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Flashcards in Puberty Deck (63)
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1

Prepubertal Development:

When does brain growth plateau?

6-8 yrs

2

Are the ovaries essential for female prepubertal development?

No

3

The Migration of the testes to scrotal position is mediated by which 2 ligaments?

Gubernaculum and Suspensory ligaments

4

What kind of activity does the neonatal HPG axis undertake at birth until puberty?

Transient

5

What week does sexual differentation occur?

5-6 Wks

6

Fetal development:

At what week does the hypothalamic neural cells secreted GnRH?

Wk 11

 

7

Prepubertal testosterone levels:

Fetal: onset of secretion?

Secretion from 8-10 weeks onwards

8

Prepubertal testosterone levels:

Prenatal: Peaks at what week? How much T?

PEaks at wk 13- 15 (2ng/ml)

9

Prepubertal testosterone levels:

Post natal: Peaks when? How much? When is the decline

 

Peaks @ 3 months after birth (2-3ng/ml)

Postnatal decline at 3-4months.

10

Prepubertal testosterone levels:

What happens to testosterone levels at 1yr after birth? (Concentration?)

Second modest rise until prepubertal peak (9ng/ml)

11

Triggers of puberty:

Sleep, explain?

Earlyin puberty, GnRH is released during sleep -> long term development of pulsative GnRH release w/ positive feedback initiating ovulation or spermatogenesis.

Helps perpetuate further release of LH and FSH from Pit. = Gonadal development.

12

Triggers of puberty:

Leptin?

Before puberty leptin levels rise in proportion to adipose tissue mass (fat levels). Leptin may be a way for the body to tell the hypothalamus that (Dude we got enough long term energy storage lets go). But also there is a growth hormone- induced acceleration of body growth- increase body weight.

13

What trigger puberty, Secondary factors?

 

  • psychological factors (internal)
    • happiness vs. stress
  • environmental stimuli (external)
    • smell
    • photoperiod in some species
      • circadian (circa = approximately, diem = day) rhythms
        • supra chiasmatic nuclei (tiny region in brain controlling circadian rhythms
      • circannual rhythms
  • colours
  • temperature (more relevant to animals)

14

Female Tanner stages (5)

P1: Prepubertal.

P2: Early development of subareolar breast bud and small amounts of pubic hair and axillary hair.

P3: Increase in size of palpable breast tissue and areolae, increase in pubic/axillary hair

P4: Breast tissue and areolae protrude above breast level. Further increase in hair development.

P5: Mature adult breast Complete pubic/axillary growth

15

What is the first sign of female puberty?

Thelarche (Breast development)

16

What hormones initiate breast growth?

Oestrogen, Prolactin and GH

17

Male Tanner stages

P1: Prepubertal, testicular volume <1.5ml

P2: Testicular volume between 1.6-6ml. Small amounts of axillary and pubic hair (9-11 year)

P3: Testicular volume 6-12ml, lengthening of penis and areola, increase in pubic/axillary hair (11-12.5 yrs)

P4: Testicular volume 12-20ml, scrotum enlarges + darkens. (12.5-14 yrs) Further increase in hair development

P5: Testicular volume (>20ml). Adult genitalia

18

What hormone is higher during puberty than adulthood (Male + Female)?

LH

19

Reproductive function and maturation is coordinated by the ...

Hypothalamic-pituitary-gonadal axis

20

What is the most significant structural remodelling during female puberty?

Uterine Chages

21

What hormones cause uterine remodelling during puberty?

Oestrogen, Progesterone, Prolactin and Growth Factors

22

When does the second stage of sertoli cell and germ cell proliferation occur?

Puberty

23

What does this show?

Endocrine control of puberty and spermatogenesis in males

24

What are the target cells of FSH in Males?

Sertoli cells

25

What are the target cells of LH in males?

Leydig cells

26

What are the target cells of LH in females? 

Theca Cells

27

What cells are the target of FSH in females?

Granulosa cells

28

When is the prostate fully functionally grown?

Puberty

29

What characteristics are defined by the sexual dimophism of the musculoskeletal system?

  • Enlarged pelvis in females and enlarged shoulders in males
  • Men: 1.5x more lean body mass and 1.5x more skeleton than women
  • Women: 2x more body fat

30

What hormones are responsible for the closure of epihpyses?

Oestrogen and Thyroid hormones