Review 4 Chap 12-16

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Biology 430: Unit #4 Spring2010

Chapter 12: Nervous Tissue

1. What are the two general cell types found within nervous tissue? What are their general

functions? Which is excitable? Which can become cancerous? (see also Chapter 4, p139-140)

Nervous Tissue

Two general types:

1) Neuron: nerve cell

Fxn: responds to a stimulus with an action potential

2) Neuroglia

Fxn: to support neurons (protects, feeds, etc.)

NEUROGLIA can become cancerous by forming brain tumors from glia, called gliomas.

2. Describe the overall organization of the nervous system (CNS, PNS, ANS, etc.). What are the

functions of each specific system? (p425-426)

CNS: brain and spinal cord

Peripheral NS: Nervous tissue outside of the brain and spinal cord.

Somatic NS: FXN= voluntary movement(somatic motor neuron stimulate skeletal muscle),Perceived sensation (sensation that you are conciously aware of)

Autonomic NS: FXN=Involuntary movement (autonomic motor neurons stimulate skeletal MT

cardiac MT and glands), NON-Percived sensation (ex. Sensing Blood Pressure)

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3. Describe the anatomy of a neuron. What are the function(s) of each part/component? Define

neurotransmitter.

4. Describe the two ways substances are transported up and/or down the axon. What is the ratof axon healing in the PNS? At what rate does the rabies virus travel to get to the CNS?

Pg.419

Axonal transport-2 ways

1) Slow- ~3mm/day

-one direction only (away from cell body)

FXN=to move axoplasm down axon from growth and repair.

2) Fast- ~300mm/day

-uses microtubules & ATP

FXN: moves vesicles up and down axon (2 directions)

Axon: FXN: Transport APAxolemma: Plasma mbn of axonAxoplasm: Cyotplasm of axon

Axon terminalSynaptic end bulb: FXN: to release

neurotransmitter (chemical released

by the synaptic end bulb thatstimulates an effector (ex. Ach)

Dendrite: FXN: receives stimulation

Nucleus: FXN: codes for protein (exNeurotransmitter)

Nissle bodies: Rough ERNeurofibrils: FXN: structural

support, through intermediatefilament.

Trigger Zone: fxn: triggers Actionpotential.

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5. Describe the functional and structural names of neurons. Where are each located?

Pg.420 (figure 12.11)

3 functional names for neurons

1) Sensory Afferent Neurons (AP arrives at CNS)

2) Motor Efferent Neuron (AP exits the CNS)

3) Interneuron (btwn two neurons)

3 structural names for neurons

Definition: process= outgrowth from cell body (dendrite)

1) Multipolar neuron -> 2 processes

2) Bipolar neuron -> 2 processes

LOC: the eye

3) Unipolar Neuron-> 1 process

LOC: sensory afferent neuron

6. Describe the different types of neuroglia in the PNS and CNS. What are their functions ?

Neuroglia

-FXN: supports neurons

-6 types: (2 in peripheral NS, and 4 in the central NS)

2 PNS Neuroglia

1) Satellite cell- surround cell bodies of the unipolar neurons

FXN: provide a proper chemical environment for the neuron.

2) Schwann cell-

FXN: forms the myelin sheath around axon, and forms the neurolemma.

4 CNS Neuroglia

1) Oligodendrocyte:

FXN: myelinates axons in CNS

~ one cell mylenates many axons.

Thus there is no neurolemma in the CNS.

Thus axons dont heal well in the central nervous system.

2) Astrocyte: large, star shaped cell

- Most numerous neuroglia

FXN:

1) Provides structural support

2) Guide the neuron connection for learning.

3) Provides the proper chemical environment for neurons.

4) Remove excess NT (neurotransmitter)

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5) Helps form the Blood Brain Barrier=FXN: prevents harmful substances from entering th

brain

3) Microglia: phagocyte

FXN: remove debree or microbes, etc.

4) Ependymal cell:

-line the spaces in the CNS

FXN:

1) produce cerebrospinal fluid (CSF) which fills the spaces (ventricles)

2) Help circulate the cerebral spinal fluid

What are the functions of the myelin sheath and neurolemma?

Myelin sheath: multilayered lipid and protein covering, insulates axons & increase thespeed of nerve impulse conduction.

Neurolemma: nucleated cytoplasmis layer of Schwann Cell which encloses myelin sheath,

only found around axons in PNS

FXN: when axon is injured it helps aid regeneration by forming tube that guides &

stimulates regrowth of axon.

What is the blood-brain barrier?

