THE PHYSIOLOGICAL DEVELOPMENT OF THE ADOLESCENT
Introduction
In trying to discuss adolescence, most adults tend to confuse the terms adolescence and puberty, and use them synonymously. However, puberty refers to the physiological changes involved in the sexual maturation of a child, as well as other body changes that may occur during this period of time. Adolescence refers to the stage from puberty to adulthood, and includes the psychological experiences of the child during this period. Adolescence is described as being the teenage years from thirteen to eighteen years of age; however, puberty decides the onset of adolescence. Therefore, adolescence occurs in some children as early as nine years of age. During this period of time the child has a great deal of concern over his/her body image and any discrepancies in the child’s eye such as obesity, early or late maturation, etc., may be manifested through a variety of disorders.
During adolescence there is a large degree of psychological growth as children make adjustments in their personality due to the rapid physical and sexual development which are characteristic of this period of life. Adolescents face ongoing conflict and difficulty adapting to the sudden upsurge of sexual and aggressive drives. These changes cause unrest and confusion in the adolescents’ inner selves and in the way they perceive the world.
What is Puberty?
Puberty refers to the physiological changes that the adolescent undergoes in order to reach sexual maturity. It is best characterized as the gradual onset of mature reproductive hormonal activity, triggered by the central nervous system, mainly the hypothalamus and pituitary gland. Most people look at puberty in three distinct stages railed the pre-pubescent, pubescent, and postpubescent. The prepubescent stage includes the first evidence of sexual maturation—primary sexual characteristics—and terminates at the first appearance of pubic hair. During this stage, reproduction is virtually impossible. During the pubescent stage the growth spurt begins to accelerate, males experience their first emission of semen usually in the form of “wet dreams,” and menarche occurs in the females. The postpubescent stage is characterized by the deceleration of growth spurt, completion of both primary and sexual characteristics, and fertility is possible.
The Anatomical Development of the Adolescent
Adolescent growth first centers on the extremities—the legs and arms during the early stages of adolescence. Changes also occur in the facial configurations of both sexes.The lower portion of the head begins to grow because the chin lengthens and the nose grows in width and/or length. Additional changes in proportion of the face is accredited to changes in tissue distribution. Even though both sexes undergo this change, within females a layer of subcutaneous fat develops which causes the rounding and softening of contours of the face and body. Whereas, the male subcutaneous fat development is much less pronounced, but the development of muscles and bones in the face is clearly seen. This gives the males a leaner and more angular face than the females.
Changes also occur on the surface of the body in both sexes. The most observable change is the growth on body hair, both pubic and axillary (armpit). The development of pubic hair is the first sign of a child ending the prepubescent stage and entering the pubescent stage. This process begins about the same time as the growth spurt begins, and is in the form of slightly coarse, straight hairs that grow at the base of the penis and an the labia majora. The growth of pubic hair continues throughout adolescence, it spreads horizontally and then vertically until it surrounds the genital areas. Characteristically, pubic hair becomes longer, thicker, darker and kinkier as it spreads over the genital areas. In males, the growth of facial and chest hair may be pronounced, and tends to represent virility in the eyes of the adolescent. Noticeable chest hair, with a thickness in texture does not usually appear until the postpubescent stage and continues to grow during manhood. Facial hair usually appears in the form of a dark shadow above the lip. Then it appears on the chin, along the jaw line, and then develops along the neck. Females may also find small amounts of facial and chest hair.
Both male and female skin undergoes other changes, such as becoming coarser with the sebaceous glands becoming more active, producing oily secretions which usually help cause acne or blackheads. Sweat usually causes an odor in adolescents because the chemistry and composition of sweat is altered by the oils that the sebaceous glands emit. Adolescents also show an increase in their blood pressure, and a decrease in both basal metabolic rate—the rate at which the body in a resting state (basal) consumes oxygen—and in pulse rate.
The Onset of Puberty in Adolescents
Amazing as it may seem, sexual maturation is programmable for the primary sexual characteristics to begin their development, the pituitary gland must first release stimulating agents called gonadotropins into the bloodstream. Once they reach the testes in the male and the ovaries in the female, a number of changes will occur.
