Biological Foundations: Puberty
How to cope with others’ responses;How to deal with sexual arousal;Puberty is the key developmental challenge in adolescence.The marker event for entry into adolescence.
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Puberty
Pubertal status Pubertal timing What is pubescence? Neuro-physical activities that stimulate
puberty
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Pubertal systems
What’s going on in there?
• Hypothalamic-pituitary-gonadal axis
• Hypothalamic-pituitary-adrenal axis
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The Major Endocrine Glands Involved in Pubertal Change
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Hypothalamus
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Monitors levels of androgens and estrogens.
LH-RF (lutenizing hormone-releasing factor) and FSH-RF (follical stimulating hormone-releasing factor) stimulate pituitary gland.
The pituitary gland
• The master gland, it: • Regulates LH (lutenizing hormone) and
FSH (follicle-stimulating hormone);
• stimulates growth of the gonads (e.g., testes in males, ovaries in females).
Copyright (c) 2001 by The McGraw-Hill Companies, Inc. All rights reserved.
Puberty
Physical Changes Boundaries and Determinants
Hormonal Changes
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Hormone Levels by Sex and Pubertal Stage for Testosterone
The 5 Pubertal Stages of Male and Female Sexual
Development
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Timing and onset of puberty
The average age of onset of puberty shows a secular trend over the past century towards earlier occurrence.
This is thought to be related to better nutrition and health care.
Puberty
Physical Changes
Height and Weight
Sexual Maturation
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Sequence of changes
Female Characteristics• Growth of breasts (7-13 years)• Growth of pubic hair (7-14 years)• Body growth (9.5-14.5 years)• Menarche (10-16.5 years)• Underarm hair (1-2 years after pubic hair)• Skin oil & sweat
Copyright (c) 2001 by The McGraw-Hill Companies, Inc. All rights reserved.
Sequence of changes
Male Characteristics• Growth of testes (10-13 years)• Growth of pubic hair (10-15 years)• Body growth (10.5--16 years)• Growth of penis (11-14.5 years)• Voice change (11-14.5 years)• Facial and underarm hair (1-2 years after
pubic hair)Copyright (c) 2001 by The McGraw-Hill Companies, Inc. All rights reserved.
Primary sex characteristics
FEMALE• Ovaries• Fallopian tubes• Uterus• Vagina
MALE• Testes• Penis• Scrotum• Seminal vesicles• Prostate gland
Secondary sex characteristics
FEMALES• Breasts• Pubic hair• Axillary
(underarm) hair• Voice changes• Skin changes• Increased width
and depth of pelvis
MALES• Pubic hair• Axillary hair• Muscular
development• Facial hair• Voice changes• Skin changes• Broadened
shoulders
Pubertal Timing
-Early maturers
-On time maturers
-Late maturers
Copyright (c) 2001 by The McGraw-Hill Companies, Inc. All rights reserved.