Blood Brain Barrier: FXN= prevents harmful substances from entering the Brain

How do axons heal?

-Some axons can not heal, like the ones in the CNS, but those in the PNS may still be able.

Where do axons heal better in the CNS or in the PNS? Why? (p453)

Axons heal better in the PNS those in the CNS have little or no repair. In the PNS Axons and

dendrites in the associate d with a neurolemma may undergo repair if the CELL BODY isintact, if SCHAWN CELLS are functional & if scar tissue formation does not occur to rapidly.

7. Distinguish the following pairs:

sensory vs. motor: Sensory: feeling & being aware of internal & external changes. Sensoryreceptors detect internal stimuli, increase blood acidity, external stimuli. (EX. Raindrop

landing on the arm.) Sensory info is carried through brain & spinal cord through brain andspinal nerves.

Motor: Once sensory info is intergraded; the nervous system may elicit an appropriate motoresponse by activating (effectors: ex..muscle & glands) through the cranial and spinal nerve

stimulation causing muscles to contract and glands to secrete.

afferent vs. efferent: Afferent: aka sensory(means: carried towards) contain sensory

receptors @ there distal ends(dendrites). When sensory neuron forms AP in its axon itsconveyed to the CNS through cranial and spinal nerves (most are unipolar.)

Efferent: aka motor(means: away from) they carry AP away from the CNS to effectors in thPNS through cranial and spinal nerves. (most motor neurons are mulitpolar)

somatic vs. autonomic: Somatic: convey info from somatic receptors in: head, body wall, &limbs, special senses like; vision, hearing, taste and smell. Motor neuron ONLY conduct

impulses to skeletal muscle. (voluntary)

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Autonomic: convey senory receptors mainly in visceral organs (ex: stomach & lungs) to the

CNS, motor neurons conduct impulses from CNS to smooth muscle, cardiac muscle andglands. (involuntary) contains 2 types: sympathetic division which is ex. Increase in heartrate (fight-or-flight) & parasympathetic division which is ex. Slowing down of heart rate (res

and-digest).

nerve vs. tract: Nerve: bundle of neuronal axons and/or dendrites that is outside of the CNS

Tract: bundle of nerve axons in the CNS.

nucleus vs. ganglion:Nucleus: Cluster of unmylienated nerve cell bodies in the CNS.

Ganglion: small masses of nervous tissue, containing neuron cell bodies that are locatedoutside the brain and spinal cord.

white matter vs. gray matter: White matter: composed primarily of myelinated axons,whitish color bc myelin gives white color.

Gray matter: nervous system contains neuronal cell bodies, dendrites, & unmyelinatedaxons, axon terminals and neuroglia. GRAY bc nissle bodies give gray look & has very little o

my myelin.

8. What are leakage, ligand-gated, voltage-gated, and mechanically-gated channels? Where ar

each located on a neuron? What type of membrane potential do each cause?

9. What are the equilibrium potentials of potassium and sodium (EK+ and ENa+)? What forces are

acting on these ions?

Membrane potential: voltage difference across a plasma membrane.

*if there is only K+ leakage channel, K+ diffuses out.

: K+ diffuses out until Equilibrium, when K+ concentrated graded= K+ electrical gradient.

-EK+= potassium equilibrium potential= membrane potential @ equilibrium when only K+ channels

present.

**EK+= -90mv (by measurement)

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*if there is only Na+ leak channel: sodium will diffuse IN until equilibrium

- ENa+= +60 mv (by measurement)

What is the resting membrane potential? Describe how the resting membrane potential is set up.

Resting membrane potential: resting Mbn potential, if there was only K+ leakage channel

then Em= ENa+= + 60 mvReality: 1) there are both channels.THUS, Em is between -90&+60.

2) There are many more K+ leakage channels.THUS, is closer to -90mv then to +60mv.

-Em=-70 mvTHUS, the membrane is polarized.

1)leakage=always leaking (randomly open/close)

Loc: everywhere on plasma membrane (black)

FXN: sets up RMP (due to mostly K+ leakage channels)

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**10 will be on test

10. What is a graded potential? Describe the ion movement during each of the two types of

graded potentials.

Graded Potential (GP): small variable change in the membrane potential.

Key points for graded potential: size of GP depends on the # of channels open. Whichdepends on the number of amount of NT

What is the function of a graded potential?

Fxn: to trigger or block an action potential

**Can also use: trigger= excite/ and block=inhibit

NT#1 open LG sodium channel & NT#2 open LG K+ channel

What is an action potential? (AP) large, non-variable change in Mbn potential.

