Week 13: Sexual Organs and Reproductive Function Flashcards
What is the Scrotum?
Skin-covered, muscular sac located behind the penis that houses the testes.
When is sperm production most efficient?
Sperm production is most efficient 2–4°C below core body temperature.
What happens when the muscle contract, the scrotum shrinks, and the testes move closer to the body?
Sperm get too cold, need to be warmer
What happens when the muscle relax, the scrotum expands, and the testes move farther from the body?
Sperm get too hot, need to be cooler
What is the Raphae?
A raised medial ridge on the scrotal surface.
What are the Testes?
Produce sperm & androgens (e.g., testosterone) and housed in the scrotum.
What is the Cryptorchidism?
Failure of one or both testes to descend before birth.
When do the testes descend in fetal months?
Occurs in the 7th fetal month
What are Seminiferous tubules?
They are the location of sperm production.
What is the pathway of sperm through the testes?
Seminiferous tubules → Straight tubules → Rete testes → Efferent ductules (exit testes).
What are Sertoli Cells (Sustentacular Cells)?
Support & nourish developing sperm cells; they secrete signaling molecules that regulate sperm production & germ cell survival
What are Spermatogonia?
Stem cells lining the basement membrane that can divide and differentiate throughout adulthood
What are Blood-Testis Barrier (BTB)?
Formed by tight junctions between Sertoli cells, they protect germ cells from harmful bloodborne substances; Prevents immune system from attacking sperm-specific antigens
What is Spermatogenesis?
Creation of sperm
Where does Spermatogenesis occur?
Occurs in the seminiferous tubules of the testes.
When does Spermatogenesis begin?
Begins at puberty and continues throughout life.
How long is a Spermatogenesis cycle?
~64 days per sperm production cycle with a new cycle starting every 16 days.
When does sperm count decline?
Sperm count declines after age 35
How might smoking impact Sperm production?
It may reduce sperm count
What are the 4 BASIC stages of Spermatogenesis?
- Spermatogonium → Primary spermatocytes (2n)
- Primary spermatocytes → Secondary spermatocytes (1n, haploids)
- Secondary spermatocytes → Spermatids (1n, haploids)
- Spermatids → Mature sperm
Describe how sperm cells split and multiply
- Mitosis of spermatogonia
- Meiosis I (Primary spermatocyte → Secondary spermatocytes)
- Meiosis II (Secondary spermatocytes → Spermatids)
- Spermiogenesis (Spermatids → Spermatozoa)
- Spermatozoa formation & transport
T or F: Sperm are 85,000 times smaller than the female gamete
True
How many sperm are produced every day?
100–300 million sperm are produced daily
What are the 4 structures of the sperm cell?
- Head
- Mid-piece
- Tail
- End piece
What is the Head of the sperm cell?
Contains haploid nucleus (highly compact, little cytoplasm)
What is the Acrosome Cap found in the Head of sperm?
It contains lysosomal enzymes aid in fertilization
What is the Mid-Piece of the sperm cell?
Packed with mitochondria → Produces ATP for movement
What is the Tail of the sperm cell?
Axial filament from centriole powers sperm motility
What is the End Piece of the sperm cell?
The tip of the tail
What is the sperm transport pathway?
- Seminiferous tubules
- Epididymis
- Vas deferens (ductus deferens)
- Ampulla
How do sperm move through the Seminiferous tubules?
Sperm begin their journey in the seminiferous tubules of the testes, where they are produced.
How do sperm move through the Epididymis?
- From the seminiferous tubules, sperm are moved into the epididymis (coiled tube where they mature)
- (~12 days to travel through, mature along the way, gaining ability to swim)
- Sperm start off immotile and acquire motility
- Sperm are stored in the tail of the epididymis until ejaculation.
How do sperm move through the Vas deferens (ductus deferens)?
