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The oestrous cycle with particular reference to the neural control of the ovary
Author(s) -
HUTCHINSON J. S. M.
Publication year - 1972
Publication title -
mammal review
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.574
H-Index - 76
eISSN - 1365-2907
pISSN - 0305-1838
DOI - 10.1111/j.1365-2907.1972.tb00092.x
Subject(s) - corpus luteum , ovulation , estrous cycle , follicular phase , hypothalamus , ovary , endocrinology , medicine , biology , hormone , luteal phase , gonadotropin
Summary The differing types of oestrous cycle found in mammals seem to be manifestations of the degree to which the external environment participates in the control of the three main phases of the ovarian cycle, the follicular phase, ovulation, corpus luteum phase. The question of the importance of the external and the internal environment for the manifestations of cyclicity has been discussed by reference to the factors involved in the control of ovarian function. The control of the ovarian cycle involves an interrelated fluctuation in the secretion of the anterior pituitary gonadotrophins FSH and LH, and in certain species LTH, which are under the control of hypophysiotrophic hormones produced in the hypothalamus. The production of these hormones is modified by other hypothalamic and extra–hypothalamic mechanisms, including a probable preoptic cycling mechanism controlling the ovulatory surge of gonadotrophins. These mechanisms can be triggered and timed by means of nervous reflexes arising from a variety of sensory end organs. Also this brain–hypothalamus–pituitary unit appears to contain sex steroid and gonadotropin sensitive elements through which these factors can influence the system. The additional luteotrophin and luteolytic factors involved in corpus luteum control have not been discussed. A brief idea as to how all these factors are integrated for the control of ovarian cyclicity is presented.