Anatomy of the external nose and nasal cavity. The structure of the na

Anatomy of the external nose and nasal cavity. The structure of the nasal mucosa. Nasal passages, their topography, which paranasal sinuses open in them.

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1) External nose: anatomy

The external nose is a pyramidal projection on the face with:

Root (continuous with forehead)
Dorsum
Apex (tip)
Alae
Nares (nostrils) opening inferiorly

Its framework has:

Bony part (superior): nasal bones, frontal bone, and maxilla
Cartilaginous part (anterior/inferior): septal cartilage, lateral nasal cartilages, major and minor alar cartilages

This framework keeps the anterior nasal airway open.
Source: Gray’s Anatomy for Students, p. 1213-1214

2) Nasal cavity and passages (topography)

Each nasal cavity extends from:

Anterior nares to
Posterior choanae (opening into nasopharynx)

Main walls:

Medial wall: nasal septum
Lateral wall: has conchae (superior, middle, inferior), creating passages:
- Superior meatus
- Middle meatus
- Inferior meatus
- Sphenoethmoidal recess (above superior concha)

Other key parts:

Roof: highest at cribriform plate of ethmoid
Floor: hard palate region

Source: Gray’s Anatomy for Students, p. 1217-1219; Color Atlas of Human Anatomy Vol. 2, p. 184-186

3) Structure of nasal mucosa

Nasal mucosa is divided into three regions:

Nasal vestibule
- Lined by skin (stratified squamous keratinized epithelium)
Respiratory region
- Pseudostratified ciliated columnar epithelium
- Cells: ciliated cells, goblet cells, brush cells, small granule cells, basal cells
- Lamina propria rich in venous plexuses and seromucous glands
- Function: warm, humidify, filter inspired air
Olfactory region (roof, upper septum, upper lateral wall)
- Specialized pseudostratified olfactory epithelium
- Cells: olfactory receptor neurons (bipolar), supporting cells, basal cells, brush cells
- No goblet cells
- Lamina propria contains Bowman (olfactory) glands, vessels, olfactory nerve bundles

Sources:

Histology: A Text and Atlas, p. 1763-1764, 1824, 1828
Color Atlas of Human Anatomy Vol. 2, p. 175, 179

4) Which paranasal sinuses open where

Inferior meatus

Nasolacrimal duct (not a sinus)

Middle meatus (major drainage pathway)

Frontal sinus via frontonasal duct/infundibulum
Maxillary sinus via ostium in semilunar hiatus
Anterior ethmoidal cells (into infundibulum/frontonasal duct)
Middle ethmoidal cells (onto/near ethmoidal bulla)

Superior meatus

Posterior ethmoidal cells

Sphenoethmoidal recess

Sphenoidal sinus

Sources: Gray’s Anatomy for Students, p. 1215, 1218-1219; Color Atlas of Human Anatomy Vol. 2, p. 184-186

Key diagrams

If you want, I can also provide this as a one-page exam table (columns: structure, epithelium, function, drainage site).

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