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ANSC3104 Nervous system > Special senses > Flashcards

Flashcards in Special senses Deck (100)
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1

Primary sensory cell

Sensory cell contained within nerve ending, with own axon (skin & olfactory)

2

Secondary sensory cell

Lack an axon
Synapse with sensory nerve fibres (ear, eye, taste)

3

Lacrimal

Tear producing apparatus in the eye

4

Lens function

Focusing light onto retina

5

Where are sensory cells located in the eye?

Retina

6

Optic nerve function

Transmits visual information to the brain

7

Are the cornea and sclera attached?

Yes

8

When the ciliary muscle contracts the lens is...

The lens is wide

Zonular fibres have more room

9

When ciliary muscle relaxes the lens is

The lens is flat (contracted)

Less space for zonular fibres - puts pressure on lens

10

How is the ciliary muscle attached to the lens?

Via zonular fibres (connective tissue)

11

Eye ball

Fluid filled sphere
Covered by three layers (tunic)

1. Fibrous (outer)
2. Vascular (mid)
3. Nervous (internal)

12

Vitreous body

Gel-like material

13

Why is cornea transparent and sclera white? (made out of same fibres)

Fibre arrangement

- neatly layered in cornea
- Scattered and tightly packed in sclera

14

Fibrous tunic of the eye

Outer layer
Contains:
Sclera
Cornea

Only complete tunic
Protects the eye

15

Vascular tunic of the eye

Mid layer
Contains:
Choroid (lines sclera)
Ciliary body
Iris

Blood vessels and smooth muscle
Nourishes retina
Regulates shape of lens and size of pupil
Produces aqueous humour

16

Cornea

Like a window it allows light to enter to eye

17

Iris

Regulates the amount of light that enters your eye by adjusting the size of the pupil opening.

Contains muscles that allow the pupil to become larger (open up or dilate) and smaller (close up or constrict).

18

Tapetum lucidum

Located within choroid directly behind retina

it reflects visible light back through the retina, increasing the light available to the photoreceptors

- cause animal eyes to glow in the dark

19

What produces aqueous humour

Ciliary processes

20

Nervous tunic

Inner layer
Contains:
Retina

The retina contains photoreceptor cells:
- Rods (night)
- Cones (colour)

Ora serrata
- Junction between optic & non-sensory parts of retina

Optic disc
- Axons of nerve cells contracted - blind spot (no receptor cells)

21

Blind spot also known as

optic disc

22

What is the junction between optic and non-sensory parts of the retina

Ora serrata

23

Colour vision

Cones

24

Black and white vision

Rods

25

Lens

Consists of fibres arranged in concentric rings
Transparent
Secured by zonular fibres (extend from ciliary body) around equator
Focuses light

26

How many voluntary muscles control the rotation, retraction and sideways movement of the eye?

7

Muscle control is complex

27

Eyelids

2 folds of muscular & fibrous tissue
Skin outside, conjunctiva (mucous membrane) inside

28

Glands associated with eyelid

Lacrimal glands: nourish and keep eye moist

Tarsal glands: secrete fatty , lipid barrier substance (open along eyelid

29

Lacrimal glands

nourish and keep eye moist

30

Tarsal glands

secrete fatty , lipid barrier substance (open along eyelid