Biological Changes Flashcards
from 0-6, what do children have in common?
their bodies look very similar regardless of sex
major changes in females:
early, middle, late
early: breast buds start to form, hair growth, growth spurt starts
middle: menarche, end of growth spurt, fat deposition
Stops around 15-16
major changes in males:
early, middle, late
early: testes + genitals grow
middle: spermarche, growth spurt starts
late: more muscle + body hair
Puberty:
sexual reproduction changes
What system is associated with physical changes and regulates hormones to the body?
Endocrine system: 6-9, adrenals start to grow and produce DHEA (androgen) = pubic hair, odor, rough skin
What are the 3 key changes in puberty?
- rapid growth: in height + weight
- primary sex characteristics: hormonal changes: gonads + reproductive hormones
- secondary sex characteristics: breasts, muscle, hair growth
What makes up the Endocrine System:
Glands: organs that release hormones in the bloodstream
Hormones: substances secreted by the glands/ chemical messengers
GnRH neurons: in the brain - control the release of reproductive hormones into other glands (pituitary)
Hypothalamus
Bean-sized/ under cortex
- produces hormones that act on the pituitary
- affects hunger, thirst, sexuality
- checks and responds to the levels of hormones in the blood
- activates GnRH neurons
What could cause/ happen if there is damage to the hypothalamus?
TBI’s, Infections
mood disorders, obesity
Pituitary Gland
Pea-sized/ under hypothalamus
MASTER GLAND
- stimulates other organs to secrete hormones - knows when to pump estrogen/testosterone
- releases hormones before puberty that act on thyroid + adrenals (stress) to start secreting hormones
Adrenarche:
- the first phase of puberty
- maturation of the adrenals (around 6)
- leads to first feelings of sexual attraction
What does ACTH (Adrenocorticotropic hormone) do?
regulates androgen production by the adrenals + gonads
cortisol:
- Adrenals release this (stress hormone)
- teens are sensitive to it - 0-100 rly quick
when the pituitary sends signals to the gonads, what hormones are secreted? what do they do?
LH + FSH
- for sperm and egg production
(gametes)
what sex hormones are found in males and females?
estrogen (estradiol): female
androgen (testosterone): men
what is the difference in sex hormones in males and females from childhood to ado?
female: 8x more estrogen, 4x more testosterone
males: 20x more testosterone, 2x more estrogen
what percentage of fat do we need in our body to begin puberty? what does fat increase cause to increase?
23%
leptin increases which creates Kisseptin (influences GnRH secretion)
Explain the hormone feedback loop:
The hypothalamus senses when a sex hormone level is too low, so it sends GnRH to the Pituitary which creates more LH and FSH to send to the gonads to produce more sex hormones
3 processes in somatic development:
1: growth spurt
2. peak height velocity
3. epiphysis
growth spurt:
dramatic increase in weight + height
Peak height velocity:
the highest point of growth ( grow as fast as toddlers
girls: ass 8cm/year, boys add >9cm/year
Asynchronicity:
different body parts develop at different rates -> unproportionate hands, head, etc…
Epiphysis:
the closing of the ends of bones (growth is complete) = growing pains
when do girls have their growth spurts? why do boys end up taller if they get theirs later?
around 11-12
when they start their growth spurt, they are already 4 inches taller than girls were when they started
