Hormonal Control of the Reproductive System

Follicular Phase: 1st what of the ovarian cycle End of the previous oc, p and e levels dramatically d Day 1 of the new cycle: the drop in p and e promotes the release of g from the hypothalamus Primary follicle at this stage develops an outer layer of g cells and the tf FSH than causes the d of the pf into a sf Increasing levels of LH act primarly on the t cells of the sf, promoting the release of a, a are then taken up by gc under the influence of f and converted to e FSH: promotes the g cells to release i, which has a negative effect on h release from the h at this stage, initiates follicular g and the follicles are still undergoing m and g Rising level of e=i effect on the release of hormones from the h and apg 3 hormones still being synthesized bu no longer being s, which causes a what of these hormones in their r l Inhibin produced by the gc also i, causing an i effect on 2 hormones FSH levels do what during this period, but receptors present on the c surface become more sensitive to what (better able to what) Which allows the continue conversion of a into e, which results in a i in the c of e in the blood Causes the c of growth and subsqeunt a of the weaker f, remaining m follicle survives

1st half of the ovarian cycle End of the previous ovarian cycle - progesterone and estrogen levels dramatically decrease. Day #1 of the new cycle, the drop in progesterone and estrogen promotes the release of GnRH from the hypothalamus Primary follicle at this stage develops an outer layer of granulosa cells, and the theca folliculi. FSH then causes the differentiation of the primary follicle into a secondary follicle. Increasing levels of LH act primarily on the thecal cells of the secondary follicle, promoting the release of androgens. Androgens are then taken up by the granulosa cells under the influence of FSH and converted to estrogens FSH Promotes the granulosa cells to release inhibin Which has a negative effect on hormone release from the hypothalamus at this stage Initiates follicular growth and the follicles are still undergoing maturation and growth Rising level of estrogen = inhibitory effect on the release of hormones from the hypothalamus and anterior pituitary gland. GnRH, FSH, and LH are still being synthesized, but no longer being secreted Which causes a build up of these hormones in their respective locations Inhibin produced by the granulosa cells also intensifies Causing an inhibitory effect on FSH and LH release FSH levels drop significantly during this period but receptors present on the cell surface become more sensitive to FSH (better able to use) Which allows the continued conversion of androgens into estrogen Which results in an increase in the concentration of estrogen in the blood Causes the cessation of growth and subsequent atresia of the weaker follicles. Remaining mature (Graafian) follicle survives

Other Hormones in the Regulation of the Female Reproductive Cycle: A, R, HCG

Activin Relaxin Human chorionic gonadotropin (HCG)

Dihydrotestosterone (DHT): androgen converted from t, an e Secreted by: t, p, ac Function: same effacts as t, a more significant role in the development ssc: enlargment of so and development of fh and d of the voices

Androgen converted from testosterone an enzyme Secreted by Testes, prostate, and Adrenal Cortex Function Same Effects As testosterone A more significant role in the development secondary sexual Characteristics Including the enlargement of the sex organs and the development of facial hair and deepining of the voice

Menstrual Phase: at the end of the last mc, levels of e and p greatly decline, promoting the release of GnRH from the hypothalamus, g release of what hormone from the apg During these five days, the e lining of the e is shed and a combination of b, ec, and m is lost Ovarian hormones e and p are their lowest during the mp, Subsequent release of p stimulate the spiral a of the u to constrict, causing the cells they supply to d and the fl of the e to detach from the uw Commonly called a p

At the end of the last menstrual cycle Levels of estrogen and progesterone greatly decline Promoting the release of GnRH from the hypothalamus Gradual release of FSH and LH from the anterior pituitary gland During these five days, the epithelial lining of the endometrium is shed and a combination of blood, epithelial cells, and mucus is lost Ovarian hormones estrogen and progesterone are at their lowest during the menstrual period Subsequent release of prostaglandins stimulate the spiral arterioles of the uterus to constrict, causing the cells they supply to die and the functional layer of the endometrium to detach from the uterine wall Commonly called a period

Luteal Phase (after ovulation): what number days LH transforms the ch into a cl, stimulates the cl to produce p, i, and some Negative feedback effect on the h and ap=i the release of 2 hormones Reduction of these h inhibits the development of new f in the o Drop in LH levels prevents further o Fertiestrogenlization: cells around the developing embryo begin to produce what hormone, which maintains the secretory activity of the cl

