Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > Sense Organs > Flashcards

Sense Organs Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

define receptors

A

any specialised tissue or cell sensitive to a specific stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

orbits

A

eyes are located in these deep sockets
on the front side of the head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

tear glands

A

at the upper sideward portion of orbit
6 to 12 glands present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

function of lacrimal gland

A
  1. blinking spreads the liquid which acts as lubricant
  2. washing away dust
  3. antiseptic due to lysozyme which kills germs
  4. tears communicate emotions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

conjuctiva

A

thin membrane covering front part of the eye
continuous with the inner lining of eyelids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

layers of wall of eyeball

A
  1. outer sclerotic
  2. middle choroid
  3. inner retina
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

sclerotic layer

A

tough fibrous tissues
white in colour
bulges out and becomes transparent in front, where it covers the coloured part of eye, called cornea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

choroid layer

A

blood vessels for nourishment
contains melanin which prevents light rays from reflecting and scattering inside eye
in front, choroid expands to form ciliary body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

iris

A

extension of choroid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

function of radial muscles in iris

A

widen the pupil- adjust amount of light entering

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

function of circular muscle

A

constrict the pupil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

rod cells in retina

A

sensitive to dim light
do not respond to colour
contain rhodopsin/ visual purple
throughout retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

cones in retina

A

sensitive to bright light
responsible for colour vision
iodopsin/ visual violet
only in yellow spot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

yellow spot

A

AKA macula lutea
at the BACK OF THE EYE, CENTRE ON THE HORIZONTAL AXIS OF EYEBALL
has maximum sensory cells
region of brightest vision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

blind spot

A

LATERAL TO YELLOW SPOT ON NASAL SIDE
no sensory cells
all sensory cells’ nerve fibres converge and bundle together here to leave as optic nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

lens

A

transparent, flexible, biconvex
just behind the pupil
contains lens fibres transparent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

suspensory ligaments

A

lens is held in position by these fibres, and are attached to ciliary body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

ciliary body

A

at junction of choroid and iris
contains muscles which on contraction/relaxation, change shape of lens for viewing different distances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

chambers of eye

A
  1. aqueous
  2. vitreous
20
Q

aqueous humour

A

between lens and cornea

  1. keeps lens moist
  2. protects from shock
  3. refracts light

aqueous humour is clear watery liquid

21
Q

vitreous chamber (humour)

A

behind the lens

  1. helps in keeping shape of eyeball
  2. protects retina and its ending

vitreous humour is jelly-like thicker fluid

22
Q

define accomodation

A

the process of focusing the eye to see objects at different distances, brought about by making a change in the curvature of elastic lens (by ciliary muscles)

23
Q

dark adaptation due to

A
  1. regeneration of rhodopsin, which was earlier broken down due to light
  2. dilation of pupil
24
Q

light adaptation due to

A

1.visual purple of rods is bleached
2. pupil constricts

25
Q

myopia caused due to

A
  1. eyeball is lengthened from front to back
  2. lens is too curved

corrected by concave lens

26
Q

hypermetropia due to

A
  1. shortening of eyeball from front to back
  2. lens is too flat
27
Q

astigmatism

A

when some objects are seen in focus while others are blurred

  1. uneven curvature of cornea

corrected by cylindrical lenses

28
Q

presbyopia

A

lens loses flexibility
cannot see near objects clearly
convex lens

29
Q

cataract

A
  1. lens turns opaque, vision is cut down to blindness

use highly convex lens, remove lens, small plastic lens behind or front of the iris

30
Q

night blindness

A
  1. non formation of rhodopsin
  2. deficiency of vit A which is required for synthesis of pigment
31
Q

colour blindness

A
  1. due to genetic defect

rare in females

32
Q

corneal opacities

A
  1. cornea gets scarred and turns opaque/white
    can cause irritation or vision problems or blindness

defective cornea is replaced with healthy cornea

33
Q

squint

A

two eyes converge- cross eye
two eyes diverge- wide eye

may cause double vision/ diplopia
fixed by surgery and exercise

34
Q

functions of ear

A
  1. hearing
  2. body balance
35
Q

divisions of ear

A
  1. outer
  2. middle
  3. inner
36
Q

outer ear

A
  1. projecting part called pinna/ auricle
  2. auditory canal leading to ear drum/tympanum
37
Q

middle ear

A
  1. malleus, incus, stapes
  2. eustachian tube connects cavity of middle ear to throat
38
Q

oval window and round window

A

oval- membrane covered opening leading to inner ear
round- membrane covered, connects middle and inner ear

39
Q

inner ear

A

AKA membranous labyrinth
1. cochlea
2. semicircular canals
3. vestibule

40
Q

cochlea

A

spiral shapes, looks like snail shell
has two and a half turns
inner winding is divided into 3 parallel canals
middle canal has areas possessing sensory cells
sensory cells lie on basilar membrane

41
Q

organ of Corti

A

lie in the middle canal of the cochlea
possess sensory cells
spiral organ

42
Q

semicircular canals

A

set of 3
arranged at right angles to each other in three different planes (one horizontal, two vertical)

43
Q

ampulla

A

one end of each semicircular canal is widened to form ampulla
contains sensory cells for dynamic balance while body is moving

44
Q

vestibule

A

short stem joining the bases of semicircular canals to the cochlea have UTRICULUS and SACCULUS

contain sensory cells for static balance when body is not moving

45
Q

function of eustachian tube

A

equalises air pressure on either side of ear drum, allowing it to vibrate freely

46
Q

why is vibration of stapes amplified

A

due to lever like action of the first two ossicles

Biology (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions