Document 2EVbjGpRrGYGbVMnBmKO3adb

SFALTf BOUXTPT for KtCRFKS Su^eatcd List of Tonic* 1941 -- 1942 Rwooi ftp Health gf the ifrtloH Je:itoaher -- Out of Old Field*. 3ea Cow. October -- Sanitary ininarlai< end the Eavlronaeat. forsaber -- A Good Sod for nother rod Child. Oooaebnr -- Bm Sehool Health dereiee rad the Sahoal Child. January -- The Teeehcr and Health fdaortioo. Fabraary -- The Fcreota end the Correction of itoyalaol Defeeta. brdi .& Frail? end the OacBonit?. Aaril -- The Health of the ifarher. Say -- Tmiag Baalit?. _ *" ' June -- The Tetr*e ProF*v in ltadicina/(-nd Puilic fla.-.ith. OR. LARZA UEKOEiHEUIl March 18, 1941 ' s' Ife shall appreciate having^ycnjr''commeats and crlticloos on the attached manuscript", which has been prepared for the March HEALTH B3tULCETIN FOR TEACHERS. / school Health Bureau * 0.* DR. ARMSTRONG March 17, 1941 We shall appreciate having your comments and criticisms _ on the attached manuscript, which has been prepared for the March HEALTH BULLETIN TOR TEACHERS. School Health Bureau t / lUOtilODI B,March 1 19X1 HR. OQBLH DR, IOTXA la aball appradata having your caveats and eritieisas oo tha Attached aaauaerlpt, tiiieh baa baaa praparad far tha March HEALTH BOLUXXI TOR TEAifXRH. School Health Bureau MSlOEilDDM March IS, 1941 ppt HTA^KT Wa shall appreciate having your oouaata aad erltioims oa tha attached aanuacript, ehlch haa bean prepared far tha March HEALTH BDLLETH TOR TEACHERS, School Health Bureau BU KOLZ Ve ehall appreciate farrlaf your ooaaenW'and eritialMui on the attaohed aanueoript, blab boo been prepared for the Itareb BUSH B0LLKH FOR TE1CHXBS, Sehool Health Bnreau Same tab oent to i Or* Shepard Dr* Coopor Dr. Burnette Dr. McConnell Kies ibbot Ulea fair health bolleth for teachers Special Sanslbllltlse Sight, hearing, tarts, tcueh, and nail - the faeiliar *fiva sanser* - were first classified as special sensibilities in the early part of tha lttfc century, it that tlae all tha other lose 'istinct sensations vara lisped to gether as general sensibilities. low touch is no longer called a "special* sense. It belongs enong the sensations designated as sonatie or body sensi bilities vhieh sake us avare of pressure, pain, hast, and sold. Tha ether senate, vision, hearing, taste, and snail, are called "special* for convenience to distinguish than fron the aore ancient (in point of adniaslan to consciousness) sonatie sensibilities. A**" The faster of 4tm Sense Perception. The neehanlsn fttense perception con- ^ eists of s vast systea of aenaozy nervs endings or 'receptors"eonnected by devious but sell-defined nerve paths with definite sensory areas in tha cerebral cortex shore tha different types of sensation are trenelated into eonseloas Impressions. The sls?lsst sort of diagram upon which an llluatratlon of the sensory neehanlsn night be roughed in is that of a circle. On tha periphery ve should plaoe dots repressnting the sensory nerve endings, and fron than ea should draw radii repre senting tha nerve fibers. Soaethare along each radios we should place other dots to stand for the neurons or nerve cells through ehieh the inpalaa fron a receptor is relayed to tha canter of tha elrcla, or cerebral oortaac. Actually this simple wbeelllke dlagran would rateable a far norm highly ooaplloated web than any spider could ever spin If we attcapted to abow the devious routes, the cross reads, the relay stations by which tha lapulses finally reach the particular central areas where they "sake senes** /vj/7, .( ) t\f Volume HI, Vo. T arch 1U1 The Cause of a Sensation. The primary cause of a sensation of any irfnd ifl tha reaction of a sensory receptor to a stimulus to rhich It la eenatlrle. The sensation laata Just as long as tha snasoiyWud organ resets to the stimulus. The reaction is/ outlast tha application of the stimulus just as a rocking chair may continue to rook after it has ones been sat in notion. This is true especially of tha sensation of pain* On tha other bead, reaction aay cease while the stimulus is still being applied* This is true especially of the sensation of touch. The nerre fibers Involved gat used to or adapt thenaelrea to