Menstrual Cycle and Reproductive Hormones Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What happens during high levels of oestrogen in the menstrual cycle?

Promotion of corpus albicans formation

Development of new follicles

Inhibition of GnRH, LH, and FSH release

Stimulation of GnRH, LH, and FSH release (correct)

What effect do moderate levels of oestrogen have during the menstrual cycle?

Facilitate ovulation

Stimulate the release of GnRH

Prevent the development of new follicles (correct)

Promote menstruation

How does the progesterone component of hormonal birth control work primarily?

Enhancing ovum maturation

Increasing the levels of oestrogen

Stimulating ovulation

Inhibiting LH release (correct)

What is the primary role of the GnRH hormone in the menstrual cycle?

Regulate the release of LH and FSH Signup and view all the answers

What occurs after the formation of the corpus albicans in the menstrual cycle?

Promotion of GnRH, LH, and FSH release Signup and view all the answers

Which hormone is secreted by Leydig cells in the testes?

Testosterone Signup and view all the answers

What is the primary function of Sertoli cells in the testes?

Form blood-testes barrier Signup and view all the answers

Which hormone is primarily responsible for stimulating spermatogenesis?

Testosterone Signup and view all the answers

What role does inhibin play in the male reproductive system?

Reduces FSH production Signup and view all the answers

What is the function of GnRH in the male reproductive system?

Triggers the release of FSH and LH Signup and view all the answers

Which vitamin is most associated with the production of testosterone?

Vitamin D Signup and view all the answers

What is the main consequence of the action of 5-alpha-reductase?

Conversion of testosterone into DHT Signup and view all the answers

Which hormone is also known as interstitial cell-stimulating hormone (ICSH)?

LH Signup and view all the answers

What condition is characterized by the enlargement of the prostate in males over 60?

Benign hyperplasia Signup and view all the answers

Which hormone is primarily responsible for stimulating the release of FSH and LH from the anterior pituitary?

Gonadotropin-releasing hormone (GnRH) Signup and view all the answers

What treatment involves the use of a PDE5 inhibitor to address erectile dysfunction?

Sildenafil citrate (Viagra) Signup and view all the answers

What is the main function of progesterone in the female reproductive cycle?

Prepare and maintain the endometrium Signup and view all the answers

In which phase of the female reproductive cycle does ovulation occur?

Ovulatory phase Signup and view all the answers

Which of the following functions is NOT associated with estrogens?

Stimulate ovarian follicles to secrete progesterone Signup and view all the answers

What is the primary physiological role of relaxin during pregnancy?

Relaxes the uterus and dilates the cervical canal Signup and view all the answers

Which treatment option blocks testosterone and dihydrotestosterone actions for prostate cancer?

Antiandrogens like flutamide Signup and view all the answers

How does sildenafil work to treat erectile dysfunction?

By enhancing nitric oxide's effect on cGMP levels Signup and view all the answers

What happens to the stratum functionalis if implantation of a fertilized ovum does not occur?

It is shed during menstruation Signup and view all the answers

What condition can result from thalidomide use during weeks 3-6 of pregnancy?

Phocomelia Signup and view all the answers

What role does cortisol play during pregnancy?

Facilitates lung maturation Signup and view all the answers

Which hormone begins to be secreted significantly at week 12 of pregnancy?

Human placental lactogen (hPL) Signup and view all the answers

What effect does progesterone have during pregnancy?

Inhibits uterine contractions Signup and view all the answers

Which hormone's release increases oxytocin receptors in the uterine muscle?

Estrogen Signup and view all the answers

What initiates the milk ejection reflex during lactation?

Oxytocin stimulating myoepithelial cell contraction Signup and view all the answers

What effect does suckling have on prolactin secretion?

Stimulates prolactin secretion Signup and view all the answers

What occurs during the menstrual phase of the female reproductive cycle?

Follicles begin to develop in the ovaries. Signup and view all the answers

What physiological change occurs during the positive feedback mechanism of contractions?

Increase in estrogen and relaxin levels Signup and view all the answers

Which hormonal changes occur during the pre-ovulatory phase?

Oestrogens stimulate the repair of the endometrium. Signup and view all the answers

What is the primary effect of levonorgestrel when used as a morning-after pill?

It inhibits ovulation by decreasing LH Signup and view all the answers

What is the result of administering bromocriptine during lactation?

Decreases milk secretion Signup and view all the answers

What is the main event that characterizes ovulation?

Surge of GnRH and LH due to high estrogen levels. Signup and view all the answers

Which hormone is critical for the digestion of collagen fibers during labor?

Estrogen Signup and view all the answers

What happens to the corpus luteum if fertilization does not occur?

It is transformed into a corpus albicans. Signup and view all the answers

During which stage of gestation does organogenesis occur?

17 - 60 days Signup and view all the answers

Which of the following teratogenic drugs is associated with causing cleft palate?

Corticosteroids Signup and view all the answers

Which condition is associated with the absence of an entire sex chromosome?

