Sex hormones Flashcards
(97 cards)
1
Q
Where are androgens made in female body?
A
Ovary (25%) Adrenal glands (25%) Peripheral conversion of androstenedione (50%)
2
Q
What is the primary oestrogen of pregnancy?
A
Oestriol (E3)
3
Q
When is Oestriol (E3) mainly produced?
A
During pregnancy
4
Q
What is the primary oestrogen of non-pregnant women?
A
Oestradiol (E2)
5
Q
When is oestradiol (E2) produced?
A
Primary oestrogen in non pregnant females
6
Q
When is oestrone (E1) produced?
A
Primarily in the menopause
7
Q
What is the primary oestrogen of the menopause?
A
oestrone (E1)
8
Q
Which oestrogen is E1?
A
Oestrone - menopause
9
Q
Which oestrogen is E2?
A
Oestradiol - non-pregnant
10
Q
Which oestrogen is E3?
A
oestriol - pregnant
11
Q
Where is oestrogen produced?
A
ovarian follicles, corpus luteum, placenta, liver, adrenal glands, adipocytes, breast tissue
12
Q
How is oestradiol excreted?
A
By kidneys as oestriol glucronide
13
Q
Effect of oestrogen on the kidney
A
Water and sodium retention
14
Q
Where is progesterone produced?
A
Corpus luteum, adrenal glands, placenta
15
Q
Effect of progesterone on the kidney
A
Increases aldosterone production and therefore sodium and water retention
16
Q
Which hormones are released by the placenta?
A
Oestrogen, progesterone, beta HCG, human placental lactogen
17
Q
What is the rate of blood flow to uterus in non-pregnant woman?
A
45ml/min
18
Q
What is the rate of blood flow to uterus in pregnant woman at term?
A
750ml/min - 12% of maternal cardiac output
19
Q
Where is DHEA secreted in the fetus?
A
Adrenal glands
20
Q
What is the function of fetal DHEA on the placenta?
A
Stimulates oestrogen release
21
Q
At which times in life is DHEA released?
A
In the fetus until birth
From age 7 and peaks in mid-20s
22
Q
What is purpose of Sex Hormone Binding Globulin?
A
Binds to testosterone, progesterone, oestrogen so they can be transported in the blood
23
Q
How much of testosterone is transported in a bound state?
A
99% - 70% bound to SHBG, 29% bound to Albumin
24
Q
What is the effect of Cushing’s Syndrome on SHBG levels?
A
SHBG levels reduce
25
What is the effect of PCOS on SHBG levels?
SHBG levels reduce
26
What is the effect of Pregnancy on SHBG levels?
SHBG levels increase
27
What is the effect of liver cirrhosis on SHBG?
SHBG levels increase
28
What is the effect of hypothyroidism on SHBG levels?
SHBG levels decrease
29
What is the effect of anabolic steroids on SHBG levels?
SHBG levels decrease
30
What is the effect of anorexia nervosa on SHBG levels?
SHBG levels increase
31
What is the effect of obesity on SHBG levels?
SHBG levels decrease
32
What is the effect of hyperthyroidism on SHBG levels?
SHBG levels increase
33
Which hormones bind to SHBG?
Testosterone, Oestrogen and progesterone
34
What is the effect of SHBG?
It limits the effect of oestrogen and testosterone by binding to them leading to less free hormone and therefore less active hormone
35
Where is SHBG produced?
The liver
36
During menstruation, when does the LH surge occur?
24-36 hours before ovulation
37
Are FSH receptors on thecal cells or granulosa cells?
Granulosa cells
38
How does FSH effect oestrogen synthesis?
Stimulates Granulosa cells to produce aromatase to turn androstenedione to oestrogen
39
Where in the ovary is progesterone secreted?
From the corpus luteum - large(granulosa) and small (thecal) luteal cells synthesise progesterone from cholesterol
40
What does the placenta make from 16-OH DHEAS?
Oestriol
41
What is Oestriol made from?
16-OH DHEAS by the placenta under the influence of fetal DHEA
42
What is the precursor of fetal DHEA?
Pregnenolone
43
How does the placenta synthesis pregnenolone and what is its function?
Placenta synthesises pregnenolone from cholesterol, it is the precursor for DHEA in the fetal adrenal glands. fetal DHEA stimulates the placenta to make oestriol (the major pregnancy oestrogen)
44
How does LH stimulate ovulation?
Stimulate the theca externa via CAMp and PGF2 to contract and release the egg
45
What is the definition of premature menopause?
At or before 40 years old
46
Which hormone peaks on day 21 on the menstrual cycle?
Progesterone
47
When do progesterone levels peak during the menstrual cycle?
Day 21
48
Where is relaxin produced?
corpus luteum, placenta and the decidua
49
How is oestriol synthesised?
