Many tiny hair-like cilia protrude from the olfactory receptor cell's dendrite into the mucus covering the surface of the olfactory epithelium. The surface of these cilia is covered with olfactory receptors, a type of G protein-coupled receptor.
Respiration -10 to 30. The normal respiratory rate for dogs is 16 to 20 breaths per minute. The normal heartrate is 70 to 160 bpm. Large dogs tend to have slower heart rates so your dog should be in the 70 to 120 bpm range. This varies according to the cardiovascular fitness of the dog, too.
The dog respiratory rate may be influenced by a number of factors, but the average respiratory rate of the pet is considered to be 24 breaths every minute. Knowing your dog's normal range of breaths per minute is important, so that you can detect if he is ill.