nasal sacs

na·sal sacs

the deepened nasal pits that develop into the definitive nasal cavities.
Farlex Partner Medical Dictionary © Farlex 2012

na·sal sacs

(nāzăl saks)
Deepened nasal pits that develop into definitive nasal cavities.
Medical Dictionary for the Dental Professions © Farlex 2012
References in periodicals archive ?
Scientists theorize that orcas force air between the nasal sacs and the blowholes to produce a range of sounds from 0.1 kilohertz to 40 kilohertz.
At an early age each dolphin adopts a personalized call--a unique whistle of rising and falling tones that emanates from nasal sacs below the blowhole (the single nostril atop a dolphin's head).