Puberty Flashcards
What are some physical changes in puberty
Significant regression of lymphoid tissue
Brain development complete
Growth of CNS
Heart, lungs and viscera increase in size and mass
What is one metabolic factor that affects puberty initiation
Leptin appears to play a permissive role in puberty initiation and maintenance of reproductive function
What does the KNDy Neuron release
Kisspeptins and Dynorphin
What has a negative feedback of GnRH neurons
Dynorphin
What stimulates GnRH
Kisspeptin
What reduces inhibition of gonadotrophs by GnIH
Leptin
A decrease in what signal reduces GnIH
Melatonin
What inhibits GnRH (apart from dynorphin)
GnIH
What does GnIH work on
Kisspeptin, GnRH, Gn
What receptors does Kisspeptin bind to
GPCR KISS1R, expressed by GnRH neurones
When is mini puberty
postnatal, 1-6 months
Does gonadarche or adrenarche come first and by how much
Adrenarche, 2 years
What is the first sign of puberty in females
Thelarche
Does thelarche or menarche come first and by how much
Thelarche, 2 years
Which tanner stage does growth spurt take place in
Stage 2-3 in girls and 3-4 in boys
Which tanner stage is start of gonadarche
Stage 2
Which stages are thelarche and menarche
3-4 respectively
When does pubic hair grow in males and does it reflect adrenarche or gonadarche
Stage 2, can reflect both
does pubic hair or genital develop first in males and by how many year
Genitals, 1-1.5 years
What happens in gonadarche in males
activation of HPG axis leads to enlargement of testes and scrotum
What is produced during adrenarche and where
DHEA, androstenedione in ZR
Does peak strength velocity or peak height velocity occur first and by how much
Peak height velocity, a year or two
Effect of estrogen on cholesterol
Protects the heart from cholesterol and regulates cholesterol production regulation
Causes of precocious puberty
CNS or pituitary lesion. McCune-Albright syndrome, Gn-secreting tumours
Causes of contrasexual development in girls
PCOS, cushing, acromeglay, exogenous androgens, adrenal or ovarian tumours, hyperprolactinaemia
Causes of contrasexual development in boys
estrogen secreting tumours
Which type of ossification occurs in physis of long bones
Endochondral ossification- leads to longitudinal growth
Which type of ossification occurs in bone fractures in a plaster cast and which occurs when bone fracture is treated with rigid plate and screws
EC, IM
What do we call bone that grows in width and what type of ossification
Subperiosteal bone growth
What happens in primary spongiosa and secondary spongiosa
Osteoprogenitor cells invade calcified materix and lay down woven bone.
In 2* spongiosa, woven bone is remodelled into lamellar bone
How does GH affect growth during puberty
Has effects on the physis
How do steroids affect growth
Affects cartilage cell division