11. What is the normal threshold voltage? (-55=threshold voltage normal)Graphicallyrepresent a graded potential, summation of graded potentials and an action potential

include the correct units in your graph.

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12. What specific steps are involved in the production of an action potential? i.e. Describe how

the voltage-gated sodium channels and voltage-gated potassium channels causedepolarization, repolarization and hyperpolarization.

-voltage gated channels on axon: starting @ trigger zone

Green= VG Na+ ch. Orange= VG K+ ch

Which gates respond fastest to the threshold voltage? Sodium gates respond fastest.

Why is the timing of these gates important?

13. What are the absolute and relative refractory periods? When do they occur?

Absolute refactory period: time that a second action potential cant be triggered.

WHEN: ?? during the depolarizing & reploarizing phases. (Na+ action gate is already open)

Relative refactory period: time that a 2nd AP can be triggered but it takes longer then norma

stim.WHEN??: during the hyperpolarizing phase.

14. Describe how action potentials propagate. Why do they propagate on axons but not on

dendrites or cell bodies?

AP Propagate: AP move along the plasma mbn

- this is the purpose the AP (to send the signal)

- requires voltage gated channels begin @ the trigger zone (TZ), cell body does not have

these channels, THUS no AP.

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- Inside of a neuron is -70 (Em) voltage selted channels open if -55mv threshold is hit.

EX. Na+ channel opens ..Na+ comes in hits nxt channel & it opens cause its threshold

etc..which is a domino effect.

How do local anesthetics work? Local anesthesia blocks the VG Na+ channels

-pain triggers pain receptors- sends AP to brain lidocaine would block the VG Na+ channel sono AP to brain

Distinguish between continuous and saltatory conduction.

2 types of conduction:

1) Continuous: unmyelinated axon (no myelin sheath-but the Schwann cell still provideselectrical insivation)

2) Saltatory: uses myelinated axons AP leaps from node to node

*not many VG channels under myelin sheathso threshold occurs due to electrical

impulse so the ionic current is fast in salutatory conduction (electricity is fast) bcskipping from node to node.

15. What factors influence action potential speed?

Factors of AP speed:

1) Myelin sheath (faster)

2) Diameter of axon big=faster

3) in temperature in speed

What are the different axon fiber types? Where are they located? Which are the fastest,

largest, myelinated, etc.? Distinguish between fast pain and slow pain.

3 types of axons aka nerve fibers

1) A fiber: myelinated and large diameter fast up to 250 mi/hr, short refactory perios

LOC: a) somatic motor neuron

b) sensory neurons for touch, pressure, & proprioception (since of body position) sometemp., sharp pain

* sharp pain is felt fast aka fast pain, dull pain = slow pain

2) B Fiber : myelinated & small diameter medium speed (~25mph) have longer refactory

periodlower freq. of AP. Loc: Autonomic nervous system (ANS)

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3) C Fibers : unmyelinated & small diameter- slow conduction of AP (~2.5mph)

dull ache= slow brain; has the longest refactory period THUS lowest AP frequency.

Loc: a) ANS & b) sensory afferent neurons for some temp & dull pain

16. Define synapse. Describe the steps of synaptic transmission.

Synaptic transmission: between 2 neurons

What are the two main types of neurotransmitters? What is an EPSP and IPSP? Describe howneurotransmitters cause either an EPSP or an IPSP.

2 types of neurotransmitters (NT):

1) Excitatory NT- opens LG Na+ channel (excitatory EPSP)

2) Inhibitory NT- opens LG K+ or Cl- channel (inhibitory IPSP)

(* EPSP= excitatory post synaptic potential)(*IPSP=inhibitory post synaptic potential)

* Post synaptic neurons get hit with both @ same time.

Steps:1) AP moves down presynaptic

endbulb to SEB.

2) AP opens the VG Ca2+

channels3) Ca2+ diffuses into SEB

4) Ca2+ triggers exocytosis ofsynaptic vesicles- releasing

the NT.5) NT binds its specific LG

channel on postsynaptic endbulb.

6) LG channel open & causes aGP called a postsynapticpotential.

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17. What are temporal and spatial summation? How do they produce an action potential in the

post-synaptic neuron?

Summation of AP: 1 post synaptic neuron may binf many neurotransmitters @ the sametimeIF the sum of all EPSP/ IPSP cause threshold @ TZ=AP.

