Chapter 16- sense organs

visual projection pathway

1. bipolar neurons 2. retinal gangglion cells 3. optic nerve 4. optic chiasm 5. optic tracts 6. thalamus 7. occipital lobe.

Give the steps to produce sound.

1. sound waves collected by auditiory canal 2. sound waves vibrate tympanic membrane which vibrate ossicles to vibrate inner fluid 3. ossicles inreas the force of vibrations against the oval window 4. stapes pushes on perilymph of scala vestibuli 5. perilymph pushes down on endolymph of cochlear duct 6. basilar membrane puts pressure on perilymph of scala tympani 7. hair cells that detect vibrations are on the basilar membrane. movement of the basilar membrane move the cilia and depolarizes them so they release an NT that stimulates dendrites at their base.

Define emmetropia

Emmetropia is the term for normal vision. (20/20)

Why do kids get more ear infections?

Eustachian tube is smaller and more horizontal in children Poor fluid drainage from middle ear

What is 1st pain?

Its a quick signal of pain sent by myelinated pain fibers. feelings of sharp, local, stabbing pain at the time of injury

what is 2nd pain?

Its a slow signal of pain sent by unmyelinated pain fibers. feelings of dull, longer lasting, diffused feeling

a patient with diabetes mellitus comes in with a gangrenous toe and doesn't know how it happened. Can you explain why?

People with diabetes mellitus destroy their own nerves. Injuries are likely to be neglected and then become infectious.

What does the cornea do?

Refracts light into the eye

T or F: the retina can detach with a blow to the head.

T

Tor F: the optic disc contains no receptors cells

T

the chemical stimuli of taste is called...

a tastant

sensory projection

ability of the brain to identify the site of stimulation

define light adaptation

adjustment to bright light after experiencing darkness. Rods bleach quickly and cones take over, nociceptors can activate here sometimes

what is the perception of sound energy, intensity, or loudness of a vibration?

amplitude

The central nervous system has _____mechanisms to relieve pain secreted in the form of ______.

analgesic;opioids

the eye consists of two cavities: ___ and ____

anterior and psoterior

receptive field

any sensory neuron that detects a stimulus in a certain area

What is the suspensory ligament?

attaches the lens to the ciliary body, holding lens in place and in shape

What is a "tip link" protein?

attaches tip of each stereocilium in a hair bundle to the side of the next longer stereocilium

optic disc is

attachment point where optic nerve EXITS back of eye

the passage to the nasopharynx that equalizes air pressure and drains the middle ear is called...?

auditory (Eustachian) tube

what does the outer ear consist of?

auricle and auditory canal (external aud. meatus)

free nerve endings

bare dendrites that have no special association with other accessory cells, organs, or tissues -include warm + cold receptors -include pain

What part of the whole taste bud structure contains the stem cells that multiply and replace old taste cells?

basal

why dont cones work in the dark?

because they dont have convergence or spatial summation (like rods do) so they dont have enough sensitivity

rods and cones synapse with the dendrites of this ______neuron and then synapse with ganglion cells. Also make up first order neurons in the visual pathway

bipolar neuron

the _____ papillae is in the same place that you would find the _____ portion on the tongue (bitter/sweet, umamai, salty, sour etc)

bitter

this taste association is associated with alkaloids, spoiled foods, and poisons (Ex: caffeine)

bitter

what is the visual pigments for photopsin?

blue, green, and red; replaces photopsin in 90 seconds

the scala tympani is on top or bottom?

bottom

what is the most potent pain related chemical released by injured tissues to stimulate nociceptors?

brandykinin

which pain chemical promotes healing?

brandykinin

How do taste buds regenerate?

by mitosis

what is the actual name for earwax?

cerumen

what layer of the eye does the retina depend on for nourishment, oxygen, and waste removal?

choroid layer

aqueous humor is a serous fluid secreted by the _____ ____ into a space called the _____ _____ between the iris and the lens. flwos through the pupil into the _____ ______ between the cornea and the iris

ciliary body, posterior chamber, anterior chamber

in the dark, what is the retinal bent shape of a rod called?

cis-retinal

What does cataracts look like?

cloudiness of the lens; red reflex may be absent or appear black.

cataract

clouding of the lens of the eye

What is the organ of hearing?

cochlea because of organ of corti

Explain sour sensation

come from acidic fruits, and H+ in food.

