Steinberg Chapter 1 Flashcards
(168 cards)
What is puberty?
Puberty is a flood of biological events leading to an adult size body and sexual maturity, thus enabling young people to fulfill their biological destiny specifically sexual reproduction and survival of the species. It also more broadly encompasses all the physical changes that occur in adolescents as they pass from childhood into adulthood (Dorn & Biro, 2011).
If no new hormones are produced at puberty then what’s changing hormonally?
The levels of some hormones (that have been present since before birth) increase, whereas others decrease.
Describe the disproportionate production of different types of gender-related hormones during adolescence?
Males: androgens > estrogens
Females: estrogens > androgens
During adolescence the average male produces more androgens compared to estrogens. The opposite is true of females who produce more estrogens compared to androgens (Susman & Dorn, 2009).
What is the name of the mechanism responsible for maintaining certain levels of androgens and estrogens?
When these hormonal levels fall below the HPG axis set points, what is responsible for disinhibiting the pituitary?
This disinhibition permits the pituitary to stimulate the release of sex hormones by the gonads, and other puberty-related hormones by the adrenal gland. When hormone levels reach the set point, the hypothalamus responds by inhibiting its stimulation of the pituitary gland. Your brain is constantly monitoring a variety of signals and adjusting your hormonal set points in response.
HPG axis
hypothalamus
What are the 3 chief physical manifestations of puberty? (PSR)
- Development of primary sex characteristics (gonads, hormonal changes) ultimately enabling reproduction
- Development of secondary sex characteristics (genitals, breasts, pubic, facial, and body hair)
- Rapid acceleration of growth, specifically height and weight.
Puberty is the result of the development of what 2 systems?
Clint Eastwood
Central nervous system (Clint) Endocrine system (Eastwood)
When does puberty begin?
Puberty may appear to come on suddenly, judging from its external signs, but in fact it is part of a gradual process that begins at conception.
What is the function of the endocrine system during puberty?
It produces, circulates, and regulates levels of hormones
What are hormones?
Highly specialized substances secreted by one or more endocrine glands and then enter the bloodstream and travel throughout the body.
What are glands?
Organs that stimulate particular parts of the body to respond in specific ways to particular hormones.
What are gonadotropin-releasing hormone (GnRH) neurons?
Specialized neurons that are activated by certain pubertal hormones.
Where does the endocrine system receive its instructions from to increase or decrease circulating levels of particular hormones?
The central nervous system
In what way is the endocrine system like a thermostat?
Hormonal levels are “set” at a certain point, which may differ depending on the stage of development. When a particular hormonal level in your body dips below the endocrine system’s set point for that hormone, secretion of the hormone increases; when the level reaches the set point, secretion temporarily stops. Hormone can be adjusted up or down, depending on environmental or internal bodily conditions.
At the onset of puberty, a feedback loop ensues. What are the 3 components of this feedback loop?
Hypothalamus
Pituitary gland
Gonads
What are gonads?
Glands that release sex hormones: in males, the testes; in females, the ovaries.
What is the pituitary gland?
Responsible for regulating levels of hormones in the body.
What is the hypothalamus?
Part of the brain that controls the pituitary gland, and where there is a concentration of GnRH neurons. When the hypothalamus malfunctions puberty is delayed. Seeing a reproductive endocrinologist is recommended.
It is inaccurate to say that adolescence is an inherently stressful time. But what is true about stress during adolescence?
Adolescents experience a heightened vulnerability to stress.
What is one reason adolescence is a period of great vulnerability for the onset of many serious mental disorders?
The hormonal changes of puberty make adolescents more responsive to stress (Monahan, Guyer, Silk, Fitzwater, & Steinberg, 2016; Romeo, 2013; Stroud et al., 2009; Trépanier et al., 2013; Worthman, 2011). This leads to excessive secretion of the stress hormone cortisol, a substance that at high and chronic levels can cause brain cells to die (Carrion & Wong, 2012; Gunnar, Wewerka, Frenn, Long, & Griggs, 2009).
Hormonal changes during puberty—> more responsive to stress—> excessive secretion of cortisol —> chronic levels of cortisol = possible brain damages
What is adrenarche?
The maturation of the adrenal gland. More specifically, the adrenal gland releases a slightly higher level of sex hormones between 6 and 8. By the age of 10 levels of those sex hormones (adrenal androgens) have increased 10 fold, evidenced by most people report having their first sexual attraction at the magical age of 10 before they went through puberty. (From Berk and Steinberg Texts)
What triggers puberty?
GENETIC FACTORS
a) the HPG axis reawakens (the first awakening occurs prenatally) signaling to the body it’s ready for puberty.
b) a “puberty alarm” is set very early in life by information coded in the genes. In other words, the age at which someone goes through puberty is largely inherited. Genetics determine the upper and lower age limits (as opposed to a fixed absolute age).
c) an increase in the brain chemical kisspeptin. Leptin stimulates its production and melatonin suppresses it.
d) Quantity of fat cells (leptin) (obese children will go through puberty on the early side of their inherited propensity)
e) levels of melatonin. Low levels means kisspeptin is NOT being suppressed.
ENVIRONMENTAL FACTORS (some of the reawakening of the HPG axis at puberty is due to multiple environmental signals)
a) availability of sexually mature mating partners in the environment
b) sufficiency of nutritional resources to support a pregnancy
c) physically maturity and sufficient health to begin reproducing
d) frequency of exposure to light (children who live close to the equator
are more likely to go through puberty on the early side of their inherited propensity)
e. the environment determines the timing and rate within the upper and lower age limits that were genetically predetermined.
By far the 3 most important environmental influences on pubertal maturation are what?
What 5 factors predict pubertal timing from an environment perspective?
Nutrition Health The overall physical well-being of the individual from conception through preadolescence 1) Height 2)Weight 3) history of protein and/or caloric deficiency 4) Chronic illness 5) Excessive exercise
How do researchers know that the timing and tempo of pubertal timing is largely inherited, involving both genetic and chromosomal components?
Researchers compare identical twins and individuals who are not genetically identical. Also, a specific region on chromosome 6 has been identified as one of the markers for pubertal timing in both boys and girls (Bogin, 2011)
Why do obese children tend to start puberty early?
Obese children have more body fat and therefore produce a lot more leptin, which stimulates kisspeptin production