Male and Female Reproductive Endocrinology

Question 1

Puberty

• Triggered by increasing pulses of …-… hormone

Answer 1

Triggered by increasing pulses of gonadotropin-releasing hormone

Question 2

• What is shown?
• What is it used for?

Answer 2

• Tanner Staging System
• Puberty staging

Question 3

… Staging, also known as Sexual Maturity Rating (SMR), is an objective classification system that providers use to document and track the development and sequence of secondary sex characteristics of children during ….

Answer 3

Tanner Staging, also known as Sexual Maturity Rating (SMR), is an objective classification system that providers use to document and track the development and sequence of secondary sex characteristics of children during puberty.

Question 4

What is shown below?

Answer 4

Normal age ranges of pubertal stages

Question 5

Age ranges for Puberty - Girls

• … - 8-13 years
• Growth of … - 8-14 years
• Growth … - 9.5-14.5 years (… between 11 and 13)
• … - 10-16 years
• Growth of … - 10.5-16.5 years
• Change in … - 11-15.5 years
• … - 12.5 - 16.5 years

Answer 5

• Breast budding - 8-13 years
• Growth of Pubic Hair - 8-14 years
• Growth Spurt - 9.5-14.5 years (peak between 11 and 13)
• First period - Menarche - 10-16 years
• Growth of Underarm Hair - 10.5-16.5 years
• Change in Body Shape - 11-15.5 years
• Adult Breast Size - 12.5 - 16.5 years

Question 6

Age ranges for Puberty - Boys

• Growth of …. - 10.5-17 years
• Change in … - 10.5-18 years
• … of … - 11-15 years
• Growth of … - 11-14 years
• Growth … - 12-17 years (… is 13-15)
• Change in … - 12-17 years
• Growth of … and … Hair - 13-18 years

Answer 6

• Growth of Scrotum and Testes - 10.5-17 years
• Change in Voice - 10.5-18 years
• Lengthening of Penis - 11-15 years
• Growth of Pubic hair - 11-14 years
• Growth Spurt - 12-17 years (peak is 13-15)
• Change in Body Shape - 12-17 years
• Growth of Facial and Underarm Hair - 13-18 years

Question 7

What Affects Timing of Puberty?

• Genetic factors influence timing
• May be delayed by stresses, e.g. nutrition problems
• May also be early for example in …-… syndrome

Answer 7

• Genetic factors influence timing
• May be delayed by stresses, e.g. nutrition problems
• May also be early for example in McCune-Albright syndrome

Question 8

Male Reproductive Endocrinology:

• …-… hormone is released from the …
• This stimulates release of LH and FSH from … …
• LH works on the … Cells in the …
  
  • Stimulates … production -> this has a … feedback effect on the pituitary and hypothalamus to … … and …
• FSH stimulates cells in … tubule to make …

Answer 8

• Gonadotropin-releasing hormone is released from the hypothalamus
• This stimulates release of LH and FSH from anterior pituitary
• LH works on the Leydig Cells in the Testes
  
  • Stimulates testosterone production -> this has a negative feedback effect on the pituitary and hypothalamus to decrease GnRH and LH
• FSH stimulates cells in seminiferous tubule to make sperm

Question 9

Effects of Testosterone

• _​_Increased … and …
• Enlargement of the …
• Male pattern … hair
• Maturation of …
• … development
• … production
• … growth
• A…

Answer 9

• _​_Increased aggression and libido
• Enlargement of the larynx
• Male pattern pubic hair
• Maturation of genitalia
• Muscle development
• Sperm production
• Bone growth
• Acne

Question 10

Female Reproductive Endocrinology

• …-releasing hormone is released from the hypothalamus
• Stimulates the … pituitary to release LH and FSH
• In the … phase of the menstrual cycle, FSH acts on the ovary to recruit and mature primordial follicles to become primary follicle - one dominates and becomes secondary follicles
  
  • … … makes progesterone and Oestrogen
  • Mature graafian follicle releases egg and Corpus luteum
  • … follicles makes oestrogen - levels rise in conjuction with LH
• Uterine Cycle:
  
