THE SPECIAL SENSES.
229, 230. What is a sense? Name the five senses. To what organ do all the senses minister? If the nerve leading to any organ of sense be cut, what would be the effect? [Footnote: Each, organ is adapted to receive a peculiar kind of impression. Hence we can not smell with, the eyes nor see with the nose. Thus, if the nerve communicating between the brain and any organ be destroyed, that means of knowledge is cut off.] Sometimes persons lose feeling in a limb, but retain motion; why is this? What is the sense of touch sometimes called? Describe the organ of touch. What are the papillæ? Where are they most abundant? [Footnote: If we apply the points of a compass blunted with cork to different parts of the body, we can distinguish the two points at one twenty-fourth of an inch apart on the tongue, one sixteenth, of an inch on the lips, one twelfth of an inch on the tips of the fingers, and one half inch on the great toe; while, if they are one inch on the cheek, and two inches on the back, they will scarcely produce a separate sensation.—HUXLEY.] What are the uses of this sense? What special knowledge do we obtain by it? Why do we always desire to handle any curious object? Can the sense of touch always be relied upon? Illustrate. What is the tactus eruditus? Tell how one sense can take the place of another. Give illustrations of the delicacy of touch possessed by the blind.
230-232. Describe the sense of taste. How can you see the papillæ of taste? What causes the velvety look of the tongue? Why do salt and bitter flavors induce vomiting? Why does an acid "pucker" the face? What substances are tasteless? Illustrate. Has sulphur any taste? Chalk? Sand? What is the use of this sense? Does it not also add to the pleasures of life? Why are the acts of eating, drinking, etc., thus made sources of happiness?
232, 233. Describe the organ of smell. State the intimate relation which exists between the senses of smell and taste. Name some common mistakes which occur in consequence. Must the object to be smelled touch the nose? What is the theory of smell? How do you account for the statement made in the note concerning musk and ambergris? What are the uses of this sense? Are agreeable odors healthful, and disagreeable ones unhealthful?
234-236. Describe the organ of hearing. Describe the external ear. What is the tympanum or drum of the ear? Describe the middle ear. Name the bones of the ear. Describe their structure. Describe the internal ear. By what other name is it known? What substances float in the liquid which fills the labyrinth? What is their use? Describe the fibers of Corti. What do they form? Use of this microscopic harp? Give the theory of sound. Where is the sound, in the external object or in the mind? Can there be any sound, then, where there is no mind? What advice is given concerning the care of the ear? How can insects be removed? Which sense would you rather lose, hearing or sight? Does not a blind person always excite more sympathy than a deaf one? How does the sight assist the hearing? [Footnote: In hearing, the attention is more or less characteristic. If we wish to distinguish a distant noise, or perceive a sound, the head inclines and turns in such a manner as to present the external ear in the direction of the sound, at the same time the eyes are fixed and partially closed. The movement of the lips of his interlocutor is the usual means by which the deaf man supplies the want of hearing; the eyes and the entire head, from its position, having a peculiar and painful expression of attention. In looking at the portrait of La Condamine, it was easily recognized as that of a deaf person. Even when hearing is perfect, the eyes act sometimes as auxiliaries to it. In order to understand an orator perfectly, it seems necessary to see him—the gestures and the expression of the face seeming to add to the clearness of the words. The lesson of a teacher can not be well understood if any obstacle is interposed between him and the eyes of the listening pupil. So that if a pupil's eyes wander, we know that he is not attentive.— Wonders of the Human Body.]
236, 237. Describe the eye. Name the three coats of which it is composed. Is it a perfect sphere? Ans. The cornea projects in front, and the optic nerve at the back sticks out like a handle, while the ball itself has its longest diameter from side to side. How is the interior divided? Object of the crystalline lens? How is the crystalline lens kept in place? Describe the liquids which fill the eye.
238. What is the pupil? Describe the eyelids. Why is the inner side of the eyelid so sensitive? What is the cause of a black eye? Use of the eyelashes? Where are the oil glands located? What is their use? Describe the lachrymal gland. The lachrymal lake. What causes the overflow in old age?
239. Explain the structure of the retina. Use of the rods and cones. What is the blind spot?
240. Illustrate. What is the theory of sight? Illustrate.
241, 242. State the action of the crystalline lens. Its power of adaptation. Do children ever need spectacles?
243. What is the cataract? How cured? What is color blindness? Illustrate. What care should be taken of the eyes? Should one constantly lean forward over his book or work? What special care should nearsighted children take? By what carelessness may we impair our sight?
