Brainscape's Knowledge GenomeTM

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


See full index

BIO 176 LAB + LEC > The Nervous System: VISION > Flashcards

The Nervous System: VISION Flashcards

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

what is VISION?

A

VISION:
uses of VISIBLE LIGHT (part of the ELECTROMAGNETIC SPECTRUM)
- has wavelengths between 400-700 nm
(range from violet —red)

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

define WAVELENGTHS

A

distance between TWO CONSECUTIVE PEAKS of an electromagnetic wave

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

what are the eye’s ACCESSORY STRUCTURES?

A

ACCESSORY STRUCTURES:
- eyelids
- eyelashes
- eyebrows
- lacrimal glands
- extrinsic eye muscles

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

describe accessory structure; EYELASHES

A
  • helps with the PREVENTION of foreign matter from entering the eye
  • root of eyelash hair; has important NERVE ROOT PLEXUSES + reflex of blinking
  • has SEBACEOUS GLANDS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

describe accessory structure; LACRIMAL GLANDS

A

FUNCTION:
- production of tears
- reduces friction + removes DEBRIS + prevention of BACTERIAL INFECTION
- has specific ANTIBODIES

ANATOMY:
- specific TEAR DUCTS; has continuous tears being produced
- draining system between LACRIMAL PUNCTA

(drainage through LACRIMAL CANALICULI, LACRIMAL SAC, then lastly the NASOLACRIMAL DUCT)

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

describe accessory structure; EYEBROWS

A
  • continuous with the skin (integumentary sys.)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

function of PALPEBRAL MUSCLES

A

helps control eyelid movement and extrinsic eye muscles

EXTRINSIC EYE MUSCLES
- responsible for moving the eyeball itself in all directions

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

CONJUNCTIVA, what are its layers?

A

DESCRIPTION;
a thin, protective mucous membrane
- formed from stratified squamous tissue
- shaped like a culdesac; FORNIX
- has several layers;
1. PALPEBRAL CONJUNCTIVA
2. OCULAR CONJUNCTIVA/BULBAR CONJUNCTIVA
(does not cover cornea area–transparent)

FUNCTION;
helps line the eyelids and covers the sclera

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

TARSAL PLATE

A

DESCRIPTION;
- fold of connective tissue
- has row of SEBACEOUS GLANDS (TARSAL GLANDS/MEIBOMIAN GLANDS)

FUNCTION:
- helps prevent eyelids from sticking together

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

what are our EXTRINSIC/EXTRAOCULAR MUSCLES?

A

we have SIX EXTRINSIC EYE MUSCLES:

  1. SUPERIOR RECTUS
    - controlled by CN III
    - pulled eye up
  2. INFERIOR RECTUS
    - controlled by CN III
    - pulls eye down
  3. LATERAL RECTUS
    - controlled by CN VI
    - pulls eye laterally/abducts
  4. MEDIAL RECTUS
    - controlled by CN III
    - pulls eye medially/adducts
  5. SUPERIOR OBLIQUE
    - controlled by CN IV
    - depresses & abducts the eye
  6. INFERIOR OBLIQUE
    - controlled by CN III
    - elevates & abducts the eye
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are our eye TUNICS?

A

we have TWO TUNICS (COATS):

  1. FIBROUS TUNIC
    - seen in cornea & sclera
  2. VASCULAR TUNIC
    - seen in choroid, ciliary body, & iris
    - contains the intrinsic muscles
  3. **RETINA (NEURAL TUNIC)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

describe SCLERA

A

DESCRIPTION:
- the “white” of our eyes
- made up of dense irregular connective tissue
- penetrated by blood vessels
- consists of the fibrous tunic

FUNCTION:
provides shape and protects inner parts

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

describe CORNEA

A

DESCRIPTION:
the transparent area of the FIBROUS TUNIC
- receives nutrients and oxygen from the chamber from being (the aqueous humor)
- nourished by oxygen and tears

FUNCTION:
- admits and refracts light

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

describe IRIS

A
  • functions to help constrict and dilate the pupil through AUTONOMIC REFLEXES
  • the “colored” part of the eye

PUPIL CONSTRICTION
- reaction to bright light
PUPIL DILATION
- reaction to dim light

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

describe CILIARY BODY

A
  • attaches to the iris and stringlike projections to the lens
  • aids in ACCOMMODATION;
    the eye’s ability to reshape the lens to aid in controlling/viewing objects at various distances
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

describe the CHOROID

A
  • an extensive network of capillaries
    (supplies nutrients to the retina)
  • contains an abundance of blood vessels
17
Q

describe the RETINA (aka NEUTRAL TUNIC)

A

DESCRIPTION:
has a pigmented layer
- attached to the choroid
- the lining of the post. 3-quarters of the inner layer of the eyeball
- can see the optic (II) nerve + OPTIC DISC/BLIND SPOT

FUNCTIONS:
- serves as a “dark room” (pigmented blac)
this allows light to be absorbed specifically by photoreceptors)
- light absorbed through the neural layer (NEURAL SIGNALS) + PHOTORECEPTORS (rods + cones)
- specific image is ACTUALLY INVERTED :O due to refraction

18
Q

describe the MACULA LUTEA

A
  • the CENTER of the retina
  • absorbs UV light
19
Q

describe the FOVEA CENTRALIS

A
  • the CENTER of the MACULA LUTEA
  • area of the HIGHEST VISUAL ACUITY
20
Q

describe the PHOTORECEPTORS within our eye :)

A

DESCRIPTION:
- found within the retina, specific sensors
- known as RODS + CONES

RODS:
- aid to see the DIM light
- contains only photopigment RHODOPSIN

CONES:
- production of COLOR VISION
- contains three different photopigments; RED, GREEN, BLUE

PHOTOPIGMENTS:
- helps ABSORB LIGHT and produces RECEPTOR POTENTIALS
- response through CYCLICAL PROCESS
- this converts the light energy into NEURAL IMPULSES

21
Q

what is the PHOTORECEPTOR SENSORY FLOW?

A
  1. Outer synaptic layer
  2. Bipolar cells
  3. Innter synaptic layer
  4. Ganglion cells
  5. Optic (II) Nerve
22
Q

describe the EYE DIVISIONS

A

ANTERIOR CHAMBER
- between the iris & cornea
- filled with AQUEOUS HUMOR

POSTERIOR CHAMBER
- behind the iris and front of the lens
- filled with AQUEOUS HUMOR

VITREOUS CHAMBER/POSTERIOR CAVITY
- behind the posterior chamber
- filled with VITREOUS HUMOR (more gelatinous in texture)

23
Q

describe REFRACTION

A

where light can bend when passing through various transparent substances with varying densities

24
Q

describe the LENS

A

FUNCTION:
use of accommodating to properly focus on specific object
- able to accommodate during short or long distances

25
Q

describe the CENTRAL FOVEA

A

area of where the image is projected onto; sharpest/highest visual acuity

26
Q

describe the typical EYE CONDITIONS:

A

EMMETROPIC EYE:
- our “normal” eye
- refraction of light is correct
- clear image on retina

MYOPIA (NEARSIGHTEDNESS):
- eyeball is “longer”
- image is CONVERGING in FRONT of the retina
- CONCAVE LENS used to correct

HYPEROPIA (FARSIGHTEDNESS)/HYPERMETROPIA:
- eyeball is shorter
- image is CONVERGING BEHIND the retina
- CONVEX LENS used to correct

ASTIGMATISM:
- a condition where CORNEA/LENS has IRREGULAR CURVES
- causes blurred or distorted vision

27
Q

describe VISION ADAPTATION (and LIGHT + DARK ADAPTATION)

A

VISION ADAPTATION:
- rates of BLEACHING + REGENERATION of photopigments within rods and cones

LIGHT ADAPTATION:
- decreases the release of inhibitory neurotransmitter GLUTAMATE
(from dark to light –takes SECONDS)

DARK ADAPTATION:
- RELEASES the inhibitory neurotransmitter GLUTAMATE
(from light to dark–takes MINUTES)
- stops transmission signals from BIPOLAR CELLS to GANGLION CELLS (stops signal from retina to brain)

28
Q

describe the NEURAL PATHWAY

A

PATHWAY:
- beginning of where RODS + CONES start CONVERSION of light energy into neural signals

  1. Optic (II) Nerve
  2. Optic chiasm
  3. Optic Tract
  4. Lateral geniculate nucleus of thalamus
  5. Optic radiation
    • allows info to be received in primary visual areas
  6. Primary visual area of the cerebral cortex (area 17) in the occipital lobe
29
Q

describe our VISUAL FIELDS + BINOCULAR VISION

A

BINOCULAR VISION:
- The anterior location of our eyes leads to our visual fields to OVERLAP

VISUAL FIELDS:
- NASAL (MEDIAL)
- TEMPORAL (LATERAL)
these fields work similarly in OPPOSITES
*visual info from RIGHT of each field – LEFT SIDE of brain
*vice versa

30
Q

describe the EYE DEVELOPMENT

A
  • typically begin to develop around 22 DAYS after fertilization
  • ECODERM of the FOREBRAIN [PROSENCEPHALON]:
    • formation of the optic grooves (which will eventually become the optic vesicles)
  • OPTIC VESICLES:
    • thicken into the lens placodes
    • also form distally into optic cups
    • continue being attached to the prosencephalon through the optic stalks
31
Q

describe clinical condition; PRESBYOPIA

A

difficulty focusing on close objects due to loss of elasticity in lens

32
Q

describe clinical condition; PINK EYE

A

inflammation of the conjunctiva from infection or allergies

**bacterial infection specifically for pink eye

33
Q

describe clinical condition; CHAAZION vs. STYE

A

CHALAZION
- build of secreted sebum from tarsal glands (inflamed)
STYE
- pimple on the eye

34
Q

describe clinical condition; CORNEAL TRANSPLANT

A

where the cornea is surgically removed from a donor

BIO 176 LAB + LEC (20 decks)

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