in the macula lutea you have a tiny pit called the fovea centralis

concentrated color receptors allowing for finely detailed images

What structure of the eye prevents it from drying and is highly sensitive to pain?

conjuctiva

the _______ is a transparent mucous membrane that covers the inner surfaces of the eyelid and front surface of eyeball (EXCEPT FOR CORNEA. DOES N O T COVER CORNEA). -it is also VERRRRRY vascular. But the cornea is not.

conjuctiva -this gives you the bloodshot eyes appearance

what are the three processes of near response/focusing on an image/ accommodation?

convergence ( example: moving finger close to babies face) constriction of pupil to target light lens accommodation (adjusting thickness)

The optical components/apparatus are transparent elements that admit light rays, bend them, and focus images on the retina. what makes up the optical apparatus/components? (4)

cornea, aqueous humor, lens, vitreous body

astigmatism

defective curvature of the cornea and lens, which causes light rays to focus unevenly over the retina rather than being focused on a single point, resulting in a distorted image

Hair receptors (peritrichial endings)

dendrites that coil around a hair follicle and respond to movements of the hair

unencapsulated nerve endings are __________________________________.

dendrites with no connective tissue wrapping

pupil - adjusts size based on how much light needs to enter the eye refraction- bending the light emmetropia- normal vision accommadation- near response; adjustment to close range vision

describing the 4 steps of image formation

Give three examples of endogenous opioids.

endorphins, dynorphins, enkephalins

the sense of body orientation, movement, and balance is known as _____.

equillirium

hyperopia; eyeball too short

farsightedness; light rays focus behind the retina

Which papillae is the most abundant on the tongue?

filiform

which papillae doesn't sense taste and why?

filiform because it has no taste buds

which papillae serve in the sense of mouthfeel?

filliform and fungiform

unencapsulated nerve endings (3)

free nerve endings tactile (Merkel) discs hair receptors

The number of wave cycles(movement of object vibrating back and forth)

frequency

What is visceral pain?

from viscera such as stretch, chemical irritants, or ischemia (lack of oxygen)

Name the four papillae found on the tongue

fungiform filliform foliate vallate

which neuron is the largest neuron in the eye?

ganglion

the RESPONSE to vibrating air molecules is...

hearing

in 1st order fibers, there are small, unmyelinated fibers (slow). What do they detect?

heat and cold

presbyopia

impaired vision as a result of aging, loss of lens elasticity, near point vision is gone

whee would you find the inner ear?

in bony labyrinth (maze of passageways) within the temporal bone

astigamatism leads to

inability to focus on light rays that enter the eye on different planes

Glaucoma

increased intraocular pressure results in damage to the retina

equilibrium is the coordination and balance of the body is controlled by the ____ ____

inner ear

everything that we hear comes from which hair cell? inner or outer? What does the latter do?

inner; the outer fine tunes

what does endogenous opioid mean?

internally produced opium like substances

if receptor potential exceeds the threshold....

it releases an NT

what is the purpose of pigment epithelium?

its hella pigmented for a reason, it absorbs stray light so it doesnt reflect back into the retina and distort the image

a sensory nerve fiber that is labeled based on the type of receptor it comes from so the brain can interpret where they come from

labeled line code

describe image formation:

light rays enter eye, becomes focused on retina, produce tiny images in brain 1. pupil pupillary constrictors or dilators adjust diameter of pupil to increase/decrease amount of light that enters eyes 2. refraction- image formation -> bending of light rays by the cornea, lens, and humors 3. emmtropia- far vision; this is a state in which the eye is relaxed and focused on an obect thats kind of far. (eye spread out) 4. accomodation adjustment to close range vision -convergence- eyes turn inward (see picture) -pupil constriction- remove excess light -lens accommodation- change in curvature of lens for near vision

difference in end bulbs and tactile corpuscle

like tactile corpuscle but found in mucous membrane and not skin

The visible bumps on the tongue are not taste buds but called.... (there are 4 types too)

lingual papillae

if the brain receives signals from the inner hair cells @the DISTAL end of the basilar membrane, the brain interprets it as what kind of sound...?

low pitched

the saccule and utricle both have supporting hair cells called what?

