Senses

Question 1

Sense organs bring information about the external environment….

Answer 1

To the CNS so that the appropriate response can be taken.

Question 2

What 4 parts of the eye are involved in vision?

Answer 2

1. Eyelashes - prevent foreign material entering the eye
2. Eyelids - Blinking keeps eye lubricated.
3. Iris - coloured region that surrounds pupil.
4. Pupil - centre of the eye through which light passes.

Question 3

What is the conjunctiva?

Answer 3

Epithelial layer that lines inner surface of eyelid and covers the outer surface of the eye.

Question 4

What are the lacrimal glands?

Answer 4

They continually produce tears to keep the conjunctiva moist and clean.

Question 5

What is conjunctivitis?

Answer 5

Inflammation of the conjunctiva due to infection or abrasion.

Question 6

What are the 2 fluid filled cavities of the eyeball called?

Answer 6

The anterior and posterior cavities.

Question 7

What are the 3 layers of the eyeball wall called?

Answer 7

Fibrous, vascular and neural.

Question 8

What is the fibrous layer of the eyeball?

Answer 8

Surface layer of the eyeball - Provides protection for the eye and attachment for muscles that move the eye.

Question 9

What is the vascular layer of the eyeball?

Answer 9

Contains blood vessels and smooth muscle - consists of the iris, ciliary body and choroid.

Question 10

What is the neural layer of the eyeball?

Answer 10

Contains photoreceptors called rods and cones which respond to light.

Question 11

What is the optic chiasma?

Answer 11

A part of the brain where the optic nerves partially cross.

Question 12

The ear is an organ of…

Answer 12

Hearing and balance.

Question 13

What parts is the ear divided into?

Answer 13

External, Middle ear and inner ear.

Question 14

What 3 parts is the external ear divided into?

Answer 14

1. Auricle
2. External acoustic meatus
3. Tympanic membrane

Question 15

The middle ear is connected to the nasopharynx by the…

Answer 15

Auditory tube

Question 16

What are the 4 part that the inner ear is connected to?

Answer 16

1. Semicircular canals
2. Vestibulocochlear nerve
3. Vestibule
4. Cochlea

Question 17

List the 5 steps of sound transmission…

Answer 17

1. Sound waves are collected by the auricle
2. Sound waves hit the tympanic membrane causing it to vibrate.
3. Vibration is amplified through the ossicles.
4. Vibration of stapes on oval window causes fluid in cochlea to vibrate.
5. Vibration stimulate the spiral organ which triggers action potentials in the vestibularcochlear nerve.

Question 18

The sense of smell is the response to…

Answer 18

Airbourne molecules that enter the nasal cavity.

Question 19

What term are airborne molecules also known by…

Answer 19

Odorants

Question 20

Where is the olfactory epithelium located?

Answer 20

The upper region of the nasal cavity.

Question 21

What are the 4 steps in smell detection?

Answer 21

1. Odorants enter the nasal cavity and dissolve in the mucus.
2. Presented to receptor proteins on olfactory epithelium
3. Olfactory nerve is stimulated
4. Information transmitted to olfactory cortex.

Question 22

Where are taste buds located?

Answer 22

On the tongue, soft plate, pharynx and epiglottis.

Question 23

What is the epiglottis?

Answer 23

Flap made of elastic cartilage covered with a mucous membrane, attached to the entrance of the larynx

Question 24

How many taste cells does each taste bud contain?

Answer 24

40 taste cells

Question 25

Sensory axons leave the base of each taste bud…

Answer 25

In the cranial nerve.

Question 26

What are the 4 steps of taste detection?

Answer 26

1. Tastants bind to receptors on hair cells.
2. Action potential initiated in sensory neurone
3. Sensory axons for taste are contained in the facial, glossopharyngeal and vagus nerves.
4. Information transmitted to taste cortex in the parietal lobe.

Question 27

List the 3 types of taste loss…

Answer 27

1. Ageusia - Total loss of taste
2. Hypogeusia - Partial taste loss
3. Dysgeusia - Distortion of taste.