Days 15-28 LH transforms the corpus hemorrhagicum into a corpus luteum LH Stimulates the corpus luteum to prodce progesterone, inhibin, and some Negative feedback effect on the hypothalamus & anterior pituitary = inhibiting the release of FSH & LH Reduction of these hormones inhibits the development of new follicles in the ovaries Drop in LH levels prevents further ovulation Fertiestrogenlization Cells around the developing embryo begin to produce HCG, which maintains the secertory activity of the corpus luteum

Integumentary System (female): decrease in bh growth except in p and a regions increase in fd in the skin Increase in sg secretions

Decrease in body hair growth except in pubic and axillary regions Increase in fatty deposits in the skin Increase in sebaceous gland secretions

Respiratory System: enlargement of tc, causes voice to do what

Enlargement of thyroid cartilage. What does that cause? Voice to depen

Phases of the Ovarian Cycle: F phase, o, and lp Cycle length commonly v Lutel phase remains fairly c, follicular phase will vary in what

Follicular phase, ovulation, and the luteal phase Cycle length commonly varies (21 to 40 days) luteal phase remains fairly constant follicular phase will vary in length

Androgen-Binding Protein (ABP): g Secreted by: sc Function: thought to play a role in regulating s by influencing the levels of t and d in the testes Binds to testosterone, c it within the lf, thus stimulating s

Glycoprotein Secreted by Sertoli cells Function Thought to play a role in regulating spermatogenesis by influencing the levels of testosterone and dht in the testes Binds to testosterone, concentrating it within the luminal fluid, thus stimulating spermatogenesis

Principle Hormones that control the Female Reproductive Cycle: GnRH, FSH, LH, E, P, I

Gonadotropin-releasing hormone (GnRH) Follicle stimulating hormone (FSH) Luteinizing hormone (LH) Estrogen Progesterone Inhibin

Principle Hormones that Control the Male Reproduction: GnRH, LH, T, DHT, ABP, I, FSH

Gonadotropin-releasing hormone (GnRH) Luteinizing hormone (LH) Testosterone Dihydrotestosterone (DHT) Androgen-Binding Protein (ABP) Inhibin Follicle stimulating hormone (FSH)

Signs of Ovulation: increase in b body temperature Changes in c mucus, mucus does what/more a for sperm Cervix Softens: for better p/delivery of the s Mittelschermz: p

Increase in basal body temperature Changes in cervical mucus Mucus increases/More acceptable for sperm Cervix softens For better penetration/Delivery of the Sperm Mittelschmerz---pain

Integumentary System: increase in h growth in f, c, b, p, a, a, and l T and c hair Increase in st Enlargement and increase sg

Increase in hair growth Where? Face, chest, back, pubic, axilla, arms, and legs Thicker and coarser hair Increase in skin thickness Enlargement and increase sebaceous glands

Musculoskeletal System: Increase in s and m B of the shoulders Overall what in muscle mass Increase in bd Change in s of bones, especially where Slower fusion of the ep, does what to bones

Increase in size and mass Broadening of the shoulders Overall increase in muscle mass Increase in bone density Change in shape of bones, especially of the face Slower fusion of the epiphyseal plate - What effect does that have, longer bones

Follicle Stimulating Hormone (FSH): Indirectly to stimulate s (secreted by ap gland) W/sertoli cells to stimulate the secretion of a binding protein into the l of st ABP binding to testosterone keeps its what high

Indirectly to stimulate spermatogenesis (ap gland) W/ Sertoli cells to stimulate the secretion of androgen-binding protein (ABP) into the lumen of seminiferous tubules ABP binding to testosterone - keeping its level high

Testosterone: Main a, s, synythesized from c Lipid soluble into i fluid and b Secreted by: l cells Function: development of ss characteristics during puberty, d of voice, growth of what hair, md, stimulates/maintains maturation of mr organs and s glands Stimulates production/development of s by stimulating s Metabolic effects:; stimulating ps and mg Associated with the development of ab and the male l

