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Female Reproductive Organs Summary – Copy and complete. The _________ of the human female produces eggs and the ovarian hormone ______ and ___________. The egg is protected by the _______ ___________. Once ovulation occurs the ______ __________ turns into the _______ _______.
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Female Reproductive Organs Summary – Copy and complete • The _________ of the human female produces eggs and the ovarian hormone ______ and ___________. • The egg is protected by the _______ ___________. • Once ovulation occurs the ______ __________ turns into the _______ _______.
Frame of Reference Hormone Hormones What you know Examples ... progesterone and oestrogen Where from Examples ... Last lesson / standard grade / the news etc.
Hormonal Control • Hormones are chemical messengers. • Produced in the endocrine glands (ductless) and secreted in the blood. • Generally but slower long lasting effect. • Have specific effect on target tissue. • Hormones control; - the onset of puberty, - sperm production - the menstrual cycle.
Learning Outcomes • The influence of pituitary hormones (FSH and LH) on the testes and ovaries • The influence of testosterone on the testes • The influence of the ovarian hormones (oestrogen +progesterone) on the uterus and the pituitary • Changes during the menstrual cycle and how they are controlled by hormones
Puberty Onset • At puberty, the hypothalamus secretes a releaser hormone whose target is the pituitary gland. • Hypothalamus – small structure located at the base of the brain, where the nervous and hormonal systems interact. • Pituitary gland – gland hanging from the underside of the brain. It secretes hormones that control many other glands in the body, and is regulated by the hypothalamus. • Pituitary gland then produces two hormones.
Puberty Onset Hypothalamus Pituitary gland Luteinising hormone (LH) Follicle-stimulating hormone (FSH) Stimulates ovulation in females and brings the development of corpus leutem Follicle develops in females or stimulates sperm production in seminiferous tubules At puberty, the hypothalamus secretes a releaser hormone whose target is the pituitary gland, stimulates 2 gonadotropic (target is gonads, reproductive organs) hormones FSH in both, then in women LH and men ICSH. Interstitial cell-stimulating hormone (ICSH) Testosterone stimulates development of male sexual characteristics
Hormonal control of sperm production • Follicle stimulating hormone (FSH) in the blood stream promotes sperm production • Interstitial cell-stimulating hormone (ICSH) stimulates interstitial cells to produce the male sex hormone testosterone. • Testosterone stimulates sperm production in seminiferous tubules. • Also activates accessory glands to produce secretions. What are accessory glands? What do they produce? All from last lesson .....
Accessory Glands 2 main, prostate and seminal vesicles. Seminal vesicles produce fructose for energy for sperm to swim and prostaglandins which cause contractions in female reproductive tract. Prostate produces enzyme whose action enables fluid medium viscosity for optimum sperm motility.
Negative Feedback Control of sperm production Negative feedback ensures that, in any control system, changes are reversed and returned back to the set level, so it self regulates. As [testosterone] builds up in the bloodstream, it reaches a level where it inhibits the secretion of FSH and ICSH. Thus leads to decrease in testosterone concentration. However after a while, the hypothalamus stimulates pituitary gland. Maintaining an steady secretion of sperm = stimulates = inhibits gonadotropin releasing hormone (GnRH) Pituitary
FSH – Follicle Stimulating Hormone ICSH – Interstitial cell-stimulating hormone ICSH ICSH Hormonal Control
Hormonal control of menstrual cycle FSH and LH from pituitary gland affects ovaries in several ways; FSH stimulates development and maturation of follicle. FSH stimulate ovary tissue to secrete the sex hormone oestrogen. LH triggers ovulation. LH develops corpus luteum and stimulates it to produce progesterone. NB; Oestrogen and Progesterone are ovarian hormones FSH and LH are known as pituitary hormones
Ovarian Hormone Affect • Oestrogen - • stimulates proliferation (cell division) of the endometrium (inner layer of the uterus) • Secretion of LH by the pituitary gland. • Stimulates cervix cells which secrete cervical mucus, which lubricate vagina and watery mucus allow easier penetration by sperm. • Inhibit pituitary hormone FSH so no more follicles are developed.
