bone.
  2. Distal epiphysis The wide end furthest from the body, also filled with spongy bone.

Inside the bone: 5 1

  1. Red marrow Fills the spaces of the spongy bone.

Coverings and openings: 4 2

  1. Endosteum A delicate membrane lining the medullary cavity. Bone growth, repair and remodeling happen there.
  2. Nutrient foramen A small opening in the diaphysis. Arteries and nerves enter the bone here.

How this list was compiled: Read 2026-09-26. OpenStax Anatomy and Physiology 2e, section 6.3 Bone Structure, https://openstax.org/books/anatomy-and-physiology-2e/pages/6-3-bone-structure : a long bone's diaphysis (the tubular shaft between the proximal and distal ends) and epiphyses; the medullary cavity filled with yellow marrow; walls of compact bone; epiphyses filled with spongy bone whose spaces hold red marrow; the metaphysis holding the epiphyseal plate of hyaline cartilage, which becomes the epiphyseal line when growth stops at about 18 to 21 years; the endosteum lining the medullary cavity, site of growth, repair and remodelling; the periosteum over the outer surface except at joints, carrying blood vessels, nerves and lymphatic vessels, with tendons and ligaments attached; articular cartilage reducing friction and absorbing shock; arteries entering through the nutrient foramen in the diaphysis. Licence: own work

The drawing: Drawn for this site by script, 2026-09-26. Own work, nothing traced. Licence: own work

How it works

The parts of a long bone on one drawing cut open lengthwise: the regions of the bone, what is inside it, and what covers it. Start with the 8 main parts, or print the long bone diagram unlabeled.

Read the full guide

Ends and shaft

The diaphysis is the shaft; the wide ends are the proximal and distal epiphyses; the metaphysis joins them. In a growing bone the metaphysis holds the growth plate, which becomes the epiphyseal line in adults.

Inside and outside

Compact bone forms the walls, spongy bone with red marrow fills the ends, and yellow marrow fills the medullary cavity. The endosteum lines the cavity; the periosteum covers the outside except where articular cartilage caps a joint.

  • Peri- means around and endo- means inside: the periosteum wraps the bone, the endosteum lines the hollow.

Questions and answers

What are the main parts of a long bone?

The diaphysis, or shaft, and the two epiphyses at the ends, joined by the metaphysis. Inside are compact bone, spongy bone, marrow and the medullary cavity.

What is the difference between red and yellow marrow?

In a long bone, red marrow fills the spaces of the spongy bone in the ends, and yellow marrow fills the medullary cavity of the shaft.

What does the blank long bone diagram show?

The same cut-open bone with its 13 numbered rings and no names, so you can write each part in yourself.

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