Growth and Puberty Flashcards
How far a part are centile lines spaced?
2/3 of a standard deviation a part
When does puberty occur?
When secretion of gonadotrophin releasing hormone (GnRH) increases so that pulsatile secretion of luteinizing hormone (LH) increases
Where is GnRH secreted from?
Hypothalamus
What cells does LH stimulate in boys and what do these cells produce?
Leydig cells
Testosterone
Where does FSH bind in boys and what does this stimulate?
Sertoli cells to enhance spermatogenesis
What modulates LH secretion in boys?
Testosterone
What exerts a negative feedback on FSH secretion?
Inhibin B from Sertoli cells
What does LH stimulate in girls?
Proliferation of follicular and thecal cells
During the follicular phase of the menstrual cycle it induces androgen secretion by theca cells
What does FSH do in girls?
Induces proliferation of granulosa cells
Increases expression of LH receptors on granulosa cells
Enhances aromatase activity so that androstenedione is converted to oedstradiol
Increases progesterone production
What does oestradiol (E2) act on to cause proliferation of follicular cells in addition to inducing secondary sexual development?
FSH receptors on granulosa cells
Where is inhibin B produced?
Granulosa cells in small antral follicles
Where is inhibin A produced?
Large antral follicles and by the corpus luteum
What do inhibins have a role in?
Inhibit FSH secretion
Dominant follicle selection
How is puberty staged?
Tanner staging
What is thelarche?
Breast budding
What is adrenarche?
Body hair and odour
What is true central precocious puberty?
Normal pubertal development occuring abnormally early
What are the cut off ages for precocious puberty in girls and boys?
Girls - 8yrs
Boys - 9yrs
What are the cut off ages for pubertal delay?
13yrs girl
14yrs boy
A patient presents worrying that they have a growth problem. What questions should you ask?
ICE Birth PMHx Pubertal symptoms FHx -Parental heights -Parental puberty
What should you examine on a patient presenting with a growth problem?
Height, weight, height velocity
Signs suggestive of pathology
Pubertal status
What investigations should you do for a patient presenting with a growth problem?
Bloods
- gonadotrophins
- growth factors
- testosterone/oestradiol
- thyroid
- karyotype
- etc
Bone age
Dynamic function tests
MRI brain, USS uterus
What is genetic short stature?
Healthy, normal child that has inherited short stature from parents
What is a constitutional growth delay?
Late maturation causing short stature
