Chapter 12

Front 1

Senses transmit sensory information in the form of ________ _________ to the ________

Back 1

electrochemical impulses to the brain

Front 2

Sensory receptors initiate

Back 2

neural impulses

Front 3

Occurs when the neural impulse reaches the cerebral cortex

Back 3

sensation

Front 4

Perception results from how the cerebral cortex _________ the meaning of the sensory information

Back 4

interprets

Front 5

The filtering by the brain of redundant, insignificant sensory information. For example: no longer feeling clothes on your skin

Back 5

sensory adaption

Front 6

Photoreceptors

Back 6

rods and cones absorb light and allow us to sens different levels of light

Front 7

Types of chemoreceptors (3)

Back 7

taste, smell, internal senses

Front 8

Types of mechanoreceptors (4)

Back 8

touch/pressure/pain, hearing, balance, body position

Front 9

Thermoreceptors

Back 9

detect heat and cold on the skin

Front 10

3 layers of the eye

Back 10

external (sclera), intermediate (choroid), internal (retina)

Front 11

Transparent part of sclera at the front of the eye is the

Back 11

cornea

Front 12

Function of the cornea

Back 12

bends light rays into the eye

Front 13

Function of the choroid

Back 13

absorbs stray light rays that are not detected by the photoreceptors and also contains blood vessels that nourish the eye

Front 14

Function of the iris

Back 14

regulates the amount of light that enters the eye by constricting and dilating

Front 15

Function of the pupil

Back 15

opening for light to enter the inner eye

Front 16

Function of ciliary muscle

Back 16

changes shape of lens to focus images

Front 17

Location of ciliary muscl

Back 17

behind the iris where the choroid thickens

Front 18

The retina is a ____ layer of tissue that contains the __________

Back 18

thin, photoreceptors

Front 19

Function of rods

Back 19

photoreceptors that are sensitive to light intensity

Front 20

Function of cones

Back 20

photoreceptors that are sensitive to different colours (different wavelengths of light)

Front 21

The rods and cones send _______________ to the brain via the _______ ________

Back 21

sensory impulses, optic nerve

Front 22

External layer of the eye contains (2)

Back 22

sides and back of sclera, cornea

Front 23

Intermediate layer of the eye contains (4)

Back 23

sides and back of choroid, iris, pupil, ciliary muscles

Front 24

Internal layer of the eye contains (3)

Back 24

rods, cones, fovea centralis

Front 25

The cones are packed densely at the back of the eye in an area called the

Back 25

fovea centralis

Front 26

Two chambers of the eye

Back 26

anterior in front of the lens and posterior behind the lens

Front 27

What is aqueous humour and its function

Back 27

clear, watery fluid that maintains shape of the cornea and provides oxygen and nutrients for surrounding cells

Front 28

Aqueous humour found in which chamber of the eye

Back 28

anterior

Front 29

Posterior chamber is surrounded by the ____

Back 29

retina

Front 30

Posterior chamber contains what fluid and what is its function

Back 30

vitreous humour and helps maintain shape of eyeball and supports surrounding cells

Front 31

Image fixed on the fovea centralis of of the retina is (3)

Back 31

smaller, upside down and reversed from left to right

Front 32

Function of the lens of the eye

Back 32

focuses light rays onto the fovea centralis

Front 33

What happens to the lens when an object is far away? (2)

Back 33

- ciliary muscles relax,

- suspensory ligaments become taut causing lens to flatten

Front 34

What happens to the lens when an object is nearby? (2)

Back 34

- ciliary muscles contract

- suspensory ligamens relax causing lens to become more rounded

Front 35

What is glaucoma?

Back 35

condition when ducts that drain the aqueous humour in the eye are blocked, the pressure ruptures delicate blood vessels in the eye and causes deterioration of the cells due to lack of oxygen and nutrients

Front 36

What is cataracts?

Back 36

when the lens ages protein structure can start to degenerate making it opaque and preventing light from passing through -> causing white-grey spots

Front 37

Astigmatism is due to the?

Back 37

uneven curvature of part of the cornea which makes it so that the cornea cannot bend light rays to meet at correct focal point

Front 38

Ability to see close but not far

Back 38

nearsighted

Front 39

Nearsighted people have ? What is it caused by?

Back 39

myopia which is cause by and elongated eyeball and when the ciliary muscles are too strong

Front 40

Ability to see far but not close

Back 40

farsightedness

Front 41

Farsighted people have what? What is this caused by?

Back 41

hyperopia, cause by eyeball being too short or ciliary muscles too weak

Front 42

nearsighted people need ______ lenses and farsighted people need ________ lenses

Back 42

concave (diverge light), convex

Front 43

4 functions of the rods

Back 43

- sensitive to light

- detects degrees of black and white

- detect motion

- responsible for peripheral vision

Front 44

What is colour blindness?

