Reproductive System, Part 4 - Pregnancy & Development: Crash Course Anatomy & Physiology #43

Description
We've reached the grand finale of our four-part series on human reproduction: BABIES! Today Hank walks you through the stages of pregnancy, beginning with how a zygote develops into blastomeres to a morula to a blastocyst, and finally to an embryo and a fetus. He also explains some of the amazing anatomical changes that take place in the mother and the hormonal sequence of events that lead to labor. Pssst... we made flashcards to help you review the content in this episode! Find them on the free Crash Course App! Download it here for Apple Devices: https://apple.co/3d4eyZo Download it here for Android Devices: https://bit.ly/2SrDulJ Chapters: Introduction: How Did You Get Here? 00:00 Cleavage Stage: Zygote, Blastomeres, Morula, Blastocyst1:34 Implantation 3:08 The Placenta 4:50 Embryonic Stage 5:07 Female Anatomical Changes During Pregnancy 5:30 Hormonal Sequences Leading to Labor 7:12 Stages of Labor: Dilation, Expulsion, Placental Delivery 8:35 Review 9:34 *** Crash Course is on Patreon! You can support us directly by signing up at http://www.patreon.com/crashcourse Thanks to the following Patrons for their generous monthly contributions that help keep Crash Course free for everyone forever: Mark, Eric Kitchen, Jessica Wode, Jeffrey Thompson, Steve Marshall, Moritz Schmidt, Robert Kunz, Tim Curwick, Jason A Saslow, SR Foxley, Elliot Beter, Jacob Ash, Christian, Jan Schmid, Jirat, Christy Huddleston, Daniel Baulig, Chris Peters, Anna-Ester Volozh, Ian Dundore, Caleb Weeks -- Want to find Crash Course elsewhere on the internet? Facebook - http://www.facebook.com/YouTubeCrashCourse Twitter - http://www.twitter.com/TheCrashCourse Tumblr - http://thecrashcourse.tumblr.com Support Crash Course on Patreon: http://patreon.com/crashcourse CC Kids: http://www.youtube.com/crashcoursekids
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The Journey from Zygote to Baby 👶
Early Developmental Stages 🌱
- Humans start as a tiny cell (2mm) and grow to be ~850 times larger
- Key developmental instructions: Divide, Differentiate, Develop
- Stages of early cell development:
- Cleavage phase: Cells split rapidly
- Morula stage: Berry-shaped cell cluster
- Blastocyst stage: Hollow sphere with inner cell mass
Implantation and Hormonal Control 🔬
- Blastocyst travels to uterus and implants in endometrium
- Hormones play a crucial role, especially:
- Human Chorionic Gonadotropin (hCG)
- Estrogen
- Progesterone
Placenta Formation 🌈
- A unique temporary organ formed from maternal and embryonic tissues
- Transfers nutrients, hormones, and waste between mother and baby
Maternal Body Changes 🤯
Incredible physiological transformations include:
- 40% increase in blood volume
- Uterus expansion
- Breast changes
- Hormonal shifts
- Joint loosening
- Increased metabolism
Labor and Delivery 🏥
- Triggered by hormonal changes
- Stages include:
- Cervical dilation
- Pushing
- Placenta delivery
Key Takeaway 💖
Pregnancy is a complex, hormonally-driven process of creating new human life!