From the epididymis, sperm move through the ductus (vas) deferens, which is part of the spermatic cord (a bundle of connective tissue, blood vessels, and nerves).
During ejaculation, sperm are pushed through the ductus deferens, a muscular tube, to be transported further into the reproductive tract.
How do sperm move through the Ampulla?
The ductus (vas) deferens ends near the bladder, where it dilates into the ampulla, a region that stores sperm temporarily before ejaculation.
Sperm make up what percentage of semen’s final volume?
Only 5%
Where is the other 95% of semen produced?
In the seminal vesicles, prostate, and bulbourethral glands
What do the additional glands used for semen production contribute to the sperm?
These glands contribute fluids that nourish the sperm and help transport them during ejaculation.
How much do the Seminal Vesicles contribute to total semen volume?
Seminal vesicles contribute approximately 60% of semen volume.
What does the secretion of the Seminal vesicles contain?
Secretion contains fructose, which provides energy for sperm motility via ATP production.
How do sperm mix with the seminal vesicle’s fluid?
Sperm pass through the ampulla of the ductus deferens during ejaculation and mix with seminal vesicle fluid.
What is the Transition to the Ejaculatory Duct?
Fluid (both sperm and seminal vesicle fluid) moves into the ejaculatory duct.
Ejaculatory ducts transport seminal fluid from the ampulla of the ductus (vas) deferens and the seminal vesicle to the prostate gland.
The ejaculatory duct is a short structure formed by the fusion of…
- Ampulla of the ductus (vas) deferens
- Duct of the seminal vesicle
Where is the Prostate Gland?
The prostate gland is situated anterior to the rectum and surrounds the prostatic urethra at the base of the bladder.
What types of tissues does the Prostate Gland consist of?
The Prostate Gland consists of both muscular and glandular tissues.
How is the Prostate Gland involved in semen production?
The prostate excretes an alkaline, milky fluid into the seminal fluid, which helps in two key processes:
- Coagulation: The fluid temporarily thickens the semen after ejaculation, helping it remain in the female reproductive tract.
- De-coagulation: After some time, the semen returns to a fluid state, allowing sperm to move deeper into the female reproductive tract.
When does the Prostate double in size?
During Puberty, begins to enlarge after age 25 as well
What can Prostate enlargement lead to in some men?
Benign Prostatic Hyperplasia (BPH)
What can Benign prostatic hyperplasia (BPH) lead to?
- Frequent and urgent need to urinate
- Weak urine stream
- Feeling that the bladder is not fully empty
What are treatments for Benign prostatic hyperplasia (BPH)?
Medications, Surgery
How many men may experience Benign prostatic hyperplasia (BPH)?
Around 40% of men over 60 experience some degree of BPH, and by age 80, up to 80% of men may be affected.
How prevalent is Prostate Cancer?
Prostate cancer is the second most common cancer in men.
How is Prostate Cancer diagnosed?
Prostate cancer is diagnosed through a combination of a medical history, a blood test (for prostate-specific antigen, PSA), and a rectal exam to palpate the prostate for abnormal masses.
If a mass is found, a biopsy is performed to confirm the diagnosis.
What are Bulbourethral glands (Cowper’s glands)?
Glands that release a thick, salty fluid that has multiple purposes for lubrication and cleaning.
How does Bulbourethral glands (Cowper’s glands) aid in lubrication?
It helps lubricate the end of the urethra and the vagina, facilitating smoother passage during intercourse.
How does Bulbourethral glands (Cowper’s glands) aid in cleaning?
It helps clear any remaining urine residues from the penile urethra, providing a cleaner passage for semen during ejaculation.
When do Bulbourethral glands (Cowper’s glands) release fluid?
The fluid is released after the male becomes sexually aroused, just before the ejaculation of semen. This fluid is sometimes referred to as pre-ejaculate.
T or F: Although it typically doesn’t contain large amounts of sperm, pre-ejaculate can still cause pregnancy if sperm are present.
