Changes

* Longest phase of the oestrous cycle, which usually laste 10-14 days in polyoestrous females.   

* Longest phase of the oestrous cycle, which usually laste 10-14 days in polyoestrous females.   

* The [[The_Ovary_-_Corpus_Luteum_-_Anatomy_%26_Physiology|corpus luteum]] is present on the [[Female_Reproductive_Tract_-The_Ovary_-_Anatomy_%26_Physiology|ovary]] and secreting large amounts of progesterone. The duration of this phase is directly related to the time that the [[The_Ovary_-_Corpus_Luteum_-_Anatomy_%26_Physiology|corpus luteum]] remains functional.

* The [[The_Ovary_-_Corpus_Luteum_-_Anatomy_%26_Physiology|corpus luteum]] is present on the [[Female_Reproductive_Tract_-The_Ovary_-_Anatomy_%26_Physiology|ovary]] and secreting large amounts of progesterone. The duration of this phase is directly related to the time that the [[The_Ovary_-_Corpus_Luteum_-_Anatomy_%26_Physiology|corpus luteum]] remains functional.

* High progesterone levels prompt the uterus to prepare a suitable environment for development of the embryo, and eventual attachment of the conceptus to the endometrium (implantation).

* High progesterone levels prompt the uterus to prepare a suitable environment for development of the embryo, and eventual [[Fertilisation%2C_Implantation_and_Early_Embryonic_Development_-Implantation-_Anatomy_%26_Physiology|attachment of the conceptus to the endometrium]] (implantation).

* Uterine glands undergo hyperplasia and hypertrophy.

* Uterine glands undergo hyperplasia and hypertrophy.

* Cervix becomes constricted

* Cervix becomes constricted