Squamous part (squama)The largest and highest of the four parts: a thin, scale-like plate. Its upper edge overlaps the parietal bone at the squamous suture, and a chewing muscle, the temporalis, attaches to its outer face.
Zygomatic processA long, arched bar that runs forward from the lower squamous part. Its front end meets the zygomatic bone, and the two together make the zygomatic arch. The masseter, a chewing muscle, attaches to it.
Articular tubercleThe rounded bump where the front root of the zygomatic process ends. It forms the front edge of the mandibular fossa, and both take part in the jaw joint.
Mandibular fossaThe oval hollow just in front of the ear opening. The lower jaw meets the skull here at the temporomandibular joint. Only its front half is a joint surface. The tympanic part forms the back half.
External acoustic meatus (ear canal opening)The large opening on the outer side of the bone. It is at the start of the canal that ends at the eardrum. The tympanic part forms its front wall, its floor and part of its back wall. The squamous part forms the roof.
Tympanic partA small curved plate that wraps the bony ear canal. It lies below the squamous part and in front of the mastoid process. Its lower edge splits to sheathe the root of the styloid process.
Styloid processA thin spike named after a stylus, the pointed writing tool. The stylohyoid ligament runs from its tip to the hyoid bone, and muscles attach to it too. It is described with the petrous part, and the tympanic part sheathes its root.
Mastoid processA cone-shaped projection that points down from the mastoid part. Four muscles attach to it: the sternocleidomastoid, the splenius capitis, the longissimus capitis and the posterior belly of the digastric.
Mastoid partThe back part of the bone, behind and below the squamous part. Inside, it is hollowed into air spaces called mastoid cells, which vary a great deal in size and number from one skull to the next.
Inner surface: 5 parts 5
Grooves for the middle meningeal vesselsBranching grooves on the inner face of the squamous part. The middle meningeal vessels left them. The same face has shallow hollows that match the folds of the temporal lobe of the brain.
Arcuate eminenceA rounded rise near the center of the petrous part's front surface. It marks where the superior semicircular canal of the inner ear lies underneath.
Petrous partHouses the middle and inner ear. A pyramid of very dense bone wedged between the sphenoid and occipital bones. Its name means stone-like. It separates the middle cranial fossa from the posterior one.
Internal acoustic meatusAn opening near the center of the petrous part's back surface. It leads into a canal about 1 cm long. The nerve of hearing and balance and the nerve to the facial muscles pass through it.
Groove for the sigmoid sinus (sigmoid sulcus)A deep, curved groove on the inner surface of the mastoid part. It holds the S-shaped channel that carries blood from the brain down to the jugular foramen, and only a thin plate of bone parts it from the mastoid cells.
From below: 5 parts 5
Apex of the petrous partThe rough front tip, between the sphenoid and the occipital bone. The carotid canal opens here on the inside, and the tip forms the back and outer edge of the foramen lacerum.
Carotid canalA large round opening on the underside of the petrous part. The tunnel rises straight up, then bends forward and toward the midline, and carries the internal carotid artery into the skull.
Jugular fossaA deep hollow behind the carotid canal. It holds the bulb of the internal jugular vein. With the jugular notch of the occipital bone it forms the jugular foramen. Its depth and size differ from skull to skull.
Stylomastoid foramenA small hole between the styloid and mastoid processes. It is the end of the facial canal: the nerve to the facial muscles leaves the skull here, with a small artery beside it.
Mastoid notchA deep groove on the inner side of the mastoid process. The digastric muscle attaches here. Just toward the midline from it, a shallower furrow, the occipital groove, holds the occipital artery.
How this list was compiled: Names and detail lines were checked on 2026-09-19 against OpenStax Anatomy and Physiology 2e, section 7.2 (https://openstax.org/books/anatomy-and-physiology-2e/pages/7-2-the-skull), and the English Wikipedia articles on the temporal bone and its parts, starting from https://en.wikipedia.org/wiki/Temporal_bone. A correction made on 2026-09-20 was checked on https://en.wikipedia.org/wiki/Temporal_styloid_process. Every name was checked again on 2026-09-30 against OpenStax section 7.2, the same Wikipedia articles and an independent second source, Kenhub, Temporal bone (https://www.kenhub.com/en/library/anatomy/the-temporal-bone), with TeachMeAnatomy, The Temporal Bone (https://teachmeanatomy.info/head/osteology/temporal-bone/) for the four parts. Licence: own work
The drawing: Drawn for this site on 2026-10-05 by script. The outline of each of the three views is taken from a public domain plate of the left temporal bone in Henry Gray, Anatomy of the Human Body (20th US edition, 1918): fig. 137, outer surface (https://commons.wikimedia.org/wiki/File:Gray137.png), fig. 138, inner surface (https://commons.wikimedia.org/wiki/File:Gray138.png) and fig. 141, inferior surface (https://commons.wikimedia.org/wiki/File:Gray141.png); Wikimedia Commons credits the plates to Henry Vandyke Carter. The lines inside the outlines were placed by eye after the same plates. Simplified: the plates' shading is left out, the grooves for the middle meningeal vessels are a trunk and two branches, the sigmoid groove is drawn narrower than on the plate, and the articular tubercle is drawn flatter than it is. In the view from below the tint of the petrous part runs along the whole inner edge, further back than the petrous part itself reaches. Licence: own drawing; outlines after public domain plates
How it works
Temporal bone labeling is easier with the bone out of the skull. One left temporal bone is drawn three times: outer surface, inner surface and from below. Its 19 parts are 4 named parts plus 15 processes, openings and grooves.
Read the full guide
Three views, one at a time
The quiz takes one view at a time and zooms to it: rings 1 to 9 on the outer surface, then 10 to 14 on the inner surface, then 15 to 19 on the underside. It names a part and you tap its ring. A wrong tap shows the right part.
Drill one part of the bone
Under Start from, The 4 named parts asks only for the squamous, tympanic, mastoid and petrous parts. Petrous part: 8 adds what belongs to it, from the internal acoustic meatus to the carotid canal. Name it lights a ring for you to name. The drawing prints blank, numbered 1 to 19, or labeled as the key.
From below, the carotid canal is the round opening in front. The jugular fossa is the smooth hollow behind it, past a bony ridge.
The stylomastoid foramen sits where its name says: between the styloid process and the mastoid process.
Do not look for the jugular foramen here. It is a gap between two bones, so a single temporal bone has only the jugular fossa.
Questions and answers
What are the four parts of the temporal bone?
The squamous, tympanic, mastoid and petrous parts. The squamous part is the largest and highest. The tympanic part is a small plate around the ear canal, the mastoid part lies behind it, and the petrous part is the dense pyramid that houses the inner ear.
Is it a left or a right temporal bone?
A left one. On the outer surface the zygomatic process points left, toward the face. On the inner surface it points right, because you are looking from inside the skull. From below, the front of the bone is up.
What does this quiz leave out?
Small markings such as the mastoid foramen, the suprameatal triangle and the petrotympanic fissure, and everything inside the bone, such as the facial canal and the ossicles. The jugular foramen and foramen lacerum are gaps between bones, so the skull labeling quiz rings those.