PH1124 - Reproductive hormones Flashcards

1
Q

what is a hormone? (2)

A
  • chemical substance produced by ductless glands within the endocrine system
  • often then secreted directly into bloodstream
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what molecule hormones mostly derived from?

A
  • most hormones derived from cholesterol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the physiological functions of hormones? (6)

A
  • reproductive cycle; lactation
  • growth and development
  • metabolism
  • digestion
  • sleep
  • stress and mood (brain)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q
  • reproductive cycle; lactation
  • growth and development
  • metabolism
  • digestion
  • sleep
  • stress and mood (brain)
A
  • are synthesized and secreted at different levels throughout a person’s lifetime
  • increasing at puberty and normally decreasing with old age
  • feedback mechanisms regulate these hormones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the main modes of action for hormones? (3)

A
  • endocrine action
  • paracrine action
  • autocrine action
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the endocrine action of hormones? (2).

A
  • hormones are secreted from a secreting cell in the ductless gland directly into the circulatory system
  • they act on distant cells/organs via their target receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the paracrine action of hormones?

A
  • hormones are secreted and then diffuse through the interstitial spaces to act on nearby target cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the autocrine action of hormones?

A
  • hormones act on the same cell that secreted them via their receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the endocrine system? (2)

A
  • collection of glands located throughout the body that manufacture and secrete hormones to regulate physiological functions
  • generally act in a paracrine or endocrine manner
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are the major endocrine glands? (4)

A
  • adrenal gland
  • hypothalamuc
  • ovaries and testes
  • pituitary gland
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the general classes of hormones derived from different building blocks? (3)

A
  • hormones derived from amino acids
  • protein and peptide hormones
  • hormones derived from lipids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the structure of cholesterol? (3)

A
  • 3 cyclohexane rings (A to C)
  • 1 cyclopentane ring (D)
  • large 6C hydrocarbon side chain (C22 to C27)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is cholesterol the precursor for the biosynthesis of? (4)

A
  • vitamin D
  • bile acid; lipid digestion
  • steroid hormones; adrenal steroids, glucocorticoids, mineralocorticoids
  • sex steroid hormones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

where are reproductive steroid hormones mainly produced? (2)

A
  • produced mainly by the gonads (ovaries or testes)

- some production by placenta and adrenal glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are reproductive hormones soluble in? (3)

A
  • they are water-insoluble but are lipid soluble
  • can easily move across the plasma membrane but not stored in the body
  • bound to the carrier steroid hormone-binding globulin
    (SHBG) during transport in the bloodstream
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are the classes of reproductive steroid hormones? (3)

A
  • oestrogens
  • androgens
  • progestogens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how are reproductive steroid hormones produced?

A
  • produced through the metabolic process called steroidogenesis
18
Q

what do reproductive steroid hormones specifically interact with?

A
  • oestrogen (ER), androgen (AR) or progesterone (PR) receptors to exert their effects
19
Q

what are the types of oestrogen reproductive

steroid hormones? (3)

A
  • oestradiol
  • oestriol
  • oestrone
20
Q

what are the types of androgens reproductive

steroid hormones? (3)

A
  • testosterone and 5a-dihydrotestosterone (DHT)
  • androstenedione
  • dehydroepiandrosterone (DHEA)
21
Q

what are the types of progestogens reproductive

steroid hormones?

A
  • progesterone
22
Q

what is the potency of DHT?

A
  • DHT is a metabolite of testosterone and is a more potent androgen than testosterone as it binds more strongly to androgen receptors
23
Q

what are the precursors for all reproductive

steroid hormones? (2)

A
  • cholsterol

- pregnenolone

24
Q

what is the main site for progesterone synthesis? (2)

A
  • in the ovaries (corpus luteum cells)

- in the placenta during pregnancy

25
Q

what is the main site for testosterone synthesis? (3)

A
  • testes; leydig cells
  • ovaries; theca cells
  • adrenal gland, prostate gland and placenta
26
Q

what is the main site for estradiol synthesis? (3)

A
  • ovaries (granulosa cells)
  • placenta
  • adipose tissue in breast
27
Q

what is the main site for oestrogen synthesis?

A
  • ovarian granulosa cells
28
Q

what is the main site for androgen precursor synthesis?

which in turn are converted into oestrogen by the granulosa cells

A
  • ovarian theca cells
29
Q

what is the corpus luteum?

A
  • corpus luteum develops from ovarian follicle during the luteal phase of menstrual cycle after ovulation
30
Q

how is progesterone made by the placenta?

A
  • by the placental syncytiotrophoblasts [SYN] surrounding the placental villi
31
Q

what is the primary role of the reproductive system? (2)

A
  • to support gametogenesis; oogenesis in women and spermatogenesis in men
  • to cause maturation of the reproductive organs, underpin fertility and pregnancy
32
Q

what is the secondary role of the reproductive system?

A
  • drive development of male or female physical characteristics
33
Q

what are the effect on androgen on the body? (2)

A
  • maturation of the sex organs and deepening of the voice

- growth of pubic and axillary hair in pubic regions/underarm

34
Q

why are circulating levels of testosterone important for the effects of androgens?

A
  • peaking post-puberty but present into late adulthood
35
Q

what are the anabolic effect of androgen in the body? (3)

A
  • growth of muscle mass and strength
  • increased bone density and strength
  • stimulation of linear growth and bone maturation
36
Q

what is androgen clinically used to treat? (3)

A
  • delayed puberty caused by androgen deficiency (in males)
  • hypogonadism causes diminished production of androgens by gonads (in males)
  • Hot flushes (in females)
37
Q

what are the side effects of clinically using androgen? (3)

A
  • early use of androgens for treating delayed puberty can lead to premature closure of epiphysis of long bone, resulting in short stature
    • can cause acne (androgen’s impact on skin’s sebaceous glands)
    • FDA report (2014); increased incidence of cardiovascular disease can be associated with testosterone replacement therapy
38
Q

what is the role of oestrogen on the body?

A
  • regulate growth (proliferation & cell survival) by altering expression of many genes in tissues that express the ER
39
Q

what are the effects of oestrogen on the female body? (4)

A
  • increasing growth and development of the breast and uterus
  • broadening of the pelvis and also favours bone formation
  • gain of further female secondary sexual characteristics eg. growth of axillary hair
  • impact on adipose tissue & muscle mass
40
Q

what is oestrogen clinically used to treat?

A
  • Hormone Replacement Therapy (HRT) after menopause
41
Q

what are the side effects of clinically using oestrogen? (3)

A
  • a very slightly increased risk of breast cancer with certain HRT strategies