Ovarian Hormone Affect • Progesterone - • Promotes futher development and vascularisation of endometrium into spongy layer rich in blood vessels ready for blastocyst (early stage embryo) implantation. • If fertilisation occurs progesterone inhibits secretion of FSH and LH in pituitary gland (no more follicles developed)
Menstrual Cycle The events of these hormones, LH, FSH, progesterone and oestrogen interact to form the synchronised menstrual cycle in women. Cycle lasts for approximately 28 days (varies) with the first day of menstruation (bleeding) regarded as day one of the cycle (generally for ease rather than any “first event”).
Menstrual Cycle • The events of these hormones, LH, FSH, progesterone and oestrogen interact to form the synchronised menstrual cycle in women. • Cycle lasts for approximately 28 days (varies) with the first day of menstruation (bleeding) regarded as day one of the cycle (generally for ease rather than any “first event”). 2 phases; Follicular phase (developing follicle in ovary) Day 1-14 Luteal phase (developing corpus luteum) Day 14-28
Follicular Phase FSH (pituitary) stimulates; • development of maturation of follicle • Production of oestrogen by ovarian tissue [Oestrogen] then builds up (repair and proliferate endometrium) . High[] of oestrogen triggers LH at approx. day 14, causing ovulation as follicle blister wall ruptures, egg moves along oviduct 3-4 days waiting for sperm and fertilisation
Luteal Phase LH (pituitary) stimulates; • Follicle to become corpus luteum (which secretes progesterone and oestrogen). Progesterone (pituitary) stimulates; • Endometrium and vascular blood vessels development by ovarian tissue • with high [oestrogen] trigger inhibitory effect on pituitary gland. (negative feedback control)
Hormonal Control – feedback systems Positive – amplifies Negative – counter balances change to return to normal Watch and listen......
Hormonal Control Now answer these multiple choice questions READ question CAREFULLY in MCQ! Watch and answer ......
Activity ;plot the period! • Use the data given the plot the points. Best to use X, different lines / colours for each plot. • Make sure you use the right scale!
Fertilise or not to fertilise No fertilisation • LH levels drop, so corpus luteum (day 22) degenerates • No corpus luteum causes rapid drop of oestrogen and progesterone. • Low levels of ovarian hormones means endometrium no longer maintained, so by day 28 menstruation (loss of innner layer of endometrium and blood) begins. • Stop feedback on pituitary hormones, so new follicle can develop with FSH increase
Fertilise or not to fertilise Fertilisation • Embryo secretes human chorionic gonadtrophic hormone (HCG), similar to LH (maintains corpus luteum that produces ovarian hormones, which maintains endometrium development) for ~6 weeks until placenta takes over.
Demonstrate your understanding 4 female hormones explain their; • their roles in the menstrual cycle • where they are produced • what order they occur in in each menstrual cycle. • Display however you feel easiest – table / Venn diagram or simple notes. • Remember transferring knowledge is where learning occurs!
Second hormone - Spike day 14, LH First to rise ~ day 4 FSH Made in pituitary Triggers ovulation Stimulates graffian follicle development FSH stimulates ovary to produce oestrogen Corpus Luteum - Made by LH - Makes progesterone Hormones Oestrogen inhibits FSH Initiates the repair of the uterus wall Inhibits pituitary hormones (both FSH /LH) Made in ovary Progesterone Oestrogen Quite high throughout, peaks ~ day 12 Consistency of cervical mucus altered so easily penetrated by sperm Vascularisation of the uterus wall
Male and Female Hormones • FSH – promotes sperm production in males. In females stimulates development of the graafian follicle and the ovary to produce oestrogen • ICSH (males) – stimulates testosterone production. • Testosterone – stimulates sperm production and activates prostate gland and seminal vesicles • LH (in females)- triggers ovulation and stimulates the graafian follicle to become corpus luteum (which produces progesterone) • Oestrogen - Initiates the repair of the uterus wall and stimulates the pituitary to produce a sudden upsurge of LH • Progesterone - Encourages vasculariation (blood vessels) development of the uterus lining and inhibits the pituitary gland (and therefore FSH).