Introductory information MAIN Androgen Steroid Synthesized from Chlosterol Lipid soluble into interstitial fluid and blood Secreted By Leydig cells Function Development of the secondary sexual characteristics during puberty Deepening of the voice, the growth of facial hair, and muscle development Stimulates & maintains maturation of the male reproductive organs and secretory glands Stimulates production/development of spermatozoa By stimulating spermatogenesis Metabolic effects Stimulating protein synthesis and muscle growth Associated with the development of aggressive behavior and the male libido

Postovulatory Phase (Secretory Phase): what phase, more t, vacuralization due to p, p in the cl Occurs simultaneously w/the l phase of the ovarian cycle Endometrium prepares for implantation of the e

Last phase More thickening, Vascularazation due to Progesterone Progesterone in the Corpus Lutenem Occurs simultaneously with the luteal phase of the ovarian cycle. Endometrium prepares for implantation of the embryo.

Hormonal Control of Development (female): Main sex hormones: e (mainly e) and p (mainly p), s hormones produced in the o Before birth: several of the s hormones that act upon the rs, adulthood also influence the d of the rs in u Estrogen play a particular role in the d and m of the female reproductive s and secondary sc Secondary Sex characterisitics: systems, m and i

Main sex hormones Estrogens (mainly Estroadiol) and Progestins (Mainly Progesterone) Steroid hormones produced in the ovary Before birth Several of the Sex hormones that act upon the reproductive system Adulthood also influence the development of the reproductive system in utero Estrogen play a particular role in the development and maintenance of the female reproductive structures and secondary sex charcteristics Secondary sex characteristics What are they? Systems Muscular/Integumentary system

Control of Testosterone Production: Negative feedback system controls bl of tesosterone Receptors in h detect increase in bl Secretion of what hormone is slowed Anterior pituitary hormones (2) are what Leydig cells of testes s Blood level returns to what

Negative feedback system controls blood levels of testosterone Receptors in hypothalamus detect increase in blood level Secretion of GnRH slowed Anterior pituitary (FSH & LH hormones) slowed Leydig cells of testes slowed Blood level returns normal

Luteal Phase: no f, corpus luteum does what after about 10 days into a ca Levels of p, i, e, drop sharply The decline of theese hormones marks the end of one oc and the what of the next

No fertilization Corpus luteum degenerates after about 10 days into a corpus albicans, Levels of progesterone, inhibin, and estrogen drop sharply. The decline of these hormones marks the end of one ovarian cycle and the beginning of the next.

Preovulatory Phase (Proliferative Phase): Occurs s with the l part of the f phase of the oc Start=increasing c of FSH and LH FSH and LH cause the e to become highly v Level of estrogen in the blood causes the s of p receptors to prepare for the increased levels of p later on in the c

Occurs simultaneously with the latter part of the follicular phase of the ovarian cycle Start = increasing concentrations of FSH and LH FSH and LH cause the endometrium to become highly vascularized Level of estrogen in the blood causes the synthesis of progesterone receptors to prepare for the increased levels of progesterone later on in the cycle

Ovulation: Preovulatory phase works to cause o Within 28 day cycle, the ovulation phase usually takes place around what day, some may have e/l, what part is variability Lining continues to grow and thickent due to the i of the EGG

Preovulatory phase works to cause ovulation Within a typical 28-day cycle, the ovulation phase usually takes place around day 14 Some may have ovulation earlier/later, beginning part is variability Lining continues to grow and thicken. Why? Implantation of the EGG

Luteinizing Hormone (LH): released due to elevated levels of what hormone What it does: stimulates l cells to produce t, elevated levels of t regulate lh Secreted: pg Funciton: lh stimulates the i cells leydig to produce ah, of which t is one What feedback loop: causes the what of LH by anterior pituitary

Released due to elevated levels of GnRH What does it do? Stimulates Leydig cells to produce testosterone Elevated Levels of testosterone regulate lh Secreted Pituitary gland Function LH stimulates the Intersitital cells Leydig to produce andgrogenic hormones, of which testosterone is one Negative feedback loop - causes the reduction of LH by anterior pituitary

Inhibin: Released in response to high levels of what hormone Secreted by: s cells Function: acts to reduce what hormone release from the ap gland

Released in response to high levels of follicle-stimulating hormone (FSH) Secreted by Sertoli cells Function Acts to reduce FSH release from the anterior pituitary gland