True
What are the 2 states of the Penis?
- Flaccid state: The penis is soft and flexible when not aroused, and it serves functions like urination.
- Erect state: The penis is rigid, which enables it to penetrate the vagina and deliver semen.
What is the Shaft of the Penis?
The shaft surrounds the urethra and is made up of three columns of erectile tissue (Corpus Cavernosum, Corpus Spongiosum, Glans Penis).
What is the Corpus Cavernosum of the Penis?
Two larger lateral chambers that make up the majority of the penis.
What is the Corpus Spongiosum of the Penis?
A smaller chamber that surrounds the urethra and can be felt as a raised ridge during erection.
What is the Glans Penis?
The sensitive, bulbous tip of the penis, which is rich in nerve endings and plays a significant role in ejaculation.
What is the Prepuce (foreskin)?
The skin covering the glans penis, which is also sensitive and provides protection and lubrication.
How does an erection occur?
Vasocongestion
What is Vasocongestion?
Engorgement of erectile tissues with blood, resulting from an increased flow of arterial blood and restricted venous drainage.
During sexual arousal, nerve endings near the blood vessels release what?
Nitric oxide (NO)
What does Nitric oxide (NO) do to the smooth muscles around the penile arteries?
Causes them to relax, allowing them to dilate and increase blood flow into the penis.
What happens as the penile arteries dilate?
More blood enters the erectile chambers (corpora cavernosa and corpus spongiosum), the veins become compressed, which prevents blood from flowing out and leading to an erection
The penis increases in size during erection, with the average erect length being approximately ______cm.
15cm
Erections can occur during…
Sexual arousal and REM sleep
What is Erectile Dysfunction (ED)?
ED is the inability to initiate or maintain an erection sufficient for sexual intercourse.
What are causes of ED?
- Physical: Includes diabetes, vascular disease, prostate disorders, and low testosterone.
- Psychological: Emotional factors, such as stress and depression, can also contribute.
- Medication: Some drugs, such as certain antidepressants, may interfere with erectile function.
How does ED work?
- Nitric oxide induces relaxation of smooth muscles around penile arteries, leading to vasodilation (expansion of blood vessels), which is crucial for achieving an erection.
- To reverse vasodilation, an enzyme called phosphodiesterase (PDE) degrades cGMP, a key molecule in the NO signaling pathway.
- PDE5 is the form of PDE found in the penis, and it limits vasodilation
How do PDE5 Inhibitors (Sildenafil, Viagra®) work?
- PDE5 inhibitors, like sildenafil, were initially tested for hypertension and angina. The trials showed that sildenafil wasn’t effective for these heart conditions but caused erections in many men, leading to a trial for ED treatment.
- Sildenafil increases blood flow by inhibiting PDE5, allowing vasodilation to occur and improving erectile function.
What are some precautions when taking PDE5 Inhibitors?
Men with certain health conditions, especially cardiac disease or those taking nitrates (for chest pain), should avoid Viagra or consult a physician, as the combination may lead to serious side effects or even death.
What are Leydig cells?
They produce testosterone.
Where are Leydig cells located?
They are located between the seminiferous tubules in the testes.
When do Leydig cells begin to secrete testosterone in male embryos?
Leydig cells begin secreting testosterone by the seventh week of development, with peak concentrations reached during the second trimester.
Why is it important that Leydig cells begin to secrete testosterone early?
This early secretion is crucial for the anatomical differentiation of male sexual organs.
When do testosterone levels rise significantly?
During puberty
What are functions of Testosterone in the MALE reproductive system?
Testosterone is essential for the normal functioning of the male reproductive system, including maintaining spermatogenesis; Low testosterone levels can lead to infertility.
What are functions of Testosterone in the testicular steroidogenesis?
The testes produce testosterone at 100 times higher concentrations than in the blood, ensuring effective regulation of reproductive and physiological functions.