Types of summation of the AP: they all work together

1) Temporal summation: due to amount of NT from one presynaptic neuron (depends onfrequency of AP in presynaptic neuron)

2) Spatial summation: due to amount of NT from more than one presynaptic N. (depends on# of presynaptic N.)

18. Describe all the ways that neurotransmitters are removed.

NT removal: so the NT effects are short lined

1) Via diffusion- NT diffuses away from synaptic cleft and more taken up by astroctyes

2) Enzymes break down- ex. AChE

3) Reuptake- NT taken back into synaptic vesicle (this is by active transport) -ATP needed.

19. Know all the neurotransmitters discussed in class including their locations and their functionsat those locations. (Know the material from the supplemental notes) What diseases and/or drugsare associated with the various NTs? What are MAOI and SSRI? What are their functions?Why do you have to be careful if taking an MAOI?Compare agonist versus antagonist.

**READ OVER ATTACHED LECTURE NOTES PRINTED FROM D2L!!!****

SSRI: Selective serotonin reuptake inhibitors SSRI blocks the active transport+ pump- soblocks reuptake - NT stays in cleft longer= greater effect of the NT.

20. For both Alzheimers Disease and Parkinsons Disease, describe the neuronal damage thatcauses them. What are the resulting NT deficits and results of those deficits?

Chapter 13: The Spinal Cord and Spinal Nerves (Lab material may be tested in the lecture exam

1. What are the three layers of the meninges? Describe the spaces associated with these layers

3 types of meninges:

1) Spinal meninges: surround the spinal cord and continuous with cranial meninges.

2) Crainal meninges: encircles the brain.

3) Dura mater: most superficial of the three, composed of dense irregular CT

Arachnoid mater: middle of the 3 meninges of brain & spinal cord.

Pia mater: innermost of the 3 meninges of

Spaces:

1) Epidural space: btn the dura mater & wall of vertebral column

2) Subdural space: btn the dura mater & arachronoid mater & contains intestinal fluid.

3) Subarachnoid space: btn the arachnoid mater and pia mater has CSF that serves as a

shock absorber.

picture on the next page..know for lab stuff too

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What are the conus medullaris, cauda equina, and filum terminale?(Discussed in lab)

2. Define reflex? Reflex: involuntary response to stimuli.

What is a reflex arc? What are the components of a reflex arc?

Reflex arc= AP pathway for reflex. (5 components)

pg. 482 figure 13.14

Concus medullaris: spinal cord

terminates/ends as a tapering

Filum terminale: extention of pia mater,extends inferiorly, blends with arachnoidmater & dura mater and anchors to the

spinal cord & coccyx.

Cauda equine: (horse tail hair) a groupname to distinguish the nerves that arise

from the lumbar, sacral, and coccyx regionof spinal cords.

Stimulus1) Sensory receptor(Responds to stimulus by

producing a generator orreceptor potential)

2) Sensory Neuron 3) Intergrating Center

Either the spinal cord orbrain stem.

4) motor neuronAxon conducts impulses fromintergrating center to effecto

5) Effector-skeletal muscle

-smooth muscle-gland

**effector will cause ares onse

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Distinguish between spinal vs. cranial, autonomic vs. somatic, monosynaptic vs. polysynaptic

and ipsilateral vs. contralateral reflexes.

Examples for Types of reflexes:

Spinal R: knee jerk reflex

Cranial R: shining light into pupil & the pupil constricts

Somatic R: Knee Jerk reflex; uses muscles to kick out

Autonomic R: effector is smooth muscle or gland

Monosynaptic R:

Polysynaptic R: most are polysynaptic reflexes

Ipsilateral: On the same side

Contralateral: On the opposite side

3. Describe and diagram the stretch reflex. What is the stimulus, receptors and response of thisreflex? What is the purpose/function of the stretch reflex? Describe the reciprocal innervationduring the stretch reflex.

Stretch relax:

Stim: stretch of a muscle

Reflex: stretched muscle contracts

Purpose: 1) it maintains position homeostasis2) Controls muscle tone

Type: spinal reflex, somatic reflex monosynaptic reflex, ipsilateral reflex.

Reciprocial Innovation of stretch reflex:

Stim: stretch of muscle

Response: relaxation of antagonist muscle

Purpose: allows movement

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4. What are the Tendon Reflex and the Flexor and Cross-Extensor Reflex? What are their

purposes/functions? Pg.484

Tendon reflex:

Stimulus: increase tention in a muscle.

