Middle lamellaThe layer between two neighboring cells. It is rich in pectin and cements their walls together.
Primary cell wallThe first wall a cell makes. It is thin and flexible, so it can stretch while the cell grows.
Secondary cell wallA thick layer laid down inside the primary wall. Some cells add it once they stop growing, and lignin often stiffens it.
Plasma membraneThe living boundary of the cell. It lies just inside the wall and lines each pit.
PlasmodesmaA channel of cytoplasm through the wall. It joins the two cells, and the plural is plasmodesmata.
PitA spot with no secondary wall. The pits of two neighbors line up as a pit pair.
CytoplasmThe living contents of the cell inside the membrane. It runs on through each plasmodesma into the next cell.
Inside the wall 4
Cellulose microfibrilA long, stiff thread of many cellulose molecules. Microfibrils carry the pull on the wall.
HemicelluloseShorter, branched molecules that tie one microfibril to the next.
PectinThe soft matrix of the primary wall. The microfibrils and their tethers sit in it.
LigninA hard filling in many secondary walls. It stiffens and waterproofs them, and wood is full of it.
How this list was compiled: Every name was checked on 2026-10-01 and kept only where two independent sources use it. (1) Wikipedia, text only: Cell wall, https://en.wikipedia.org/wiki/Cell_wall ; Middle lamella; Secondary cell wall; Plasmodesma; Pit (botany). (2) USDA Forest Service, Forest Products Laboratory, Wood Handbook (General Technical Report FPL-GTR-190, 2010), chapter 3, Structure and Function of Wood, https://www.fpl.fs.usda.gov/documnts/fplgtr/fplgtr190/chapter_03.pdf : the middle lamella, the primary wall, the secondary wall, pits, cellulose microfibrils, hemicelluloses, pectin and lignin. (3) Kimball's Biology Pages, The Plant Cell, https://www.biology-pages.info/P/PlantCell.html : primary and secondary cell walls, plasmodesmata, the plasma membrane, cellulose fibrils, pectin and lignin. (4) The American Heritage Dictionary of the English Language, fifth edition, https://www.ahdictionary.com/ : plasmodesma, pit (the botany sense), hemicellulose, lignin. Licence: own work
The drawing: Drawn for this site on 2026-10-01 from plain geometry; nothing traced. Licence: own work
How it works
This cell wall has no label on it. The large drawing is the stretch of wall two plant cells share, cut across so the layers show. The two blocks under it are wall enlarged again: primary left, secondary right.
Read the full guide
Cell wall, no labels: the eleven names
Seven go on the large drawing: middle lamella, primary cell wall, secondary cell wall, plasma membrane, plasmodesma, pit, cytoplasm. Four go on the blocks: cellulose microfibril, hemicellulose, pectin, lignin.
Which shape takes which name
The narrow strip down the middle is the middle lamella. The band on each side of it is a primary cell wall, the thick striped layer beyond that a secondary cell wall, and the thin outline round that the plasma membrane. The dashed box marks a pit, the channel across the wall is a plasmodesma, and the open space at each side is cytoplasm. In the left block the long rods are cellulose microfibrils, the wavy strands hemicellulose and the speckled filling pectin. The filling of the right block is lignin.
The ovals with lines inside are chloroplasts, and the big rounded shape at each edge is a vacuole. Neither takes a name.
No line is drawn for you: write each name on its part, or rule a line out to the margin.
The rods of the right block are cellulose microfibrils too, laid side by side as in a secondary wall.
Questions and answers
Where is the cell wall in a plant cell diagram with no labels?
Round the outside of each cell. On this sheet the two small cells at the top show the wall as the outline of each cell, and their dashed box marks the stretch that is enlarged below.
Is the cell wall an organelle?
By the strict definition, no. An organelle is a structure within a cell, and the cell wall is the cell's outermost layer, outside the plasma membrane. If your course lists it with the organelles of a plant cell, label it as your course does.
Which layer of the plant cell wall is outermost?
The middle lamella. It is laid down first, as the cell divides, and each cell then builds its primary wall inside it. A secondary wall, where there is one, comes last and lies between the primary wall and the plasma membrane.
Do animal cells have a cell wall?
No. Cell walls are found in plants, fungi, algae and most bacteria, and they are absent from animal cells.