u3 - compendium review nervous function: part 2

8/14/2019 U3 - Compendium Review Nervous Function: Part 2

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Compendium Review

Major Topic One: Nervous FunctionTable of ContentsTable of Contents

Part 1

• The Organization of the Nervous System• The Central Nervous System: Brain & Spinal Cord• The Limbic System & Mental Functions

• The Peripheral Nervous System• Nervous System Diseases• Drug and Alcohol Effects

Part 2

• Sensory Receptors and Occurrence• Proprioceptors and Cutaneous Receptors• Taste and Smell• Vision

• Hearing• Equilibrium



• Sensory Receptors and OccurrenceSen

sory Receptors and Occurrence• Proprioceptors and Cutaneous ReceptorsProprioceptors and Cutaneous Receptors

• Taste and SmellTaste and Smell• VisionVision

• HearingHearing• EquilibriumEquilibrium

Picture & Verbiage from

http://www.britannica.co

“The cranial

nerves (I–XII)

and their

areas of

innervation”

http://www.britannica.com/eb/art-46720




Sensory Receptors and OccurrenceSenso

ry Receptors and OccurrenceExteroceptorsExteroceptors andand interoceptorsinteroceptors are dendrites, knownare dendrites, known

asas sensory receptorssensory receptors, that detect stimuli within the, that detect stimuli within the

PNS.PNS. ExteroceptorsExteroceptors identify stimuli that is outside theidentify stimuli that is outside the

body such as smell or hearing, whilebody such as smell or hearing, while interoceptorsinteroceptors identify stimuli inside the body such as blood pressureidentify stimuli inside the body such as blood pressure

rising. A receptor reacts to stimuli by sending nerverising. A receptor reacts to stimuli by sending nerve

impulses to the brain where theimpulses to the brain where the sensationsensation is perceived.is perceived.

The brain receives messages from nerves in differentThe brain receives messages from nerves in different

areas depending on the origin of the impulse. Once aareas depending on the origin of the impulse. Once a

sensory receptor has detected stimuli, they decode itsensory receptor has detected stimuli, they decode itand then send the signal. This process is known asand then send the signal. This process is known as

integrationintegration. If a particular stimuli becomes constant,. If a particular stimuli becomes constant,

sensory receptors may adapt and responses maysensory receptors may adapt and responses may

lessen. This is known aslessen. This is known as sensory adaptationsensory adaptation..

Types of Sensory ReceptorsT

ypes of Sensory ReceptorsChemoreceptors:Chemoreceptors: React to chemical substances such as taste, smell, and blood pH. NakedReact to chemical substances such as taste, smell, and blood pH. Naked

dendrites known asdendrites known as nociceptorsnociceptors (pain receptor) are responsible for responding to tissue damage.(pain receptor) are responsible for responding to tissue damage.

Photoreceptors:Photoreceptors: React to light, both rod cells and cone cells are found in our eyes.React to light, both rod cells and cone cells are found in our eyes.

Mechanoreceptors:Mechanoreceptors: React to pressures such as sound waves, motion and balance, and touch. TheReact to pressures such as sound waves, motion and balance, and touch. The

sensory organ they are found in is the ear.sensory organ they are found in is the ear.Thermoreceptors:Thermoreceptors: React to temperature changes (warmth and cold receptors).React to temperature changes (warmth and cold receptors).

Pic from Human

Biology Pg 275



• Sensory Receptors and OccurrenceSensory Receptors and Occurrence

• Proprioceptors and Cutaneous ReceptorsP

roprioceptors and Cutaneous Receptors• Taste and SmellTaste and Smell

• VisionVision• HearingHearing• EquilibriumEquilibrium

Muscle Spindle

Muscle Fiber

Tendon

Quadriceps

Muscle

1. Impulse to spinal

cord by sensory nerve

2. Impulse from spinal

cord by motor nerve

Pic from Human

Biology Pg 276



Proprioceptors & Cutaneous ReceptorsPro

prioceptors & Cutaneous Receptors• The bodies posture, balance, and reflexes are controlled by a type of mechanoreceptor (sensoryThe bodies posture, balance, and reflexes are controlled by a type of mechanoreceptor (sensory

receptor) known asreceptor) known as proprioceptorsproprioceptors. They help inform the brain about the position of limbs from joints. They help inform the brain about the position of limbs from joints

and skeleton muscles.and skeleton muscles.

