Question 1

Which of the following best describes the process by which an odorant molecule leads to the generation of an action potential in an olfactory sensory neuron?

Accepted Answer

Odorant binds to receptor, activating a G protein, which then activates adenylate cyclase to convert ATP to cAMP. cAMP opens cation channels, allowing Na$$^+$$ and Ca$$^{2+}$$ influx, causing depolarization.

Question 2

Which cranial nerve is primarily responsible for transmitting taste information from the anterior two-thirds of the tongue?

Accepted Answer

Facial nerve (VII)

Question 3

A patient presents with a loss of smell following a head injury. Which structure is most likely damaged, resulting in anosmia?

Accepted Answer

Filaments of the olfactory nerve (cranial nerve I)

Question 4

Which of the following statements about olfactory receptor cells is TRUE?

Accepted Answer

Each olfactory receptor cell expresses only one type of odorant receptor gene.

Question 5

Which of the following best explains why humans can distinguish thousands of different odors?

Accepted Answer

Each odorant can bind to multiple receptor types, and each receptor can bind multiple odorants, creating a combinatorial code.

Question 6

Which of the following is NOT a basic taste sensation detected by taste buds?

Accepted Answer

Spicy

Question 7

A person with a blocked nose reports that food tastes bland. This is best explained by which of the following?

Accepted Answer

Olfactory input contributes significantly to flavor perception, accounting for about 80% of taste.

Question 8

Which of the following best describes the role of mitral cells in the olfactory pathway?

Accepted Answer

They are second-order neurons that amplify, refine, and relay olfactory signals from the olfactory bulb to the cortex.

Question 9

Which of the following best explains the mechanism of salty taste transduction?

Accepted Answer

Na$$^+$$ ions enter gustatory epithelial cells directly, causing depolarization.

Question 10

Which of the following cranial nerves does NOT carry gustatory (taste) information?

Accepted Answer

Abducens nerve (VI)

Question 11

Which of the following best describes the adaptation of taste receptors?

Accepted Answer

Taste receptors adapt rapidly, with partial adaptation in 3–5 seconds and complete adaptation in 1–5 minutes.

Question 12

Which of the following is a correct sequence for the gustatory pathway from the tongue to the cortex?

Accepted Answer

Taste bud → cranial nerve (VII, IX, or X) → solitary nucleus (medulla) → thalamus → gustatory cortex (insula)

Question 13

Which of the following best explains why bitter taste receptors have the lowest threshold for activation?

Accepted Answer

Many bitter substances are potentially toxic, so high sensitivity provides a protective mechanism.

Question 14

Which of the following is TRUE regarding the regeneration of olfactory neurons?

Accepted Answer

Olfactory neurons are replaced every 30–60 days by stem cells in the olfactory epithelium.

Question 15

Which of the following best describes the role of the glomerulus in the olfactory bulb?

Accepted Answer

It is a structure where axons of sensory neurons with the same receptor type converge and synapse with mitral cells.

Question 16

Which of the following best explains the mechanism of sour taste transduction?

Accepted Answer

H$$^+$$ ions enter gustatory epithelial cells and open cation channels, allowing other cations to enter and depolarize the cell.

Question 17

Which of the following is a function of the salivary glands in taste perception?

Accepted Answer

They secrete saliva, which acts as a solvent to dissolve tastants and facilitate their interaction with taste buds.

Question 18

A patient experiences olfactory hallucinations (phantosmia) before an epileptic seizure. Which brain region is most likely involved?

Accepted Answer

Temporal lobe (olfactory cortex)

The Chemical Senses: Smell (Olfaction) and Taste (Gustation)

Study Guide - Practice Questions

Study Guide - Flashcards