244. How is squinting caused? Cured? What care should be used after an illness? Should we ever read or write at twilight? Danger of reading upon the ears? What course should we take when objects get into the eye? How may they be removed?
245. Are "eyestones" useful? Why should we never use eyewashes except upon the advice of a competent physician? What rule should be observed with regard to the direction of the light when we are at work? Name some causes of near-sightedness. Remedies.
346. Give the account of Laura Bridgman.
347-350. Describe the anatomy of the nose. In what part of the nose is the function of smell performed? Why do we "sniff" when our attention is attracted by an odor? Give some experiments which illustrate the connection between smell, taste, and touch. Why should we retain our food in the mouth as long as possible? Of what use are gastronomic odors?
350. Why should a child's ear never be boxed? Illustrate. How can we detect inattention from deafness in a child? What should we consider in this respect?
351. Why should we avoid direct draughts in the ear? Explain the use of earwax. What common habit is very injurious? Why?
352, 353. What is the office of the Eustachian tube? Illustrate.
353, 354. Describe the action of the "eye curtain." Give experiments. What are "Purkinje's Figures"? Describe experiment.
HEALTH AND DISEASE.
251-254. State some of the benefits of health. Contrast it with sickness. How were diseases formerly supposed to be caused? What remedies were used? What does modern science teach us to be the nature of disease? Give some illustrations showing how diseases may be prevented. Is it probable that the body was intended to give out in any one of its organs? What is the first step to be taken in the cure of a disease? What should be the object of medicine? What is now the chief dependence of the best physicians? What do you think concerning the common use of patent nostrums? Ought we not to use the greatest care in the selection of our physician?
GLOSSARY.
Ab do' men (abdo, I conceal). The largest cavity in the body, in which are hidden the intestines, stomach, etc.
Ab sorb' ent (ab, from sorbeo, I suck up).
Ac' e tab' u lum (acetum, vinegar). The socket for holding the head of the thigh bone, shaped like an ancient vinegar vessel.
A ce' tic (acetum, vinegar).
Ad' i pose. Fatty.
Al bu' men (albus, white). A substance resembling the white of egg.
Al bu' mi nous substances contain much albumen.
Al' i men' ta ry. Pertaining to food.
Al' ka line (-lin) substances neutralize acids.
An' æs thet' ic. A substance that destroys the feeling of pain.
A or' ta. The largest artery of the body.
Ap' o plex y (pleks y). A disease marked by loss of sensation and voluntary motion.
A' que ous (a'-kwe-us). Watery.
A rach' noid (arachne, a spider; eidos, form). A membrane like a spider's web covering the brain.
Ar' bor vi'tæ means "the tree of life."
Ar' tery (aer, air; tereo, I contain). So named because after death the arteries contain air only, and hence the ancients supposed them to be air tubes leading through the body.
Ar tic' u late (articulo, I form a joint).
Ar tic' u la tion. A joint.
As phyx' ia (-fix-i-a). Literally, no pulse; apparent death.
As sim' i la' tion is the process of changing food into flesh, etc.
At' las. So called because, as in ancient fable the god Atlas supported the globe on his shoulders, so in the body this bone bears the head.
Au' di to ry Nerve. The nerve of hearing.
Au' ri cle (-kl) (auris, ear) of the heart. So named from its shape.
Bi' ceps. A muscle with two heads, or origins.
Bi cus' pid. Tooth with two points; also a valve of the heart.
Bron' chi (-ki). The two branches of the windpipe.
Bron' chi al Tubes. Subdivisions of bronchi.
Bur sa (a purse). Small sac containing fluid near a joint.
Ca nine' (canis, a dog) teeth are like dog's teeth.
Cap' il la ries (capillus, a hair). A system of tiny blood vessels.
Car' bon. Pure charcoal.
Car bon' ic Acid. A deadly gas given off by the lungs and by fires.
Ca rot' ids (karos, lethargy). Arteries of the neck, so named because the ancients supposed them to be the seat of sleep.
Car' pus. The wrist.
Car' ti lage. Gristle.
Cell. A minute sac, usually with soft walls and fluid contents.
Cel' lu lar (cellula, a little cell). Full of cells.
Cer' e bel' lum. The little brain.
Cer' e brum. A Latin word meaning brain.
Cer' vi cal. Relating to the neck.
Chlo' ral (klo) Hy' drate. A drug used to induce sleep.
Cho' roid. The second coat of the eye.
Chyle (kile). A milky juice formed in digestion.
Chyme (kime). From chumos, juice.
Cir' cu la' tion. The course of the blood through the body.
