Chapter 16 Nervous System: Senses

When the ______ membrane moves, the ______ on the spiral organ hair cells distort because they are anchored by the tectorial membrane.

Basilar, stereocilia

The optic disc contains ______ photoreceptors.

No

Optic tracts ultimately are directed to the primary visual cortex in the ______ lobe.

Occipital

We use the sense of ______ to sample our environment for information about the food we will eat, the presence of other individuals in the room, or potential danger.

Olfaction

The segment of each photoreceptor that is composed of hundreds of discs containing photopigments that are capable of absorbing light energy is the ______ segment.

Outer

The middle and inner ear are in which bone?

Temporal bone

Optic tracts extend to which structures after they leave the optic chiasm?

The lateral geniculate nucleus of the thalamus, superior colliculi

Which are true of rods?

They function well in dim light. There are more than 100 million rod cells per eye.

The cornea is ______.

Transparent

Which are the characteristics of the cornea?

Transparent and avascular

True or false: The primary purpose of the eyebrows is to keep sweat out of the eyes.

True

The external acoustic meatus terminates at the _______ membrane, which is most commonly called the eardrum.

Tympanic

Sensory receptors in which structures help monitor and adjust our equilibrium?

Utricle, saccule, semicircular ducts

Hearing and our sense of balance comes from the stimulation of which cranial nerve?

Vestibulocochlear

The most visible part of the external ear is called the ______ or ______ .

Auricle, pinna

Gustatory cells are found in taste ______

Buds

Receptors initiate sensory input to the ______.

Central nervous system

Earwax is a combination of dead skin cells and ______.

Cerumen

What substance, produced in the external ear, impedes microorganism growth?

Cerumen

What is the largest structure of the vascular tunic?

Choroid

What structure is filled with pigment from melanocytes?

Choroid

The iris is continuous with the ______.

Ciliary body

The auditory tube is normally ______.

Closed

The auditory sensory axons of the ______ branch of cranial nerve number ______ terminate in the cochlear nucleus within the brainstem.

Cochlear, VIII/8

What type of photoreceptors detects color?

Cones

Which events occur during bright light adaptation?

Cones gradually adjust, rods become inactive, pupils constrict

As we adjust to low light, our ______ becomes nonfunctional and it may take ______ for rhodopsin to become regenerated sufficiently so that you can see well in low-light conditions.

Cones; 20-30 minutes

The sphincter pupillae ______ the pupil.

Constricts

Which are a part of the fibrous tunic?

Cornea and Sclera

The optic disc is associated with ______.

Cranial nerve II

When you go from a bright light environment to a dark environment, you have a slow sensitivity to low light levels. This is called ______ ______ .

Dark adaptation

Light rays are refracted or bent when they pass through two media of different ______.

Densities

The auricle has ______ cartilage that supports its structure.

Elastic

The auricle directs sound waves into the bony tube called the ______ ______ meatus.

External, acoustic

Cutaneous receptors are a type of ______.

Exteroceptors

What type of receptor is found in the mucous membranes?

Exteroceptors

Which is an accessory structure of the eye?

Eyebrow

True or false: The eye is spherical, measuring about 5 centimeters in diameter, and most of it is receded into the orbit of the skull.

False

The outmost layer of the eye is called the ______ tunic.

Fibrous

When the bipolar cells release their neurotransmitter, the ______ cells propagate a nerve signal along the ______ nerve.

Ganglion, optic

The term equilibrium refers to our awareness and monitoring of our ______ position.

Head

The vestibulocochlear nerve transmits ______ information.

Hearing and equilibrium

Each type of photoreceptor has both an outer segment that extends into the ______ layer of the retina and an inner segment.

In the neural layer of the retina

When the photoreceptors stop ______ the bipolar cells, the bipolar cells can then release their neurotransmitter that binds to receptors on the ganglion cells.

Inhibiting

The segment of each photoreceptor that contains organelles for the cell such as mitochondria is the ______ segment.

Inner

The segment of the photoreceptors that connects directly to the cell body is the ______ segment.

Inner

The retina is the ______ layer of the eye wall.

Internal

The process by which your eyes adjust from low light to bright light conditions is ______.

Light adaptation

The sphincter pupillae is controlled by the ______ division of the nervous system.

Parasympathetic

Olfactory receptors ______.

Perceive odors

If stimulated over a period of time, ______ receptors lose eventually sensitivity.

Phasic

What type of receptor can undergo adaptation?

Phasic

In phototransduction, the ______ responds to light stimulation by changing its resting membrane potential, resulting in a change in the neurotransmitter it releases.

Photoreceptor

The process by which photoreceptors become activated when the photopigments are altered by light entering the eye is ______.

Phototransduction

Aqueous humor is secreted into the ______ chamber before traveling to the _____ chamber of the eye.

Posterior, anterior

A feature common to all receptors is ______.

Ability to respond to a stimulus

The tympanic cavity is filled with ______.

Air

Which cavity of the eyeball is divided into an anterior and posterior chamber?

Anterior cavity

What chamber is between the iris and cornea?

Anterior chamber

The sclera ______.

Provides for eye shape, is made of dense connective tissue

The iris controls the size of the ______.

Pupil

Most of the eye is ______ the orbit of the skull.

Receded into

The area that a receptor cell gathers information from is called the ______.

Receptive field

Some individuals experience pain in their left shoulder during a heart attack. This is an example of ______.

Referred pain

______ occurs when impulses from an organ are perceived as originating from the skin.

Referred pain

What structure is the "white" of the eye?

Sclera

What structure makes up the posterior 5/6 of the fibrous tunic?

Sclera

Which part of the eye is an attachment site for extrinsic eye muscles?

Sclera

Receptors for general senses are usually ______.

Simple structure

Receptors for general senses are distributed throughout the ______ and viscera.

Skin

Localization and sensitivity are easily determined in a ______ receptive field.

Small

In the eye, the ________ humor is gelatinous

Vitreous

The posterior cavity contains the ______ humor.

Vitreous

Olfaction is the sense of ______.

Smell

What type of fluid is found in the anterior cavity of the eyeball?

Aqueous humor

Gustation is the sense of ______

Taste

The vascular tunic of the eye is also called the ______.

Uvea

The primary function of the ______ is to prevent large objects from contacting the eye.

Eyelashes

Which layer of the eye contains the blood and lymph vessels?

Vascular tunic

Taste buds are found on the tongue and ______.

Soft palate

Mechanoreceptors located in the skin and mucous membranes are called ______ receptors.

Tactile

What is the most numerous type of receptor?

Tactile receptors