Chapter 16

Changes in the external and internal environment are ________ that are detected by the sensory system.

Stimuli

Conscious awareness of incoming sensory information is called

Sensation.

By definition, transducers

Change one form of energy into another form.

Which statement accurately describes the merits of different receptive field properties?

Having small receptive fields allow for more precision, but since more receptors are needed it increases overall energy costs.

Our ability to precisely locate a stimulus is ________ proportional to receptive field size.

Inversely

The entire area through which the sensitive ends of the receptor cells are distributed is the:

Receptive field.

If the receptive fields of the skin's receptors were smaller, then

Precision would be greater, but we would need more receptors to monitor the environment for stimuli.

The type of receptor that readily adapts to a stimulus is known as a ________ receptor

Phasic

In general, you become unaware of the shirt on your back because your touch receptors

Undergo adaptation.

A reduction in sensitivity to a continually applied stimulus is called

Adaptation.

Which of the following is not one of the three criteria used to describe receptors?

Stimulus strength (intensity of stimulus)

The classification of a receptor as a photoreceptor or a mechanoreceptor depends on

The modality of the stimulus it perceives.

Which term best describes receptors that detect stimuli from the external environment?

Exteroceptors

Which term best describes receptors that detect stimuli from internal organs?

Interoceptors

Which term best describes receptors that detect body and limb movements, skeletal muscle contraction and stretch, and joint capsule structure?
A. Interoceptors
B. Exteroceptors
C. Proprioceptors
D. Nociceptors
E. Thermoreceptors

Proprioceptors

These receptors detect specific molecules in our external and internal environments.

Chemoreceptors

These receptors respond to changes in temperature.

Thermoreceptors

These receptors detect changes in the color, intensity, and movement of light.

Photoreceptors

These receptors respond to touch, pressure, vibration, and stretch.

Mechanoreceptors

These receptors detect changes in pressure within the body caused by the stretch or distention of internal structures.

Baroreceptors

These receptors respond to pain caused by external and internal stimuli.

Nociceptors

The most numerous type of receptor in the body is the

Tactile receptor.

There are three types of unencapsulated tactile receptors. Select the exception.

Sebaceous filaments

The battery of your electric toothbrush is running down and so you feel a low frequency vibration in your oral cavity. Which receptors detect this stimulus?

End bulbs

There are four types of encapsulated receptors. Select the exception.

Arrector pili corpuscles

The receptors responsible for detecting deep pressure and high-frequency vibration are

Lamellated corpuscles.

This receptor detects continuous deep pressure and distortion of the skin.

Ruffini corpuscles

Phasic receptors for light touch and texture are

Tactile corpuscles.

A person having a heart attack may feel pain along the medial side of the left arm. This pain is known as

Referred pain.

Because numerous cutaneous and visceral sensory neurons conduct signals on _______ ascending tracts of the spinal cord, the brain sometimes falsely localizes the location of a pain stimulus.

The same

Which papillae, distributed on the anterior two-thirds of the tongue surface, lack taste buds?

Filiform

The papillae located mainly on the tip and sides of the tongue that contain only a few taste buds each are the _______ papillae.

Fungiform

The least numerous but the largest of the papillae are arranged as a V-shape on the posterior dorsal surface of the tongue. They contain the majority of taste buds and are called _____ papillae.

Vallate

The least developed of the papilla types are the ______ papillae, which house only a few taste buds during infancy and early childhood.

Foliate

Which statement accurately describes structures at a taste bud?

The gustatory microvillus of a gustatory cell extends through the taste pore of a taste bud.

Gustatory cells within a taste bud are specialized neuroepithelial cells that have a _________ life span.

7-10 day

There are five basic taste sensations. Select the one mismatched with its causative agent.

Bitter; acids such as those in toxins or poisons

Caffeine and unsweetened chocolate both taste bitter, as they are

Alkaloids.

The flavor of food depends upon

Both olfaction and gustation.

The route that the sensation of taste follows is

a, b, c, d

Olfactory receptor cells are _____ neurons.

Bipolar

Which is not a cell type found in the olfactory epithelium?

Fungiform cell

Where would you find olfactory hairs?

At the apical surface of olfactory neurons

Certain odors can initiate behavioral and emotional reactions because

There are widespread olfactory associations within the hypothalamus and limbic system.

The olfactory tracts project

Directly to the primary olfactory cortex of the temporal lobe of the cerebrum.

Olfactory glomeruli are located in the

Olfactory bulbs

Some odors cause visceral reactions, such as a gagging response to the smell of rotten food. Such responses are a result of olfactory pathways through the

Hypothalamus.

What molecules help concentrate odorants at the olfactory receptor cells?