Cil' i a (the plural of cilium, an eyelash). Hair-like projections in the air passages.
Clav' i cle (klav'-i-kl). From clavis, a key.
Co ag' u la'tion. A clotting of blood.
Coc' cyx (a cuckoo). A bony mass below the sacrum.
Coch' le a. A Latin word meaning snail shell. See Ear
Com' pound. A substance composed of two or more elements.
Con ta' gious diseases are those caught by contact, the breath, etc.
Con' trac til' i ty (con, together; traho, I draw).
Con' vo lu' tion (con, together; volvo, I roll).
Cor' ne a (cornu, a horn). A transparent, horn-like window in the eye.
Cor' pus cle (kor'-pus-l). From a Latin word meaning a little body. It is applied to the disks of the blood.
Cra' ni al. Relating to the skull.
Crys'tal line (crystallum, a crystal).
Cu ta' ne ous (cutis, skin). Pertaining to the skin.
Cu' ti cle (ku'-ti-kl). From a Latin word meaning little skin.
Cu' tis, the true skin.
Den' tal (dens, dentis, a tooth).
Di' a phragm (-fram). The muscle dividing the abdomen from the chest.
Di as' to le (diastello, I put asunder). Dilation of the heart.
Dis' lo ca' tion. A putting out of joint.
Dor' sal (dorsum, the back).
Duct. A small tube.
Du o de' num (duodeni, twelve each).
Du' ra Ma' ter (durus, hard; mater, mother). The outer membrane of the brain.
Dys pep' si a is a difficulty of digestion
E lim' i nate. To expel.
Ep' idem' ic. A disease affecting a great number of persons at once.
Ep' i der' mis. The cuticle.
Ep' i glot' tis (epi, upon; glottis, the tongue). The lid of the windpipe.
Ep' i the' li um. The outer surface of mucous or serous membranes.
Eu sta' chi an (u-sta'-ki-an) Tube. So named from its discoverer, an
Italian physician.
Ex cre' tion. Waste particles thrown off by the excretory organs.
Fer' men ta' tion. The process by which sugar is turned into alcohol.
Fi' brin (fibra, a fiber).
Fil' a ment (filum, a thread).
Func' tion. See Organ.
Gan' gli on (gang'-gli-on). From ganglion, a knot; plu. ganglia.
Gas' tric (gaster, stomach).
Glands (glandz). From glans, a Latin word meaning acorn.
Their object, is to secrete in their cells some liquid from the blood.
Glot' tis. The opening at the top of the larynx.
Hu' me rus. The arm bone.
Hu' mor. A Latin word meaning moisture.
Hy' dro gen. The lightest gas known, and one of the elements of water.
Hy' gi ene. From a Greek word meaning health.
Hyp' o glos' sal. Literally "under the tongue"; a nerve of the tongue.
In ci' sor (incido, I cut) teeth are cutting teeth.
In' spi ra' tion (in and spiro, I breathe in).
In tes' tine (-tin). From intus, within.
Lach' ry mal (lachryma, a tear). Pertaining to tears.
Lac' te al (lac, lactis, milk). So called from the milky look of the chyle during digestion.
La cu' na, plu. lacunæ (lakos, a hole). Cavities in the bone structure.
Lar' ynx (lar'-inx). The upper part of the windpipe.
Lig' a ments (ligo, I bind) tie bones together.
Lu' bri cate. To oil in order to prevent friction.
Lum' bar (lumbus, a loin). Pertaining to the loins.
Lymph (limf). From lympha, pure water.
Lym phat' ic (lim-fat-ik).
Mas' ti ca' tion. The act of chewing.
Me dul' la Ob lon ga' ta. The upper part of the spinal cord.
Mam' brane. A thin skin, or tissue.
Mes' en tery. The membrane by which the intestines are fastened to the spine.
Met' a car' pal (meta, after; karpos, wrist).
Met' a tar' sal (meta, after; tarsos, the instep).
Mi' cro scope (mikros, small; skopeo, I see).
Mo'lar (mola, a mill) teeth are the grinders.
Morp' hine (Morpheus, the Greek god of sleep).
Mo' tor. Giving motion.
Mu' cous (-kus) Membrane. A thin tissue, or skin, covering the open cavities of the body. See Serous.
Mu' cous. A fluid secreted by a membrane and serving to lubricate it.
Mus' cle (mus-l). A bundle of fibers covered by a membrane.
My o' pi a (muo, I contract; ops, the eye).
Nar cot' ic. A drug producing sleep.
Na' sal (na'-zal). From nasus, the nose.
Nerve (neuron, a cord).
