Textbook Question
Indicate which primary tissue classes derive from each embryonic germ layer.
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Ch. 28 Pregnancy and Human Development
Marieb, Hoehn11th EditionHuman Anatomy & PhysiologyISBN: 9780136874034
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Table of contents
- Ch. 1 The Human Body: An Orientation24
- Ch. 2 Chemistry Comes Alive25
- Ch. 3 Cells: The Living Units21
- Ch. 4 Tissue: The Living Fabric20
- Ch. 5 The Integumentary System11
- Ch. 6 Bones and Skeletal Tissues19
- Ch. 7 The Skeleton14
- Ch. 8 Joints7
- Ch. 9 Muscles and Muscle Tissue26
- Ch. 10 The Muscular System26
- Ch. 11 Fundamentals of the Nervous System and Nervous Tissue19
- Ch. 12 The Central Nervous System26
- Ch. 13 The Peripheral Nervous System and Reflex Activity32
- Ch. 14 The Autonomic Nervous System19
- Ch. 15 The Special Senses26
- Ch. 16 The Endocrine System23
- Ch. 17 Blood25
- Ch. 18 The Cardiovascular System: The Heart24
- Ch. 19 The Cardiovascular System: Blood Vessels27
- Ch. 20 The Lymphatic System and Lymphoid Organs and Tissues14
- Ch. 21 The Immune System: Innate and Adaptive Body Defenses27
- Ch. 22 The Respiratory System21
- Ch. 23 The Digestive System31
- Ch. 24 Nutrition, Metabolism, and Energy Balance26
- Ch. 25 The Urinary System26
- Ch. 26 Fluid, Electrolyte, and Acid-Base Balance24
- Ch. 27 The Reproductive System24
- Ch. 28 Pregnancy and Human Development25
- Ch. 29 Heredity11
Marieb, Hoehn11th EditionHuman Anatomy & PhysiologyISBN: 9780136874034Not the one you use?Change textbook
Chapter 28, Problem 16
The life span of the ovarian corpus luteum is extended for nearly three months after implantation, but otherwise it deteriorates.
(a) Explain why this is so.
(b) Explain why it is important that the corpus luteum remain functional following implantation.
Verified step by step guidance1
Step 1: Understand the role of the corpus luteum before and after implantation. The corpus luteum forms from the ruptured follicle after ovulation and secretes progesterone, which is crucial for maintaining the uterine lining for potential pregnancy.
Step 2: For part (a), explain that the corpus luteum normally deteriorates after about 10-14 days if fertilization does not occur, due to the absence of luteinizing hormone (LH) support. However, after implantation, the developing embryo produces human chorionic gonadotropin (hCG), which signals the corpus luteum to continue functioning and producing progesterone, thus extending its lifespan for nearly three months.
Step 3: For part (b), clarify that the continued function of the corpus luteum is important because progesterone maintains the thickened endometrium, preventing menstruation and creating a supportive environment for the developing embryo and placenta during the early stages of pregnancy.
Step 4: Emphasize that without the corpus luteum's progesterone production post-implantation, the uterine lining would break down, leading to miscarriage or failure of the pregnancy to establish.
Step 5: Summarize that the corpus luteum's extended lifespan is hormonally regulated by hCG from the embryo, and its function is critical to sustaining the early pregnancy until the placenta can take over hormone production.
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Corpus Luteum Function and Lifespan
The corpus luteum is a temporary endocrine structure in the ovary that forms after ovulation. It produces progesterone, which is essential for maintaining the uterine lining. Normally, it degenerates after about 14 days if pregnancy does not occur, but its lifespan is extended during early pregnancy to support gestation.
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06:04
Functional Groups
Role of Human Chorionic Gonadotropin (hCG)
After implantation, the developing embryo secretes hCG, a hormone that signals the corpus luteum to continue producing progesterone. This hormone prevents the corpus luteum from deteriorating, thereby sustaining the uterine environment necessary for embryo development during the first trimester.
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1:04Implantation Example 2
Importance of Progesterone in Early Pregnancy
Progesterone maintains the thickened endometrium, preventing menstruation and creating a supportive environment for the embryo. Its continued production by the corpus luteum is crucial until the placenta takes over hormone production, ensuring the embryo's survival and proper development.
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0:49Early Embryonic Development Example 1