Anatomy, Hormones, Puberty, Menstrual Cycle Flashcards
What releases gonadotrophin-releasing hormone (GnRH)?
Hypothalamus
What does GnRH do?
Stimulates the anterior pituitary to produce LH and FSH
What cells secrete oestrogen?
Theca granulosa cells around the follicles in the ovaries
What effect does oestrogen have on the hypothalamus and anterior pituitary?
Negative feedback effect to suppress the release of GnRH, LH and FSH
What stimulates the production of oestrogen?
LH and FSH
What is the most prevalent and active version of oestrogen?
17-beta oestradiol
List 4 actions of oestrogen.
- Breast tissue development
- Development of female sex organs at puberty
- Blood development in uterus
- Development of endometrium
What is progesterone produced by?
Corpus luteum
When is progesterone produced?
After ovulation
When pregnancy occurs, what mainly produces progesterone from 10 weeks gestation onwards?
Placenta
What is the action of progesterone (3)?
Acts on tissues previously stimulated by oestrogen:
- Thickens and maintains endometrium
- Thickens cervical mucus
- Increases body temperature
At what age does puberty start in girls?
8-14
At what age does puberty start in boys?
9-15
How long does puberty usually take from start to finish?
4 years
Why do overweight children tend to enter puberty at an earlier age?
Aromatase is an enzyme found in adipose (fat) tissue, that is important in the creation of oestrogen.
Therefore, the more adipose tissue present, the higher the quantity of the enzyme responsible for oestrogen creation.
List 4 situations where puberty might be delayed in girls.
- Low birth weight
- Chronic disease
- Eating disorders
- Athletes
In what order does puberty occur in girls?
- Development of breast buds
- Development of pubic hair
- Menarche
What scale is used to assess the stage of pubertal development in girls?
Tanner Staging
How many stages are there in Tanner Staging?
5