Module 7.3

Most theorists believe that the first sensory system was:

chemical

In adult humans, the taste buds are:

concentrated along the outside edge of the tongue.

How many kinds of olfactory receptors do we have?

hundreds

Analogous to lateral inhibition, when olfactory receptors are stimulated, they:

inhibit the activity of other receptors.

The primary taste cortex is known as the:

insular cortex

Each receptor responds to a limited range of stimuli and sends a direct line to the brain. This type of coding is referred to as :

labeled-line

Repeated exposure to male pheromones may be associated with ____ in young women who are not sexually active.

more regular menstrual cycles

The taste nerves initially project to the:

nucleus of the tractus solitarius

Olfactory receptors carry their message to the:

olfactory bulb.

Pheromone receptors in humans are located in the:

olfactory mucosa

Olfactory receptor sites are located:

on cilia

Many women living in a college dormitory will gradually begin to synchronize their menstrual cycles. The research indicates that this is, at least in part, based on:

pheromones

Olfaction also plays a subtle role in:

social behavior

A person who "sees" spoken language or music may be experiencing:

synesthesia

What are found in papillae?

taste buds

One reason why we have difficulty tasting low concentrations of a bitter chemical is that:

we have dozens of different types of bitter receptors

After soaking their tongues in a sour solution, what do most people experience?

Other sour substances taste less sour

How is olfactory information coded in receptor cells?

There are hundreds of types of receptor molecules, each responsive to a different chemical

After soaking your tongue in a sour solution you try tasting salty, sweet, and bitter substances. How are these tastes affected?

There will be little or no effect on these three tastes.

What is unusual about olfactory receptors compared to most other mature mammalian neurons?

They are replaceable when old neurons die.

The receptors for taste are not true neurons, but are actually modified skin cells. In what way are these cells like neurons?

They release neurotransmitters

One major difference between olfaction and VNO receptors is that:

VNO receptors do not adapt

Each receptor responds to a wide range of stimuli and contributes to the perception of each of them. This type of coding is referred to as:

across-fiber

Sweetness, bitterness and umami receptors operate by:

activating a protein which causes the release of a second messenger

Exposure to an extremely salty substance decreases sensitivity to other salty substances. What is this phenomenon called?

adaptation

Information carried to the brain along the chorda tympani comes from the:

anterior two-thirds of the tongue.

The receptors for taste are like skin cells in that they:

are continuously being replaced

Reduced response to one taste after exposure to another is referred to as:

cross-adaptation

Given a very faint odor of air freshener, who is most likely to detect it?

cycling female

Taste and smell axons converge onto many of the same cells in an area called the:

endopiriform cortex.

In mammals, each olfactory cell has threadlike dendrites that:

extend from the cell body into the mucous surface of the nasal passage

The vomeronasal organ (VNO) is a set of receptors located:

near, but separate from, the olfactory receptors

Chemicals that prevent sodium from crossing the membrane:

reduce the intensity of salty tastes

Taste perception in the brain depends on:

relative activity of different taste neurons

Pheromones are important for the ____ behaviors of many mammalian species.

sexual

Studies indicate that pheromones may play a role in humans':

sexual behaviors

We can identify a wide variety of bitter substances because:

we have many different bitter receptors

If you are a supertaster, then:

you are more sensitive than the average person to nearly all tastes