CHAPTER 15: Special Senses

The sensory neurons within the olfactory organ are stimulated by _____ in the air.

chemicals

olfactory glands

coat the olfactory epithelium with a pigmented mucus.

Some neural tissues retain stem cells and thus the capacity to divide and replace lost neurons. Which of these special senses can replace its damaged neural receptors?

Olfaction

Olfactory receptors send axons through the cribriform plate. They synapse on neurons in the

Olfactory bulb

Axons leaving the olfactory epithelium collect into ___ or more bundles that penetrate the cribriform plate of the ethmoid.

20

How would a molecule that mimics cAMP NOT affect an olfactory receptor?

It would decrease sodium permeability

Olfactory organs are located in the nasal cavity inferior to the perforated bony structure known as the

cribriform plate

Each gustatory cell extends ___(or taste hairs) into the surrounding fluids through narrow taste pore

microvilli

the sense of taste is also known as

gustation

An adult has approximately _____ taste buds, each of which contains ____ different receptor cells

5,000 ; 40-100

Which of the following is NOT one of the six primary taste sensations?

Peppery

The taste sensation that is triggered by amino acids and small peptides is known as

umami

the largest numbers of taste buds in adults are associated with the

circumvallate papillae

Taste buds are monitored by cranial nerves

VII, IX, and X

A patient who experienced head trauma has lost the ability to taste spicy food. You should expect damage to cranial nerve

V.

Stimulation of nociceptive receptors within the trigeminal nerve might produce a perception of

Peppery hot

The membrane proteins that respond to chemical stimuli to produce sweet, bitter, and umami sensations are called

gustducins

The palpebrae do not

produce tears

the palpebrae are connected at the

lateral and medial angles of the eye

A structure that is located at the medial angle of the eye and contains glands that contribute to a gritty deposit is the

lacrimal caruncle

All of the following is a function of tears EXCEPT

maintains acidic environment

The opening in the iris through which light passes is the

pupil

______ glands are modified sebaceous glands located along the margin of the eyelid that secrete a lipid-rich product.

Tarsal

The gap that separates the free margins of the upper and lower eyelids is the

palpebral fissure

pupillary muscle groups are controlled by the ANS. Parasympathetic activation causes pupillary _____, and sympathetic activation causes ______.

constriction; dilation

what structure changes the shape of the lens for far and near vision?

ciliary body

A sudden rise of room brightness would cause

contraction of the pupillary constrictor muscles.

A ray of light entering the eye will encounter these structures in which order?

cornea -- aqueous humor -- lens -- vitreous body -- retina -- choroid

The ciliary muscle contracts to

adjust the shape of the lens for close vision.

why do things look blurry underwater without dive googles or a mask?

Rather than air, light is moving from water into the cornea and is thus refracted too little for a sharp focus

In which of the following cases would the focal distance be greater?

A. An object 10 inches away from your nose

B. An object 20 feet away

C. It doesn't matter, focal distance does not change with how far away an object is.

An object 10 inches away from your nose.

In which of the following cases would the focal distance be greater?

A. A round lens

B. A flat lens

C. It doesn't matter, focus distance doesn't change with the shape of the lens.

A flat lens

______ cells connect photoreceptors to ganglion cells.

Bipolar

_______ are photoreceptor cells that are most useful in dim light.

Rods

______ are photoreceptors cells that convey our ability to see color.

Cones

An elongated outer layer containing membranous discs and a narrow connecting a stalk that attaches the outer segment to the middle layer describes a(n).

Photoreceptor

The visible spectrum for humans extends between a wavelength of 400 nm and _____ nm.

700

There are three different types of cones, each one sensitive to different light energies. These cones are designated

Red, green, and blue

A ______ is a basic unit or packet of light energy.

Photon

The visual receptors of the retina are called

Photoreceptors

When all three cone populations are stimulated equally, we perceive

white

visual pigments are derivatives of the compound

rhodopsin

A pigment synthesized from vitamin A is

retinal

the first step in the process of photoreception is

absorption of a photon by a visual pigment.

The following steps occur in rods when they are excited by photons of light.