Turner’s syndrome. Signup and view all the answers

What is a significant risk associated with maternal use of alcohol during pregnancy?

Retarded growth Signup and view all the answers

What is the primary treatment option for endometriosis?

GnRH analogues to prevent oestrogen production. Signup and view all the answers

What is a common risk associated with long-term hormone replacement therapy during menopause?

Increased risk of endometrial cancer. Signup and view all the answers

What is the effect of methotrexate during pregnancy?

Causes neural tube defects Signup and view all the answers

Which drug is known to cause phocomelia and heart defects when used during pregnancy?

Thalidomide Signup and view all the answers

What role does human chorionic gonadotropin (hCG) play after fertilization?

It preserves the corpus luteum to maintain hormone levels. Signup and view all the answers

Which of the following is NOT a typical symptom associated with menopause?

Increased fertility. Signup and view all the answers

What is the primary effect of retinoids like etretinate in pregnant women?

Causes hydrocephalus and other defects Signup and view all the answers

Which gene mutation is related to a higher susceptibility to breast cancer?

BRCA1. Signup and view all the answers

Which teratogenic drug is primarily utilized as an anticoagulant?

Warfarin Signup and view all the answers

What is the consequence of using tetracycline during pregnancy?

Impaired bone growth and staining of teeth Signup and view all the answers

Which process is primarily affected by teratogens between 17 - 60 days of gestation?

All of the above Signup and view all the answers

Study Notes

Reproductive Endocrinology

Recommended Reading:
Rang and Dales Pharmacology - Chapter 34
Tortora and Derrickson's Anatomy and Physiology - Chapter 28
Practice MCQ questions: Available on Moodle
Topics to cover:
Hormonal regulation of the male reproductive system
Hormonal regulation of the female reproductive system
Contraceptive pill
Reproductive pathology and treatment
Pregnancy/birth/lactation
Teratogens

Male Reproductive System

Leydig Cells: Located between seminiferous tubules, secrete testosterone.
Sertoli Cells: Embedded with spermatogenic cells in the tubules; form blood testes barrier, nourish spermatocytes, mediate effects of testosterone and FSH on spermatogenesis, and phagocytose excess spermatids. Secretes inhibin which regulates sperm production by inhibiting FSH production.
Hormonal Control of Spermatogenesis:
GnRH (gonadotropin-releasing hormone): Main hormone, stimulates the anterior pituitary to secrete FSH and LH.
FSH (follicle-stimulating hormone): Stimulates spermatogenesis
LH (luteinizing hormone): Stimulates testosterone secretion (also called interstitial cell-stimulating hormone, ICSH, in the male).
Testosterone and DHT (dihydrotestosterone): 5α-reductase converts Testosterone to DHT, DHT is responsible for development of external genitalia and prostate.
Inhibin: Helps to regulate sperm production by inhibiting FSH.
Control of Testosterone Production:
Negative feedback system controls blood levels of testosterone.
Receptors in hypothalamus detect increased blood level of testosterone.
Inhibits secretion of GnRH from hypothalamus.
Reduced secretion of LH from anterior pituitary.
Leydig cells secrete less testosterone.
Blood level returns normal.
Male Hypogonadism: (disorders of hormone production by the testes).
Primary congenital: Testicular agenesis (failure), Klinefelter syndrome (47XXY)
Primary acquired: Bilateral orchitis (inflammation of testes)
Secondary: Pituitary disorders, hypothalamic disorders (e.g., Kallman's syndrome - GnRH deficiency).
Aging in the male reproductive system: Enlargement of prostate (benign hyperplasia) in ⅓ of males over 60
Prostate Cancer: Leading male cancer death. Blood test for prostate-specific antigen (PSA). Antiandrogens (e.g., flutamide, cyproterone) used in treatment to block testosterone/DHT actions, preventing stimulation of prostate cancer growth.
Erectile Dysfunction Treatment: Viagra (Sildenafil citrate) – PDE5 inhibitor.

