Chapter 17 Outline
The Two Worlds of Reproductive Physiology
What Aspects of Reproduction Do Physiologists Study?
- BOX 17.1 A New Discovery: Genetically Linked Sets of Reproductive Traits
The Environment as a Player in Reproduction
- Temperature and photoperiod are often used as cues
- Latitudinal trends graphically illustrate the importance of the environment
- Animals living in distinctive habitats often use distinctive cues for reproduction
Reproduce Once or More Than Once?
- BOX 17.2 Semelparity in a Mammal
Eggs, Provisioning, and Parental Care
External or Internal Fertilization?
The Timing of Reproductive Cycles
- Sperm storage permits flexible timing between copulation and fertilization
- Embryonic diapause permits flexible timing between fertilization and the completion of embryonic development
- Embryonic diapause and other forms of diapause are common in insects
- Delayed implantation and postpartum estrus play important timing roles in mammals
- Some iteroparous animals reproduce only once a year
Sex Change
Reproductive Endocrinology of Placental Mammals
- Females ovulate periodically and exhibit menstrual or estrous cycles
- Males produce sperm continually during the reproductive season
- BOX 17.3 Sex Determination and Differentiation, Emphasizing Mammals
- Pregnancy and birth are orchestrated by specialized endocrine controls
- Lactation, a costly part of reproduction, is governed by neuroendocrine reflexes