Human Reproduction:
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Reproductive Anatomy: Humans share common reproductive anatomy with other primates, including males (testes) and females (ovaries).
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Sexual Dimorphism: Sexual dimorphism refers to distinct physical differences between males and females. In humans, this includes differences in body size and secondary sexual characteristics.
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Menstrual Cycle: Human females have a menstrual cycle involving the release of eggs (ova) from the ovaries, changes in the uterine lining, and menstruation.
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Pair Bonding: Some humans engage in pair bonding, forming social and emotional connections between males and females.
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Parental Care: Humans exhibit extended parental care, with infants requiring nurturing and support from parents.
Menstrual Cycle:
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Menstrual Phase (Days 1-5): Menstruation begins with the shedding of the uterine lining. It lasts 3 to 7 days.
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Follicular Phase (Days 1-13): Follicle-stimulating hormone (FSH) stimulates ovarian follicles to develop. Usually, one dominant follicle matures.
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Ovulatory Phase (Day 14): Luteinizing hormone (LH) surge triggers ovulation, the release of a mature egg from the dominant follicle.
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Luteal Phase (Days 15-28): The ruptured follicle becomes the corpus luteum, producing progesterone. This phase prepares the uterus for potential pregnancy.
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Hormonal Regulation: Hormones, including FSH, LH, estrogen, and progesterone, tightly regulate the cycle.
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Cycle Length: The average menstrual cycle is around 28 days, with variations considered normal (21-35 days).
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Menstruation and Fertility: Menstruation indicates a healthy reproductive system. Conception is possible during the fertile window around ovulation.
Endometrium:
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Location: The endometrium is the inner lining of the uterus.
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Function: It supports a potential pregnancy by undergoing cyclical changes in response to hormones.
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Menstrual Cycle Phases: Menstrual (shedding), Proliferative (thickening), Secretory (preparing for implantation).
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Implantation: If fertilization occurs, the embryo can implant in the receptive endometrium.
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Hormonal Control: Estrogen and progesterone regulate endometrial changes.
Graafian Follicle:
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Development: The Graafian follicle is a mature ovarian follicle containing a developing egg.
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Ovulation: It releases a mature egg during ovulation.
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Corpus Luteum: After ovulation, it becomes the corpus luteum, producing progesterone.
Primates and Reproduction:
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Shared Traits: Humans, as primates, share reproductive characteristics and evolutionary traits with other primates.
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Sexual Dimorphism: Many primates, including humans, exhibit sexual dimorphism with distinct physical differences.
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Menstrual Cycle: Primates, including humans, have a menstrual cycle with ovulation, changes in the uterine lining, and menstruation.
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Pair Bonding: Some primate species, including humans, engage in pair bonding.
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Parental Care: Primates, especially humans, provide extended parental care to their offspring.