• In the dermis layer of the skin are sensory receptors known asIn the dermis layer of the skin are sensory receptors known as cutaneouscutaneous receptors which allowreceptors which allow

the skin to feel temperature, touch, pressure, and pain. The specific cutaneous receptors which arethe skin to feel temperature, touch, pressure, and pain. The specific cutaneous receptors which are

responsible for touch areresponsible for touch are Meissner corpusclesMeissner corpuscles,, Krause end bulbsKrause end bulbs, and, and Merkel disksMerkel disks. The specific. The specific

cutaneous receptors which are responsible for pressure arecutaneous receptors which are responsible for pressure are Pacinian corpusclesPacinian corpuscles andand RuffiniRuffini

endingsendings..

When tissue isWhen tissue is

damaged it releasesdamaged it releases

chemicals which arechemicals which are

recognized byrecognized by

nociceptorsnociceptors (pain(painreceptors).receptors).

Pic from

Human Biology

Pg 277



• Sensory Receptors and OccurrenceSensory Receptors and Occurrence• Proprioceptors and Cutaneous ReceptorsProprioceptors and Cutaneous Receptors

• Taste and SmellTaste and Smell•

VisionVision


Types of PapillaeFungiform papillae - slightly mushroom shaped if looked at in section. These are present

mostly at the apex (tip) of the tongue, as well as at the sides. Innervated by facial nerve.

Filiform papillae - these are thin, long papillae "V"-shaped cones that don't contain taste buds

but are the most numerous. These papillae are mechanical and not involved in gustation.

Characterized increased keratinization.

Foliate papillae - these are ridges and grooves towards the posterior part of the tongue foundon lateral margins. Innervated by facial nerve (anterior papillae) and glossopharyngeal nerve

(posterior papillae).

Circumvallate papillae - There are only about 3-14 of these papillae on most people, and they

are present at the back of the oral part of the tongue. They are arranged in a circular-shaped

row just in front of the sulcus terminals of the tongue. They are associated with ducts of Von

Ebner's glands. Innervated by the glossopharyngeal nerve.Papillae picture & verbiage from http://en.wikipedia.org/wiki/Taste_buds

http://en.wikipedia.org/wiki/Fungiform_papillae

http://en.wikipedia.org/wiki/Filiform_papillae

http://en.wikipedia.org/wiki/Foliate_papillae

http://en.wikipedia.org/wiki/Circumvallate_papillae

http://en.wikipedia.org/wiki/Image:Gray1018.png

http://en.wikipedia.org/wiki/Circumvallate_papillae

http://en.wikipedia.org/wiki/Foliate_papillae

http://en.wikipedia.org/wiki/Filiform_papillae

http://en.wikipedia.org/wiki/Fungiform_papillae



TasteTaste• Classified asClassified as chemoreceptorschemoreceptors,, tastetaste andand smellsmell ((olfactoryolfactory) receptors react to molecules) receptors react to molecules

in the air and food. Chemoreceptors attach to certain molecules and react differently.in the air and food. Chemoreceptors attach to certain molecules and react differently.

Direct stimuliDirect stimuli is detected by taste cells, whereasis detected by taste cells, whereas distant stimulidistant stimuli is detected by olfactoryis detected by olfactorycells.cells.

• The little bumps on our tongues are known asThe little bumps on our tongues are known as papillaepapillae, and contain about 3,000 taste, and contain about 3,000 taste

buds (sweet, sour, salty, bitter, and umami). When we eat or drink something, our tastebuds (sweet, sour, salty, bitter, and umami). When we eat or drink something, our taste

buds open and allow molecules to attach to receptor proteins. Sensory nerve fibers sendbuds open and allow molecules to attach to receptor proteins. Sensory nerve fibers send

messages to the brain which processes the information in themessages to the brain which processes the information in the gustatorygustatory cortex (taste)cortex (taste)

and interpret it.and interpret it.

Pic from Human Biology Pg 278



SmellSmell• In the roof of the nasal cavity is theIn the roof of the nasal cavity is the olfactory epitheliumolfactory epithelium which contains millions of which contains millions of

olfactory cellsolfactory cells. Similar to neurons, these cells end in. Similar to neurons, these cells end in olfactory ciliaolfactory cilia where receptor where receptor

proteins attach to odor molecules. Certain neurons in the olfactory bulb are aroused byproteins attach to odor molecules. Certain neurons in the olfactory bulb are aroused by

certain odor molecules.certain odor molecules.

Pic fromHuman Biology

Pg 279



• Sensory Receptors and OccurrenceSensory Receptors and Occurrence• Proprioceptors and Cutaneous ReceptorsProprioceptors and Cutaneous Receptors• Taste and SmellTaste and Smell

• VisionVision• HearingHearing• EquilibriumEquilibrium




VisionVisionThe eyeball has 3 layers: theThe eyeball has 3 layers: the sclera (outer)sclera (outer), the, the choroid (middle)choroid (middle), and the, and the retina (posterior retina (posterior

compartment)compartment)..

