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Flashcards in Reproductive System Deck (162)
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1

sperm production facts

- 300 million per day
- constant fertility post puberty, gradual decline with age
- 1500 sperm/second

2

oocyte production facts

- 7 million follicles at birth
- 400 ovulate
- 0 follicles at menopause

3

relative size of egg and sperm

sperm is the smallest cell in the body, whereas egg is the largest

4

hierarchal arrangement of the neurons between the pituitary and the hypothalamus allows for...

signal amplification

5

function of the gonads (ovaries, testes)

1. produce gametes
2. produce reproductive hormones

6

the hypothalamus sends ____________ neurons to the posterior pituitary, where it releases _________ which is made in the __________ and affects ________ organs.
___________ neurons within the hypothalamus release ______ into _______ vessels which lead into the anterior pituitary, stimulating the release of __________ (___ and __). These hormones stimulate ___________ in males and ___________ in females.

the hypothalamus sends _neurosecretory_ neurons to the posterior pituitary, where it releases _oxytocin_ which is made in the _hypothalamus_ and affects _target_ organs.
_Neuroscretory_ neurons within the hypothalamus release _GnRH_ into _portal_ vessels which lead into the anterior pituitary, stimulating the release of _gonadotrophins_ (_LH_ and _FSH_). These hormones stimulate _spermatogenesis_ in males and _oogenesis_ in females.

7

4 water soluble, peptide and protein, reproductive hormones and their sites of secretion

1. GnRH - gonadotrophin releasing hormone, which is released from the hypothalamus
2. FSH - follicle-stimulating hormone, which is released from the anterior pituitary
3. LH - Luteinising hormone, which is released from the anterior pituitary
4. Oxytocin, which is made in the hypothalamus but released at the posterior pituitary

8

3 lipid soluble, steroid reproductive hormones and their sites of secretion

1. androgens, which are released from the testes
2. Oestrogens, which are released from the ovaries
3. progestagens, which are released from the ovaries

9

how are lipid soluble hormones transported?

transport proteins

10

steroid hormones made from?

cholesterol

11

2 androgens and their differences

1. testosterone
2. 5α dihydrotestosterone (more active)

12

3 oestrogens and their differences

1. oestradiol
2. oestrone (weaker)
3. oestriol

13

oestradiol is active during which stage of a girls life? (how does it compare to oestrone)

puberty through to menopause.
Oestradiol is a weaker oestrogen

14

oestriol

produced by the placenta
softens the cervix to prepare for birth

15

progestogens

PROGESTERONE (menstrual cycle and pregnancy)

16

Neurosecretory cells of the posterior pituitary

NEUROHYPOPHYSIS
1. hormones synthesised in the hypothalamus
2. carried down the axon
3. stored in secretory vesicles in the posterior pituitary
4. nerve impulse leads to exocytosis
5. OXYTOCIN or ADH released into the blood from the posterior pituitary

17

effects of oxytocin

- smooth muscle contraction
- milk ejection
- contraction of the uterus during childbirth (used to induce labour)

18

ADH

water retention in the kidneys

19

neurosecretory cells involved with the anterior pituitary

ADENOHYPOPHYSIS
- Don't leave the hypothalamus, release hormones (GnRH) into hypophyseal portal vessels
- Hormones act on the gonadotrophs of the anterior pituitary to release FSH and LH

20

somatotrophs, lactotrophs, thyrotrophs, and corticotrophs are all...

secretory cells

21

why does the hypothalamus release GnRH into hypophyseal portal vessels?

if it was diluted in the blood stream it wouldn't be effective

22

neurosecretory neurons

can conduct a nerve impulse, synthesis and carry and release neurosecretory hormones

23

true/false
"the reproductive system only has single positive hormone"

TRUE
= GnRH

24

how do hypothalamic secretions release?

Pulsatile release.
secretions occur in discrete bursts, separated by periods of little or no secretion.
Prevents desensitisation and down-regulation

25

LH effect on Males vs. females

Male: stimulates production of testosterone

Female: secretion of female sex hormones and stimulate ovulation

26

FSH effect on Males vs. females

Male: growth of spermatozoan

Female: growth of ovarian follicles

27

negative feedback effect of sex hormones

inhibit hypothalamus from releasing GnRH and inhibit Anterior pituitary from releasing FSH and LH

28

true/false
females produce no androgens and Males produce no oestrogens

false. they produce some

29

key properties of androgens in males

- Male sex development
- spermatogenesis
- sexual behaviour
- muscle development

30

site of oestrogen production

granulosa cells of the growing follicle