Postovulatory Phase: Rising levels of p (produced by the cl) causes the e to thicken and become more v Glycogen secreted from the e glands into the u cavity: use to glucose for e Cervical plug is also formed as the cm becomes more v because they block other s from coming in If fertilization does not occur: no cl, no d of the lining

Rising levels of progesterone (produced by the corpus luteum) causes the endometrium to thicken and become more vascular Glycogen secreted from the endometrial glands into the uterine cavity Why? Glucose for energy Cervical plug is also formed as the cervical mucus becomes more viscous Why? Block other sperm from coming in If fertilization does not occur No corpous lutenum, no development of the lining

Luteinizing hormone (LH) (f): secreted by ap Function: l after ovulation, production of p from cl

Secreted Anterior Pituitary gland Function Lutenization after ovulation Production of progesterone from the corpus luteum

Inhibin: Secreted by g cells of f Function: released after o, acts to inhibit further secretion of 2 hormones Stops further development of sf in the ovary after a mature f has developed Ensuring that only one mf is released per mc

Secreted Granulosa cells of follicles Function Released after ovulation - acts to inhibit further secretion of FSH and LH Stops further development of secondary follicles in the ovary after a mature follicle has developed Ensuring that only one mature follicle is released per menstrual cycle

Activin: Secreted: g cells of the secondary f Function: released after o and acts to increase further secretion of 2 hormones Promotes the development of sf in the ovary

Secreted Granulosa cells of the secondary follicles Function Released after ovulation and acts to increase further secretion of FSH and LH Promotes the development of secondary follicles in the ovary

Human Chorionic Gonadotropin (hCG): produced after f, initially by developing e and later by a region of the p Function: major role is to prevent the d of the cl, causes the continued production of p, needed to maintain the e lining of the uterus required for p

Secreted Produced after fertilization, initially by the developing embryo and later by a region of the placenta Function Major role is to prevent the disintegration of the corpus luteum Causes the continued production of progesterone Needed to maintain the endometrial lining of the uterus required for pregnancy

Gonadotropin-releasing Hormone (GnRH) (female): Secreted: produced by h and ap Function: promotes sd by stimulating teh secretion of lh and fsh, prevents d of the corpus luteum

Secreted Produced by the hypothalamus Released by anterior pituitary Function Promotes sexual development by stimulating the secretion of lutenizing hormone and follicle stimulating hormone Prevents disintegration of the corpus luteum

Estrogen: Secreted: t interna cells of the developing f and cells of the cl Function: Stimulates the rc, development of ss characterisitics Promotes the m of oocytes and stimulate growth of the u lining during the p and p phases it is released into the b and travels to many to, u, mg, bt, b, and h

Secreted Theca interna cells of the developing follicles and cells of the corpus luteum Function Stimulates- the reproductive cycle, development of secondary sex characteristics Promotes the maturation of oocytes and stimulate growth of the uterine lining during the preovulatory and postovulatory phases It is released into the blood and travels to many target organs Uterus, mammary glands, breast tissue, liver, bone, and heart

Follicle Stimulating Hormone (FSH) (f): Secreted by ap gland Function: promotes fg and m, simulates the ti cells of the developing follicles to secrete e

Secreted By anterior pituitary gland Function Promotes follicle growth and Maturation Stimulates the THECA interna cells of the developing follicles to secrete estrogen

Progesterone: Secreted by the cl Function: p for pregnancy, m of pregnancy should f occur, if fertilization occur, progesterone would maintain p Targets the u, to support e growth and supressing c of us muscle for maintenance of p Palcental progesterone is a sh produced by the p during pregnancy Stimulates growth of mg

Secreted By the corpus luteum Function Preparation For pregnancy Maintenance of pregnancy should fertilization occur If fertilization occur, progesterone would maintain pregnancy Targets the uterus To support endometrial growth and suppressing contractility of uterine smooth muscle for maintenance of pregnancy Placental progesterone is a steroid hormone produced by the placenta during pregnancy Stimulates growth of the mammary glands

Relaxin: Secreted: cl Function: relax the contractions of the m, enabling implantation of the b to occur In pregnancy: relaxin is released in l amounts from the p, increases the flexibility of j and help to dilate the c