macula- they lie on the wall/floor of the saccule/utricle

where would you find nociceptors in the brain

meninges

sensory receptors transmit 4 types of info remember MILD

modality, location, intesity, and duration

conjuctiva

mucous membrane that lines the anterior surface of the eye is highly vascular

myopia; eyeball too long

nearsightedness; light rays come into focus before they reach retina

encapsulated nerve endings

nerve fibers wrapped in glial cells or connective tissue to increase sensivity

Endogenous opioids function as ________by blocking pain messages from entering dorsal horn and produce feelings of pleasure. <<<an example of _____ _____.

neuromodulators; spinal gating

any rods in the fovea centralis?

no

are there any rods in the fovea centralis?

no

Are hair cells neurons?

no, but they connect to them at their bases

The smell of hot peppers, ammonia, chlorine, and other toxic like substances stimulate a different receptor. What is it?

nociceptor

What does "bleaching" mean in regards to rhodospin?

occurs asrhodopsin pigment is used and replaced

Which taste sensation tastes for fats?

oleogustus

olfactory pathway

olfactory fibers through roof of nose -> olfactory bulb -> olfactory tract -> olfactory nerve ->temporal lobe (in primary olfactory cortex -> insula and obritofrontal to identify odor

olfactory neruons (cells) are bowling pin shaped cells which are modified dendrites with cilia called _____ _____ which are bonding sites for odor molecules

olfactory hairs

where would you find foliate papillae?

on the sides of the tongue (Look where the yellow arrow is pointing)

cochlear duct: what does it contain and where it at?

organ of corti, between scala vestibule and scala tympani

what transducer converts vibrations into nerve impulse in the ear?

organ of corti/ spiral organ

Define static equilibrium

orientation of the head when we aren't moving

ear is divided into 3 parts. what are they?

outer, middle, inner

what does spinal gating mean?

pain signals stopped by opioids etc at the dorsal horn so it doesnt reach the brain

what is the pathway for pain from the head?

pain signals travel to brainstem by way of 4 cranial nerves 2nd order neurons pop up in medulla and then send those signals to thalamus thalamus sends to cerebral cortex

Define dynamic equilibrium

perception of motion or acceleration

_____ receptors burst for short time and then ADAPT

phasic "just a phase"

lamellar corpuscle

phasic, deep pressure and vibration

Tactile corpuscles (Meissner's corpuscles)

phasic; light touch, texture, pressure -concentrated in sensitive hariless areas

what is the visual pigment for cones?

photopsin; cones work better with light. also works with color vision

what is photopsin?

pigment in cones

Our sense of how high or low a sound is is called (think of sopranos, tenors, altos, and basses)

pitch

the nature of sound is defined by...? (2)

pitch and amplitude

Which receptor determines stretch: mechano or proprio?

proprio

The initial effect of a stimulus on a sensory receptor is a local electrical change specifically called a(an) _____ _____.

receptor potential

Where are odorants detected in the nose?

receptors in the olfactory mucosa

three kinds of cones

red, green, blue

a person with a heart ttack might feel the pain going down his arm instead of where one thinks it would be. This is an example of ______ and deals with converging neural pathways in the body

referred pain

the structure that works the conversion of light energy into action potentials is called what

retina

the neural components are the ____ and the ____ ___.

retina and the optic nerve

what is the visual pigment for rods and why is it there?

rhodospin (visual purple); to absorb light

which photoreceptor is responsible for scoptic (night) vision?

rods

what are the 2 types of photoreceptor cells?

rods and cones

which take longer to regenerate: rods or cones?

rods because they go through a whole bleaching process. takes 5 minutes

what is the superior portion of the cochlea called? The inferior?

scala vestibuli; scala tympani

From superior to deep: the layers of the eye (not the tunica stuff)

sclera, choroid, retina

which order neuron descussates?

second; leads to contralateral thalamus

Define gustation

sense of taste chemicals dissolved in saliva to make them detectable by taste buds

_____ ____ is the transmission of information from a receptor, or receptive field to a specific spot in the brain

sensory projection

what other things does tissue release in response to injury? (the answer is not substance P and brandykinin)

serotonin histamine k ions prostaglandins ATP

Proprioceptive signals are the only ones that don't follow typical first-third order neuron path. What makes them different?

signal ends up carried by 2nd order neuron to cerebellum instead of cerebrum

What is somatic pain?

skin muscles joints superificial/deep

audible vibration of molecules when they collide with each other

sound

this taste sensation is associated with acids and spoiled foods

sour

Dim light requires high sensitivity to different levels of low light so that one can see in the dark. This is due to neural convergence of a lot of rods falling onto a single bipolar cell. What is this an example of?