How is Testosterone used in other physiological functions?
- Muscle development
- Bone growth
- Secondary sex characteristics
- Libido (M & F)
What are functions of Testosterone in the FEMALE reproductive system?
The ovaries secrete small amounts of testosterone, most of which is converted into estradiol (a form of estrogen).
The adrenal glands also secrete a small amount of testosterone in both sexes.
What is the role of the hypothalamus and pituitary in regulating testosterone?
The hypothalamus releases a hormone called gonadotropin-releasing hormone (GnRH) in a pulsatile manner; GnRH stimulates the anterior pituitary gland to release FSH and LH.
What is the role of the Follicle-stimulating hormone (FSH) in regulating testosterone?
Binds to Sertoli cells in the seminiferous tubules of the testes; Promotes spermatogenesis (the production of sperm);
Stimulates Sertoli cells to produce inhibins, which act to inhibit FSH release from the pituitary, thereby regulating testosterone levels.
What is the role of the Luteinizing hormone (LH)
in regulating testosterone?
Binds to Leydig cells in the testes and stimulates testosterone production.
How is the regulation of testosterone controlled by a negative feedback mechanism?
When blood testosterone levels are low, the hypothalamus releases more GnRH, which stimulates the pituitary to secrete LH. LH stimulates the Leydig cells to produce more testosterone.
Once testosterone levels rise to a critical threshold, testosterone binds to androgen receptors on both the hypothalamus and anterior pituitary, inhibiting the release of GnRH and LH, which slows testosterone production.
What is the role of Inhibin?
Inhibin produced by Sertoli cells inhibits the secretion of FSH, providing further regulation of sperm production and testosterone secretion.
This feedback system helps balance the levels of hormones in the body.
Summarize the regulation of testosterone
The regulation of testosterone involves a feedback loop between the hypothalamus, pituitary gland, and Leydig cells in the testes. Testosterone production is stimulated by LH and is regulated through a negative feedback mechanism to maintain appropriate hormone levels for proper reproductive function.
What is Andropause?
Andropause is a condition associated with the gradual decline of testosterone levels in older men, leading to various physical and emotional symptoms.
When does Leydig cell activity begin to decline?
Around the ages of 40 to 50
Andropause is similar to what in women?
Menopause
What are symptoms of Andropause?
Fatigue, insomnia
Reduced muscle mass
Depression, anxiety, irritability
Loss of libido (sex drive), sexual dysfunction
A decline in spermatogenesis (sperm production) may also result in lowered fertility
What is a treatment for Andropause?
Testosterone replacement is sometimes prescribed to help alleviate symptoms of andropause, especially for conditions like depression in elderly males.
What happens to natural testosterone production in the testes when a male takes large amounts of synthetic testosterone?
a) It increases due to higher demand for muscle growth
b) It remains unchanged because synthetic and natural testosterone are separate
c) It decreases due to negative feedback on the hypothalamus and pituitary
d) It increases because the pituitary compensates by releasing more LH
c) It decreases due to negative feedback on the hypothalamus and pituitary
What are the parts of the external Female Genitals?
- Mons Pubis
- Labia
- Clitoris
- Vaginal Opening
- Bartholin’s Glands (Greater Vestibular Glands)
T or F: Vulva refers to the external female reproductive structures (sort of a blanket term)
True
What is the Mons Pubis?
Fat pad over the pubic bone, covered in pubic hair after puberty.
What is the Labia?
Protects the urethra and vaginal entrance.
What are the 2 parts of the Labia?
- Labia majora: Hair-covered skin folds that enclose and protect the inner structures.
- Labia minora: Thinner, more pigmented folds that are medial to the labia majora.
What is the Clitoris?
Clitoris (glans clitoris) originates from the same cells as the glans penis; Highly innervated and plays a major role in sexual sensation and orgasm.
What are Bartholin’s Glands (Greater Vestibular Glands)?
