Changes

===Progesterone (P₄)===

===Progesterone (P₄)===

Progesterone is a steroid hormone that along with oestrogens is based on a cholesterol molecule produced by the corpus luteum and the placenta using cholesterol as the base molecule. Progesterone is produced by the [[Corpus_Luteum_-_Anatomy_%26_Physiology|corpus luteum]] as well as by the feto-placental unit and in the zona reticularis of the adrenal cortex (to a lesser extent). More detailed information regarding corpus luteum [[Corpus_Luteum_Formation_-_Anatomy_%26_Physiology|formation]] and [[Corpus_Luteum_Regression_-_Anatomy_%26_Physiology|regression]] please use the links. Progesterone prepares the uterus for reception of fertilized oocytes and is transported via the blood bound to plasma proteins. Progesterone also prepares the mammary tissues for milk production as well as inhibiting female reproductive behaviours associated with oestrous.  

Progesterone is a steroid hormone that along with oestrogens is based on a cholesterol molecule produced by the corpus luteum and the placenta using cholesterol as the base molecule. Progesterone is produced by the [[Corpus_Luteum_-_Anatomy_%26_Physiology|corpus luteum]] as well as by the feto-placental unit and in the zona reticularis of the adrenal cortex (to a lesser extent). More detailed information regarding corpus luteum [[Corpus_Luteum_Formation_-_Anatomy_%26_Physiology|formation]] and [[Corpus_Luteum_Regression_-_Anatomy_%26_Physiology|regression]] please use the links. Progesterone prepares the uterus for reception of fertilized oocytes and is transported via the blood bound to plasma proteins. Progesterone also prepares the mammary tissues for milk production as well as inhibiting female reproductive behaviours associated with oestrous.  

 

'''Effects on reproductive organs:'''

'''Effects on reproductive organs:'''

<br />Vagina: slight mucous secretion, paleness, exfoliation

<br />Vagina: slight mucous secretion, paleness, exfoliation

Cervix: closure, formation of the mucous plug

<br />Cervix: closure, formation of the mucous plug

Uterus: stimulates uterine gland secretions, decreases uterine motility, immunosuppression, inhibition of PGF2a and PGE2

<br />Uterus: stimulates uterine gland secretions, decreases uterine motility, immunosuppression, inhibition of PGF2a and PGE2

Fallopian tube: increased secretion, decreased motility

<br />Fallopian tube: increased secretion, decreased motility

Mammary gland: stimulates lobulo-alveolar development

<br />Mammary gland: stimulates lobulo-alveolar development

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The concentration of progesterone increases after ovulation increasing the growth of glands found in the endometrium resulting in increased secretion. These secretions include mucin, carbohydrates and specific proteins that are designed for nourishment of the embryo prior to implantation. Progesterone also stimulates the growth of the endometrium and stabilises smooth muscle cells to ensure that they do not contract during foetal development. Once near term, the concentration of progesterone decreases, altering the ratio between progesterone and oestrogen. This stimulates myometrial activity and prepares the uterus for parturition.

The concentration of progesterone increases after ovulation increasing the growth of glands found in the endometrium resulting in increased secretion. These secretions include mucin, carbohydrates and specific proteins that are designed for nourishment of the embryo prior to implantation. Progesterone also stimulates the growth of the endometrium and stabilises smooth muscle cells to ensure that they do not contract during foetal development. Once near term, the concentration of progesterone decreases, altering the ratio between progesterone and oestrogen. This stimulates myometrial activity and prepares the uterus for parturition.