Physical development in adolescence

Question 1

what is the tanner stages of puberty in male genialias

Answer 1

stage- 1 prepubertal- testes less than 2.5cm

stage 2- scrotum and testes en;arge and reddending scortal skin

stage3- continual growth of penis and testes

Stage 4- development of the glans, continued growth and scrotal skin darkeneding

stage- post pubrtal

Question 2

Describe feamle breast development- tanner stages

Answer 2

stage 1- prepubertal- elevation of pilla only

stage 2- areola enlarged and breats bud appears

stage 3- breast tissues grows beyond areola but without contour seperation

stage 4- projection of areola and papilla forms secondayr mound

stage 5- post puberty- adult breast contours with rprojection of papilla only

Question 3

in male and females what hair will be present on the body in stage 1 and how does hare develop

Answer 3

villus hair only

• males–> base of penis—> thicker hair mons pubis—-> continues to psread–> medial thigh
• Females—> alongside labia—> hair coarser, pigmented- spreads acorss pubis—> spreads—–> medial thigh (not up tp linea alba)

stage 5 in both—-> spread to medial thigh

Question 4

when do growht spurts begin in boys and girls

Answer 4

10. 5 girls
11. 5 boys- begin later but grow more

2 peaks- another 2 years later 12F , 14 M

max height- gilrs 17 years

21 years in boys

growht plates (epiphys fuse later in boys)

Question 5

at what age do the following happen in girls

breats bud (thelarch)

pubic and axillary hair development (adrenarche)

growth spurts

menarch

Answer 5

breast bud- 10.5-11

pub and axillary hair (drive by adrenal androgrens form adrneal glands- 11 years

growth spurt- 11.5yrs

menarch- 13 years

ache too

Question 6

when do the following begin to occur in males?

• increase in testicle volume
• pubic and axcillary hair development
• growht spurt
• spermarch
• adult penis and texitualr size
• adult bubic hair?

Answer 6

• increase in testicular volume- 11.5 yrs- penile and scortal enlargement occur a year after tesricualr enlargment
• pubic and axillary hair development- 12 yrs
• growht sput 12.5
• spermarch- first appearacne of psermatozoa in early uirne- nocutrnal emision begin
• adult penis and testicular size by 15yr
• adult pubic hair - ealry 20s

change in body compositon,acne, deeping of the voice, gynaecomastia

Question 7

what is the hormonal basis of growhtspurts in males and femalses

Answer 7

• gonadal sex steriods (oestradial and testerone)
• growth hormone GH (due to increase in sex hormones- positive effect on pulsatile relase of GH from pituitary gland)
• insulin like growth hormone (IGF-1)- caused by increase in HG- causes omatic growht by meabolic actions
• in maels larynx and vocal cords enlarge

Question 8

about a year before puberty we see a rise in FSH and LH in males and females form P.Pituitary

before this in childhood they are low- due to slow cycling of GnRH puls egenatori in hypothalmus

why does this lead to?

Answer 8

rise in FSH- females increase in oestrogen syntheiss and oogenesis- in males- onset of sperm production

Rise in LH- females- production of progesterone, in males increase in testosteron rpoduction

as a result of these hormonal changes get physical chnages associated with puberty

Question 9

Describe the break theory of

Answer 9

• brake released for puberty to begin
• tiemd disinhibiaiton of inhbitory mechanims
• pre-pubertal low levels of steriod inhibit GnRH release
• this low sensitivtiy is lost and higher levels of steriod now needed to inhbit GnRH
  
  • levels of FSH and LH rise= higher levels of steriod but not enough to negatively feed back

Question 10

evidence agsisnt the brake theory

Answer 10

turner sysndrome- under developed ovaires (only has 1 X chromosome)

FSH/LH increase at puberty in absence of the gonadal steriods

Question 11

Describe the accelerator hypothesis

Answer 11

• currentyl accepted hypotheiis
• central maturation of CNS- activation of stimulatory centres in CNS
• induce pulsatile relase of GnRH at puberty
• requires only changes in GnRH neurosectory neurones

Question 12

what is the evidence for the accelatory hypotheiss

Answer 12

kallmans syndrome (delayed/absent puberty)

precoious puberty with CNS pituitary tumours

castrated male monkeys still go throuhg puberty

Question 13

what is the function of Kisspeptin neurones?

Answer 13

inducer of pulstatile release of gnRH in the hypothtalsmus

increass Kiss1 level at puberty

induced precocouiosu puberty in monkesy.

Question 14

what factors affect menarche age

Answer 14

• genetics (link with maternal age and hormones causing KISS1
• metabolisma nd nutriton
• gneeral health and well being
• envuronmentfla factors
• history-
  
  • faily history
  • underweight= delayed pibertyu
  • medical/surgical history/ meeication

decrease in average age of menarch in last cewntruy probably due to improved nutriton and general health

Question 15

describe the link between age at menarch and BMI?

Answer 15

onset of puberty has become eaerly due to rise in obesity- rearch ongoing

however, attianment of Criticial weighjt of 47kg must be activation of HPG axis

Question 16

describe the relationship between menarch age and weight

evidence?

Answer 16

a criticla body fat and body weight are required for intiation of menarhce

this is supported by

• competitive athletes- dleayed puberty
• delayed menarch in malnutriton
• overweight girls have ealry menachred
• patients with anorexia nervosa have delayed menarhc/primary/secodnary amenorrhea.

Question 17

describe the link between weighgt and puberty onset

Answer 17

pubity will not occur unless the boyd has enough reserves fot these high cost functuon

energy used must be less than energy taken in.stored- Psoitive enrgy balance

Question 18

how would be describe delayed puberty in males and females

Answer 18

• males
  
  • absence of testicualr development (vesticualr volume lwoer than 4m,l) by age 14
• in girls
  
  • absence of breats developemnt by age 13 or primary ammenorrhea with normal breast development by age 15