Located near the vaginal opening; it secretes lubricating mucus to reduce friction during intercourse.
T or F: The vagina is a muscular canal that is approximately 10 cm long and serves multiple functions
True
What are some functions of the Vagina?
- It is the entrance to the reproductive tract.
- It is the exit from the uterus during menses and childbirth.
- The superior portion of the vagina is called the fornix, and it meets the uterine cervix.
- The Bartholin’s glands and lesser vestibular glands (located near the clitoris) secrete mucus, keeping the vestibular area moist.
What are the 3 layers that the Vagina is made up of?
- Outer fibrous adventitia (outer layer).
- Smooth muscle (middle layer).
- Inner mucous membrane with transverse folds (rugae), which allow the vagina to expand during intercourse and childbirth.
What is the predominant bacteria found in a Vagina?
Bacteria from the Lactobacillus genus
What do bacteria from Lactobacillus genus do for the Vagina?
Secrete lactic acid, which helps maintain an acidic pH (below 4.5) in the vagina; This acidic environment protects against harmful pathogens, making the vagina a self-cleansing organ.
How can one maintain Vaginal health?
DO NOT use douches or wash out the vagina with fluid as it can disrupt the balance of healthy microorganisms, increasing the risk of infections and irritation.
What is the natural pH of the Vagina?
Below 4.5
What are the Ovaries?
The ovaries are the female gonads
Where are the Ovaries located?
They are located within the pelvic cavity and are supported by various ligaments
What 3 ligaments support the Ovaries?
- The mesovarium is an extension of the peritoneum that connects the ovaries to the broad ligament.
- The suspensory ligament contains the ovarian blood vessels and lymph vessels.
- The ovarian ligament attaches the ovary to the uterus.
What are the 4 layers of the Ovary?
- Ovarian Surface Epithelium
- Tunica Albuginea
- Ovary Cortex
- Ovary Medulla
What is the Ovarian Surface Epithelium?
The outer covering of the ovary, made of cuboidal epithelium.
What is the Tunica Albuginea?
A dense connective tissue covering beneath the surface epithelium.
What is the Ovary Cortex?
: The outer region of the ovary, composed of the ovarian stroma, which forms the bulk of the ovary.
**This is where oocytes (egg cells) develop.
The oocytes are surrounded by supporting cells, and together they form a follicle.
What is the Ovary Medulla?
The inner region of the ovary, containing blood vessels, lymph vessels, and nerves.
What are the 5 stages of the Ovarian cycle?
- Oogonia
- Primary Oocytes
- Meiosis Resumption
- Unequal Cytokinesis
- Survival of One Cell
While oogenesis produces up to four cells, how many actually survive?
Just one
What are the 3 parts of Completion of meiosis and formation of the ovum?
- Meiosis in the Secondary Oocyte
- Resumption of Meiosis II
- From Ovum to Zygote
What happens during Meiosis in the Secondary Oocyte?
The secondary oocyte is arrested in meiosis II at metaphase before ovulation; Meiosis II is only completed if a sperm successfully penetrates the barriers of the secondary oocyte during fertilization.
What happens during Resumption of Meiosis II?
Once the sperm enters the secondary oocyte, meiosis II resumes leading to:
- One haploid ovum (female gamete), which will carry the genetic material for the future embryo.
- One second polar body, which is smaller and typically degenerates.
What happens during From Ovum to Zygote?
At the moment of fertilization, the haploid ovum and haploid sperm combine, creating the first diploid cell, called a zygote; This marks the beginning of the development of the new offspring.
How does the Cytoplasm contribute during the completion of meiosis and formation of the ovum?
The ovum is the larger of the two gametes (egg vs. sperm) and contains significant amounts of cytoplasm; This cytoplasm provides the nutrients and other resources necessary for the early stages of development after fertilization and until the embryo can implant in the uterus.
Mitochondrial DNA is inherited exclusively from which parent?