the constant stlnulos of eeehanlcal pressure so that only simple impulses or at Boat a few are discharged* Tho Intenaitr of a Sensation. The strength or vealoeoe of a censatioo ap parently is connected with the number of impulses arriving at the central nerve-cell junctions (eynapees). Juat as the congestion in a railway freight yard increases ' '* with an increase in the suaber of tracks over which ea^g^ are shunted Into it, so the greater the number of nerre fibers engaged in shunting iapolses into a senrory area of the brain, the aore intense a sensation will be. Tha intensity of a sen sation depends also on tha speed ^n^wkich inpulses follow one another along individual nerre fibers* In the conduction of iapulses nerves obey tha ell or nothing lav. Either they do not transmit impulses at all^r they trahsnkt than as fast as they possibly can* The Kind end Quality of a Sensation. The starting point of an lapulae and ita destination are what deternlna tha kind and quality of a sensation, not the impulse itself. J^Maanpftnv`<^he impulses earried by sensory nerve fibers leading from light-wave receptors do not differ materially from the impulses earried by nerre fibers leading from sound-wav# receptor*. In the one oeae you aee, in the other you hear, because sensory nerre fibers leading fron the retina of the eye end in the visual center of the cerebral cortex end those frost tho inner ear in the auditory center. 3 Although all impulses in thanialrea ara more or loaa alike - no ona knows exactly what they ara Ilka* Tba passage along a narra fiber of aa excitation procaaa atartad by the stimulation of a receptor, and aaaoelatad with a aarlaa of alaotrloal and chanieal changes along tha route, la tba naaroat a can coca to daflnlng a narra lapuloa* Each sensory raeaptor ia tba station of departure for ha pasaaga of an lapulse to tba terminal station In tba brain with ablob It Is eonnaatad. Only ona kind of stimulus can lnltlata tha passage of an lapuloa froa that particular station. Just as a tlckat for Boston aould not gat a passenger past tba gate to board a train for Klaai, so tba etlaulus of light wares would not gat a sassage started on tba way to tba auditory cantar. However, It does aoaatlaas happen that a raeaptor la axeltad by an unusual stimulus. When that happens tha sensation aroused la slallar to tha sensation aroused by tha usual etlaulus. Thus tha usual stimulus of a raeaptor on tba ratine Is light wares, but an unusual stlaulus. Ilka a blow between tha ayes, also girws rise to tba sensation of light. Ona seas stars! As socaona has said, if iapulsas arising in tha ratine ware directed to tba auditory canter and lapulses froa tbs inner ear to tha rlsual center, wa should hear tba lightning and sea tha thundar. fonatlc danalbllltlaf. Tba so-alled somatic, or body, sensation# aay ba dleiddd into palso-sansibllltins and nao-asnsibilitiss. Paleo-aansibiliUea which ara tba flrat causations admitted to consciousness, ara those of extraaa degrees of pressure, pain, bast, and cold. They ara all unpleasant and all rltally laportant In aalf-prasarratlon. A hearty smack, aa likely *> not, aada many of us draw our first breaths la protest. Tha dlsooaforts of cold ness, bast, hunger, and wetness aroksd tba cries which brought us assdad attention. Than by degress, uso-eaaslbllitlea beeaae superimposed on tha older ante to supply us with critical information regarding the outside world. These sewer sensibilities Include tactile sensations, those evoi&d oy light contact with receptors la the skin, and kinesthetic sensations* those fro* receptors in tie voluntary muscles, tendons, joints, and bone coverings. Tactile sensations give us the sense of touch and Its refinasients. Kinesthetic sensations furnish us with information concerning the covenants and position of tr.e linos, trunk, end head and anable ua to eatinete resistance to nuscular contraction when we lift or wove objects. Tbe two togettier sake it possible for ua to fudge the forma, shapes, consistencies, and vaighta of objects in tne outside world. The sensation of pain is served by naked nerve endings in the akin, cornea