1. Sclera1. Sclera: Supports eyeball, fibrous and white colored, contains: Supports eyeball, fibrous and white colored, contains corneacornea (clear collagen fibers) which(clear collagen fibers) which

is responsible for refracting light. Behind the cornea is theis responsible for refracting light. Behind the cornea is the pupilpupil, a hole which admits light., a hole which admits light.

2. Choroid2. Choroid: responsible for absorbing any stray rays that have not been absorbed by: responsible for absorbing any stray rays that have not been absorbed byphotoreceptors. Dark layer which is constant with thephotoreceptors. Dark layer which is constant with the ciliary bodyciliary body (keeps lens in place, controls lens(keeps lens in place, controls lensshape, found behind iris) andshape, found behind iris) and irisiris (controls light entrance and pupil size). Attached to the ciliary body(controls light entrance and pupil size). Attached to the ciliary bodyis theis the lenslens which refracts light and helps with focus. Thewhich refracts light and helps with focus. The anterior compartmentanterior compartment (in front of lens) is(in front of lens) isfilled withfilled with aqueous humor aqueous humor , a clear fluid; the, a clear fluid; the posterior compartmentposterior compartment is filled withis filled with vitreous humor vitreous humor , a, aclear gel.clear gel.

3. Retina3. Retina: Located next to: Located next toposterior compartmentposterior compartment, contains, containsrod cells and cone cells.rod cells and cone cells. RodRodcellscells only see black-and-whiteonly see black-and-whiteand are sensitive to light rays.and are sensitive to light rays.

Cone cellsCone cells see color andsee color andcommand bright light. Betweencommand bright light. Betweenthe retina and the posterior the retina and the posterior compartment is thecompartment is the foveafoveacentraliscentralis, an area of compacted, an area of compactedcone cells which helps sharpencone cells which helps sharpenvision. Thevision. The optic nerveoptic nerve is formedis formedfrom sensory fibers off the retinafrom sensory fibers off the retinaand takes impulses to the brain.and takes impulses to the brain.

Pic from Human

Biology Pg 280


http://slidepdf.com/reader/full/u3-compendium-review-nervous-function-part-2 11/20Pic from Human Biology Pg 280

Images are focused on the retina by assistance

from the cornea, lens, and humors. Visual

accommodation occurs when looking at an

object up close. The lens will round to help with

the focusing of the image on the retina. The

ciliary muscle is responsible for giving the lens

its shape. When looking at an object in the

distance, the lens will flatten through the

relaxation of the ciliary muscle.



VisionVisionRod cellsRod cells andand cone cellscone cells areare

photoreceptorsphotoreceptors in the eyes. Both rodsin the eyes. Both rods

and cones consist of anand cones consist of an inner and outer inner and outer

segmentsegment connected to each other withconnected to each other withsynaptic endingssynaptic endings located at the bottomlocated at the bottom

of the inner segments below theof the inner segments below the

nuclei's.nuclei's. RhodopsinRhodopsin is the deep purpleis the deep purple

visual pigment in rod cells which isvisual pigment in rod cells which is

structured of structured of opsinopsin (protein molecule)(protein molecule)

andand retinalretinal (vitamin A derivative/light(vitamin A derivative/lightsensitive). Depending on their pigment,sensitive). Depending on their pigment,

cone cellscone cells, which provide color vision,, which provide color vision,

come in three colors:come in three colors: blueblue,, greengreen, and, and

redred. Although the pigments are. Although the pigments are

structured with the same proteinstructured with the same protein

molecule and retinal as rod cones, themolecule and retinal as rod cones, the

three pigmented cone cells havethree pigmented cone cells havedifferent structures to their proteindifferent structures to their protein

molecules which allows them to absorbmolecules which allows them to absorb

light differently.light differently.

Rod Cells are great for Rod Cells are great for night time visionnight time vision

andand peripheral visionperipheral vision while cone cellswhile cone cells

are utilized for are utilized for color visioncolor vision.. Pic from Human

Biology Pg 282



VisionVisionThe retina hasThe retina has 3 layers3 layers: rod & cone cell layer, bipolar layer, and the ganglion cell layer.: rod & cone cell layer, bipolar layer, and the ganglion cell layer.