Odorant-binding proteins

The conjunctiva is composed of _____ epithelium.

Stratified squamous

The conjunctiva that lines the internal surface of the eyelids is termed the _____ conjunctiva.

Palpebral

The primary function of eyebrows is to

Prevent sweat from dripping into the open eye.

Eyelids serve two purposes: one is to protect the eye and the other is to

Help distribute lacrimal fluid to cleanse and lubricate the surface.

What is the correct sequence for lacrimal fluid production and drainage?

b, a, e, c, d

The eye measures about ________ in diameter.

2.5 cm

The proper sequence of eye layers from the outermost to the innermost layer is:

d, c, a

The fibrous tunic of the eye is composed of two parts. What are they?

The cornea and the sclera

The structural continuity between the cornea and the sclera is called

The limbus.

The vascular tunic of the eye has three distinct regions. From anterior to posterior what are they?

c, a, b

The structure that functions as a diaphragm to control pupil size is the:

Iris.

If you were to cut a cross section of the retina and examine it under a microscope, what would be the order of features from the choroid to the posterior cavity?

e, a, c, d, b

Which eye feature provides vitamin A for photoreceptor cells?

Pigmented layer of the retina

What part of the retina lacks photoreceptors?

Optic disc

What part of the retina is responsible for the sharpest vision?

Fovea centralis

Where is the greatest concentration of cones located?

In the fovea centralis

Where would you find the protein crystallin?

In the lens

The lens of the eye flattens when

Ciliary muscles relax.

As a middle aged person gets older, the lenses of their eyes no longer assume as round of a shape when their ligaments slacken. This results in difficulty in

Seeing nearby objects.

A flattened lens

Is necessary for distant vision.

Accommodation of the lens occurs when

All choices are correct

The gelatinous mass inside of the eye is called the

Vitreous humor.

Which sequence correctly traces the pathway of aqueous humor in the eye?

a, b, d, c

Which photoreceptor cells function in dim light?

Rods

Which photoreceptor cells are more numerous?

Rods

Sharp, color vision is a result of the function of

Cones.

A photopsin is a protein

Of a photopigment within cone photoreceptors.

Phototransduction is the process in which

Photoreceptors convert light energy to changes in membrane potential.

When light strikes rhodopsin, the retinal is converted

From cis to trans, and retinal and opsin disassociate.

When light strikes a photoreceptor it

Hyperpolarizes and releases less neurotransmitter.

It may take nearly a half hour for rods of the retina to regenerate a full supply of photopigment during the process of

Dark adaptation.

The "dark current" of photoreceptors refers to

The entry of Na+ into the cell when light is not hitting the cell.

Which sequence correctly traces the visual pathway followed by the majority of axons?

a, b, d, c

Most axons within the optic tract terminate in the

Lateral geniculate nucleus of the thalamus.

At the optic chiasm

Ganglion cell axons from the medial region of each retina cross to the opposite side of the brain.

Some prey animals, such as rabbits, have laterally placed eyes, and the images on their two retinas do not overlap. Such animals would be expected to show _________ depth perception.

Poor

When our brains process visual information about objects directly in front of us, they are able to use information that compares signals from the two eyes (steroscopic vision) in order to provide

Depth perception.

The middle and inner ear are housed within the _____ bone.

Temporal

What is the function of the auditory tube?

To equalize air pressure between the atmosphere and the middle ear

Arrange the inner ear bones from lateral to medial.

c, b, a

Where is the saccule located?

Within the vestibule

Which structure is not considered to be part of the membranous labyrinth?

Scala vestibuli

The function of the ossicles is to

Amplify sound waves and transmit them to the inner ear.

The footplate of the stapes is

Much smaller than the tympanic membrane and the ossicles therefore amplify sound waves.

The part of the cochlea that converts pressure waves (from sounds) into changes in membrane potentials is the

Spiral organ.

What is the correct chronological sequence of events for hearing?

a, b, d, c

The stereocilia of cochlear hair cells project into the

Tectorial membrane.

High frequency sounds activate neurons within the cochlea that are

Near the oval window at the base of the cochlea.

The _______ of a sound stimulus is interpreted as its pitch and measured in hertz, whereas its _______ is referred to as its loudness and is measured in decibels.

Frequency, intensity

After being funneled by the auricle, sound waves pass (in sequence) through the

External acoustic meatus, tympanic membrane, ossicles, and oval window.

After causing vibrations of the maleus, sound waves pass (in sequence) through the

Incus, stapes, oval window, scala vestibuli perilymph, and cochlear duct endolymph.

Distortion of hair cells in the cochlea causes

Initiation of action potentials in CN VIII.