NORMAL SOLUTIONS 



173 



NORMALS, GROSS SIZES 



Owing to presence of 2 hydroxyl groups 

 it has 2 liydrogen equivalents and it is 

 necessary to divide the molecular weight 

 by 2 so that 63 gms. is made up to 1 liter 

 with aq. dest. 



The alkali sodium hydroxide (NaOPI) 

 has 1 hydroxyl group, so that the molecu- 

 lar weight is taken without division. 

 But with disodium phosphate, the 

 formula of which is Na2HP04, the 

 hj^drogen equivalent is h Na2HP04, so 

 that the molecular weight is divided by 

 2. Similarly with the salt Na2S04 the 

 molecular weight is halved. For sodium 

 triphosphate, NaaPO^, the hydrogen 

 equivalent is i Na3P04, or the molecular 

 weight is divided by 3. 



Normality. Microscopic study of tissues 

 will be of little value in medical research 

 unless their normal structure is at least 

 approximately known as a basis on which 

 to interpret the findings. Unfortu- 

 nately there is no general agreement as 

 to what constitutes normal and abnor- 

 mal, but the statistical definition of 

 normality provides at least a working 

 basis. According to it the normal state 

 is the usual one in a homogeneous group. 

 Bj' usual we mean that it is present in 

 the majority, 51% or more, of the indi- 

 viduals. By homogeneous we mean 

 that the individuals are of the same age, 

 sex, race and are living under similar 

 conditions, that, in other words, no 

 factor is to the best of our knowledge 

 operative likely to produce diversity 

 among them in the particular feature 

 the normality of which is under con- 

 sideration. Thus, if a certain measure 

 of calcification of the wall of the aorta is 

 found in 56% of individuals of a homo- 

 geneous group in St. Louis, it must be 

 regarded as normal for them. But it 

 does not follow that the same grade of 

 aortic calcification is normal for a group 

 of Japanese of the same sex and age in 

 Tokj'o. For them an entirely different 

 grade may be normal occasioned by factors 

 of race, environment, etc. not operative 

 in the same way for the St. Louis group. 

 In speaking of normality it is necessary 

 to be very specific. An aorta may be 

 normal in respect to degree of calcifica- 

 tion but abnormal, or unusual, in other 

 respects. Consequently' the normality 

 of this or any other tissue can only be 

 established for the particular property 

 measured assuming tliat the technique 

 of observation is adequate and the num- 

 ber of individuals examined is sufficiently 

 large . 



Normals, Gross Sizes. What these are is 

 only known in a very hazy way. Yet 

 if the size of an organ is distinctly ab- 

 normal this fact must clearly be taken 

 into consideration in evaluating the 

 results of its microscopic study. The 



best way is to search for papers <lcaling 

 with the organ in which one is interested 

 in the Quart. Cum. Index Med. The 

 older data are summarized by Vierordt, 

 H., Anatomische Physiologische und 

 Physikalische Daten und Tabellen. 

 Jena: Fischer, 1906, 616 pp. A sum- 

 mary of measurements on infants and 

 children is provided by R. E. Scammon 

 in Abt's Pediatrics, Philadelphia: 

 Saunders, 1923, 1, 257-444. See also 

 Coppoletta, J. M. and Wolbach, S. B., 

 Am. J. Path., 1933, 9, 55-70. Useful 

 quantitative data on the endocrines are 

 supplied by R. Pearl and his associates 

 in Human Biology, 1935, 7, 350-391, 555- 

 607; 1936, 8, 92-125; 1937, 9, 245-250. 

 For spleen and thymus see Krumbhaar, 

 E. B., Cowdry's Problems of Ageing. 

 Baltimore: Williams & Wilkins, 1942, 

 139-184. There is a wide range in indi- 

 vidual variation. Size may be greater 

 or smaller than the normal or usual 

 without being indicative of disease. 

 Stitt, E. R., Clough, P. W. and M. C, 

 Practical Bacteriology, Haematology 

 and Animal Parasitology. Phila- 

 delphia: Blakiston, 1938, 961 pp. give 

 these approximate measurements (ab- 

 breviated) : 



Adrenals — Length, 6-7 cm.; breadth, 

 3-3.5 cm.; weight, 5-6 gms. each. 



Aorta — Length, 42.5-50 cm.; thick- 

 ness of wall, 1.5-2 mm.; diameter, 

 1.7-3 cm. ; weight, 35-45 gms. 



Appendix — Length, 9-10 cm. ; diameter, 

 6 mm.; weight, 7-14 gm., quite 

 variable. 



Bladder — Capacity, 500 cc. when nor- 

 mally distended; thickness of wall, 

 2.5 mm. ; weight, 30-60 grams. 



Brain— Weight, female, 1250-1275 gms.; 

 male, 1365-1450 gms. ; length, 16.5 

 cm.; transverse diameter, 14 cm.; 

 vertical diameter, 12.7 cm.; dimen- 

 sions in female being 1 cm. less. 



Fallopian tubes — Length, 7.6-12.6 cm., 

 the right usually the longer; diameter 

 of lumen averages 2.5 mm. 



Gall bladder — Length, 7.5-10 cm. ; diam- 

 eter, 2.5-3 cm.; thickness of wall, 

 1-2 mm. ; capacity, 30-45 cc. 



Heart— Weight, female, 250-280 gms., 

 male, 270-360 gms.; length, 11.5-14 

 cm.; breadth, 7.5-10 cm.; thickness, 

 5-8 cm. ; thickness, wall left ventricle, 

 9-12 mm., right ventricle, 2.5-3 mm.; 

 circumference, mitral orifice, 10.4- 

 10.9 cm.; circumference, tricu.spid 

 orifice, 12-12.7 cm.; circumference, 

 aortic orifice, 7.7-8 cm. ; circumference, 

 pulmonary orifice, 8.5-9 cm. 



Intestines — Small intestine, length, 

 6.75 meters, 2/5 jejunum and 3/5 

 ileum; diameter from 47 mm. in 

 duodenum to 27 mm. at the end of 