Ni' tro gen Gas is the passive element of the air.
Ni trog' e nous. Containing nitrogen.
Nu tri' tion. The process by which the body is nourished.
soph' agus (e-sof'-a-gus). The gullet; literally, a "food-carrier."
Ol fac' to ry. Pertaining to the smell.
Or' gan. An organ is a portion of the body designed for a particular use, which is called its function; thus the heart circulates the blood.
Os' se ous. Bone-like.
Os' si fy (ossa, bones; facio, I make).
Ox i da' tion. The process of combining with oxygen.
Ox' y gen. The active element of the air.
Pal' ate (palatum, the palate). Roof of the mouth.
Pan' cre as (pas, all; kreas, flesh). An organ of digestion.
Pa pil' la, plu. papillæ. Tiny cone-like projections.
Pa ral' y sis. A disease in which one loses sensation, or the power of motion, or both.
Pa rot' id (para, near; ous, otos, ear). One of the salivary glands.
Pa tel' la (a little dish). The kneepan.
Pec' to ral. Pertaining to the chest.
Pep' sin (pepto, I digest). The chief constituent of the gastric juice.
Per' i car' di um (peri, around; kardia, the heart). The membrane wrapping the heart.
Per' i os' te um (peri, around; osteon, bone). The membrane around the bone.
Per' i stal' tic (peri, round; stallein, to arrange).
Applied to the worm-like movement of the alimentary canal.
Phar' ynx (far'-inx). From pharugx, the throat.
Pi' a Ma' ter (tender mother). See Brain.
Pig' ment. A paint.
Plas' ma (plaz'-ma). The nutritious fluid of the blood.
Pleu' ra (plu'-ra). From pleuar, a rib. The membrane that lines the chest and wraps the lungs.
Pres by o' pi a (presbus, old; ops, the eye). A defect in the eye common to old age.
Proc' ess. A projection. Sometimes it retains its ordinary meaning of "operation."
Py lo' rus (a gate). The doorway through which the food passes from the stomach.
Pul' mo na ry (pulmo, the lungs). Pertaining to the lungs.
Ra' di us. A Latin word meaning the spoke of a wheel, a ray, etc.
Ram' i fy. To spread like the branches of a tree.
Res' pi ra´ tion (re, again; spiro, I breathe). Act of breathing.
Ret' i na (rete, a net). The expansion of the optic nerve in the eye.
Sa' crum (sacred). So named, it is said, because this bone of the pelvis was anciently offered in sacrifice.
Sa li' va. A Latin word meaning spittle; the fluid secreted by the salivary glands.
Scap' u la. The shoulder blade.
Scav' en ger. A street sweeper.
Sele rot' ic (skie-rot'-ic). The outer coat of the eye.
Se cre' tion (secretum, to separate).
Sed' en ta ry persons are those who sit much.
Sen' so ry Nerves. The nerves of feeling.
Se' rous Membrane. A thin tissue, or skin, covering the cavities of the body that are not open to the external air.
Se' rum. The thin part of the blood.
Sub cla' vi an. Located under the clavicle.
Sub lin' gual (sub, under: lingua, the tongue). The salivary gland located under the tongue.
Sub max' il la ry (sub, under; maxilla, jawbone). The salivary gland located under the jaw.
Syn o' vi a (sun, with; oon, egg). A fluid that lubricates the joints.
Syn o' vi al Membrane packs the joints.
Sys' to le (sustello, I contract). Contraction of the heart.
Tem' po ral. An artery on the temple (tempus, time), so called because, as is said, the hair whitens first at that point.
Ten' dons (tendo, I stretch). The cords conveying motion from the muscle to the bone.
Tho' rax (a breastplate). The cavity containing the lungs, etc.
Tib' ia. The shin-bone.
Tis' sue. A general term applied to the textures of which the different organs are composed; osseous tissue forms bones.
Tra' che a (tra'-ke-a). Means rough, alluding to the roughened surface of the windpipe.
Tri' ceps. A muscle with three heads, or origins.
Tri' cus' pid (tres, three; cuspis, point). A valve of the heart.
Tym' pa num (a drum) of the ear.
Vas' cu lar (vasculum, little vessel). Full of small blood vessels.
Ven' tri cle (-kl). A cavity of the heart.
Ver' te bra, plu. vertebræ (verto, I turn). A term applied to each one of the bones of the spine.
Vil' lus (villus, tuft of hair), plu. villi.
Vi' ti ate. To taint. To spoil.
Vit' re ous (vitrium, glass). Glassy.
Vo' mer (plowshare). A bone of the nose.