Puberty Onset Influencing Factors - Anatomy & Physiology
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Female Threshold Body Size
- Nutritional intake of the newborn is directed towards body maintenance.
- The priority of the neonate is to maintain vital physiological functions.
- Non-essential processes, such as reproduction are of low priority.
- As the neonate grows, energy consumption increases and the body mass increases with a relative decrease in body surface area.
- This allows a shift in metabolic expenditure so that other physiological functions can develop.
- The excess internal energy is converted to fat stores, and a priority is then placed on reproduction so the onset of puberty begins.
- Fat accumulation alone does not determine the onset of puberty, but it is an important regulator.
- All female mammals must reach a certain body size before the onset of puberty can be initiated.
- Metabolic signals affect production of GnRH.
Nutrition
Photoperiod
Genetics
Environmental and Social Conditions
- Pheromonal substances in the urine act as a stimulus to enhance the onset of puberty.
- Females reaching puberty in the presence of a male (producing the pheromones) have a greater opportunity of becoming pregnant.
- Pubertal onset cannot be accelerated using pheromones in animals that have not achieved the appropriate metabolic body size to trigger hypothalamic responsiveness to Oestradiol (oestrogen).