of the eye, end serous aurfacas inside tbe body, such as the peritoneum and ths pleura. Pain nerve endings are not sileetive, as othsr receptors are. They respond to say type of stimulus whether mechanical, chemical, or thermal pro vided it is intsnse enough. The sensation of pain therefore gives warning of t:ie injurious nature of a stimulus rather than information as to any sore specific quality. Disturbances of somatic sensations result from any abnormal change produced by mechanical or chemical agents along the course of nerve tracts froc reewptors to senaory araaa in tbs brain. Regardless of where a mecnanical or chemical agent acta along a nerve the disagreeable sensations aroused are generally referred to tbe pert containing the receptors fro* which the particular nervo fibers arise. This explains vhy * person rhoeo leg hae been amputated refers the pain in the strap to the altering limb. The treasure of the dressings or newly formed tissue on the nerve fiber* say be coapared to the tapping of a telephone wire between station*, sad the aesaege received by the operator Ijln the body^a sensory area in the brain) Is interpreted as ooning fron the station which in the body Is the regular receptor. Sometimes the disagreeable sensations also are referred to the coarse of the peripheral nerve*, as in neuralgia. The subjective sensation of pela nay be con stant or interwittedt and dull or sharp and lancelike depending on the nature of the rtimulus, the rate of recurrence of local excitations, the adaptation of the nerve fibers concerned, and so on. The Sense of Sight. Then we see we have many cancations. Rot only do we snorr that it is light, but also we recognise different intensities of illumina tion. By virtue of this ability we avoid obstacles and recognise moving objects. Te oan distinguish colors, outlines, and fine details in the things we look at and appreciate depth, volume, and perspective. The sensory receptors Which mediate all these sensations, are located in the retina of the eye. There are two kinds rods and cones - named after their chapes. At the point where the optic nerve which condusts impulses from the retina to the brain, enters the retina, rods end cones ore absent. Hence this is a 'blind spot,* a point on the retina where light raves produce no visual sensations. Hods and cones ere arranged on the retina In a definite pattern. Beginning with a small area near the center of the retina, only cones packed eloaely together ere present. Then in a widening circle the oonea diminish progressively In number rhilo the rods increase proportionately until finally, at the outer rim, only rods remain. Distinct and accurate vision and the recognition of color are localised near the center of the retina while the ability to cee In a dim light Is almost - 6- entirely lacking, to the other hand loir light intensities and movements at ary illumination are best detected at the outer ria of the rotina, rhile color per* coption and perception of detail ere lacking. Thus it is inferred that the functions of the ooae apparatus are sharpness of vision and recognition of details and colors, while the rod apparatus, which is very sensitive to light. Is used for twilight vision. A rose-red light--sensitive pigment found in the rods is essential for normal vision in dim light. This pigment is called vistaft. purple, Since illuaination of the eye causes bleaching of the visual ourcls, this substance oust he regenerated when the eyes are in the dark. Vitaaln A is in some way intimately associated with the bleaching -regeneration cycle of visual purpte. Thus people who do not get enough vitamin A may havs night blindness, that is, inability to sea in dim lights. Tiny UDside-doma Images of objects in the outside world are orojeeted on the retina by a series of refractive surfaces forming the lens system of the aye. risturbancos of vision nost frequently occur through structural defects or ousoular reakneeees which make it Impossible for the lens systen to focus images properly on the retina. In nost instances such disturbances can be corrected by wearing suitable glasses. The fence