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.

Copyright (c) 2001 by The McGraw-Hill Companies, Inc. All rights reserved.

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).

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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

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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

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Pubertal Timing

Discussions with knowledgeable healthcare providers and parents can improve the coping abilities of the off-time adolescent

Copyright (c) 2001 by The McGraw-Hill Companies, Inc. All rights reserved.