Lecture 7- Puberty Flashcards
Puberty is a stage of human development when
when sexual maturation and growth are completed and results in ability to reproduce- morphological physiological and behaviour development
- Primary sexual characteristic established
before birth
- Sequence of events
- Age variable
- Order consistent (always happens in the same order)
- Therefore not a function of age
do girls or boy start puberty first
- Girls begin and end puberty before boys
maturation is order consistent
- Accelerated somatic growth
- Maturation of primary sexual characteristic (gonads and genitals)
- Appearance of secondary sexual characteristics (pubic and axillary hair, female breast development, male voice changes)
- Menstruation and spermatogenesis begin
therlarche
onset of breast development occurring near beginning of puberty in girls
- Adrenarche-
maturation and increased activity of the adrenal glands prior to puberty
- Gondarache-
activation of reproductive glands by pituitary hormone FSH and LH
- Menarche-
onset of menstruation at puberty
which gland is thought to be an important influence on the timing of puberty
the pineal gland
as disorders of this gland can cause early onset (precocious) puberty
key environmental factor that infleunces onset of puberty
- Body weight is a key factor in the onset of puberty in girls, as well as nutrition and leptin (released from adipose tissue)
- Age of menarche has declined (from 16.6 to 12.5) over the year
- women have a higher BMI now
- Age of menarche has declined (from 16.6 to 12.5) over the year
- Low body weight can cause
cessation of menstruation, even after puberty has occurred
other factors that effect menarche
- Onset age differs around globe
- Economic factors/ disparity may effect onset of puberty
Regardless of age of onset-
sequence of events is consistent
what is used to define Sexual maturity rating (SMR)
Tanner scale
Tanner scale
- Tanner developed a scale that divides the sexual maturity rating into 5 classed
- Based on pubic hair and breast and females
- Pubic hair and genitalia in males
tanner stage 1 in females
pre-pubertal
pubic hair- non
breasts- non
tanner stage 2 in females
pubic hair- sparse, lightly pigmented, straight, medial border of labia
breasts- breast and pappila (nipple) elevated as small mounts, areolar diamter increased
tanner stage 3 in females
pubic hair: darker, beginning to curl, increased amount
breast: breast and areola enlarged, no controu of separation
tanner stage 4 in females
pubic hair: coarse, curly, abundant, but less than adult
breast: areolar and papilla form secodnary mount
tanner stage 5 in females
pubic hair: adult feminine triangle spread to medial surface of thigh
breast: mature, nipple projects, areola part of general breast contour
tanner stage 1 in males
prepubertal
tanner stage 2 in males
pubic hair: scanty, long sligly pigmented
penis: slight enlargement
testes: emlarged scortum, texture altered
tanner stage 3 in males
pubic hair: darker, starts to curl, small amount
penis: penis longer
testes: larger
tanner stage 4 in males
pubic hair: resembles adult type, less in qauntitiy, coarse, curly
penis: larger, glans breadth increased
testes: larger
tanner stage 5 in males
pubic hair: adult. distribution, spread to medial surface of thigh
penis: adult
testes: adult
when does therlache (breast enlargment happen in girls)
8-11)
when does adrenarch- pubic hair start in girls
11-12
when does growth spurt occur in firls
10-14
when does menarche occur
11-15
female sexual characteristics
-
9-15
- Starts with
- Breast bud (thelarche) and pubic hear
- Leads to (adrenarche)
- Growth spurt and onset of menstrual
- Menstruate cycles begins (menarche)
- Punic hair adult
- Breast adult
- Starts with
Male secondary sexual characteristics
-
10-14 years
- Starts with
- Genital development
- Progresses to
- Pubic hair growth
- Spermatogenesis
- Completed by
- Growth spurt
- Genitalia adult
- Pubic hair adult
- Starts with
accelerated soamtic growth ‘growth spurt’ depends on
- Occurs in both sexes
- Depends on growth hormone and IGF-1 and sex steroid in both sexes
Accelerated somatic growth in girls
- Earlier and shorter in girls
men are larger because
- Men larger because growth spurt longer and slightly faster
genital development in boys depends on
testosterone
Accelerated somatic growthends in both sexes by
epiphyseal fusion
- Oestrogen closes epiphyses earlier in girls
fusion of epiphyses inkeeping with
child chronological age - bone age
sumamry opf puberty in male and female
- Normal range in pubertal development is broad
- Early maturation is a positive for boys but may be negative for girls
- Late maturation usually more hard than for girls
- Adolescents compare themselves to their peers and internalise the reaction of others to their changing bodies