of Hearing, rhen we hear we do not Just hear a sound - re recognise even small differences in the pitch, loudness or Intensity, and quality of the sound. Te know whother it is disagreeable (noisy) or pleasant (musical), v.e -sow usually rbat makes it - a strange voice or a familiar one; a piano or s violin; a gun shot or something dropoed with s bong on the floor. The organ of hearing, which aediates the sen Eatloss of sound, is called the organ of Corti and is located in the lynpb- CfrtA>CA. *iW v---. filled Kinnar ear or cochlea. The interior of this homy snailshell* which is about rs big es a pcs, is subdivided by walls of membrane into three spiral undereaa galleries, or chambers. Along tho floor of one of these gallerias (the soala media) - T- liee tho organ of Corti. This orgaa contain* sensory sound receptor* and hair call*. It 1* the stimulation of the hair eella far the tily variations la preesnre of the fluid surrounding then that excite* the sound receptor* to send impulses to the brain la the auditory nerve* All the othar apparatus of the ear la ecueexaed solely with sound wave con duction. Over a eysten of delieata aenbraaea and tiny booas twanging on oo* aaothar the mries of eaves set up la air by vibrating bodies in the outside eorld travel to the eoehlea where th^ are transformed into "eater* eaves of the son* frequency, amplitude, end fore. Their frsqunwy determine* the pitchf their ampli tude, the loudness) and their font, the quality of the sound heard* Impairment of hearing occurs aost frequently as a result of conditions which affect the oaeductlon of sound to the inner ear* Destruction or functional dis turbance of the orgaa of Corti or injury to the auditory netve is rare* frequent or ehronie head colds are the chief oause of the lose of hearing due to interference frith sound conduction* The fence of Taste. Te have four priaery taste sensations, reset, bitter, sour, and salty* Fach kind is mediated by the sensory receptors or tact* bods on the tongue which are smsltlv* to it* Taste buds are chemically stimulated, but it is not laown exactly whet center* in the brain are reaobed by the Impulses started off os a result of the stimulation* The greet variety of different taste sensations actually experienced lc due to a mixture of primary sensations (much aa a mixture of primary colors will pro duce different shades and tones), to the stimulation at the sane time of touch and temperature nerve endings on the tongue, end to confusion with sensations of smell* Many flavor* are really odors end disappear when the nose is "stuffed up" as ajresult of a oold* A substance that causes first a sweot taste and then e bitter stimulate la sequence the sweet reeeptors toward the front of the tongue and the bitter -8 - receptors toward the bade. Paracoal wariati as in the sense of taste occur, and tsnt< blindness for aoe or more of the primary sensation* is oomasa and hereditary. The fanse The organs of email, called the olfactory bulbs, are locatec in the roof of the nose* They are composed of a collaction of splndle-ahaped receptor: which are stimulated by the pressure of wapor moleeules glyen off ty wolatile eubstances. It la possible to distinguish many diffareat odors, but they are hard to classify cxpdpt as being pleasant, unpleasant, or neutral. Sines asnaatloos cf small may be tied up intimately with other sense impressions from the outside world, it Is no wonder that their ultimate destination in the brain is the most obscure of all the cerebral aansoxy areas. Pest associations haw# a great deal to do with psychological reactions to odors of different kinds* Thus an odor say be wary disagreeable to one person and pleasant or neutral to another. The senses of taste and smell together deter mine whether or not e food is appetising. Pormiag pleasant associations with the taste and smell of food in childhood play a leading role in creating a liking for the right kinds of food* RETERZHCE8 Carl J. diggers* Phraiologr In Health and Disease. Lea .1- Peblger, Philadelphia. 1959. Chapter XI - Somatic Sensibilities and Their Disturbances; Chapter XU Special Sensibilities*