The mother
Why is Mitochondrial DNA inherited exclusively from the mother?
Because the sperm contributes only DNA, not cytoplasm or organelles
What is Folliculogenesis?
Folliculogenesis is the maturation process of ovarian follicles, which house the oocytes (immature eggs) and their supporting cells.
99% of follicles undergo atresia, meaning what?
They do not reach ovulation
The dominant follicle is selected from _______.
The tertiary follicles
How many follicles are ovulated per cycle?
Only 1, unless twins occur
What are the 5 stages of the Ovarian Follicular Progress?
- Primordial Follicles (Resting State)
- Primary Follicles (Initiation of Growth)
- Secondary Follicles (Expansion and Hormone Production)
- Tertiary Follicles (Antral Follicles, final maturation before ovulation)
- Ovulation
What occurs during the Primordial Follicles (Resting State) of the Ovarian Follicular Progress?
Present at birth, these follicles contain a primary oocyte surrounded by a single layer of flat granulosa cells that lay dormant for years, some will undergo atresia.
What occurs during the Primary Follicles (Initiation of Growth) of the Ovarian Follicular Progress?
After puberty, a few primordial follicles are recruited each day to begin development; The granulosa cells become cuboidal and begin to multiply, indicating the follicle’s activation.
What occurs during the
Secondary Follicles (Expansion and Hormone Production) of the Ovarian Follicular Progress?
The follicle grows as granulosa cells continue dividing; An outer layer of theca cells forms, which, in coordination with granulosa cells, produces estrogens.
The oocyte secretes the zona pellucida, a glycoprotein-rich membrane that plays a role in fertilization.
What occurs during the
Tertiary Follicles (Antral Follicles, final maturation before ovulation) of the Ovarian Follicular Progress?
A fluid-filled cavity called the antrum forms inside the follicle; Several follicles reach this stage simultaneously, but most will not survive and will undergo atresia.
The dominant follicle, the one that continues growing, will prepare for ovulation.
What occurs during the
Ovulation of the Ovarian Follicular Progress?
The dominant tertiary follicle ruptures, releasing a secondary oocyte surrounded by a protective layer of granulosa cells; This marks the transition from folliculogenesis to the luteal phase of the ovarian cycle.
What are the 4 hormones that regulate the Ovarian Cycle?
- GnRH (Gonadotropin-Releasing Hormone)
- FSH (Follicle-Stimulating Hormone)
- LH (Luteinizing Hormone)
- Estrogen (Estradiol) and Progesterone
What is FSH (Follicle-Stimulating Hormone) responsible for?
Stimulates follicle (oocyte) growth
What is LH (Luteinizing Hormone) responsible for?
Triggers estrogen production
What are Estrogen (Estradiol) and Progesterone responsible for?
- High estrogen initially inhibits FSH and LH (negative feedback), but later triggers the LH surge that causes ovulation.
- The corpus luteum produces progesterone to maintain the uterine lining; If pregnancy does not occur, hormone levels drop, the uterine lining sheds, and the cycle restarts.
What are the 3 phases of Hormonal Regulation?
- Follicular phase/Folliculogenesis (Days 1-14)
- Ovulation (Day 14)
- Luteal phase (Days 15-28)
What occurs during the Follicular phase/ Folliculogenesis (Days 1-14)
The hypothalamus releases GnRH, which stimulates the anterior pituitary to release FSH and LH.
- FSH stimulates follicle growth, causing several tertiary follicles to grow in the ovary.
- LH stimulates granulosa and theca cells of the follicles to produce estradiol (estrogen).
- As follicles grow, estrogen levels rise, leading to negative feedback
What occurs during Ovulation (Day 14)?
When estrogen levels peak, the feedback loop switches from negative to positive.
High estrogen levels trigger a surge of LH from the anterior pituitary.
- This LH surge causes the dominant follicle to rupture, releasing a secondary oocyte from the ovary (ovulation).