Response: muscle relaxes

Purpose: prevent injury

* at the same time of a Flex reflex you have a cross extensor reflex

Cross extensor reflex:

Stimulus: pain (ex. step on a tact)

Response: extention of the opposite limb (ex. extend your opposite knee)

Purpose: for keeping balance

Chapter 14: The Brain and Cranial Nerves (Lab material may be tested in the lecture exam)

1. What is the blood-brain barrier? (Discussed earlier in lecture)

Blood Brain Barrier=FXN: prevents harmful substances from entering the brain.

2. What specific structure and cells create the cerebrospinal fluid (CSF)? What are the functions

of the CSF? (Discussed in lab)

CSF: is a clear, colorless liquid

FXN: protects the brain and spinal cord from chemical and physical injuries. It also carries Oglucose and other needed chemicals from blood to neurons & neurolgia. Serves as a shock

absorber.

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3. What structures make up the brain stem? What are the general functions of the brain stem?

Brain stem: 3 parts

1) Midbrain: mesencephaalon

2) Pons: a part of the metecephalon

3) Medulla oblongata: myelecephalon

General FXN:

1) Controls basic life functionsregulates the heart, breathing, digestion..etc..

2) Contains motor and sensory tracts

3) Contains nuclei and cranial nerves

4) Integration for cranial nerves.

5) Regulates consciousness & sleep

4. What are the functions of the reticular activating system? (Chapter 16, p590-591)

Reticular activating system: (RAS) in the brain stem

-clusters of neurons in a net like formation.

FXN: 1)regulates consciousness & 2)awakens you from sleep

*If asleep:

*Can be any sensory modality (special scenes types) except for smell

RASThalamus

&Cerebral Cortex

Awake

Sensoryinput going

into like analarm clock

Activates

that ifsensory isstrong

enough

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Why do you fall asleep? Describe how caffeine to keep you awake?

Why do we fall asleep:

1) When you are awake you use ATP.

2) ATP use Adenosine

3) Adenosine binds some receptors called A1 receptors. Which inhibits the RAS neuronscausing sleepiness.

* caffine blocks the A1 receptors***

Describe the stages of sleep.

Sleep: 3 main parts

A. REM= rapid eye movement

B. Non-REM=has 4 stages

Stage 1 sleep: has their eye closed & relaxed, flecting thoughts

Stage 2 sleep: light sleep, eyes roll up to the side, can be a little bit of dreaming.

Stage 3 sleep: moderate deep sleep, decrease in BP, decrease in temperature.

Stage 4 sleep: deep sleep, decrease in BP, decrease in BT, (may be sleep walking)

*REM- 3~5 episodes per night:

-dreaming, decrease muscle tone, may be paralysis, very high neuronal activity.

FXN: very much unknown.

5. What are the functions of the cerebellum, thalamus and hypothalamus?(Discussed in lab)

Cerebellum: Smoothes and coordinates contractions of skeletal muscle & regulates Posture

and balance.

Thalamus: maintenance of consciousness, relays almost all sensory input to cerebral cortex

helps with motor functions by transmitting info from cerebellum and basal ganglia to primarymotor area of the cerebral cortex.

Hypothalamus: controls and integrates activities of the autonomic nervous system,produces hormones and releasing hormones oxytocin & ADH, regulates emotional and

behavioral problems, regulates eating and drinking & controls body temperature.

6. What are the 5 lobes of the cerebrum?

5 lobes=

1) Frontal lobe

2) Parietal lobe

3) Occipital lobe

4) Temporal lobe

5) Insula pg.516 for picture

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What are the functions and locations (i.e. their specific lobe) of the following cerebral cortex areas

primary motor cortex, primary somatosensory area, pre-frontal area, Brocas Area, WernickesArea, primary visual area, primary auditory area, visual association area and auditory associationarea. (Discussed in lab)

7. What are commissural, association and projection tracts? Give specific examples of each.(Discussed in lab)

(Cerebral white matter)

Association tracts: contain axons that conduct nerve impulses btn gyrui in the same

hemisphere.

Commissural tract: contains axons the conduct nerve impulses from gyri one cerebralhemisphere to another gyri in the other cerebral hemisphere.

Projection tract: contains axons that conduct nerve impulses from the cerebrum to lower par

of the CNS.

8. What structures are associated with the basal ganglia? What is Parkinsons Disease? Whydoes L-Dopa improve the symptoms of Parkinsons Disease? (Discussed in lecture, lab & NT handout)

**READ OFF OF NEUROTRANSMITTER LECTURE NOTES**

9. Describe the structures and functions associated with the limbic system. (Discussed in lab)

***LOOK @ FLASH CARDS FOR LIMBIC SYSTEM

- sometimes referred to as the emotional brain primary roles in range of emotions:pleasure, pain, affection, fear, and anger. Also olfaction (smell) & memory.

