Egg Diagram Labeled: the Parts of an Egg

A chicken egg cut in half, from the shell in to the yolk.

Egg Diagram Labeled: the Parts of an Egg

Name Date

Tap any part to read, rename or leave it out

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

  1. Shell
  2. Shell membranes
  3. Air cell
  4. Thin white
  5. Thick white
  6. Chalazae
  7. Yolk
  8. Vitelline membrane
  9. Germinal disc

Drawn for this site on 2026-09-30 from plain geometry. 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: the parts of a chicken

All 9 parts on the diagram

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  1. Shell The hard outer case. Tiny pores let air through.
  2. Shell membranes Two thin, tough skins, inner and outer, lining the shell.
  3. Air cell A pocket of air at the large end, between the two membranes.
  4. Thin white The thin outer layer of albumen, just inside the shell membranes.
  5. Thick white The firm layer of albumen. It holds the yolk like a jacket.
  6. Chalazae Two twisted cords that hold the yolk in the center.
  7. Yolk The yellow center. It is food for a growing chick.
  8. Vitelline membrane The colorless skin that surrounds and contains the yolk.
  9. Germinal disc A small white dot on the yolk's surface.

How this list was compiled: Every name checked on 2026-09-30, a name kept only where two of these use it: (1) United States Department of Agriculture, Agricultural Marketing Service, Egg-Grading Manual (Agricultural Handbook 75), chapter III, Structure, Composition, and Formation of the Egg, https://www.ams.usda.gov/sites/default/files/media/Egg%20Grading%20Manual.pdf (the parts of an egg are the yolk, the white, the shell membranes and the shell; the yolk with its germinal disc and vitelline membrane; the chalazae; the thin and the thick white; the inner and outer shell membranes; the air cell, formed between the shell membranes at the large end as the egg cools; pores in the shell); (2) Dr. Jacquie Jacob, University of Kentucky, on the Cooperative Extension poultry site: Avian reproductive system, female, https://poultry.extension.org/articles/poultry-anatomy/avian-reproductive-female/ (yolk, thick albumen or egg white, inner and outer shell membranes, shell, vitelline membrane) and Avian embryology, https://poultry.extension.org/articles/poultry-anatomy/avian-embryology/ (air cell; the small white spot on the yolk's surface); (3) Wikipedia, text only: Chalaza, https://en.wikipedia.org/wiki/Chalaza (two spiral bands that hold the yolk at the white's center); Egg white, https://en.wikipedia.org/wiki/Egg_white (thick and thin albumen); Yolk, https://en.wikipedia.org/wiki/Yolk (chalazae, vitelline membrane, germinal disc). Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain geometry; no photograph or plate followed. Licence: own work

How it works

An egg has four main parts: the shell, the shell membranes, the white and the yolk. The drawing cuts a chicken egg in half lengthwise and names nine parts, from the outside in.

Read the full guide

From the shell in to the yolk

Numbers 1 to 3 are the outside: the shell, the shell membranes just inside it and the air cell at the large end. Numbers 4 to 6 are the white: the thin white, the thick white and the two chalazae. Numbers 7 to 9 are the yolk, the vitelline membrane round it and the germinal disc on its surface.

  • The air cell is always at the large end.
  • The layers are drawn thicker than life, so you can find each one.

Questions and answers

What are the parts of a chicken egg?

Four main parts: the shell, the shell membranes, the white and the yolk. The white has thin and thick layers and two chalazae. The yolk has a skin, the vitelline membrane, and a small spot, the germinal disc.

What is the white stringy part of an egg?

A chalaza. An egg has two chalazae, one on each side of the yolk. They are twisted cords of white that hold the yolk in the center of the egg.

Where is the air cell in an egg?

At the large end, between the two shell membranes. A newly laid egg has none. The air cell forms as the egg cools, because the contents shrink more than the shell.

Which parts of a raw egg can you see?

Crack one onto a plate. You can see the yolk, the clear white round it and often a chalaza, a white strand beside the yolk. The shell membranes line the inside of the empty shell.

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