spatial summation (input from many to produce total)

Explain bitter sensation

spoiled food, posion, alkaloids, resides at the back ot tongue

the sense of equilibrium is divided into ____ and _____

static and dynamic

what is the word for depth perception?

stereoscopic

which vision allows us to have depth perception?

stereoscopic

define sense organ

structure that combines nervous tissue with other tissues that enhance its response to a certain type of stimulus

the lens is held up by _____ _____

suspensory ligament

name the 6 encapsulated nerve endings

tactile corpuscles (Meissner) end bulbs bulbous corpuscles lamellar corpuscles muscle spindles tendon organs

Which of the encapsulated nerve endings heavily concentrated in hairless areas?

tactile corpuscles (meissner)

____ glands along edge secrete oil to reduce tear evaporation

tarsal

____ ____ onion shaped cells in grouos of cells like supporting cells and gustation (taste)cells.

taste bud

give the taste pathway.

taste buds >>>CN # 7,9, or 10>>> medulla>>>2nd order neurons carry to hypothalamus and amygdala OR thalamus

what are the microvilli of taste cells called and where do they project into?

taste hairs; taste pores

what part of the brain filters out unwanted stimulus/information so it blocks any sensation (conscious awareness of stimuli)

thalamus

what is pitch determined by?

the FREQUENCY of vibration

In response to a sudden loud noise (like a gunshot), what does the tensor tympani muscle do? (This is the tympanic reflex)

the muscle pulls the tympanic membrane inward and tenses it for protection

Mouthfeel

the tactile sensation of food in the mouth; interaction of physical and chemical characteristics of the food Basically how it feels in your mouth

rubbing your elbow after bumping into a hard surface tends to help it feel better. Explain why.

there are mechanoreceptors in the body that are received by the same interneurons (the integrating neurons) so it reduces pain

how do endogenous opioids work in the body?

they block pain signals and produce feels of pleasure and euphoria

For rods, many converge onto one neuron. For cones...

they each have their own neuron

Can you explain runner's high?

they have endogenous opioids running through their bodies so it creates feeling of euphoria

What does the middle ear consist of?

three ossicle bones (malleus, incus stapes), tympanic membrane, auditory tube

where would you find taste buds in the body? (5)

tongue pharynx epiglottis soft palate cheeks

_____ receptors adapt slowly

tonic

bulbous corpuscles

tonic receptors for heavy touch, pressure, stretching of the skin, and joint movements

Tactile discs (Merkel discs)

tonic receptors for light touch and texture, and shapes

scala vestibuli: top or bottom

top

in 1st order neurons there are large, myelinated fibers (fast). what do they detect?

touch, pressure, proprioception

when cis-retinal absorbs light and it changes into its straight form, what is it called now? what does it break away from?

trans-retinal and it breaks away from opsin

sensory receptors are sensory ______ that convert assorted types of stimuli energy into nerve energy

transducer

fundamental purpose of any sensory receptor is ______, the conversion of one form of energy into another (light > nerve signals)

transduction

T or F: our sense of smell is needed for taste

true

the three layers of the eye (tunica stuff)

tunica fibrosa- sclera + cornea tunica vasculosa- choroid +cilliary body + iris tunica interna- retina + optic nerve

organize the tunics and their components from superficial to deep. (dont worry about naming the components from superficial to deep)

tunica fibrosa- sclera and cornea (scelra is the white of the eye) (the conrea admits light into the eye) tunica uvea- choroid, ciliary body, iris (choroid is very vascular, pigmented layer of tissue) (ciliary body- thick extension of choroid that supports iris and lens and secretes aqueous humor) (iris controls diameter of pupil) tunica interna- retina (retina- lines interior of eyeball= beginning of optic nerve

Eye has three layers called

tunics

define modality

type of stimulus received

which papillae contains half of all taste buds?

vallate

receptors for equilibrium make up the vestibular apparatus. What 3 things make this up?

vestibular apparatus semiciruclar ducts saccule utricle

the chamber that contains the organs of equilibrium is called the

vestibule

The interpretation of light rays received from the environment is called_____

vision

the vitreous chamber behind the lens is filled with a fluid called ____ _____

vitreous body/humor

What is the duplicity theory of vision?

we have both rods and cones b/c one type of receptor canNOT produce high sensitivity AND high resolution @ the same time "humans need both in order to survive"

Where does the inner ear begin?

with the oval window