1. Rod & Cone Cell Layer:1. Rod & Cone Cell Layer: Closest to choroid, sensitive to light, synapse with bipolar layer,Closest to choroid, sensitive to light, synapse with bipolar layer,

integration occurs as they transmit signals to next layer.integration occurs as they transmit signals to next layer.

2. Bipolar Layer:2. Bipolar Layer: Middle layer, each bipolar cell is utilized by several rod cells, they are bipolar Middle layer, each bipolar cell is utilized by several rod cells, they are bipolar

because they can be utilized by rod or cone cells (not both), integration occurs as they transmitbecause they can be utilized by rod or cone cells (not both), integration occurs as they transmit

signals to next layer.signals to next layer.

3. Ganglion Cell Layer:3. Ganglion Cell Layer: Send nerve impulses to visual cortex via optic nerve, more integrationSend nerve impulses to visual cortex via optic nerve, more integration

occurs in visual cortex.occurs in visual cortex.

Pic from Human

Biology Pg 283



VisionVisionThe nerve impulse carried by the optic nerve are taken from theThe nerve impulse carried by the optic nerve are taken from the optic chiasmaoptic chiasma (X-shape of optic(X-shape of optic

nerves) through thenerves) through the right and left optic tractsright and left optic tracts to theto the thalamusthalamus where the nerve impulses arewhere the nerve impulses are

delivered to thedelivered to the visual cortexvisual cortex in thein the occipital lobeoccipital lobe. The combined data allows us to see the entire. The combined data allows us to see the entire

visual section.visual section.

Some abnormalities of the eyes may beSome abnormalities of the eyes may be color blindnesscolor blindnessdue to flawed cones or a deficiency in cones. Peopledue to flawed cones or a deficiency in cones. People

who arewho are nearsightednearsighted can see objects up close better can see objects up close better

than objects at a distance due to elongated eyeballs,than objects at a distance due to elongated eyeballs,

whereas people who arewhereas people who are farsightedfarsighted can see objects atcan see objects at

a distance better than they can see objects up closea distance better than they can see objects up close

due to shortened eyeballs.due to shortened eyeballs. AstigmatismAstigmatism can causecan cause

blurry vision due to an unevenness in the lens or blurry vision due to an unevenness in the lens or cornea. This can be treated withcornea. This can be treated with LASIK surgeryLASIK surgery..




• Sensory Receptors and OccurrenceSensory Receptors and Occurrence• Proprioceptors and Cutaneous ReceptorsProprioceptors and Cutaneous Receptors• Taste and SmellTaste and Smell• VisionVision


Pic from http://en.wikipedia.org/wiki/Ear

Th t i k th i hi h h th t dit l t th

http://en.wikipedia.org/wiki/Image:HumanEar.jpg



HearingHearing

The outer ear is known as theThe outer ear is known as the pinnapinna which houses the entrance, or which houses the entrance, or auditory canalauditory canal, to the, to the

tympanic membranetympanic membrane.. Sweat glandsSweat glands in the auditory canal secretein the auditory canal secrete ear waxear wax to protect againstto protect against

foreign objects entering. Theforeign objects entering. The tympanic membranetympanic membrane, or ear drum, enters the middle of the ear , or ear drum, enters the middle of the ear

and stops at a bone with two small openings known as theand stops at a bone with two small openings known as the oval and round windowsoval and round windows. The. The

boney wall consists of three bones, theboney wall consists of three bones, the malleusmalleus (sticks to tympanic membrane), the(sticks to tympanic membrane), the incusincus ,,

and theand the stapesstapes (touches the oval window), all of which amplify sound waves. All three are(touches the oval window), all of which amplify sound waves. All three are

known as theknown as the ossiclesossicles. Inside the ear is the. Inside the ear is the auditory tubeauditory tube which helps equalize pressure. Thewhich helps equalize pressure. The

inner ear inner ear is filled with fluid and contains theis filled with fluid and contains the semicircular canalsemicircular canal (contains equilibrium(contains equilibrium

mechanoreceptors), themechanoreceptors), the vestibulevestibule (contains equilibrium mechanoreceptors), and the(contains equilibrium mechanoreceptors), and the cochleacochlea

(contains hearing mechanoreceptors).(contains hearing mechanoreceptors).

The sensory

receptors in the ear

contain hair cells with

very long microvilli(stereocilia) that are

responsive to

stimulation.




