Homeostasis Ws4

Omar Bin Al-Khattab Sec. School Biology Dept

Homeostasis

( The menstrual cycle ) Worksheet – 4

Name : 1. Define the following terms : 

Menstrual cycle : _____________________________________________________________________ ____________________________________________________________________________ _______

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Menstruation : _______________________________________________________________________

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Endometrium : _______________________________________________________________________

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Implantation : ________________________________________________________________________

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Ovulation : __________________________________________________________________________

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Corpus luteum : ______________________________________________________________________

2. What is the Importance of menstrual cycle. 1. ________________________________________________________. 2. ________________________________________________________. 3. Fill in the following table : Hormune FSH Lh Oestroge

Site of production

Function

n Progeste rone

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4. What happens to the corpus luteum in the case if fertilization occurs and in the case of no fertilization. What is the effect of this in the uterus and pituitary gland. If fertilization occur

If no fertilization

Corpus luteum Effect on the uterus Effect on the pituitary gland

Stages of menstrual cycle 1. Pituitary glad secretes FSH which stimulate the ovary to develop Graafian follicle. 2. Graafian follicle starts to secrete Oestrogen which has two effects, in the following parts : a. Endometrium : cause repair and thickening. b. Pituitary : inhibit production of FSH and cause it to release LH. 3. LH trigger ovulation at day 14 of the cycle which is the bursting of follicle and release egg. 4. The remaining part of follicle forms corpus luteum which secrete progesterone.

5. Progesteron and oestrogen inhibit production of FHS and LH and stimulate growth and blood supply of endometrium. 6. If pregnancy occur : progesterone and oestrogen level remain high so endometrium stays

intact and FSH production is stell inhibited. 7. If there is no pregnancy : corpus luteum degenerate and level of oestrogen and progesterone

fall endometrium breaks down, resulting in menstruation. FHS starts to secreted again.

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