10. What is aphasia? What are the two types of aphasia? What can cause each type?*BONUS?

11. Describe hemispheric lateralization. What functions are associated with each hemisphere?*BONUS ?

12. Know the twelve cranial nerves and their functions, brain exits and skull exits. (Discussed in lab)

**look at lab material for cranial nervesplace by this page.

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Chapter 16: Sensory, Motor, and Integrative Systems

1. Define sensation.

Sensation: bodys awareness of stimulus.

CNS

Define sensory modality: A unique type of sensation (ex. touch, pain, vision, etc.)

Ex. Each sensory neuron carries only 1 modality.

What is a generator potential?

-A depolarizing in the dendrites of a sensory neuron.

What are the possible CNS responses to a sensation? Define perception.

CNS Responces:

1) Reflex: involuntary response

2) Perception=conscious awareness of sensation.

3) Ignore the sensation = problem in people with Autism.

4) Intergration is the process of learning.

2. Describe the organization of the sensory modalities. What specific receptors are associatedwith each of the different modalities?

Organization of Senses

Stim. Sensoryrece tor

AP

Dendrites respond tostimulus by opening LGor MG channels(casuingde olarizin GP

Senses

SpecialSenses General

Senses

5 Special Senses

1. Vision2. Hearing

3. Taste4. Smell

5. Equilibrium

Visceral Senses:

for the autonomic

NS

Somatic Senses: are

perceived But notspecial senses.

Ex. touch

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Somatic sensory modality: & receptors1) Touch recp: Meissner corpuscle, merkel disk, hair root plexus

2) Pressure recp: pacinian corpuscle

3) Vibration recp: pacinian corpuscle & meissner corpuscle

4) Proprioception recp: muscle spindle + senses (muscle length/tention), tendon organ.

5) Temperature theromereceptors (free nerve ending dendrites respond to the stimulus.

6) Pain Noiceptor (free nerve ending )

Define adaptation. What causes adaptation?

Adaption: decrease perception of a stimulus while the stimulus is still present.

(ex. Jump in a cold lake & is able to adjust to the coldness)

2 causes: 1) sensory receptor: - generator potential while the stimulus is still present

Fast adapt: touch, pressure, temp.

Slow adapt: pain, proprioception

2) brain=can ignore the sensation.

3. What sensory modality information is carried by the lateral spinothalamic tract and theposterior (dorsal) column? Where do the 1st, 2nd and 3rd order neurons of these tractssynapse? Where do they cross? Be able to draw out these tracts and neurons.

Somatic Sensory Pathways

FXN: relay sensory info from sensory receptor to 1msomatosensory are (1SSA)

-(uses) 3 neurons

1) 1storder neuron (1st on)

2) 2nd order neuron (2nd on)

3) 3rd order neuron (3rd on)

** Key Points= 2nd order neuron cell body is at the same level as its decussation 9means: thecrossing to the opposite side)

**WHY 3 NEURONS?..its allows us to modify or ignore the sensation.

1) Posterior column pathways

FXN: relays info for: touch, proprioception, vibration

-KEY POINTS= 2nd order neuron cell body & decussation

is @ the medulla oblongata

Ex. Touch on the thumb

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2) Lateral spinothalamic pathways

FXN: relay information for : pain, itch, temp, & tickle

*KEY POINT: 2nd prder neuron cell body & decussation is in the spinal cord

EX. Pain on Elbow

4. Distinguish between upper and lower motor neuron. What is the function of the lateralcorticospinal tract and the anterior corticospinal tract? Where do each of these tracts cross?

Be able to draw out these tracts and neurons.

5. Describe upper and lower motor neuron damage. Describe how a clinician can test reflexes t

check for these.

6. What is referred pain? Give an example. What is a dermatome? (Chapter 13, p480)

Referred Pain: pain felt at a location that is different then the pain orgin.

EX. Heart attack felt at the left arm. (figure 16.3)

Dermatome: Sensory area of the skin that is innervated by a single spinal nerve.

Ex. Shingles > a rash is a band

-When the immune system lowers after old age the chicken pox virus will use the axon to

travel down, in a vesicle, to skin to start to divide.

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7. Define memory and learning. What neuronal structural changes are required?

What is plasticity?

Distinguish between immediate, short-term and long-term memory. What is memoryconsolidation?