The Senses

Question 1

What is sensory adaptation?

Answer 1

sensory adaptation occurs once you have adjusted to a change in the environment; sensory receptors become less sensitive when stimulated repeatedly.

Question 2

What are sensory receptors?

Answer 2

Sensory receptors are highly modified dendrites of sensory neurons that detect information about the external or internal environment.
-they convert one form of energy into another (eg. eye converts light energy into an electrochemical impulse)

Question 3

List the three layers of the eye, describe the function of each layer.

Answer 3

.Sclera: outer covering, it’s supports and protects the eye’s inner layers (referred to as the white of the eye)
.Choroid layer: middle layer, contains blood vessels that nourish the retina
.Retina: innermost layer, very thin tissue at the back of the eye containing photoreceptors

Question 4

What is the cornea?

Answer 4

Transparent part of the eye and refracts the light toward the pupil of the eye.

Question 5

What is the aqueous humour?

Answer 5

Watery liquid that protects the lens of the eye and supplies the cornea with nutrients.

Question 6

What is the iris?

Answer 6

Opaque disk of tissue surrounding the pupil that regulates amount of light entering the eye.

Question 7

What is the pupil?

Answer 7

The hole within the iris, let’s light in. (!!doesn’t regulate the amount of light entering)

Question 8

Define a rod and it’s function and location.

Answer 8

photoreceptors that operate in dim light to detect light in black and white. Rods surround the fovea centralis

Question 9

Define a cone and it’s function and location.

Answer 9

photoreceptors the operate in bright light to identify colour. Cones are more concentrated at the centre of the retina, the fovea centralis (vision is the most sharpest there)

Question 10

What is the fovea centralis?

Answer 10

Area at the centre of the retina where cones are most dense and vision is sharpest.

Question 11

What is the vitreous humour?

Answer 11

The jelly like liquid that fills the cavity of the eye, makes up 80% of the eye. (Gives it it’s spherical shape)

Question 12

Where is the blind spot?

Answer 12

Where the optic nerve attaches to the retina

Question 13

What are accommodation reflexes?

Answer 13

Adjustments made by the lens and pupil (iris) of the eye for near and distant objects.

Question 14

What’s glaucoma?

Answer 14

Disease of the eye in which increased pressure within the eyeball causes a gradual loss is sight.

Question 15

What is cataract?

Answer 15

A condition that occurs when the lens or cornea becomes opaque preventing light from passing through.

Question 16

What is astigmatism?

Answer 16

vision defect caused by abnormal curvature of surface of the lens or cornea.

Question 17

How do corrective lenses (and what kind of corrective lens) provide for normal vision?

Answer 17

.nearsightedness (myopia) is corrected with a concave lens which brings the focus of the image to the retina (brings it back)
.farsightedness (hyperopia) is corrected with a convex lens which brings the focus of the image forward to the retina

Question 18

What is rhodopsin?

Answer 18

the pigment found in the rods of the eyes
-when light hits a rhodopsin molecule it gets divided into pigment (retinene) and protein (opsin), this alters the cell membrane of the rods and creates an action potential.

Question 19

What are the 3 sections of the ear?

Answer 19

The outer ear, the middle ear, and the inner ear.

Question 20

What is the outer ear comprised of?

Answer 20

It consists of the pinna and the auditory canal

Question 21

What the the pinna?

Answer 21

The outer part of the ear that acts like a funnel, taking sound from a large area and channelling it into a small canal.

Question 22

What is the auditory canal?

Answer 22

It carries the sound waves to the eardrum.

Question 23

What are the parts of the middle ear?

Answer 23

the tympanic membrane, oval and round windows, ossicles, and the eustachian tube.

Question 24

What is the tympanic membrane?

Answer 24

the thin layer of tissue that receives sound vibrations, also know as the eardrum.

Question 25

What are ossicles? (the three found in the ear?)

Answer 25

Ossicles are tiny bones that amplify and carry sound in the middle ear. It include the malleus (the hammer), the incus (the anvil), and the stapes (the stirrup).

Question 26

What is the oval window?

Answer 26

and oval-shaped hole in the vestibule of the inner ear, covered by a thin layer of tissue

Question 27

What is the eustachian tube?

Answer 27

The eustachian tube is an air-filled tube of the middle ear that equalizes pressure between the external and internal ear.

Question 28

What are the three distinct parts that make up the inner ear?

Answer 28

The vestibule, the semicircular canals, (both involved with balance) and the cochlea (connected to hearing).

Question 29

What is the vestibule?

Answer 29

the chamber found at the base of the semicircular canals that provide information about static equilibrium

Question 30

What are the semicircular canals?

Answer 30

they’re fluid filled structures within the inner ear that provide information about dynamic equilibrium.

Question 31

What is the cochlea?

Answer 31

coiled structure of the inner ear that responds to various sound waves and converts them into nerve impulses

Question 32

What is the organ of Corti?

Answer 32

the hearing apparatus within the cochlea and comprises a single inner row and three outer rows of specialized hair cells

Question 33

What does the basilar membrane do?

Answer 33

it anchors the receptor hair cells in the organ of Corti (the hair cells respond the to vibrations of the basilar membrane)

Question 34

What is the difference between static and dynamic equilibrium?

Answer 34

.static equilibrium involves movement along one plane (ie. horizontal and vertical)
.dynamic equilibrium provides information during movement

Question 35

What is the otoliths?

Answer 35

tiny stones of calcium carbonate embedded in gelatinous coating within the saccule and utricle