The Other Senses

1. The Other Senses Smell Taste Kinesthetic and Vestibular Sensations of Motion Skin Senses Pain

2. Smell • Parts of the nose are directly connected to the amygdala and hippocampus • Smell often plays a large part in determining our likes and dislikes • Anyone remember the facial expression associated with disgust? • Animals with the best sense of smell walk on all fours • Their heads are close to the ground! Yuck! Another smelly diaper…

3. Odorant binding protein (OBP) Produced in nasal gland Activates sense of smell Olfactory epithelium Patch of tissue in each nasal cavity where receptors are located OBP is sprayed through a duct at tip of nose that binds with airborne molecules Olfactory bulb Recodes information from the axons in the epithelium SMELL CENTER OF THE BRAIN From here information travels along the olfactory tract to the temporal lobe and brain core How does your sense of smell adapt? Detecting Common Odors

4. Human Olfactory System Axons from receptors carry nerve impulse to olfactory bulb Olfactory bulb transmits impulses to the brain Molecules from flower reach receptor cells high in nasal cavity

5. VNO activates hypothalamus and amygdala Involved with reproduction and defensive behavior Pheromones can help us distinguish another animal’s identity and level of stress Hamsters use pheromones to avoid aggressive and sexial contact with family! Pheromones Chemical molecule that communicates information to other members of a species and influences behavior Stimulate receptors in the vomeronasal organ (VNO) VNO then sends messages to another olfactory bulb Communicating with Pheromones

6. Humans are omnivores - we eat anything Girls, I’m not just talking about guys Taste vs. flavor Taste can be detected with just the tongue Flavor involves not only the tongue, but also our nose Taste buds Each taste bud contains a cluster of receptor cells These cells die and are replaced every 7 days! Locate in the tongue’s papillae (those small bumps on your tongue) Taste Can you explain grow your sense of taste adapts?

7. Vestibular senses - sense of equilibrium and body position (orientation) Originate in the semicircular canals - fluid provides messages about speed and direction of body rotation Movement of fluid in the vestibular sacs provides information about movement forward, backward, up, and down Kinesthetic senses - relay information about muscle movement, posture, and strain on muscles and joints Stretch receptors - specialized nerve endings attached to muscle Golgi tendon organs - receptors attached to tendons (connect muscle to bone) Information is constantly relayed to the parietal lobes through the spinal cord Kinesthetic and Vestibular

8. Sensations of Motion • Awareness of vestibular senses • Can you think of a time when you notice your vestibular senses? • Motion sickness - our senses send contradictory information to our brain

9. Our skin is our largest sense organ Numerous nerve receptors Input travels to the parietal lobe and reticular formation by way of the medulla and thalamus Skin senses can be influenced be expectations Is there a difference between tickling yourself and being tickled by a friend? Like your other sensory organs, skin adapts As you sit in a hot bath it begins to feel tolerable The larger the area being stimulated, the longer adaptation takes The Skin Senses

10. Pain • Pain is a warning signal • Individual differences in pain threshold • Gate control theory - a “neurological gate” in the spinal cord controls the transmission of pain messages to the brain • Individual difference due to numbers of small vs. large fibers in spinal cord • Biopsychological theory - interaction of biological, psychological, and cultural factors influence the intensity and duration of pain • Individual differences depend on past experiences, our beliefs, and personality • Pain management - acupuncture and hypnosis • Placebo effect