1. Other Senses: Outline Balance (Vestibular System) Taste Smell Touch

2. Balance Three sources of balance: –Vision –Stretch receptors in muscles –Vestibular system Worst case scenario: –getting up in the middle of the night (no vision), from your futon (poor info from stretch receptors), in a yacht (poor vestibular info).

3. Balance Coordinates head & body movements Keep eyes fixed when head moves Semicircular Canals Rotations (3-D) Dizziness is triggered -By rotation (kids) -By hot water in ear: stimulates movement of fluid in vestibular chambers -vertigo Vestibular System: Functions

4. Vestibular Sacs: Function –linear accelerations –static head positions From inner ear, output goes to Medulla & from there to: - Spinal Cord, - Oculomotor Nerve, - Cortex, - Cerebellum

5. Flavor is inferred from: –Taste (5) – Smell (500-10,000 odors), and –Tactile information, & pain receptors (chili peppers) Supertasters –Genetic differences in receptors –Increased sensitivity to bitterness, sweet Taste

6. Taste Receptors Papillae Bitter Sweet Sour: Saltiness: Na+ channel Umami –elicited by the amino acid glutamate found in proteins (meat, fish, beans, ketchup) –MSG (monosodium glutamate)

7. Taste Pathway Orbitofrontal cortex (S2) Amygdala Post central gyrus and Insula (S1) Thalamus Medulla Cranial nerves Amygdala & OFC are important for valence, reinforcement

8. Olfactory System The primary mode of communication for most animals Critical for survival –eating toxic substances often smell/taste bad; good things smell good –reproduction mating partners aggression in rivals –location of predators and prey

9. Olfactory Anatomy Olfactory tract projects to –amygdala, –hippocampus –hypothalamus –Insula

10. Pheromones Airborne molecules that affect behavior Especially involved in reproduction VNO- Vomeronasal Organ –Physically distinct –evolved separately –Projects to Limbic areas VNO

11.  Somatosenses  The stimuli  The cutaneous senses respond to several different types of stimuli: pressure, vibration, heating, cooling, and events that cause tissue damage (and hence pain).  Some receptors report changes in muscle length to the brain; providing our sense of kinethesia.  Additional receptors provide information about the internal organs such as the linings of muscles and the gastrointestinal system.

12.  Somatosenses  Anatomy of the Skin and its Receptive Organs  Cuntaneous sense:  One of the somatosenses; includes sensitivity to stimuli that involve the skin.  Kinesthesia:  Perception of the body’s own movements.  Organic sense:  A sense modality that arises from receptors located within the inner organs of the body.