There are two gonadotropins: follicle stimulating hormone (FSH) and luteinizing hormone (LH). these gonadotropins are present in the adolescent during childhood, but at levels too low for sexual maturation to begin. At the beginning of puberty, the pituitary releases increased amounts of gonadotropins while the child is asleep and stops immediately after the child awakens. However, once the child enters the postpubescent stage, gonadotropins are released both during sleep and during the day. In the ovaries, follicle stimulating hormone is responsible for the development of the follicle which contains a developing ovum (egg). Follicle stimulating hormone also helps produce the female hormone estrogen within the follicle when it is stimulated by luteinizing hormone. In males, FSH incites the growth of seminiferous tubules, which produce sperm in the testes. Luteinizing hormone is responsible for producing androgen male hormone in the Leydig cells. The androgen that the Leydig cells produce, aids in the growth on the seminiferous tubules. As the adolescent grows older, the pituitary releases increased amounts of gonadotropins, ovaries and the testes grow more rapidly, and produce larger amounts of estrogen and/or androgen.
Sexual Maturation In the Male Adolescent
Even though the male adolescent’s growth rate varies from child to child, a sequential pattern has been identified. The typical sequence of events occurs as follows:
1. The testes and scrotum begin to increase in size.
2. Pubic hair begins to appear.
3. The penis begins to enlarge, and the adolescent growth spurt begins.
4. The larynx starts to grow and the voice deepens.
5. Hair growth begins on the upper lip.
6. Nocturnal emissions (ejaculation of semen during sleep) may occur as sperm production increases.
7. Pubic hair becomes pigmented, and growth spurt reaches its peak.
8. The prostrate gland enlarges.
9. Hair growth begins in the axillas (armpits).
10. Sperm production becomes sufficient for fertility, and the growth rate decreases.
11. Physical strength is at its peak.
Sexual Maturation of the Female Adolescent
Even though the female adolescent’s growth rate varies from child to child, a sequential pattern has been identified. The typical sequence of events occur as follows:
1. The adolescent growth spurt begins.
2. Non-pigmented pubic hair (downy) appears.
3. The budding stage of development (breast elevation) and the rounding of the hip begins, accompanied by the beginning of downy axillary hair.
4. The uterus, vagina, labia and clitoris increase in size.
5. Pubic hair growth becomes rapid and is slightly pigmented.
6. Breast development advances, nipple pigmentation begins, and the areola increases in size. Axillary hair becomes slightly pigmented.
7. Growth spurt reaches its peak, and then declines.
8. Menarche occurs.
9. Public hair development is completed, followed by mature breast development and completion of axillary hair development.
10. “Adolescent sterility” ends, and the girl becomes capable of conception.
Menstruation
The menstrual cycle is controlled by the hypothalamus, which acts as a menstrual clock. The clock operates through the pituitary gland located at the base of the brain. The pituitary gland cyclically secretes two hormones which directly stimulate the ovary these hormones are follicle stimulating and luteinizing hormones.
As follicle stimulating and luteinizing hormones act on the follicle, its cells multiply causing a large fluid—filled cavity to form. The growth and activity of the follicular cells result in the secretion of estrogen by the cells, and this hormone is found in the fluid of the follicle.
Luteinizing hormones cause the cells of the follicle to rupture and expel the ovum. Then the fluids and cells form a new structure called the corpus luteum. The corpus luteum is stimulated by the gonadotropins and initiate the production of the hormone, progesterone. Progesterone causes the lining of the uterus to change, thus getting it ready for the reception, embedding, and gestation of a fertilized ovum. The coordinated action of progesterone and estrogen makes the lining of the uterus an environment where an embryo can survive during pregnancy.
Menstruation occurs approximately every three to four weeks. If the ovum is not fertilized, most of the lining of the uterus mixed with blood is expelled through the cervix into the vagina. This bloody discharge is referred to as menstruation (menses) or a menstrual period. The entire cycle repeats itself with regularity throughout the reproductive life of the female. However, at its onset after puberty, menstruation may be irregular for up to a year or two.
