copyright © 2006, elsevier inc. all rights reserved c hapter 6 puberty

Copyright © 2006, Elsevier Inc. All rights reserved

CHAPTER 6Puberty


FIGURE 6-1 DIFFERENT DEGREES OF SEXUAL MATURATION AT THE SAME AGE. THE MALES ARE ALL 14.75 YEARS OLD, AND THE FEMALES ARE ALL 12.75 YEARS OLD. THIS ILLUSTRATES THAT THE DEGREE OF SEXUAL MATURITY CAN VARY WIDELY IN RELATION TO AGE.


FIGURE 6-2 CHANGES IN THE WEIGHT OF AN OVARY AND THE UTERUS WITH AGE.


FIGURE 6-3 CHANGES IN THE WEIGHT OF A SINGLE TESTIS, SEMINAL VESICLE, AND PROSTATE GLAND WITH AGE.


FIGURE 6-4 STAGES OF PUBIC HAIR DEVELOPMENT IN FEMALES. THE INFANTILE PATTERN (STAGE 1)IS NOT SHOWN. REFER TO THE DESCRIPTION OF THESE STAGES IN TABLE 6-3.


FIGURE 6-5 STAGES OF FEMALE BREAST DEVELOPMENT. REFER TO THE DESCRIPTION OF THESE STAGES IN TABLE 6-3.


FIGURE 6-6 STAGES OF MALE GENITAL DEVELOPMENT DURING PUBERTY. REFER TO THE DESCRIPTIONOF THESE STAGES IN TABLE 6-3.


FIGURE 6-7 CHANGES IN BLOOD LEVELS OF FSH, LH, AND ESTRADIOL IN FEMALES OF DIFFERENT AGES. BLOOD ANDROGEN LEVELS ARE NOT DEPICTED, BUT THESE ALSO RISE AS PUBERTY NEARS. NOTE THAT THE VALUES FOR HORMONE LEVELS ARE IN NANOGRAMS PERCENT (NG %) OR MICROGRAMS PERCENT (G%). A NANOGRAM IS OF A MICROGRAM, AND 1 NG% IS 1/1000 EQUIVALENT TO 1.0 NG IN 100 ML OF BLOOD PLASMA. THUS NOT MANY HORMONE MOLECULES ARE NEEDED TO CHANGE BIOLOGICAL FUNCTION.


FIGURE 6-8 CHANGES IN BLOOD LEVELS OF FSH, LH, AND TESTOSTERONE IN MALES OF DIFFERENT AGES. BLOOD ESTROGEN LEVELS ARE NOT DEPICTED, BUT THESE ALSO RISE SLIGHTLY AS PUBERTY NEARS. FOR AN EXPLANATION OF NG% AND G%, SEE THE LEGEND TO FIG. 6-7.


FIGURE 6-9 DAILY PATTERNS OF LH LEVELS IN BLOOD OF FEMALES AT VARIOUS STAGES OF SEXUAL MATURATION. NOTE THAT DURING PUBERTY, LH LEVELS RISE DURING SLEEP AND EXHIBIT MARKED HOUR-TO-HOUR FLUCTUATIONS. AVERAGE LEVELS AND FLUCTUATIONS IN BOTH DAY AND NIGHT THEN INCREASE DURING LATE PUBERTY, BEFORE DECREASING SOMEWHAT IN THE ADULT. LH CONCENTRATIONS ARE IN MILLI-IUS PER MILLILITER OF BLOOD (SEE FIG. 3-2.)


FIGURE 6-10 AVERAGE AGE OF MENARCHE, 1790 TO 1980. , UNITED STATES; , VARIOUS EUROPEAN COUNTRIES. THE REGRESSION LINE REPRESENTS THE AVERAGE RATE OF DECREASE, WHICH HAS BEEN 3 TO 4 MONTHS PER DECADE. THE AVERAGE AGE OF MENARCHE IN THE UNITED STATES IN THE LATE 1990S WAS 12.3 YEARS, WHICH APPEARS TO BE STABLE AT PRESENT. AGE OF MENARCHE HAS NOT BEEN DECREASING IN UNDERDEVELOPED COUNTRIES, PROBABLY BECAUSE OF MALNUTRITION.

copyright © 2006, elsevier inc. all rights reserved c hapter 6 puberty

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