Sensory Organs

Question 1

What are general senses?

Answer 1

Senses found all over the body (pain, pressure changes, etc)

Question 2

What are special senses?

Answer 2

Senses that have specialized receptor cells within a specialized organ

Question 3

Every sensation is connected to what?

Answer 3

Action potential

Question 4

What do chemoreceptors respond to?

Answer 4

Chemicals — detect taste, smells, blood pH

Question 5

What do photoreceptors respond to?

Answer 5

Light

Question 6

What do mechanoreceptors respond to?

Answer 6

Physical forces: hearing motion, vibrations

Question 7

What do thermoreceptors detect?

Answer 7

Change in temperature

Question 8

What do nociceptors respond to?

Answer 8

Tissue damage (pain)

Question 9

What is a receptive field and how does it relate to sensation?

Answer 9

An area of the body supplied by a single sensory neuron. Precision in detection depends on the size of the field

Question 10

Where do we have smaller receptive fields?

Answer 10

Areas that require more nuance of sensation (face, hands, etc)

Question 11

Sclera

Answer 11

The white fibrous outer layer of the eye

Question 12

Cornea

Answer 12

The clear covering of 5-7 layers of non-keratinized epithelial tissue that allows light to pass through the anteriormost surface of the eye

Question 13

Corneal Epithelium

Answer 13

Anterior-most layer of the cornea

Question 14

Choroid

Answer 14

Highly vascular middle layer of the eye (dark part between sclera and retina)

Question 15

Ciliary Body

Answer 15

Smooth hair-like muscle that controls the shape of the lens

Question 16

Iris

Answer 16

Pigmented portion of the eye surrounding the pupil

Question 17

Iris Diaphragm

Answer 17

Controls pupil dilation

Question 18

Pupil

Answer 18

Open hole at the center of the iris that light passes through into the eye

Question 19

Retina

Answer 19

The interior light-sensitive layer of the eye that contains photo-receptors (rod & cone cells)

Question 20

Optic Disc

Answer 20

The spot on the retina where axons leave and blood vessels enters (the optic nerve connection)

Question 21

Macula

Answer 21

Oval-shaped lightly pigmented area of higher resolution for color vision (little dot near optic disc)

Question 22

Aqueous Humor

Answer 22

Clear, watery fluid that fills the space anterior to the lens

Question 23

Lens

Answer 23

Transparent structure that focus light on the retina

Question 24

Vitreous Body

Answer 24

Clear gel that fills the space posterior to the lens (inside retina and choroid)

Question 25

What are the cells if the retina?

Answer 25

**rod cells** - rhodopsin for low light vision **cone cells** - photopsins for color vision **bipolar cells** - connect rod and cone cells to retinal ganglion **retinal ganglion cells** - transmist image-forming and non-image forming info to the brain

Question 26

The Auricle

Answer 26

The visible part of the war that collects sound waves

Question 27

External Acoustic Meatus

Answer 27

Passage for sound that runs through the temporal bone

Question 28

Tympanic Membrane

Answer 28

Aka the ear drum - transmits sound to the middle ear

Question 29

Auditory Ossicles

Answer 29

**Malleus** - Superficial-most, hammer-shaped, attached to tympanic membrane **Incus** - middle, anvil-shaped ossicle **stapes** - deepest, stirrup-shaped ossicle attached to oval window

Question 30

Auditory Tube

Answer 30

Connects middle ear to Pharynx (long tube doing down below cochlea)

Question 31

What is the purpose of the auditory tube?

Answer 31

To equalize pressure

Question 32

Oval Window

Answer 32

Small circular membrane in vestibule where stapes attaches

Question 33

Vestibule

Answer 33

Midsection/Central Canal of inner ear

Question 34

Semicircular canals

Answer 34

Swooping horn-like parts superior to vestibule that maintain equilibrium and detect rotation of the head

Question 35

Cochlea

Answer 35

Snail-shaped cavity filled with fluid involved in hearing

Question 36

Parts of the Cochlea

Answer 36

**Vestibular duct** (behind oval window) **Vestibular membrane** (separates vestibular and cochlear ducts) **cochlear duct** (contains the spiral organ) **basilar membrane** (separates cochlear and tympanic ducts) **tympanic duct** (behind round window)

Question 37

Parts of the cochlear duct

Answer 37

**hair cells** - convert fluid movements to nerve signals **stereocilia** - extensions on hair cells that send signals when bent and transmist via CN VIII **tectorial membrane** - layers iver stereocilia of hair cells

Question 38

How do sound waves travel through the ear?

Answer 38

Collected by the *auricle* into the *external auditory meatus*. As the *tympanic membrane* moves the *auditory ossicles* (malleus to incus to stapes). Vibrations of the stapes causes the *oval window* to move back and forth, which generates waves in the *vestibular duct* This causes displacement of the *basilar membrane* which moves the stereocilia and bends hair cells, which generates a nerve impulse in CN VIII

Question 39

What are the parts of the tongue responsible for gustation (taste)?

Answer 39

**lingual papillae** - bumps on the tongue that grip and reposition food **taste buds** - on the side of lingual papillae that detect taste stimuli

Question 40

What are the 4 structures of olfaction (smell)?

Answer 40

**olfactory neurons** - have receptors that bind with chemicals in the air **olfactory nerves** - are bundles of axons from olfactory neurons **olfactory bulb** - structure where the olfactory nerves synapse **olfactory tracts** - bilateral bundles of nerve fibers connected to the brain