Biology of Reproduction Summers |
Endocrinology Homeostasis/Feedback Adult Female Steroid Production Ovulation |
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Adult Male Gonadal Axis Regulation Sexual Differentiation Sexual Behavior Puberty |
Reproductive Cycling Estrous Cycles Menstrual Cycle Menopause Fertilization |
Fertilization Systems Gamete Interaction Pregnancy Labor and Parturition Lactation |
Sexual Response & Behavior Pheromones STDs text: Human Reproductive Biology4th Edition- RE Jones & KH Lopez,: pp 303-319, 149 - 152 Acronyms/Abbreviations end |
XVII. Estrous Cycles A. estrus = restricted period of sexual receptivity in female mammals 1. changes in genital tract a. stimulated by ovarian steroids B. Estrous cycles are periodic changes in reproductive function 1. includes estrus 2. ovarian cycles include follicular and luteal phases a. separated by ovulation 3. three types of cycle a. reflex or induced ovulation i. mating stimulates ovulation (1) cats, voles, rabbits (2) in humans the most fertile period for coitus is just prior to ovulation ii. luteal phase only occurs following copulation iii. follicular phase includes follicle growth, E2 priming of the brain b. spontaneous (+feedback driven) ovulation i. functional corpus luteum requires copulation (rats, mice) (1) pseudopregnancy ensues without implantation c. functional CL regardless of copulation (guinea pigs, humans) 4. CL may be required to make P throughout gestation a. rabbit, mouse, pig and goat 5. CL may be replaced by placenta to make P a. rat, guinea pig, sheep, humans