Vertebrate Physiology Study Guide
Vertebrate Physiology Study Guide
Last Part of Chapter 10
□ Cilia are specialized for odor detection (They have receptors and second messenger machinery
□ Mucus from the olfactory glands traps odorants
□ Linda Buck identified a large family of odorant receptor genes in rats(1,000 types); belong to the G protein associated 7-transmembrane receptor family
□We only have 400 odorant receptors; the olfactory system appears to use combinations of receptors(words) to greatly reduce the number of actual receptor types(letters) required to convey a broad range of odors(vocabulary)
□Activation of channels: Golf protein activates adenylyl cyclase; this causes an increase in intracellular cAMP; cAMP binds to and rapidly opens a cation-selective channel(Na+, K+, Ca++) from the inside; these are known as cyclic nucleotide gated (CNG) channels; this activity depolarizes the cell.
□ Olfactory receptor neurons--> olfactory bulb
Frontal cortex
Conscious
Perception of smell
Hypothalamus
Amygdala
Motivational and
Emotional aspects of
Smell
Hippocampus
Odor Memory
□ Five Tastes: sweet, salty, bitter, sour, and recently umami(flavor of meat--sensitive to MSG
□ Molecules are tasted by taste buds which are located in papillae on the tongue; each taste bud has an opening called a taste pore; each taste pore contains 50-100 taste cells along with supporting and basal cells; these extend gustatory hair or microvilli into the pore where transduction occurs; the taste cells are innervated by the gustatory nerve □ Taste cells are nonneural--they contain voltage gated Na+, K+, and Ca++ channels which can generate AP’s
□Genetic elimination of ionotropic purinergic receptors (P2X2 and P2X3) eliminates taste responses in the taste nerves; nerves remain responsive to touch, temperature, and menthol
□Knockouts have greatly reduced responses to sweetners, glutatmate, and bitter substances
□Salty: Na+ ions in salty food enter Na+ channels and cause depolarization
Last Part of Chapter 10
□ Cilia are specialized for odor detection (They have receptors and second messenger machinery
□ Mucus from the olfactory glands traps odorants
□ Linda Buck identified a large family of odorant receptor genes in rats(1,000 types); belong to the G protein associated 7-transmembrane receptor family
□We only have 400 odorant receptors; the olfactory system appears to use combinations of receptors(words) to greatly reduce the number of actual receptor types(letters) required to convey a broad range of odors(vocabulary)
□Activation of channels: Golf protein activates adenylyl cyclase; this causes an increase in intracellular cAMP; cAMP binds to and rapidly opens a cation-selective channel(Na+, K+, Ca++) from the inside; these are known as cyclic nucleotide gated (CNG) channels; this activity depolarizes the cell.
□ Olfactory receptor neurons--> olfactory bulb
Frontal cortex
Conscious
Perception of smell
Hypothalamus
Amygdala
Motivational and
Emotional aspects of
Smell
Hippocampus
Odor Memory
□ Five Tastes: sweet, salty, bitter, sour, and recently umami(flavor of meat--sensitive to MSG
□ Molecules are tasted by taste buds which are located in papillae on the tongue; each taste bud has an opening called a taste pore; each taste pore contains 50-100 taste cells along with supporting and basal cells; these extend gustatory hair or microvilli into the pore where transduction occurs; the taste cells are innervated by the gustatory nerve □ Taste cells are nonneural--they contain voltage gated Na+, K+, and Ca++ channels which can generate AP’s
□Genetic elimination of ionotropic purinergic receptors (P2X2 and P2X3) eliminates taste responses in the taste nerves; nerves remain responsive to touch, temperature, and menthol
□Knockouts have greatly reduced responses to sweetners, glutatmate, and bitter substances
□Salty: Na+ ions in salty food enter Na+ channels and cause depolarization