1. Ganglia cells detect changes in bipolar cell activity.

2. Neurotransmitter release changes.

3. Retinal changes to a more linear form

4. Rhodopsin breaks down (bleaches)

5. Opsin changes the membrane permeability of the outer segment to Na+

6. Opsin activation occurs.

What is the proper sequence for these steps?

3, 6, 5, 2, 1, 4

In the retina, the correct sequence of neural wiring is

Rod -- bipolar cell -- ganglion cell -- thalamus

A person suffering from ____ can see objects that are close, but close, but distant objects appear blurred.

Myopia

A person suffering from ___ can see distant objects more clearly than those that are close.

Hyperopia

The senses of equilibrium and hearing are provided by receptors of the

internal ear

When an external force bends the stereocilia of the inner ear hair cells,

there is a change in the transmembrane potential of the hair cells.

Which of the following anatomical sequences is correct?

tympanum -- malleus -- incus -- stapes -- oval window -- round window

Movement of the endolymph in the semicircular canals

Signals rotational movements.

Perception of gravity and linear acceleration depends on

the force exerted by otoliths on hair cells of the maculae in the utricle or saccule

The ______ convey(s) information about head position with respect to gravity.

Utricle and saccule

Which of the following descriptions best matches the term stereocilia?

bending these produces receptor potential in hair cells

The quantity of neurotransmitter that is release by a hair cell corresponds to all of the following EXCEPT

is greatest when the hair cells is at a neutral position.

The following is a list of the steps that occur in the production of an auditory sensation.

1. the pressure wave distorts that basilar membrane on its way to the round window.

2. movement of the tympanic membrane causes displacement of the malleus

3. Displacement of the stereocilia stimulates sensory neurons of the cochlear nerve.

4. Movement of the malleus causes movement of the incus and stapes

5. Distortion of the basilar membrane forces the hair cells of the organ of Corti toward or away from the tectorial membrane.

6. Movement of the oval window establishes pressure waves in the perilymph of the vestibular duct.

What is the proper sequence for these steps?

2, 4, 6, 1, 5, 3

A sound with a frequency of 12,000 hertz would be

high-pitched

Interference with the transfer of vibrations from the tympanic membrane to the oval window is ______ deafness.

conductive

Compare olfactory receptors with receptors for the other special senses.

Olfactory receptors are the dendrites of specialized excitable olfactory neurons, whereas the receptors for the other special senses are receptor cells with inexcitable membranes and form synapses with the processes of sensory neurons.

Trace the olfactory pathway, beginning at the olfactory epithelium

Axons from the olfactory epithelium bundle together and synapse at the olfactory bulb. Axons from the olfactory bulb travel along the olfactory tract to the olfactory cortex, hypothalamus, and portions of the limbic system.

Trace the gustatory pathway from the taste receptors to the cerebral cortex.

taste receptors -- facial, glassopharyngeal, and vagus nerves -- synpase in the solitary nucleus of the medulla oblongata -- medial lemniscus -- synapse in the thalamus -- gustatory cortex of the insula

Identify the accessory structures of the eye.

Eyelids, eyelashes, the superficial epithelium of the eye, and structures associated with the production, secretion, and removal of tears

Name the three layers of the eye.

Outer fibrous layer, middle vascular layer, deep inner layer

What happens to the pupils when light intensity decreases?

The pupils dilate to let in more light

When the ciliary muscles are relaxed, are you viewing something close up or something in the distance?

something in the distance?

What is the eye's blind spot?

optic disc

compare rods with cones

Rods are active in dim light, and objects appear black and white. Cones require intense light, and objects appear in color.

Define optic radiation

bundles of projection fibers linking the lateral geniculate bodies of the thalamus with the visual cortex in each cerebral hemisphere.

which type of lens would correct hyperopia?

Converging lens (with at least one convex surface)

Identify the structures of the bony labyrinth

semicircular canals, vestibule, and cochlea

When the basilar membrane moves, what happens to the hair cells of the spiral organs?

They press against the tectorial membrane

Where are the hair cell receptors for equilibrium located?

Vestibule and semicircular ducts

What is your reflexive response to hearing a loud noise, such as a firecracker?

turn your head and eyes toward the source of the noise

Which cranial nerves provide taste sensations from the tongue?

Cranial nerves VII, IX, and X