Paranasal sinus drainage in Nasal cavity : Mnemonic

Lateral wall of nasal cavity has:

1. Conchae or turbinates: shelf like projections
2. Meatus: air space inferior to each concha

Mnemonic: SPIN

1. Superior meatus: Posterior ethmoidal sinus

2. Inferior meatus: Nasolacrimal duct

The sphenoidal sinus drains into spheno-ethmoidal recess (superior to superior concha).

All others drain into middle meatus:

Mnemonic: AM/FM

1. Anterior ethmoidal sinus
2. Middle ethmoidal sinus
3. Frontal sinus
4. Maxillary sinus