Female Reproductive System

The Female Reproductive Cycle: Encompasses ovarian and uterine cycle, hormonal changes regulating them, and changes in breasts and cervix. Controlled by monthly hormone cycle of anterior pituitary, hypothalamus, and ovary.
Ovarian cycle: Changes in ovaries during and after oocyte maturation.
Uterine (menstrual) cycle: Concurrent series of changes in uterine endometrium preparing for fertilized ovum arrival. If not fertilized, stratum functionalis shed during menstruation.
Hormonal control of the female reproductive cycle:
GnRH (gonadotropin-releasing hormone): Secreted by hypothalamus, controls ovarian and uterine cycle, stimulates release of FSH and LH from anterior pituitary.
FSH (follicle-stimulating hormone): Initiates follicular growth, stimulates ovarian follicles to secrete estrogens.
LH (luteinizing hormone): Stimulates further development of ovarian follicles, stimulates ovarian follicles to secrete estrogen, triggers ovulation. Prompts the formation of corpus luteum; produces estrogens, progesterone, relaxin, and inhibin.
Ovarian hormones:
Estrogens (mainly β-estradiol): Secreted by ovarian follicles. Promotes female reproductive structures and secondary sex characteristics, increases protein anabolism (building strong bones), lowers blood cholesterol, inhibits GnRH, LH, and FSH release.
Progesterone: Secreted mainly by corpus luteum. Works with estrogens to prepare and maintain endometrium for implantation and mammary glands for milk production, inhibits GnRH and LH secretion.
Relaxin: Produced by corpus luteum. Relaxes uterus by inhibiting myometrium contraction. Increases pubic symphysis flexibility and dilates uterine cervix at end of pregnancy.
Inhibin: Secreted by granulosa cells of growing follicles. Inhibits FSH and LH secretion.
Secretion and physiological effects of hormones in the female reproductive cycle: (detailed description of hormonal interactions and their effects)
Phases of the female reproductive cycle: Menstrual, pre-ovulatory, ovulation, post-ovulatory.
Corpus Luteum: If not fertilized, lasts 2 weeks. Degenerates into corpus albicans and decreases progesterone, estrogens, and inhibin, and releases GnRH, FSH, and LH. If fertilized, hCG (human chorionic gonadotropin) is produced by chorion that stimulates further production of progesterone and estrogens, and the cycle continues.
Postovulatory phase (days 15-28) – Secratory Phase:
Progesterone and estrogen produced by corpus luteum promote endometrial growth.
If fertilization doesn't occur, levels of progesterone and estrogen decline causing menstruation.
Hormonal Interactions in the ovarian and uterine cycles: (detailed description of feedback loops)
Causes of female hypogonadism:
Primary congenital: Turner syndrome (45XO), Noonan syndrome (46XX)
Primary acquired: Chemotherapy, irradiation
Secondary (indirect): Pituitary disorders, hypothalamic disorders
Treatment: Clomiphene
Aging in the female reproductive system: Menopause (hot flushes, vaginal dryness, depression). Treatment for short term (2–5 years) includes HRT (estrogen/progesterone) such as Tibolone. Drawbacks of long-term HRT include increased cancer risk.
Endometriosis: Growth of endometrial tissue outside the uterus, GnRH analogues (buserelin) prevent estrogen production, progesterone (medroxyprogesterone acetate), Danazol.
Breast Cancer: Leading cause of cancer in UK, genes BRCA1 and BRCA2 increases susceptibility, hormone therapy/lumpectomy/mastectomy/radiation treatment treatment options.

Teratogens

Definition: Substances affecting fetal development
Chemicals and Drugs: Thalidomide, Warfarin, Corticosteroids, Stilbestrol, Phenytoin, Valproate, Carbamazepine, Cytotoxic drugs (methotrexate), Aminoglycosides, Tetracyclines, Ethanol, Retinoids.
Mechanism: Affects different stages of gestation (blastocyst formation, organogenesis, maturation).
Effects: Specific effects on the fetus vary based on the teratogen. Can include phocomelia (limb malformation), heart defects, cleft palate, mental retardation, and other developmental abnormalities.

Pregnancy and Labor

Hormonal changes during pregnancy: Human chorionic gonadotropin (hCG) rescues corpus luteum and maintains estrogen and progesterone production, human placental lactogen (hPL), and cortisol are also important.
Labor (Parturition): Progesterone prevents uterine contractions, corticotropin-releasing hormone (CRH) secretion increases, and oestrogen levels overcome progesterone, inducing prostaglandin release.
Contractions (positive feedback mechanism): Oestrogen and relaxin soften the cervix. Activation of stretch receptors in the cervix increases oxytocin release from posterior pituitary resulting in contraction of uterine muscles and pushing the baby towards the cervix. Positive feedback loop.
Lactation (milk secretion and ejection): Prolactin produced by anterior pituitary, but progesterone inhibits prolactin effects. Suckling stimulates nerve impulses released from stretch receptors in the nipples leading to hypothalamic release of prolactin-releasing hormone (PRH), which increases prolactin further increasing milk secretion. Oxytocin stimulates contraction of myoepithelial cells in breasts, squeezing the ducts and causing milk secretion.

Contraceptives

Combined Pill: Oestrogen inhibits FSH and follicle development, and progesterone inhibits LH preventing ovulation and makes cervical mucus inhospitable for sperm, together making endometrium unsuitable for implantation.
Progesterone-only Pill: Makes cervical mucus inhospitable for sperm, inhibits ovulation by reducing LH.
Morning-after Pill: Effective within 72 hours; either combined or progestin-only pills; inhibits FSH and LH, reducing oestrogen and progesterone in the ovary.

Additional Notes

The provided material covers a wide variety of topics related to reproductive endocrinology. Each topic requires detailed study to fully understand the mechanisms, interactions, and examples mentioned.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on the roles of hormones in the menstrual cycle and male reproductive system. This quiz covers the effects of estrogen and progesterone, as well as the functions of GnRH, Sertoli cells, and testosterone production. Explore the complexities of reproductive hormones and their impacts.