BIO 264 Olfactory Quiz

A

Which of the following is NOT a step in odorant binding to an olfactory hair membrane? A) IP3 is released by PLC and this causes an influx of Ca++ B) An associated G protein is activated as an odorant binds to a receptor C) ATP is converted to cyclic AMP (cAMP) D) Ion channels are opened due to presence of cAMP and depolarize the neuron

A

A "less than brilliant" teenager tried to sniff some glue for a cheap thrill. A spark caught the fumes on fire and he burned his olfactory epithelium. Which of the following are TRUE? A) If enough Basal cells survived he may retain his sense of smell B) Mitral and Tuft cells are likely gone C) The intermediate olfactory area is likely burned D) The G protein receptors that attach to odorants are likely uninvolved

B

Damage occurs to some of the olfactory neurons of a person's nasal cavity. What will result from this damage? A) The olfactory neurons degenerate and they will not be replaced. B) The olfactory neurons degenerate and new olfactory neurons will replace them. C) Apoptosis will occur causing a massive amount of tissue damage.

C

Gary walks into the house and senses a strong odor of fish. When he asks his roommate about it, the roommate is surprised—he had fish for lunch over an hour ago and doesn't smell it anymore. Based on your knowledge of olfaction, what is the most reasonable answer to Why does the roommate not smell the fish when Gary does? A) Gary has an extra-sensitve sense of smell B) the roomate has a cold C) the odorant receptors of the roommate have become saturated so the receptors no longer respond D) Gary's odorant receptors have a higher specificity in the olfactory epithelium than the roommmate's

A

Hospitals can have unpleasant smells in them that medical professionals and patients eventually tolerate. What allows a person to adapt to these unpleasant smells? A) saturation of odorant receptors by the odorant B) downregulation of odorant receptors of the olfactory neuron C) release of odorant receptor inhibitors D) release of enzymes that destroy odorant receptors

C

If the olfactory bulb is in the cranial cavity, how does the neuron interact with the olfactory epithelium? A) The odorants pass through the epithelium and then synapse with the synaptic ends of the olfactory bulbs B) The dendrites of the olfactory neurons extend through small formina in the cribriform plate C) The olfactory neurons have axons that project through small formina in the cribriform plate D) None of the above. The olfactory bulb is part of the olfactory epithelium and is NOT located in the cranial cavity

C

N.O. Spicker received an olfactory mutation from his father that causes adenylyl cyclase to be constantly active. Select the answer(s) that best reflects the consequences of this mutation. 1. N.O.'s olfactory neurons are always permeable to Na+ and Ca++ ions 2. N.O.'s olfactory neurons are never permeable to Na+ and Ca++ ions 3. N.O.'s brain receives a constant stream of action potentials whether his receptors are stimulated or not 4. G-protein coupled receptors on N.O.'s olfactory neurons are nonfunctional A) 1,4 B) 2,3 C) 1,3 D) 1,3,4 E) 2,3,4

A

Neurons beginning from the olfactory bulb travel through the olfactory tract and synapse at the: Correct Answer A) olfactory cortex B) intermediate olfactory area C) thalamus D) parietal lobe

B

P.U. Lotts is depressed. She has the worst B.O. None of the guys seem to want to date her (more than once). But she is hopeful now because she is being set up on a blind date and this new guy is rumored to have a very poor sense of smell. Which of the following is something that will LIKELY decrease the ability of this guy to smell P.U. ? A) Damage to Cranial Nerve VIII B) Inability to activate adenylate cyclase C) Damage to the thalmus D) Actually, all of the above will make it more difficult to smell odors

B

Pertaining to olfaction, once the odorant binds to a odorant receptor it will cause the activation of a G protein to activate adenylate cyclase. This enzyme helps to form cAMP which will: A) open potassium channels. B) open sodium or calcium channels. C) produce ATP. D) produce protein kinase.

C

Sensory receptors that are stimulated by odor are located A) extreme inferior region of the nasal cavity B) in the epithelial lining over the entire region of the nasal cavity C) extreme superior region of the nasal cavity D) in the cerebral cortex of the brain

B

The entire olfactory epithelium degenerates and is lost from the surface approximately A) every 10 days B) every 2 weeks C) every 2 months D) never, the epithelium is unique in that it doesn't regenerate

D

The olfactory epithelium lines this part of the respiratory system: A) Hard palate B) Nasopharynx C) Vestibule D) Olfactory region

C

This type of cell contains olfactory receptors that can bind to odorants once they are dissolved in solution. This cell type is known as: A) Support cells B) Basal cells C) Olfactory neurons D) Brush cells

C

Which cell type does NOT contribute to the olfactory epithelium? A) Basal cell B) Supporting cell C) Gustatory cell D) Olfactory neuron

B

Which is the only major sensation that is relayed directly to the cerebral cortex without first passing through the thalamus? A) taste B) smell C) sight D) touch

D

Which is true about the olfactory epithelium A) This tissue is found in the posterior / superior cavity of the nasal passages B) olfactory neurons are found in this layer C) support cells and olfactory neurons come from basal cells in this layer D) Actually all of the answers are correct

C

Which of the following words related to initial olfactory stimulation would occur last? A) Stimulation of G-protein receptor B) Activation of Adenylyl cyclase C) Release of Neurotransmitters D) Inflow of Na+ and Ca++ ions

E

Which of these statements is TRUE with respect to olfaction? A) Olfactory sensation is relayed directly to the cerebral cortex without passing through the thalamus. B) Olfactory neurons are replaced about every 2 months. C) The olfactory cortex is involved in the conscious perception of smell. D) The medial olfactory area of the cortex is responsible for visceral and emotional reactions to odors. E) All of the statements are actually true for olfaction.

B

Which statement best describes the main difference between olfactory receptor neurons and most other neurons? A) Olfactory receptor neurons possess G-protein coupled receptors B) Olfactory receptor neurons are capable of regeneration C) Olfactory receptor neurons synapse directly with the frontal lobe of the brain D) Olfactory receptor neurons must synapse with an epithelial receptor cell in order to process external stimuli