What occurs during the Luteal Phase (Days 15–28)?
After ovulation, the ruptured follicle transforms into the corpus luteum; The corpus luteum secretes progesterone (and some estrogen) to prepare the uterus for possible implantation.
- If fertilization does not occur, progesterone and estrogen levels drop, leading to the breakdown of the corpus luteum and the start of menstruation.
The decline in hormones removes negative feedback on GnRH, which…
Restarts the cycle
To summarize: LH surge =
Ovulation
To summarize: Corpus Luteum =
Progesterone Secretion
To summarize: No Pregnancy =
Corpus Luteum Degenerates → Menstruation
To summarize: Low Progesterone =
FSH & LH Increase → New Follicular Growth
What are the Uterine Ducts?
The uterine tubes (fallopian tubes/oviducts) are essential for transporting the oocyte from the ovary to the uterus
What are the 3 key regions of the Uterine Ducts (from closest to the uterus to furthest)?
Isthmus
Ampulla
Infundibulum
Which key region of the Uterine Ducts is the most narrow, and closest to the Uterus?
Isthmus
Of the 3 key regions of the Uterine Ducts, where does fertilization often occur?
Ampulla
Which key region of the Uterine Ducts has fimbriae (finger-like projections)?
Infundibulum
Since the oocyte cannot move on its own, it relies on 3 methods of movement:
- Fimbriae movement
- Muscular contractions
- Cilia beating
What is Fertilization?
If sperm meets the oocyte in the ampulla, fertilization occurs, forming a zygote that undergoes cell division while traveling to the uterus.
What happens if there is no fertilization?
The oocyte degrades and is shed during menstruation.
What are 3 clinical issues of the Uterine Ducts?
Pelvic Inflammatory Disease (PID)
Ectopic Pregnancy
Sepsis Risk
What is Pelvic Inflammatory Disease (PID)?
Caused by infections (e.g., gonorrhea, chlamydia) and can lead to scarring of the uterine tubes and infertility.
What is an Ectopic Pregnancy?
Occurs if the fertilized egg implants in the tube instead of the uterus; A life-threatening condition requiring medical intervention.
What is Sepsis Risk?
Non-sterile procedures can introduce bacteria, infections spreading through the reproductive tract can become life-threatening.
What is the Uterus?
The uterus is a muscular organ responsible for nourishing and supporting a growing embryo.
What are the 3 sections of the Uterus?
- Fundus: The superior portion, located above the uterine tubes.
- Body (Corpus): The middle and largest portion of the uterus.
- Cervix: The narrow inferior portion that projects into the vagina.
What are the 3 Uterine Ligaments that support the Uterus?
- Broad ligament: Attaches the uterus to the pelvic wall.
- Round ligament: Extends to the labia majora.
- Uterosacral ligament: Connects the cervix to the pelvic wall.
What are the 3 layers of the Uterine Wall?
- Perimetrium
- Myometrium
- Endometrium
What is the Perimetrium?
The outermost serous membrane (epithelial tissue).
What is the Myometrium?
The thick, smooth muscle layer responsible for contractions, menstrual cramps (to expel blood), and muscle contractions to aide in transporting sperm to ovulated oocyte.
What is the Endometrium and its two layers?
The innermost lining made up of the Stratum basalis (permanent layer), and the Stratum functionalis (thickens in response to hormones and sheds during menstruation).
What is the Follicular Phase of the Menstrual Cycle?
Estrogen from growing follicles thickens the stratum functionalis to prepare for implantation
What is the Luteal Phase of the Menstrual Cycle?
Progesterone (from corpus luteum) maintains the thick endometrial lining.
- If fertilization occurs, the embryo sends signals to maintain the corpus luteum.
- If fertilization does not occur, the Corpus luteum degenerates, progesterone drops, and the endometrium sheds (menstruation).
What is Menarche?
