ANATOMY Unit 2 NOTES: Taste, Touch, Smell

(1) Smell Smell is the binding of organic molecules to receptors deep within the nose. Your nose is lined with olfactory receptors… Air flows in carrying organic molecules Organic molecules dissolve in mucus lining Organic molecules bind to receptors Impulse sent through Olfactory Nerve

(2) Taste Taste is the binding of molecules to receptors on tongue. Tongue is covered in papillae projections, covered in “taste buds” or gustatory cells: Organic Molecules dissolve in saliva Molecules bind to gustatory cells Impulse sent to brain

(3) Taste Regions on Tongue Sweet: Receptors bind with monosaccharides and amino acids Location: Front & Center of Tongue Sour: Receptors bind with hydrogen ions (acid) Location: Sides of Tongue Salty: Receptors bind with metal ions Location: Front & Sides of Tongue Bitter: Receptors bind with alkaloids (typically nitrogenous) Location: Very Back of Tongue

(4) Touch Touch = Pressure against skin Skin contains pressure + temperature receptors… Meissner’s Receptors = Super Sensitive Palms, Feet, Lips, Eyelids Minimal pressure needed Paccinian Receptors = Deep Receptors Pressure + Vibration Nociceptor Receptors= Sense Pain Most Abundant on body Thermoreceptors = Sense Temperature Individual neurons for hot and for cold Increase nerve impulses with changes in temperature