Chpter 5: The peripherl nervous system Lerning ctivity suggested nswers Lerning Activity 5.1 (p. 222) 1 Briefly descrie the two min functions of the somtic nervous system. Description should refer to: sensory function: trnsmission of sensory informtion from sensory receptors in the ody (skin, muscles, ones nd joints) to the CNS motor function: control of skeletl muscle ctivity to enle voluntrily movements. Give n exmple of ech of these functions, ut use exmples not referred to in the text. Exmples include: sensory function:when you hold n ice cue sensory receptors in the skin detect the temperture chnge nd trnsmit this informtion to the CNS motor function: ny voluntry movement, i.e. intentionl/delierte nd not reflexive. 2 Distinguish etween the roles of sensory nd motor neurons. Sensory neurons lso clled fferent neurons specilised nerve cells tht receive nd crry sensory informtion Motor neurons lso clled efferent neurons - specilised nerve cells tht crry messges to skeletl muscles cusing them to contrct or relx. 3 Wht re interneurons nd where re they found? Interneurons lso clled connecting neuronsmke the connection etween sensory neurons nd motor neurons. Only found in the CNS 4 Whenever you rech to pick up glss, oth the sensory nd motor functions of the somtic nervous system re involved. Explin oth the sensory nd motor roles in grsping the glss. sensory function, e.g. detection of presence of the glss through touch (pressure) senstions nd trnsmission of sensory informtion to CNS for meningful interprettion (such s comining with other informtion to determine sptil loction, weight etc.) motor role, e.g. inititing movements to grsp nd pick up the glss, such s holding the glss ppropritely, control of skeletl muscles ttched to finger ones to enle pen grsping nd lifting Mcmilln Eduction Austrli 2013 1
Lerning Activity 5.2 (p. 222) Prepre poster with digrm nd rief notes to show the wys tht informtion is trnsmitted y the somtic nervous system, oth to nd from the centrl nervous system. An exmple of sensory nd motor ctivity should e used to descrie the ction of the somtic nervous system. Use rrows (for direction) nd lels (for identifiction) to illustrte the flow of sensory nd motor informtion. Ensure tht the correct nmes re used for the vrious structures identified in the digrm. Student responses will vry, dependent on the exmple they pply to the model, ut the formt could e reflective of the figure elow. 5. Neurotrnsmitters re relesed onto foot nd leg muscles cusing them to expnd or contrct, instructing movement. Tking step, you lnd on nother prickle. 1. Brefoot on lwn, you step on prickle. SNS sensory neurons detect the pin nd trnsmit this informtion (fferent trnsmission) vi nerves to the spinl cord (CNS). Why you should wer thongs in your ckyrd 4. SNS motor neurons (efferent trnsmission) ctivte the ones nd muscles required to tke step. Prickles nd the PNS 2. The spinl cord trnsmits this informtion to the rin to e processed. 3. The rin receives this sensory informtion nd trnsmits motor signls ck vi nerve pthwys through the CNS to the SNS, relting instructions to step. Mcmilln Eduction Austrli 2012 2
Lerning Activity 5.3 (p. 224) 1 Explin why the utonomic nervous system is descried s utonomous. Explntion should refer to the fct tht orgns, glnds nd processes under ANS control re usully self- regulting/functioning independently of the rin/not normlly under voluntry or conscious control. Is utonomous n ccurte term for descriing this nervous system? Explin with reference to n exmple. Explntion should demonstrte understnding tht the ANS is not completely self- regulting, e.g. iofeedck trining to enle control of certin utonomic responses such s hert rte, respirtion, perspirtion etc. 2 Explin the reltionship of the utonomic nervous system to the centrl nervous system with reference to physiologicl response. Explntion should demonstrte understnding tht the ANS regultes ctivity of viscerl muscles, orgns nd glnds ut lso provides feedck to the rin out their ctivities, which cn in turn influence (increse or decrese) their ctivity, e.g. fight- flight response demonstrtes role of ANS (inititing involuntry fight or flight responses) nd the rin (interpreting the event in wy which mintins or chnges utonomic responses). 3 Wht is the key difference etween skeletl muscles nd viscerl muscles? Difference my refer to: skeletl muscles involved in or enling voluntry movements of ody prts nd viscerl muscles involved in or enling ctivity of internl orgns nd glnds skeletl muscle ctivity requiring initition y motor neuron messges from the rin nd viscerl muscle ctivity not requiring motor neuron informtion/under ANS control/hving uilt- in mechnisms for generting ctivity. 4 Which is more importnt in mintining our survivl: the utonomic nervous system or the centrl nervous system? Explin with reference to n exmple. Responses should demonstrte understnding of the respective roles of the ANS nd CNS in survivl, tking ccount of the mening of survivl per se, i.e. mintining n orgnism in living stte. Lerning Activity 5.4 (p. 225) Which division of the peripherl nervous system is more likely to e involved in ech of the following responses: the somtic nervous system (S), the utonomic nervous system (A) or oth (B)? pressing key to nswer moile phone eting dinner sweting efore hving to give n importnt speech B B A Mcmilln Eduction Austrli 2012 3
