frontonasal

29 They are lined by mucous membrane, and each communicates with the corresponding nasal cavity by means of a passage called the frontonasal duct.

II. Osteology. 5a. 3. The Frontal Bone 1918

The anterior ethmoidal cells open into the front part of the infundibulum, and this in slightly over 50 per cent. of subjects is directly continuous with the frontonasal duct or passage leading from the frontal air sinus; but when the anterior end of the uncinate process fuses with the front part of the bulla, this continuity is interrupted and the frontonasal duct then opens directly into the anterior end of the middle meatus.

X. The Organs of the Senses and the Common Integument. 1b. The Organ of Smell 1918

To understand this it must be borne in mind that three processes are concerned in the formation of the palate—the palatine processes of the two maxillæ, which grow in horizontally and unite in the middle line, and the ethmovomerine process, which grows downward from the base of the skull and frontonasal process to unite with the palatine processes in the middle line.

II. Osteology. 5d. The Interior of the Skull 1918

The term nasion is applied to the middle of the frontonasal suture.

II. Osteology. 5a. 3. The Frontal Bone 1918

Through the hiatus semilunaris the meatus communicates with a curved passage termed the infundibulum, which communicates in front with the anterior ethmoidal cells and in rather more than fifty per cent. of skulls is continued upward as the frontonasal duct into the frontal air-sinus; when this continuity fails, the frontonasal duct opens directly into the anterior part of the meatus.

II. Osteology. 5d. The Interior of the Skull 1918

Below the frontonasal suture is the bridge of the nose, convex from side to side, concavo-convex from above downward, and formed by the two nasal bones supported in the middle line by the perpendicular plate of the ethmoid, and laterally by the frontal processes of the maxillæ which are prolonged upward between the nasal and lacrimal bones and form the lower and medial part of the circumference of each orbit.

II. Osteology. 5c. The Exterior of the Skull 1918

On and above the glabella a trace of the frontal suture sometimes persists; beneath it is the frontonasal suture, the mid-point of which is termed the nasion.

II. Osteology. 5c. The Exterior of the Skull 1918

Each opens into the anterior part of the corresponding middle meatus of the nose through the frontonasal duct which traverses the anterior part of the labyrinth of the ethmoid.

X. The Organs of the Senses and the Common Integument. 1b. The Organ of Smell 1918

Behind and below the frontonasal suture the frontal articulates with the frontal process of the maxilla and with the lacrimal.

II. Osteology. 5c. The Exterior of the Skull 1918

The roof of the nasal cavity is narrow from side to side, except at its posterior part, and may be divided, from behind forward, into sphenoidal, ethmoidal, and frontonasal parts, after the bones which form it.

X. The Organs of the Senses and the Common Integument. 1b. The Organ of Smell 1918