Introduction
In trying to discuss adolescence, most adults tend to confuse the terms adolescence and puberty, and use them synonymously. However, puberty refers to the physiological changes involved in the sexual maturation of a child, as well as other body changes that may occur during this period of time. Adolescence refers to the stage from puberty to adulthood, and includes the psychological experiences of the child during this period. Adolescence is described as being the teenage years from thirteen to eighteen years of age; however, puberty decides the onset of adolescence. Therefore, adolescence occurs in some children as early as nine years of age. During this period of time the child has a great deal of concern over his/her body image and any discrepancies in the child’s eye such as obesity, early or late maturation, etc., may be manifested through a variety of disorders.
During adolescence there is a large degree of psychological growth as children make adjustments in their personality due to the rapid physical and sexual development which are characteristic of this period of life. Adolescents face ongoing conflict and difficulty adapting to the sudden upsurge of sexual and aggressive drives. These changes cause unrest and confusion in the adolescents’ inner selves and in the way they perceive the world.
What is Puberty?
Puberty refers to the physiological changes that the adolescent undergoes in order to reach sexual maturity. It is best characterized as the gradual onset of mature reproductive hormonal activity, triggered by the central nervous system, mainly the hypothalamus and pituitary gland. Most people look at puberty in three distinct stages railed the pre-pubescent, pubescent, and postpubescent. The prepubescent stage includes the first evidence of sexual maturation—primary sexual characteristics—and terminates at the first appearance of pubic hair. During this stage, reproduction is virtually impossible. During the pubescent stage the growth spurt begins to accelerate, males experience their first emission of semen usually in the form of “wet dreams,” and menarche occurs in the females. The postpubescent stage is characterized by the deceleration of growth spurt, completion of both primary and sexual characteristics, and fertility is possible.
The Anatomical Development of the Adolescent
Adolescent growth first centers on the extremities—the legs and arms during the early stages of adolescence. Changes also occur in the facial configurations of both sexes.The lower portion of the head begins to grow because the chin lengthens and the nose grows in width and/or length. Additional changes in proportion of the face is accredited to changes in tissue distribution. Even though both sexes undergo this change, within females a layer of subcutaneous fat develops which causes the rounding and softening of contours of the face and body. Whereas, the male subcutaneous fat development is much less pronounced, but the development of muscles and bones in the face is clearly seen. This gives the males a leaner and more angular face than the females.
Changes also occur on the surface of the body in both sexes. The most observable change is the growth on body hair, both pubic and axillary (armpit). The development of pubic hair is the first sign of a child ending the prepubescent stage and entering the pubescent stage. This process begins about the same time as the growth spurt begins, and is in the form of slightly coarse, straight hairs that grow at the base of the penis and an the labia majora. The growth of pubic hair continues throughout adolescence, it spreads horizontally and then vertically until it surrounds the genital areas. Characteristically, pubic hair becomes longer, thicker, darker and kinkier as it spreads over the genital areas. In males, the growth of facial and chest hair may be pronounced, and tends to represent virility in the eyes of the adolescent. Noticeable chest hair, with a thickness in texture does not usually appear until the postpubescent stage and continues to grow during manhood. Facial hair usually appears in the form of a dark shadow above the lip. Then it appears on the chin, along the jaw line, and then develops along the neck. Females may also find small amounts of facial and chest hair.
Both male and female skin undergoes other changes, such as becoming coarser with the sebaceous glands becoming more active, producing oily secretions which usually help cause acne or blackheads. Sweat usually causes an odor in adolescents because the chemistry and composition of sweat is altered by the oils that the sebaceous glands emit. Adolescents also show an increase in their blood pressure, and a decrease in both basal metabolic rate—the rate at which the body in a resting state (basal) consumes oxygen—and in pulse rate.
The Onset of Puberty in Adolescents
Amazing as it may seem, sexual maturation is programmable for the primary sexual characteristics to begin their development, the pituitary gland must first release stimulating agents called gonadotropins into the bloodstream. Once they reach the testes in the male and the ovaries in the female, a number of changes will occur.