Fetal adrenal glands synthesis DHEA from pregnenolone and this is then converted in the fetal liver to 16-hydroxy-DHEA which is then converted by aromatase in the syncytiotrophoblast to oestriol
50
How is the fetus protected from the effects of producing excess oestrogen?
Sulphate group attached to DHEA stops it being active in the fetal circulation, sulphate group is removed once it reaches the placenta
51
What is the effect of oestrogen on the cardiovascular system?
Vasodilation by increasing NOS and therefore NO. Prevents atherosclerosis
52
What is the effect of oestrogen on the bone?
Maintains bone density, decreases resorption by bone, fusion of epiphyseal plates in children
53
What is the effect of oestrogen on clotting?
Increases factors 2,7,9,10 and plasminogen + platelet adhesiveness
54
What is the effect of oestrogen on the bowel?
Increase gut motility
| Increase bile production
55
What is the effect of oestrogen on metabolism?
Increases HDL, decreases LDL, decreases overall cholesterol
56
What is the effect of oestrogen on skin?
Pigmentation of nipples, areola, genitals
57
What is the effect of oestrogen on the kidney?
Water and sodium retention
58
What is the effect of oestrogen on the endometrium?
Proliferation
59
Where is progesterone produced?
Syncytiotrophoblast of the placenta
Large and small luteal cells of corpus luteum
Adrenal glands
60
What are progesterone levels like at term compared to non-pregnant women?
10 x higher at term
| Pre ovulation = <2ng/ml, post ovulation >5ng/ml, at term 250mg/day produced by the placenta
61
Where is progesterone stored in the body?
Adipose tissue
62
Where is progesterone metabolised and what is it's bi-product?
Metabolised to pregnanediol in the liver
63
Where is progesterone excreted?
In the urine as a glucuronide
64
What is the role of progesterone on female pelvic organs?
Converts proliferative endometrium to secretory endometrium, thickens the cervical mucus, inhibits uterine contraction until term
65
What effect does progesterone have on appetite and body temperature?
```
Increases core body temp
Increases appetite (catabolic)
```
66
What effect does progesterone have on respiration?
Increase minute ventilation
67
What effect does progesterone have on the kidney?
Increases aldosterone production and therefore sodium and water retention
68
Which hormone does inhibin act on?
Inhibits FSH...... NOT LH
69
Which hormone does activin act on?
Stimulates FSH.... NOT LH
70
Which inhibin is screened for in Down's syndrome screening?
Inhibin A
71
Where is inhibin produced?
Granulosa cells, pituitary gland and placenta
72
Where is activin produced
Granulosa cells and pituitary gland
73
What type of hormones are inhibin and activin?
Peptide hormones of the transforming growth factor beta family (TGF-B family)
74
What is the role of relaxin?
Inhibits myometrial contractility, plays a role in cervical dilation, relaxes pelvic ligaments in pregnancy
75
Where is the gene for sex hormone binding globulin located?
Chromosome 17
76
Where are FSH receptors located in the ovary?
Only on Granulosa cells
77
BHCG has two subunits, which subunits are similar to other hormones?
Alpha - similar to LH, FSH, TSH
| Beta - unique
78
Where is the gene for the alpha subunit of LH located?
Chromosome 6
79
What is the function of LH?
Triggers ovulation, stimulates progesterone and oestrogen synthesis in the developing follicle, stimulates resumption of the meiotic cycle in the oocyte, maintains progesterone production in the corpus luteum and maintains corpus luteum function
80
Where are LH receptors located in the ovary?
On both thecal and granulosa cells
81
When is the peak of betaHCG production?
8 weeks post ovulation
82
Directly before menstruation what happens to basal body temp?
It falls
83
Directly before menstruation what happens to progesterone and oestrogen levels?
They fall
84
Directly before menstruation, what is the appearance of the endometrium?
Thickened and rich in glycogen
85
What is the molecular weight of Beta HCG/
13000 Daltons
86
What is the effect of Beta HCG on the testes?
Stimulates the interstitial cells like LH to produce testosterone
87
What kind of hormone is Beta HCG?
A petide (glycoprotein)
88
Where is DHEAS produced in pre-menopausal women?
Almost exclusively in the adrenal glands
89
Where and what proportion of androgens are produced at different sites in pre-menopausal women?
25% in ovaries
25% in adrenal glands
50-70% in the peripheral tissues by conversion of andestenidione to testosterone
90
Which cells become large luteal cells?
Granulosa cells
91
Which cells become small luteal cells?
Thecal cells
92
Which luteal cells are more active in terms of steroidogenesis?
Large luteal cells
93
Which luteal cells release inhibin?
Large luteal cells
94
Which luteal cells release relaxin?
Large luteal cells
95
What is the alternative name for the follicular phase?
Proliferative phase
96
What is the average menstrual blood loss?
40-80ml
97
Which phase of the menstrual cycle are prostaglandins raised?
Late secretory phase/menstruation (leading to dysmenorrhea)
