Class notes
Human Biology Lecture Notes
- Course
- Human Biology (HUB228)
- Institution
- University Of The Western Cape (UWC)
Human Biology lecture notes about labor and the stages of labor and lactation.
[Show more]
Seller
Follow
Content preview
Lecture 24Labor and Lactation
B Nursing II HUB228 2022
Dept. Medical Biosciences
University of the Western Cape
, Labor
Labor = series of events that expel the fetus from the uterus
Parturition or birth = forcible expulsion of the fetus
Labor consists of three stages:
1) Dilation stage
2) Expulsion stage
3) Placental stage
• but before labor is triggered, a number of chemical events are first
initiated…
, Initiation of labor
1) Estrogen levels peak during the last weeks of pregnancy, leading
to:
- increased expression of oxytocin receptors on myometrial cells (smooth
muscle cells) of uterus
- suppression of inhibitory influence of progesterone (the levels of which
peak before parturition, inhibiting contraction of myometrial cells)
→ myometrium becomes increasingly irritable
→ weak, irregular uterine contractions called Braxton Hicks contractions (false
labor pains) occur
2) Oxytocin and prostaglandins convert false labor into true labor:
- certain fetal cells begin to produce oxytocin, which causes the placenta to
release prostaglandins
→ both hormones produce powerful, frequent uterine contractions
(myometrium “primed” to respond to oxytocin because of increased receptor
expression caused by estrogen peak)
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller anlifourie. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R50,00. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
56326 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy summaries for 14 years now