Biological Transitions

Adolescence

Stage of development, transition to adult roles

Puberty

Period of time where an individual becomes capable of sexual reproduction (hormones regulated by endocrine system)

Manifestations of Puberty

• Increased growth

• Changes to primary sex characteristics

• Secondary sex changes (ex. Breasts pubic hair)

Pre-Peri-Post Pubescent

Variable series of transitions( spermarchy (sexual reproduction), age, emotional, interpersonal, no new hormones

Triggers

Genetics, Nutrition, Physical health, presence of mature sexual partners

Endocrine System

Produces circulate regulate hormones in the body

Gonadotropin-releasing Hormone Neurons

Neurons in the brain that play important roles at puberty

Glands

Organs that stimulate particular parts of the body to respond in specific ways (ex. Thyroid or pancreas)

Hormones

Specialized substances secreted by endocrine glands

HPG (Hypothalamus-Pituitary Gonads) Axis

Hormonal regulation feedback loop

Adrenarchy

Maturation of the adrenal gland that takes place during adolescence

• before puberty the pituitary gland begins to secret hormones → act in thyroid→ and in adrenal gland

Somatic Development

Physical body change

Types of Physcial Body changes

• Adolescent growth spurt

• Peak Height Velocity: Timing of fastest growth

• Epiphysis: Closing the ends of the bones terminates growth after adolescent growth spurt has been completed

Cortisol

Hormone produced by stress

Daily Cortisol Cycle and hunger

Peaks in morning decreases though out day, increases for food

Park of circadian rhythm (levels of melatonin and temperature)

Delayed Phase Prefernce

Pattern of sleep characterized by later sleep and wake times, which usually emerges during puberty insufficient sleep can contribute to; Depression alcohol tobacco drug use, obesity cognitive impairment delinquency

Pheromones

Class of chemicals secreted by animals that stimulate behaviors in other members of species (much unknown here)

Twin Adoption Studies

• Identical genetic load → share the same nature

• Same risk for disease onset duration

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Secondary Sexual Characteristics

Manifestations of sexual maturity at puberty, including the development of breasts, the growth of facial and boy hair and changes in the voice

Tanner Stages

A widely used system that describes the five stages of pubertal development

Secular Trend

Tendency, over the past two centuries, for individuals to be larger in stature and to reach puberty earlier, primary because of improvements in health and nutrition

Timing and tempo of puberty

Largely inherited, nothing specific about it, no relation between the age at onset and rate

Ethic difference in the timing and rate

• Black females (1st) Mexican females (2nd), White females (3rd)

• Difference is probably not due to ethnic differences in income either or area of residence

• Non white girls may be exposed more often to chemicals that stimulate earlier puberty

Kisspeptin

A brain chemical believed to trigger the onset of puberty

Leptin

A brain chemical produced by the fat cells that may play a role in the onset of puberty through stimulating kisspeptin

Melatonin

A hormone secreted by the brain that contributes to sleepiness and that triggers the onset of puberty through its impact of kisspeptin

Familial Influences

Social. factors for early puberty in girls e.g. father absent families, presence of step father → girls are exposed to pheromones

Precocious Puberty

Development of sexual characteristics

• Boys - 9 ( maybe fam history tumors of pituitary or brain tumors in ovaries or testes

• Girls 8 (unknown)

• Children of this age may not be ready and have psychosocial difficulties

Group Differences in Pubertal Maturation

Median age range of menarche in Africa is 14 - 17; US U.S. 12 - 13 ½

Adolescent Growth Spurt

• Increase in height is accomplished by increase in weight

• Rapid gain in fat frequently prompts grills to become overly concerned about their weight

• Girls most susceptible to feelings of body dissatisfaction with their bodies are those who mature early and begin dating early

• Boys feeling about their looks revolve around how muscular they are

Immediate Impact of Puberty

Physical Changes: self-image, mood, and relationship ms with partner whether early or late

Moodiness: Midd fluctuations, not solely from hormones, environmental factors