Secreted Corpus luteum Function Relax the contractions of the myometrium Enabling implantation of the blastocyst to occur In pregnancy Relaxin is released in larger amounts from the placenta Increases the flexibility of joints and helps to dilate the cervix

Gonadotropin-releasing Hormone (GnRH) Secreted by: produced by the h, released by ap Function: promtes sd by stimulating the secretion of l hormone and fs hormone

Secreted by Produced by the Hypothalamus Released by anterior Pituitary Function Promotes sexual development by stimulating the secretion of Luteinizing Hormone and Follicle stimulating Hormomne

Introduction to the Female Reproductive Cycle: Timeline: onset of p (around what age) until m (around what age) Female reproductive cycle: the term used to describe the events that take place in the o and u of a non-p female, as well as the h changes that regulate them Average female reproductive cycle repeats how many days, Pregnancy=c is altered to accommodate the e/f Major events: Ovarian cycle: events that take place in the o, Uterine (mc): events that take place in the u

Timeline Onset of Puberty (around age of 10) Until Menopause (Around 51 Years of Age) Female Reproductive cycle : the Term used to describe the events that take place in the ovaries and uterus of a non-pregnant female, as well as the hormonal changes that regulate them Average female reproductive cycle repeats 28 days Pregnancy=Cycle is Altered to accommodate the growing embryo/fetus Major events Ovarian cycle Events that take place in the ovaries Uterine (menstrual cycle) Events that take place in the uterus

Ovulation: Usually what day As the level of estrogen reaches a critical level, exerts a p effect on the h, stimulating the rapid release of the accumulated g hormone Increased GNRH levels promotes a surge of a LH from the APG, what other hormone also released from the apg at this point, but to a l extent LH surge stimulates the po of a dominant f to complete its first md, thus forming a so

Usually day 14 As the level of estrogen reaches a critical level Exerts a positive effect on the hypothalamus, stimulating the rapid release of the accumulated GnRH Increased GNRH Levels promotes a surge of accumulated LH from the Anterior pituitary gland FSH is also released from the Anterior pituitary gland at this point, but to a lesser extent LH surge stimulates the primary oocyte of a dominant follicle to complete its first meiotic division, thus forming a secondary oocyte

Hormonal Control: very complex system of h, both what feedbacks Hormones control the o and u events, s or i specific stages of the reproductive cycle Both m and f=a what of other effects Increased activity of sg Sebaceous glands: growing of p and ah

Very complex system of hormones Both + and - feedback mechanisms Hormones control the ovarian and uterine events Stimulate or inhibit specific stages of the reproductive cycle Both males and females = a # of other effects Increased activity of sweat glands Sebaceous Glands Growing of Pubic and armpit Hair

Secondary Sexual Characteristics: Features and traits that are associated w/p and sd but no fuctional rr Things that distinguishes m and f Systems: m, i, r system

What are they? Features and traits that are associated with puberty and sexual development but no functional reproductive role Some things that distinguishes males from females Systems Muscular system Integumentary system Respiratory system

Ovarian Cycle: Changes that of undergo as they mature in preparation for f, if no fertilization=describes the sequence of f breakdown

What is it? Changes that ovarian follicles undergo as they mature in preparation for fertilization (should it occur) If no fertilization=describes the sequence of follicular breakdown

Uterine Cycle (AKA Menstrual Cycle): The changes that take place to the e of the u in preparation for implantation of an e No fertilization=the lining of endometrium is shed during m and the mc will begin again

What is it? The changes that take place to the endometrium of the uterus in preparation for implantation of an embryo No fertilization=the lining of the endometrium is shed durin menstrauion and the menstrual cycle will begin again

Hormonal Control of Development: begins at about how many weeks of fg Male androgenic hormones begin to influence the development of t, by 6 weeks the fetal testis display epithelial sc, the r and the seminiferous tubules The hormones will influence d of the rt as well as other features of the mb

When does development of the reproductive system start Begins At about 4 weeks of fetal growth Male androgenic hormones begin to influence the development of the testicles By 6 weeks the fetal testis display epithelial sex cords, the rudiments of the seminiferous tubules The hormones will influence development of the reproductive tract as well as other features of the male body

Musculoskeletal System: w of the hips, development of pt musculature

Widening of the hips Development of posterior thigh musculature