HearingHearingSound wavesSound waves travel through thetravel through the auditory canalauditory canal

where it vibrates thewhere it vibrates the tympanic membranetympanic membrane and theand the

malleusmalleus transfers the pressure to thetransfers the pressure to the incusincus. It is. It is

then transferred to thethen transferred to the stapesstapes where it is magnifiedwhere it is magnifiedapproximately 20 times. The pressure is thenapproximately 20 times. The pressure is then

passed to the fluid in thepassed to the fluid in the cochleacochlea after theafter the stapesstapes

hits thehits the oval windowsoval windows membrane. Inside themembrane. Inside the

cochlear canalcochlear canal is theis the spiral organspiral organ, which consists of , which consists of

hair cells and a gel substance known as thehair cells and a gel substance known as the

tectorial membranetectorial membrane. The. The cochleacochlea has two canals,has two canals,

thethe vestibular vestibular and theand the tympanictympanic. Once the pressure. Once the pressureis transferred from the oval windows membrane,is transferred from the oval windows membrane,

the pressure moves across thethe pressure moves across the basilar membranebasilar membrane

to theto the tympanic canaltympanic canal..

StereociliaStereocilia on theon the hair hair

cellscells in the membranein the membranebend when the basilar bend when the basilar

membrane vibrates.membrane vibrates.

TheThe cochlear nervecochlear nerve isis

where the impulseswhere the impulses

begin and arebegin and are

transmitted to thetransmitted to the

brain as sound.brain as sound.Pic from Human Biology Pg 287

S O



• Sensory Receptors and OccurrenceSensory Receptors and Occurrence• Proprioceptors and Cutaneous ReceptorsProprioceptors and Cutaneous Receptors• Taste and SmellTaste and Smell• VisionVision


Balance Skills Developed

Pic from http://en.wikipedia.org/wiki/Equilibrioception

http://en.wikipedia.org/wiki/Image:Zuni-girl-with-jar2.png

http://en.wikipedia.org/wiki/Image:Balance.JPG



EquilibriumEquilibriumEquilibriumEquilibrium is ais a

physiological sense for physiological sense for

balance; it helps us withbalance; it helps us with

standing and walking. Therestanding and walking. There

are many factors which aidare many factors which aid

in equilibrioception: thein equilibrioception: the

vestibular nervevestibular nerve takestakes

impulses to the brain stemimpulses to the brain stem

and cerebellum,and cerebellum,

proprioceptorsproprioceptors (sensory(sensory

receptors) help inform thereceptors) help inform thebrain about the position of brain about the position of

limbs from joints andlimbs from joints and

skeleton muscles,skeleton muscles,

semicircular canal hair cellssemicircular canal hair cells

(mechanoreceptors) help(mechanoreceptors) help

detectdetect angular/rotationalangular/rotational

movements in the head,movements in the head,

andand utricleutricle (membranous(membranous

sac in inner ear) andsac in inner ear) and

sacculesaccule (membranous sac(membranous sac

in inner ear)in inner ear) hair cellshair cells helphelp

detectdetect horizontal/verticalhorizontal/vertical

movements.movements.Pic from Human Biology Pg 290



Works CitedWorks Cited"cranial nerve." Online Art. 2008. Encyclopedia Britannica Online. 30 Mar. 2008

<http://www.britannica.com/eb/art-46720>.

"Ear." Wikipedia, The Free Encyclopedia. 1 Apr 2008, 02:16 UTC. Wikimedia Foundation, Inc. 1 Apr 2008

<http://en.wikipedia.org/w/index.php?title=Ear&oldid=203198294>.

"Equilibrioception." Wikipedia, The Free Encyclopedia. 24 Mar 2008, 03:55 UTC. Wikimedia Foundation, Inc. 1

Apr 2008

<http://en.wikipedia.org/w/index.php?title=Equilibrioception&oldid=200458187>.

Mader, Sylvia S.Mader, Sylvia S. Human BiologyHuman Biology. New York: The McGraw-Hill Companies, Inc, 2008. Pages 273-293.. New York: The McGraw-Hill Companies, Inc, 2008. Pages 273-293.

"Taste bud." Wikipedia, The Free Encyclopedia. 1 Apr 2008, 00:21 UTC. Wikimedia Foundation, Inc. 1 Apr 2008

<http://en.wikipedia.org/w/index.php?title=Taste_bud&oldid=202429441>.


http://en.wikipedia.org/w/index.php?title=Ear&oldid=203198294

http://en.wikipedia.org/w/index.php?title=Equilibrioception&oldid=200458187

http://en.wikipedia.org/w/index.php?title=Taste_bud&oldid=202429441

http://en.wikipedia.org/w/index.php?title=Taste_bud&oldid=202429441

http://en.wikipedia.org/w/index.php?title=Equilibrioception&oldid=200458187

http://en.wikipedia.org/w/index.php?title=Ear&oldid=203198294


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