There are two gonadotropins: follicle stimulating hormone (FSH) and luteinizing hormone (LH). these gonadotropins are present in the adolescent during childhood, but at levels too low for sexual maturation to begin. At the beginning of puberty, the pituitary releases increased amounts of gonadotropins while the child is asleep and stops immediately after the child awakens. However, once the child enters the postpubescent stage, gonadotropins are released both during sleep and during the day. In the ovaries, follicle stimulating hormone is responsible for the development of the follicle which contains a developing ovum (egg). Follicle stimulating hormone also helps produce the female hormone estrogen within the follicle when it is stimulated by luteinizing hormone. In males, FSH incites the growth of seminiferous tubules, which produce sperm in the testes. Luteinizing hormone is responsible for producing androgen male hormone in the Leydig cells. The androgen that the Leydig cells produce, aids in the growth on the seminiferous tubules. As the adolescent grows older, the pituitary releases increased amounts of gonadotropins, ovaries and the testes grow more rapidly, and produce larger amounts of estrogen and/or androgen.
Sexual Maturation In the Male Adolescent
Even though the male adolescent’s growth rate varies from child to child, a sequential pattern has been identified. The typical sequence of events occurs as follows:
1. The testes and scrotum begin to increase in size.
2. Pubic hair begins to appear.
3. The penis begins to enlarge, and the adolescent growth spurt begins.
4. The larynx starts to grow and the voice deepens.
5. Hair growth begins on the upper lip.
6. Nocturnal emissions (ejaculation of semen during sleep) may occur as sperm production increases.
7. Pubic hair becomes pigmented, and growth spurt reaches its peak.
8. The prostrate gland enlarges.
9. Hair growth begins in the axillas (armpits).
10. Sperm production becomes sufficient for fertility, and the growth rate decreases.
11. Physical strength is at its peak.
Sexual Maturation of the Female Adolescent
Even though the female adolescent’s growth rate varies from child to child, a sequential pattern has been identified. The typical sequence of events occur as follows:
1. The adolescent growth spurt begins.
2. Non-pigmented pubic hair (downy) appears.
3. The budding stage of development (breast elevation) and the rounding of the hip begins, accompanied by the beginning of downy axillary hair.
4. The uterus, vagina, labia and clitoris increase in size.
5. Pubic hair growth becomes rapid and is slightly pigmented.
6. Breast development advances, nipple pigmentation begins, and the areola increases in size. Axillary hair becomes slightly pigmented.
7. Growth spurt reaches its peak, and then declines.
8. Menarche occurs.
9. Public hair development is completed, followed by mature breast development and completion of axillary hair development.
10. “Adolescent sterility” ends, and the girl becomes capable of conception.
Menstruation
The menstrual cycle is controlled by the hypothalamus, which acts as a menstrual clock. The clock operates through the pituitary gland located at the base of the brain. The pituitary gland cyclically secretes two hormones which directly stimulate the ovary these hormones are follicle stimulating and luteinizing hormones.
As follicle stimulating and luteinizing hormones act on the follicle, its cells multiply causing a large fluid—filled cavity to form. The growth and activity of the follicular cells result in the secretion of estrogen by the cells, and this hormone is found in the fluid of the follicle.
Luteinizing hormones cause the cells of the follicle to rupture and expel the ovum. Then the fluids and cells form a new structure called the corpus luteum. The corpus luteum is stimulated by the gonadotropins and initiate the production of the hormone, progesterone. Progesterone causes the lining of the uterus to change, thus getting it ready for the reception, embedding, and gestation of a fertilized ovum. The coordinated action of progesterone and estrogen makes the lining of the uterus an environment where an embryo can survive during pregnancy.
Menstruation occurs approximately every three to four weeks. If the ovum is not fertilized, most of the lining of the uterus mixed with blood is expelled through the cervix into the vagina. This bloody discharge is referred to as menstruation (menses) or a menstrual period. The entire cycle repeats itself with regularity throughout the reproductive life of the female. However, at its onset after puberty, menstruation may be irregular for up to a year or two.
Comments
Post a Comment