Sperm Cell Diagram – Labeled Parts of a Sperm

All 9 parts on the diagram

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First 5: the main parts 5

Head It holds the nucleus and is capped by the acrosome.
Acrosome Filled with enzymes that help the sperm reach and enter the egg.
Nucleus It holds half the usual set of chromosomes, packed very tightly.
Mid-piece It is packed with mitochondria that power the tail.
Tail It whips to push the sperm along.

Head and neck 2

Neck The flagellum starts here.
Centriole The flagellum’s central strand grows from a centriole.

Mid-piece and tail 2

Mitochondria They make the energy (ATP) that powers the flagellum.
Flagellum Beats to make the sperm swim. It runs through the mid-piece and the tail.

How this list was compiled: Every name and detail checked on 2026-09-29 against OpenStax Anatomy and Physiology 2e, section 27.1 Anatomy and Physiology of the Testicular Reproductive System (the head with its compact nucleus and acrosome cap of enzymes, the neck, the mid-piece packed with mitochondria, the tail and the flagellum, whose central strand forms from a centriole), https://openstax.org/books/anatomy-and-physiology-2e/pages/27-1-anatomy-and-physiology-of-the-testicular-reproductive-system, and against Wikipedia, Sperm, text only. Licence: own work

The drawing: Drawn for this site on 2026-09-29 from plain geometry; nothing traced. Licence: own work

How it works

A sperm cell is built for one job: to swim to an egg and deliver its nucleus. This drawing lays one out lengthwise, head cut open, with the tail shortened to fit.

Read the full guide

The main five first

Numbers 1 to 5 are the parts school classes learn: the head, the acrosome cap, the nucleus inside the head, the mid-piece and the tail. Numbers 6 to 9 add detail: the neck, the centriole in it, the mitochondria that pack the mid-piece and the flagellum that runs through it all. The drawing is not to scale: the head is about 5 micrometres long and the tail about 50.

Each part fits the job: enzymes in the acrosome, energy from the mitochondria, movement from the flagellum.

Questions and answers

What are the parts of a sperm cell?

A head holding the nucleus and capped by the acrosome, a short neck, a mid-piece packed with mitochondria, and a long tail. The flagellum runs from the neck through the mid-piece and the tail.

Why does a sperm cell have so many mitochondria?

The mitochondria in the mid-piece make the energy that powers the flagellum, so the sperm can swim.

What does the acrosome do?

It is a cap over the head filled with enzymes that help the sperm get through the layers around the egg.