Samenvatting van Voortplanting uit het vak systeemfysiologie in biomedische wetenschappen.

Inhoud
Voortplanting bij de vrouw ........................................................................................................................................................ 3
1. Het voortplantingsstelsel en neuro-endocrinologie ........................................................................................................... 3
Menstruele cyclus........................................................................................................................................................... 3
Neuro-endocrinologie .................................................................................................................................................... 3
2. Niet-zwangere vrouw ......................................................................................................................................................... 5
2.1 Ovariële cyclus .............................................................................................................................................................. 5
Ovariële follikels ............................................................................................................................................................. 5
Folliculogenese ............................................................................................................................................................... 5
Folliculaire fase van ovariële cyclus ................................................................................................................................ 6
Ovulatie van ovariële cyclus ........................................................................................................................................... 8
Lutheale fase van ovariële cyclus ................................................................................................................................... 8
Besluit ............................................................................................................................................................................. 9
2.2 Endometriale cyclus.................................................................................................................................................... 10
1. Proliferatieve fase..................................................................................................................................................... 10
2. Secretoire fase .......................................................................................................................................................... 10
3. Menstruatie (geen bevruchting) ............................................................................................................................... 11
2.3 Andere hormooneffecten ........................................................................................................................................... 12
De cervix ....................................................................................................................................................................... 12
Hormonale contraceptie (21 + 7 dagen) ........................................................................................................................... 12
3. Zwangere vrouw ............................................................................................................................................................... 13
3.1 Hormonale veranderingen ......................................................................................................................................... 14
Hormonen gesecreteerd door placenta ....................................................................................................................... 14
Andere hormonen ........................................................................................................................................................ 15
3.2 Lichamelijke veranderingen........................................................................................................................................ 16
1. Cardiovasculair systeem ........................................................................................................................................... 16
2. Urinair systeem......................................................................................................................................................... 17
3. Endocrien systeem ................................................................................................................................................... 18
4. Borsten ..................................................................................................................................................................... 18
5. Respiratoir systeem ...................................................................................................................................................... 21
6. Gastrointestinaal systeem ............................................................................................................................................ 21
Voortplanting bij de man.......................................................................................................................................................... 22
1. (Neuro-) endocrinologie ................................................................................................................................................... 22
Leydig cellen ..................................................................................................................................................................... 23
Invloed van Testosteron: .............................................................................................................................................. 23
Testosteron metabolieten ............................................................................................................................................ 24
2. Spermatogenese............................................................................................................................................................... 25
≠ Vrouwen ........................................................................................................................................................................ 25
Functies Setoli cel ............................................................................................................................................................. 25
Spermiogenese ................................................................................................................................................................. 26


1

, ‘Externe’ spermatogenese................................................................................................................................................ 26
3. Productie en afvoer van sperma ...................................................................................................................................... 27
3.1 Samenstelling sperma ................................................................................................................................................ 27
3.2 Erectie......................................................................................................................................................................... 28
3.3 Ejaculatie .................................................................................................................................................................... 29
4. Bevruchting ...................................................................................................................................................................... 31
Examen vragen ......................................................................................................................................................................... 32
Systeemfysiologie: Fysiologie van voortplanting




2

,Voortplanting bij de vrouw

1. Het voortplantingsstelsel en neuro-endocrinologie
Functies:

(1) eicel → Ovariële cyclus

(2) bevruchting (syngamie)

(3) innesteling in Baarmoeder → Endometrium cyclus

(4) voorzien voeding tijdens zwangerschap → Placenta

(5) voorzien voeding na zwangerschap → Lactatie

3 lagen in baarmoeder

- Endometrium
- Myometrium
- Perimetrium




Menstruele cyclus
1. Ovariële cyclus
= Ontwikkeling van follikels om eicel vrij te zetten bij ovulatie in de
eierstokken
o Medulla (merg): binnenste laag rijk aan Blv
o Cortex (schors): buitenste laag met follikels in verschillende stadia van ontwikkeling


2. . Endometrium cyclus
= Voorbereiding baarmoeder op mogelijke implantatie van een bevruchte eicel
(cycli van opbouw en afbraak )

➔ Onderbreking menstruele cyclus door zwangerschap


Neuro-endocrinologie
HPG as = Hypothalamus + Pituitary (hypofyse) + Gonadal (geslachtsklieren)



Steroid hormoon = afgeleid van
cholesterolen




3

, Kernen in hypothalamus:
POA= Secretie GnRH in pulsaties → GnRH-neuron
Gonadotropine
Release
Hormone



(afh van pulsaties wordtFSH of LH gesecreteerd)
ARC → KNDy-neuron
Kisspeptine
Neurokinine B (NKB)
Dynorphine

ME = Vrijzetting GnRH

Lactotrope cellen
Prolactin
Gonadotrope cellen (5-15% van aP cellen)
→ GnRH receptor activatie
Follikel stimulerend hormoon (FSH)
- Lage frequentie : FSH-beta expressie 1/4h
- FSH-beta transcriptie is snelheidsbepalende stap in FSH secretie

Luteïniserend hormoon (LH)
- Hoge frequentie: LH-beta expressie : 1/h
- Regulatie van secretie uit secretoire granules

Pulse generator:




KNDy-neuron




KNDy-neuron secreteert 3 belangrijke moleculen:

→ Kisspeptine: stimuleert GnRH secretie van GnRH neuron

→ NKB: bindt eigen neuron om frequentie van kiss secretie 

→ Dyn: bindt eigen neuron inhibeert kiss secretie ( kleine vertaging => veroorzaakt pulsen)




4