Where it is
The bones of the head, without the mandible.
- Layer
- Skeleton
- System
- Axial skeleton
- Region
- Head
What it is and what it does
The skull protects the brain and the sense organs and forms the face: the orbits in which the eyes sit, the nasal cavity with the turbinates and the maxilla with the upper teeth. It is made of several bones joined by sutures. The mandible articulates with the temporal bone at the temporomandibular joint.
Skull shape ranges from dolichocephalic breeds (longer longitudinal axis) to brachycephalic ones (short, wide skull, short muzzle, wide zygomatic arches, rounded neurocranium), with mesaticephalic breeds in the middle. The measure used is the cephalic index: skull width × 100 / skull length (from prosthion to inion); numerical thresholds per breed do not exist in a peer-reviewed source.
Palpable landmarks: the zygomatic arch, the external occipital protuberance (the highest point of the skull in the dog), the sagittal crest (variable between breeds), the temporomandibular joint and the tympanic bulla, all selectable in the skeleton layer.
Worth remembering
Skull shape differs between long-muzzled breeds, short-muzzled breeds and those in between.
Names
- Also called: bones of the head.
- Latin term: cranium.
- In Romanian: Craniul (Romanian page).
In the atlas lessons
The skeleton, from skull to tail (5 min):
The skull protects the brain and the sense organs; the mandible articulates with it at the temporomandibular joint.
Teeth: 28 deciduous, 42 permanent (4 min):
Four categories: incisors, canines, premolars and molars. On one half of the upper jaw, an adult has 3 incisors, 1 canine, 4 premolars and 2 molars; on one half of the lower jaw, 3 molars.
Journey of a scent (5 min):
The olfactory recess: ethmoturbinates lined with olfactory epithelium (~200 cm²), isolated from breathing by a bony plate; during exhalation no air passes through here, so the odor stays on the receptors.
The axons pass through the cribriform plate to the olfactory bulb, under the frontal lobes. Separately, the vomeronasal organ, above the palate, detects low-volatility chemical signals through the duct that opens behind the incisors.
Questions from the atlas
"Find it on the drawing" questions whose answer is this structure; in the atlas you will find them in the question bank and in the lessons.
- Show the skull on the skeleton. (level 1)