- Anatomy and medicine
- Nares, the plural of naris (Latin) nostril; the scientific term for many animal, and specifically bird, nostrils納雷斯，納麗絲（拉丁）鼻孔的複數; 科學術語為許多動物，特別是鳥，鼻孔
- Anterior nares, the external or frontal part of the nasal cavity, significant in rhinoplasty and infection (especially Methicillin-resistant Staphylococcus aureus (MRSA) or antibiotic-resistant Staphylococcus)前鼻孔，鼻腔的外部或正面部分，在鼻整形術和感染（特別是耐甲氧西林金黃色葡萄球菌（MRSA）或抗生素抗性葡萄球菌）中顯著，
A nostril (or naris //, plural nares //) is one of the two channels of the nose, from the point where they bifurcate to the external opening. In birds and mammals, they contain branched bones or cartilages called turbinates, whose function is to warm air on inhalation and remove moisture on exhalation. Fish do not breathe through their noses, but they do have two small holes used for smelling, which may, indeed, be called nostrils.
The Procellariiformes are distinguished from other birds by having tubular extensions of their nostrils.
In humans, the nasal cycle is the normal ultradian cycle of each nostril's blood vessels becoming engorged in swelling, then shrinking.
The nostrils are separated by the septum. The septum can sometimes be deviated, causing one nostril to appear larger than the other. With extreme damage to the septum and columella, the two nostrils are no longer separated and form a single larger external opening.
Like other tetrapods, humans have two external nostrils (anterior nares) and two additional nostrils at the back of the nasal cavity, inside the head (posterior nares, posterior nasal apertures or choanae). Each choana contains approximately 1000 strands of nasal hair. They also connect the nose to the throat (the nasopharynx), aiding in respiration. Though all four nostrils were on the outside the head of our fish ancestors, the nostrils for outgoing water (excurrent nostrils) migrated to the inside of the mouth, as evidenced by the discovery of Kenichthys campbelli, a 395-million-year-old fossilized fish which shows this migration in progress. It has two nostrils between its front teeth, similar to human embryos at an early stage. If these fail to join up, the result is a cleft palate.
It is possible for humans to smell different olfactory inputs in the two nostrils and experience a perceptual rivalry akin to that of binocular rivalry when there are two different inputs to the two eyes.
甲鼻孔（或鼻孔 / /時，多個鼻孔 / /）是的兩個通道中的一個鼻子，從那裡它們分叉到外部開口的點。在鳥類和哺乳動物中，它們含有稱為鼻甲的分支骨或軟骨，其功能是在吸入時加熱空氣，並在呼氣時除去水分。魚不能通過鼻子呼吸，但他們確實有兩個小孔用於嗅覺，其實可以稱為鼻孔。