1. Sense of Smell Olfactory System

2. SMELL Smell is the most primitive sense Evokes memories Most animals use smell to distinguish good from bad In humans, this function has shifted to our emotions and helps us determine LIKES and DISLIKES

3. SMELL Humans’ sense of smell is weak compared to other animals We don’t NEED it as much Smell also undergoes sensory adaptation: you get used to smells and don’t notice them if you have been exposed for a long time

4. SMELL Women generally have a better sense of smell than men Smell is sharpest between ages 20 and 40

5. PHEROMONES Chemicals used to communicate Undetectable molecules secreted by glands or in urine that can have effects on OTHER animals’ behaviors Provide information about an animal’s identity, health, whether it is sexually receptive, etc.

6. PHEROMONES VNO sends these pheromone messages to the brain Humans have a VNO, but scientists are not sure how much we actually communicate with pheromones