Anat Ch. 10 Part 4

Although a few taste buds are located in the lining of the mouth and on the soft palate, most are located on the sides of much larger and differing shaped bumps scattered across the tongue called papillae.About 10 to 15 large __ form an inverted "V" pattern at the back of the tongue and contain the most taste buds.

circumvallate papillae

After the olfactory cells are stimulated by odor-causing chemicals, the resulting nerve impulse travels through the olfactory neurons in the olfactory bulb and cranial nerve I and then enters the thalamic and olfactory centers of the brain, where the nervous impulses are interpreted as specific odors. The pathways taken by olfactory nerve impulses and the areas where these impulses are interpreted are closely associated with the __ of the brain, important in (2)__

limbic system; memory and emotion (seeChapter 9, p. 174).

We often combine the senses of equilibrium with __ and __ to maintain our posture and balance—thus maintaining a safe body position under changing circumstances.

vision; proprioception

After the olfactory cells are stimulated by odor-causing chemicals, the resulting nerve impulse travels through the olfactory neurons in the olfactory bulb and cranial nerve I and then enters the thalamic and olfactory centers of the brain, where the nervous impulses are interpreted as specific odors. The pathways taken by olfactory nerve impulses and the areas where these impulses are interpreted are closely associated with thelimbic system of the brain, important in memory and emotion (seeChapter 9, p. 174). For this reason,

we may retain vivid and long- lasting memories of particular smells and odors. The pleasant smell of bread or cookies baking in a grandmother's kitchen may be part of a childhood memory that lasts a lifetime.

Create and study figure 10-12 WS

(do it)

Create and sudy figure 1-13 WS

(do it)

The sense of smell, or olfaction, helps us detect certain chemicals in our environment. The __ responsible for olfaction are located in a small area of epithelial tissue in the upper part of the nasal cavity (Figure 10- 13).

chemoreceptors

We should also remind ourselves that some sensory information is processed and perceived subconsciously. (explain)

You cannot "feel" your blood pH go up or down, but your brain is constantly monitoring such changes. Likewise, you cannot state your current blood oxygen saturation—but your subconscious brain centers are getting signals about the precise level.

Looking at the "big picture" of sensation, we should remind ourselves that sensations are all perceived in the brain—not at the individual receptors scattered throughout the body. Some sensory signals never get to the brain, others are amplified or muffled in the brain. All incoming signals are integrated with other sensory signals, and even memories, to produce our perceptions, which are really a combined sensation of our world at that moment. For example, most of what we think of as flavor sensations result from

a combination of sensory stimuli detected by gustatory cells, olfactory receptors, and even touch and pain receptors. In other words, the myriad unique flavors we recognize are not just tastes alone, but are a combined sensation based on tastes, odors, touch, temperature, and pain.

Each taste bud, as you can see in Figure 10-12, B and C, opens into

a trenchlike moat that surrounds the papilla and is filled with saliva.

The olfactory receptors are extremely sensitive and respond quickly to even very slight odors. However, after a short time they develop a kind of fatigue and lose their ability to respond. This decrease in receptor sensitivity is called __ and explains why odors that are at first very noticeable are soon not sensed at all.

adaptation

Although a few taste buds are located in the lining of the mouth and on the soft palate, most are located on the sides of much larger and differing shaped bumps scattered across the tongue called papillae.About 10 to 15 large circumvallate papillae form

an inverted "V" pattern at the back of the tongue and contain the most taste buds.

Each olfactory cell has a number of sensory cilia that detect different chemicals and cause the cell to respond by generating a nervous impulse. To be detected by olfactory receptors, chemicals must

be dissolved in the watery mucus that lines the nasal cavity.

The sense of smell, or olfaction, helps us detect

certain chemicals in our environment.

Our sense of taste—or gustation—allows us to

chemically analyze food before we bite or swallow it.

Each olfactory cell has a number of sensory cilia that (2)

detect different chemicals and cause the cell to respond by generating a nervous impulse.

Our sense of taste—or __—allows us to chemically analyze food before we bite or swallow it.

gustation

The taste buds are the sense organs of taste. They contain both supporting cells and chemoreceptors called

gustatory cells.

The sense of smell, or olfaction, helps us detect certain chemicals in our environment. The chemoreceptors responsible for olfaction are located

in a small area of epithelial tissue in the upper part of the nasal cavity (Figure 10- 13).

Looking at the "big picture" of sensation, we should remind ourselves that sensations are all perceived (where)

in the brain—not at the individual receptors scattered throughout the body.

Looking at the "big picture" of sensation, we should remind ourselves that sensations are all perceived in the brain—not at the individual receptors scattered throughout the body. Some sensory signals never get to the brain, others are amplified or muffled in the brain. All incoming signals are __ to produce our perceptions, which are really a combined sensation of our world at that moment.

integrated with other sensory signals, and even memories,

Looking at the "big picture" of sensation, we should remind ourselves that sensations are all perceived in the brain—not at the individual receptors scattered throughout the body. Some sensory signals never get to the brain, others are amplified or muffled in the brain. All incoming signals are integrated with other sensory signals, and even memories, to produce our perceptions, which are really a combined sensation of our world at that moment. For example, most of what we think of as flavor sensations result from a combination of sensory stimuli detected by gustatory cells, olfactory receptors, and even touch and pain receptors. In other words, the myriad unique flavors we recognize are not just tastes alone, but are a combined sensation based on tastes, odors, touch, temperature, and pain. For this reason, severe nasal congestion can

interfere with the stimulation of the olfactory receptors by odors from foods in the mouth, which can markedly dull flavor sensations (see Figure 10-13). Some foods seem to have a different flavor if they are crispy or warm or cold. And some spicy foods stimulate pain or temperature receptors to produce a "hot" flavor. Some mints can produce a sensation of coolness that adds to our experience of flavor.