Back 44

inability to distinguish between or recognize some colours

Front 45

Does colour blindness occur more frequently in males or females?

Back 45

males

Front 46

Colour blindness is due to a

Back 46

lack of or deficiency in particular cones (usually red or green)

Front 47

Rod contain a light absorbing pigment called

Back 47

rhodopsin

Front 48

Rods reaction to darkness

Back 48

release an inhibitory neurotransmitter that inhibits nearby nerve cells

Front 49

When rods absorb light ....

Back 49

- rhodopsin splits into retinal and opsin

-this triggers a chain reaction that stops the release of the inhibitory neurotransmitter and allows transmission of neural impulse to the optic nerve

Front 50

Pigment in cones is called

Back 50

photopsin

Front 51

Once the rods and cones in the retina are stimulated what happens next in order for the neural impulse to reach the brain?

Back 51

- rods and cones permit neural impulse to pass through the bipolar cells to the ganglion cells which form the optic nerve. optic nerve transmit visual images to occipetal lob of the brain

Front 52

Area when the ganglion cells merge to form the optic nerve is called the

Back 52

blind spot q

Front 53

How does the brain integrate visual information from the eyes? (3)

Back 53

1. retina must send information to the optic nerve

2. information travels to the thalamus and then to the occipital lobe for interpretation

3. the image is split in the occipital lobe because the left optic tract carries information about the right portion of the visual field and vise versa

Front 54

What is binocular vision?

Back 54

Use both eyes to look at an collect visual information about an object, this enable the brain to perceive depth and 3D images

Front 55

Diabetic retinopathy

Back 55

capillaries to the retina burs, spilling blood into the vitreous fluid between the lens and the retina

Front 56

Macular degeneration occurs when

Back 56

the cones are destroyed due to thickened choroid vessels that no longer function as they should

Front 57

Three parts of the eyes that focus light on the retina?

Back 57

cornea, lens and humours

Front 58

Rods function in _____ light and produce _______ _______ images and the cones function in _________ light and produce __________ images

Back 58

dim, black and white, bright, colour

Front 59

3 major divisions of the ear

Back 59

outer, middle, inner

Front 60

Outer ear consists of (2)

Back 60

the pinna and auditory canal

Front 61

The pinna is

Back 61

the outside flap of the ear made of skin and cartilage, shaped in a way that enhances sound vibrations and focuses them into the ear

Front 62

The auditory canal is

Back 62

a 2.5 cm long tube that leads to the eardrum

- amplifies sound waves, effectively making sounds louder

Front 63

The middle ear is an air-filled space that is bordered on one side by the

Back 63

tympanum (aka eardrum or tympanic membrane)

Front 64

Define tympanum

Back 64

round, elastic structure that vibrates in response to sound waves

Front 65

Ossicles

Back 65

three tiny, interconnected bones in the middle ear

Front 66

Oval window

Back 66

membrane-covered opening in the wall of the inner ear -- it receives vibrations from the stapes

Front 67

Three ossicles in order

Back 67

malleus (hammer), incus (anvil), stapes (stirrup)

Front 68

Middle ear is connected to the throat by the

Back 68

eustachian tube

Front 69

Inner ear consists of three interconnecting features

Back 69

semicircular canals, vestibule, cochlea

Front 70

Where is the mechanical energy of sound converted into electrochemical impulses that are transmitted to the brain?

Back 70

in the cochlea

Front 71

Middle chamber of the cochlea contains the

Back 71

organ of Corti which is the organ of hearing

Front 72

Along the base of the organ of Corti is the

Back 72

basilar membrane -- to which sensory mechanoreceptors known as hair cells are attached

Front 73

During the transmission of soundwaves, the basilar membrane vibrates causing sensory hairs to flex against the

Back 73

tectorial membrane

Front 74

Hair cells of the organ of corti are able to distinguish both _____________ and ____________ of sound waves

Back 74

frequency and amplitude

Front 75

High frequencies most strongly stimulate hair cells

Back 75

closest to the oval window

Front 76

Repeated or sustained exposure to loud noise destroys the _________ and the resulting damage is __________

Back 76

stereocilia, permanent

Front 77

Three major structures in the ear that help you stand up straight without losing our balance

Back 77

semicircular canals, utricle and saccule

Front 78

Semicircular canals contain mechanoreceptors that detect

Back 78

head and body rotation

Front 79

Balance required while moving head forward and backwards

Back 79

gravitational equilibrium

Front 80

Gravitational equilibrium depends on the

Back 80

utricle and saccule, together make up fluid-filled vestibule

Front 81

Both the utricle and saccules contain calcium carbonate granules called

Back 81

otoliths