  • Oestrogen causes … of the lining of the uterus - more receptive
  • Oestrogen and Progesterone combined increase … supply of uterus lining - receptive to fertilised egg
  • If fertilisation doesn’t occur - levels fall - corpus luteum ages - … occurs
• … is the first hormone to rise - … rise - … released from pituitary gland - release of ovum - gradual rise in oestrogen and progesterone - … feedback to … FSH and LH levels
• LH peaks around …
• Progesterone peaks around day …

Answer 10

• Gonadotropin-releasing hormone is released from the hypothalamus
• Stimulates the anterior pituitary to release LH and FSH
• In the follicular phase of the menstrual cycle, FSH acts on the ovary to recruit and mature primordial follicles to become primary follicle - one dominates and becomes secondary follicles -
  
  • Corpus luteum makes progesterone and Oestrogen
  • Mature graafian follicle releases egg and Corpus luteum
  • Secondary follicles makes oestrogen - levels rise in conjuction with LH
• Uterine Cycle:
  
  • Oestrogen causes proliferation of the lining of the uterus - more receptive
  • Oestrogen and Progesterone combined increase blood supply of uterus lining - receptive to fertilised egg
  • If fertilisation doesn’t occur - levels fall - corpus luteum ages - menstruation occurs
• FSH is the first hormone to rise - oestrogen rise - LH released from pituitary gland - release of ovum - gradual rise in oestrogen and progesterone - negative feedback to decrease FSH and LH levels
• LH peaks around ovulation
• Progesterone peaks around day 21

Question 11

Female Reproductive Endocrinology (2)

• Gonadotropin-releasing hormone is released from hypothalamus
• Stimulates anterior pituitary to release LH and FSH
• LH acts on the theca cells - they make androgens which move to granulosa cell to make progesterone
• Oestrogen are made in the granulosa cell - these cells make activin and inhibin (+/- feedback on production of FSH)

Answer 11

• Gonadotropin-releasing hormone is released from hypothalamus
• Stimulates anterior pituitary to release LH and FSH
• LH acts on the theca cells - they make androgens which move to granulosa cell to make progesterone
• Oestrogen are made in the granulosa cell - these cells make activin and inhibin (+/- feedback on production of FSH)

Question 12

Within the ovary - Thecal and Granulosa cell

• Thecal cell - … activates receptor to encourage protein kinase A to convert … to androstenedione
• Moves over to granulosa cell to converts it to …
• … released into the blood

Answer 12

• Thecal cell - LH activates receptor to encourage protein kinase A to convert cholesterol to androstenedione
• Moves over to granulosa cell to converts it to estradiol
• Estradiol released into the blood

Question 13

Oxytocin

• Breast-feeding
  
  • Contracts the … cells of the alveoli
  • Classic … reflex
• Childbirth (…)
  
  • In late pregnancy, uterine smooth muscle (…) becomes sensitive to oxytocin
  • …. feedback mechanism

Answer 13

• Breast-feeding
  
  • Contracts the myoepithelial cells of the alveoli
  • Classic neuroendocrine reflex
• Childbirth (parturition)
  
  • In late pregnancy, uterine smooth muscle (myometrium) becomes sensitive to oxytocin
  • Positive feedback mechanism

Question 14

Breast-feeding

• Decrease in … … … (Dopamine)
• Causes increase in release of … and …
• Milk secretion and smooth muscle …
• Milk released from nipple

Answer 14

• Decrease in Prolactin inhibitory hormone (Dopamine)
• Causes increase in release of prolactin and oxytocin
• Milk secretion and smooth muscle contraction
• Milk released from nipple

Question 15

Parturition

• Fetus … …
• Cervical …
• Encourages … production from … pituitary
• … from urerine wall
  
  • Both increase uterine contractions which further increases cervical …
• Loop is a … feedback mechanism

Answer 15

• Fetus drops lower
• Cervical stretch
• Encourages oxytocin production from posterior pituitary
• Prostaglandins from urerine wall
  
  • Both increase uterine contractions which further increases cervical stretch
• Loop is a positive feedback mechanism

Question 16

Oxytocin - Parturition and Breast feeding flow chart

Answer 16