Physiologists originally counted only four "primary" taste sensations—sweet, sour, bitter, and salty—that permit us to detect sugars, acids, alkalines, and sodium ions dissolved in our saliva. However, the list of "primary" taste sensations has expanded to include several others present in most individuals. Currently, __ taste (to detect __) and a savory, meaty taste called __ (to detect __) have been added to the list of primary tastes.

metallic; metal ions; umami; the amino acid glutamate

The olfactory receptors are extremely sensitive and respond quickly to even very slight odors. However, after a short time they develop a kind of fatigue and lose their ability to respond. This decrease in receptor sensitivity is called adaptation and explains why

odors that are at first very noticeable are soon not sensed at all.

The sense of smell, or __, helps us detect certain chemicals in our environment.

olfaction

After the olfactory cells are stimulated by odor-causing chemicals, the resulting nerve impulse travels through the olfactory neurons in the __ and __ and then enters the thalamic and olfactory centers of the brain, where the nervous impulses are interpreted as specific odors.

olfactory bulb; cranial nerve I

The sense of smell, or olfaction, helps us detect certain chemicals in our environment. The chemoreceptors responsible for olfaction are located in a small area of epithelial tissue in the upper part of the nasal cavity (Figure 10- 13). The location of the __ is somewhat hidden, and we must often forcefully sniff the air to smell delicate odors.

olfactory receptors

Although a few taste buds are located in the lining of the mouth and on the soft palate, most are located

on the sides of much larger and differing shaped bumps scattered across the tongue called papillae.

Smell sensations, even more than other modes of sensation, are often powerful triggers of memory. Yet all sensations are compared to

our learned memories, which help us accurately interpret what we are sensing at any one moment.

Although a few taste buds are located in the lining of the mouth and on the soft palate, most are located on the sides of much larger and differing shaped bumps scattered across the tongue called

papillae.

Each taste bud, as you can see in Figure 10-12, B and C, opens into a trenchlike moat that surrounds the papilla and is filled with

saliva.

Each olfactory cell has a number of __ that detect different chemicals and cause the cell to respond by generating a nervous impulse.

sensory cilia

Lastly, we should not forget that senses do eventually

start to fail us as we age. Mechanoreceptors in our ears become less sensitive, our lenses become less able to adjust our visual focus, and we slowly lose taste and smell function. This may explain why some foods "just do not taste the same" as they did when we were younger.

The taste buds are the sense organs of taste. They contain both

supporting cells and chemoreceptors called gustatory cells.

Physiologists originally counted only four "primary" taste sensations—(and what they detect)

sweet, sour, bitter, and salty—that permit us to detect sugars, acids, alkalines, and sodium ions dissolved in our saliva. However, the list of "primary" taste sensations has expanded to include several others present in most individuals.

The __ are the sense organs of taste.

taste buds

After the olfactory cells are stimulated by odor-causing chemicals, the resulting nerve impulse travels through the olfactory neurons in the olfactory bulb and cranial nerve I and then enters the __ and __ centers of the brain, where the nervous impulses are interpreted as specific odors.

thalamic; olfactory

Each taste bud, as you can see in Figure 10-12, B and C, opens into a trenchlike moat that surrounds the papilla and is filled with saliva. Chemicals dissolved in the saliva stimulate

the chemoreceptor gustatory hairs.

Although a few taste buds are located in the lining of the mouth and on the soft palate, most are located on the sides of much larger and differing shaped bumps scattered across the tongue called papillae.About 10 to 15 large circumvallate papillae form an inverted "V" pattern at the back of the tongue and contain

the most taste buds.

After the olfactory cells are stimulated by odor-causing chemicals, the resulting nerve impulse travels through the olfactory neurons in the olfactory bulb and cranial nerve I and then enters the thalamic and olfactory centers of the brain, where

the nervous impulses are interpreted as specific odors.

The taste buds are the sense organs of taste. They contain both supporting cells and chemoreceptors called gustatory cells. These cells generate

the nervous impulses ultimately interpreted by the brain as taste (Figure 10-12).

Each taste bud, as you can see in Figure 10-12, B and C, opens into a trenchlike moat that surrounds the papilla and is filled with saliva. Chemicals dissolved in the saliva stimulate the chemoreceptor gustatory hairs. Nervous impulses that are generated by stimulation of taste buds travel primarily through two cranial nerves (VII and IX) to end in

the taste area of the cerebral cortex.

After the olfactory cells are stimulated by odor-causing chemicals, the resulting nerve impulse travels

through the olfactory neurons in the olfactory bulb and cranial nerve I and then enters the thalamic and olfactory centers of the brain, where the nervous impulses are interpreted as specific odors.

Each taste bud, as you can see in Figure 10-12, B and C, opens into a trenchlike moat that surrounds the papilla and is filled with saliva. Chemicals dissolved in the saliva stimulate the chemoreceptor gustatory hairs. Nervous impulses that are generated by stimulation of taste buds travel primarily through

two cranial nerves (VII and IX) to end in the taste area of the cerebral cortex.