clenching your fists while wtching scry movie crouching on the locks witing the strting siren efore swimming in 50- metre freestyle finl wshing the dog linking tlking on the phone lughing t joke flinching when you her loud noise S or A or B S or A or B S A S S A or B Lerning Activity 5.5 (p. 228) 1 In wht min wy do the sympthetic nervous system nd the prsympthetic nervous system differ? 2 Difference should refer to ctivtion or rousl of ody/incresing ctivity of most viscerl muscles, orgns nd glnds in times of vigorous ctivity, stress or thret (sympthetic nervous system) nd clming of ody/decresing ctivity/restoring to norml stte of functioning/homeosttic stte (prsympthetic nervous system). c Wht is the role of the sympthetic nervous system in enhncing survivl? Explntion should refer to it providing n immedite response, in split second, to ny kind of emergency, specificlly situtions tht re stressful, thretening nd entil vigorous ctivity. Give exmples of three odily functions tht increse their ctivity s result of the ction of the sympthetic nervous system. Exmples from Tle 5.1 (p. 278) my include: hert rte respirtion rte drenl glnd ctivity. Give three exmples of odily functions tht decrese their ctivity s result of the ction of the sympthetic nervous system. Exmples from Tle 5.1 (p. 278) my include: sliv production stomch contrctions gll ldder ctivity. Mcmilln Eduction Austrli 2012 4
3 Descrie the min roles of the prsympthetic nervous system. Functions include: keeping odily systems functioning efficiently in times of miniml stress nd in the sence of threts, helping to mintin the internl ody environment in stedy, lnced stte of norml functioning restoring the ody to stte of clm, once the need for the ctivity of the sympthetic nervous system hs pssed. Give three exmples of three odily functions tht re ffected s result of the ction of the prsympthetic nervous system. Briefly explin the purpose of these chnges resulting from the ction of the prsympthetic nervous system. Functions include: stomch nd intestine stimultion to digest food elimintion of wstes to id in odily helth production of ters nd utomtic pupil constriction in conditions of right light in the eye ffords protection of the visul system. 4 Give two resons to explin why it tkes longer for the prsympthetic nervous system to slow down odily functions thn it does for the sympthetic nervous system to speed up odily functions? Explntion should refer to the ctivtion of sympthetic nervous system in stress or thret sitution, which stimultes drenl glnd hormone secretions immeditely firing up Sympthetic NS response the prior ctivtion of the sympthetic nervous system delys onset of Prsympthetic NS effects s the lingering presence of the hormones relesed into the loodstrem still ffects phisiology (even though the rin hs given the ody the ll cler fter the thret or dnger hs pst) Lerning Activity 5.6 (p. 228) 1 Which division of the utonomic nervous system is likely to e dominnt if you re in ech of the following situtions? lying on the ech reding ook prsympthetic witing for the delivery of your VCE results sympthetic c prepring for lind dte sympthetic d hering n unexpected loud knock on the front door t 2 m while wtching TV lone sympthetic Mcmilln Eduction Austrli 2012 5
e eting dinner prsympthetic f wtching terrifying scene in movie sympthetic g sitting in clss listening to techer s explntion prsympthetic 2 Which division of the utonomic nervous system is likely to e dominnt when ech of the following physiologicl responses is oserved? incresed rte of digestion prsympthetic decresed slivtion sympthetic c incresed pulse rte sympthetic d decresed pupil size prsympthetic e incresed perspirtion sympthetic Lerning Activity 5.7 (p. 229) Photocopy nd complete the digrm elow to summrise the ctivities of the sympthetic nd prsympthetic nervous systems. Write your nswers on the lines connecting the vrious orgns nd glnds, s shown for the pupil. Refer to Tle 5.1 (p. 227) for solutions. Mcmilln Eduction Austrli 2012 6