Puberty And Menstruation (Danny Hay)

Question 1

How long does the corpus luteum live for?

Answer 1

13 days
Unless there is conception - then 13 weeks (HCG released by the conceptus allows the corpus luteum to stay alive, producing progesterone throughout the 1st trimester until the placenta takes over)

Question 2

Pulsatile release of ______ from the ______ is needed for the cycle to initiate and continue

Answer 2

GnRH
Hypothalamus

Either a lack of, or constant release of, GnRH will stop the cycle - useful for contraception

Question 3

Progesterone (P4)

6 points

Answer 3

1. Steroid hormone
2. Nuclear receptor - modulates gene transcription
3. Pro-gestational
4. Released by the corpus luteum together with oestradiol
5. Causes the secretory phase (providing the endometrium has been primed by oestradiol)
6. Maintains the endometrium, and uterine quiescence (works as a smooth muscle relaxant to prevent the uterus spewing out foreign bodies

Question 4

Oestradiol (E2)

6 points

Answer 4

1. Steroid hormone
2. Nuclear receptor - modulates gene transcription
3. Produced by the cumulus oophorus from the follicle, and then the corpus luteum
4. Causes the proliferation phase in the endometrium, and then (along with P4) the secretory phase
5. Gives negative feedback to reduce FSH release
6. Triggers LH release

Question 5

FSH

6 points

Answer 5

1. A glycoprotein
2. Released from the anterior pituitary
3. Activates cAMP
4. Only has receptors on granulosa cells
5. Modulated by GnRH, and under negative feedback from E2
6. Causes maturation of follicles

Question 6

LH

5 points

Answer 6

1. Glycoprotein
2. Released by the anterior pituitary
3. Activates cAMP
4. Modulated by GnRH and triggered by elevating E2 levels
5. Causes ovulation

Question 7

GnRH

3 points

Answer 7

1. A peptide
2. Released by the hypothalamus
3. Activates Ca2+ mobilisation

Question 8

Danny’s 6 point summary of the menstrual cycle

Answer 8

1. Corpus luteum fails
   - Therefore progesterone levels fall
   - Unsupported endometrium sloughs off (menstruation)
2. Oestradiol levels also fall
   - Loss of negative feedback on FSH
   - FSH levels rise
3. High FSH levels cause maturation of a follicle - secretes oestradiol
   - inhibits further FSH release
   - LH surge
   - Oestradiol also causes endometrial proliferation
4. LH surge causes ovulation 24-36 hours later, and the formation of the corpus luteum
5. Corpus luteum secretes oestradiol and progesterone
6. Progesterone causes the secretory phase, which in turn causes the corpus luteum to fail… Cycle continues…

Question 9

hCG

4 points

Answer 9

1. A glycoprotein
2. Released from the zygote
3. Activates cAMP
4. Maintains the corpus luteum to support the foetus (1st trimester)

Question 10

What is menorrhagia?

Answer 10

Heavy but regular bleeding

Question 11

What is metrorrhagia

Answer 11

Erratic and heavy bleeding

Question 12

What are the causes of menorrhagia or metrorrhagia?

Answer 12

1. Idiopathic (80% of cases)
2. Local pelvic pathology
3. General medical causes (rare)
4. Iatrogenic (common)

More common at the extremities of reproductive life

Question 13

List 8 pelvic pathologies that can cause dysfunctional uterine bleeding

Answer 13

1. Fibroids - benign leiomyomata (treatment: leave/shrink/operate)
2. Endometrial polyps (treatment: remove)
3. Malignancy - cervical/endometrial/ovarian
4. Hyperplasia of the endometrium
5. Adenomyosis (treatment: hysterectomy)
6. Endometriosis (treatment: COCP (back to back)/progestogens/GnRH-a/danazole)
7. Infection (treatment: antibiotics/antivirals/antifungals)
8. RPOC (retained products of conception) can get infected if not removed

Question 14

What defines a ‘normal’ menarche

Answer 14

21-35 days (mean 28)
Predictable, regular cycle
Blood loss

Question 15

What is puberty and when does it begin?

Answer 15

The process of physical changes by which a child’s body becomes and adult body capable of reproduction

Begins at 47kg for girls, and 55kg for boys

Question 16

What triggers puberty to begin?

Answer 16

Leptin (a protein hormone produced by fat) is a strong candidate, and may explain why the weight is so significant.
- acts via the hypothalamus letting the brain know about adipose mass

GnRH pulsation is the initiation mechanism, and is vital for the start of puberty.

Question 17

What are the hormonal changes that occur in girls? (6)

Answer 17

1. LH pulses induce the THECA cells to produce TESTOSTERONE and PROGESTERONE
2. Granulosa cells convert most of the testosterone to OESTRADIOL - produces the body changes, as well as the LH surge and ovulation
3. Levels of ADRENAL ANDROGENS and testosterone increase pubic hair production
4. GH levels rise gradually throughout puberty
5. IGF-1 levels rise, then decline as puberty ends
6. OESTRADIOL levels complete closure of epiphyseal plates (therefore determining adult height)

Question 18

What are the hormonal changes that occur in boys? (2)

Answer 18

1. LH pulses induce THECA cells to produce TESTOSTERONE (a proportion of which is converted to OESTRADIOL)
   - this mediates bone maturation and epiphyseal fusion
   - also induces gynaecomastia
2. During the teenage years, TESTOSTERONE levels slowly rise
   - most of the effects are mediated through the androgen receptors by way of conversion of DIHYDROTESTOSTERONE in target organs

Question 19

What is androgen insensitivity syndrome (aka Testicular Feminisation)

Answer 19

Genetically XY, but all cells lack androgen receptors, therefore cannot respond to testosterone, so development follows the blueprint of making a girl

Important to remove gonads as they will be inteabdominal, and therefore risk of becoming malignant

Question 20

What is meant by ‘precocious’ puberty?

Answer 20

If Tanner stages 1-5 are noted early (

Question 21

What is meant by ‘delayed’ puberty?

Answer 21

If pubertal changes are not seen