The first menstrual cycle after puberty, which may or may not follow ovulation.
What are the 3 phases of the Menstrual Cycle?
- Menses = Shedding
- Proliferation = Rebuilding
- Secretory = Preparation for implantation
How long does a Menstrual Cycle last?
Typically 28 days, but can range from 21 to 32 days in different individuals
What occurs during the Menses Phase?
- Occurs during early follicular phase of the ovarian cycle for about 5 days.
- Progesterone, FSH, and LH are low.
- The endometrium (stratum functionalis) sheds/breaks down and blood, tissue, and white blood cells exit through the vagina as menstrual flow.
What occurs during the Proliferation Phase?
- Starts after menstrual flow - ends and continues until ovulation.
- Estrogen increases, FSH decreases, high estrogen levels trigger LH surge leading to ovulation on day 14.
- Endometrium thickens in preparation for possible implantation (estrogen/progesterone).
What occurs during the Secretory Phase?
- Begins after ovulation (around day 14) and continues for 10–12 days.
- Progesteron rises when Corpus luteum forms, estrogen remains high.
- Glands secrete glycogen-rich fluid to nourish a potential embryo, and spiral arteries develop to supply blood to the thickened stratum functionalis.
What happens in the Secretory Phase if pregnancy DOES NOT occur?
The corpus luteum degenerates, estrogen and progesterone levels drop.
Spiral arteries constrict, cutting off oxygen, killing the Endometrial tissue and causing it to shed.
STARTS A NEW CYCLE
HPV is linked to which type of cancer in women?
Cervical cancer
What can LOW risk HPV lead to in women?
Gential Warts
What can HIGH risk HPV lead to in women?
Cervical cancer
How can you prevent HPV infections?
HPV vaccines
Regular pap smears
Safe sex practices
What are the EXTERNAL features of the Breasts?
Nipple and areola
The areola contains lubricating glands for…
Protection against chafing during nursing.
What are the INTERNAL structures of the Breasts?
Mammary glands
Lactiferous ducts
Alveoli
Suspensory ligaments
What are Mammary Glands?
Modified sweat glands that produce milk.
What are Lactiferous Ducts?
15–20 ducts transport milk from the alveoli to the nipple.
What are Alveoli?
Clusters of milk-secreting cells, surrounded by myoepithelial cells that help push milk toward the nipple.
What are Suspensory Ligaments?
Provide structural support by anchoring breast tissue to the skin.
What are some Hormonal Influences on the Breasts?
Menstrual cycle (can make breasts swell and become tender)
Pregnancy (enlarge mammary glands for lactation)
How do Birth Control pills work?
They use a negative feedback to prevent ovulation
How do Birth Control pills impact hormones?
- Provides constant estrogen & progesterone → suppresses FSH & LH release from the pituitary.
- No FSH → follicles do not mature.
- No LH surge → ovulation does not occur.
What are the effects of Birth Control pills on the Uterus?
Some endometrial thickening occurs but it is reduced, making implantation less likely.
What can missing a Birth Control pill lead to?
Missing a pill can allow FSH & LH to increase, triggering ovulation.
How does age impact Female Fertility?
Female fertility peaks in early twenties and declines gradually until age 35. After 35, fertility decreases more rapidly
What does Menopause mark?
Menopause marks the end of fertility and menstrual cycles
When does menopause start in women?
Often occurs between 50 and 52 years of age.
What is Menopause?
Cessation of menstruation due to the loss of ovarian follicles and reduced hormone production.
What are symptoms of Menopause?
Symptoms include: Hot flashes, night sweats, vaginal dryness, mood swings, difficulty focusing, hair thinning, and facial hair growth.
What is Perimenopause?
It is a transitional phase that involves irregular cycles and declining progesterone production, leading to possible endometrial hyperplasia (abnormal growth of the uterine lining), and an increased risk of endometrial cancer.
When might Early Menopause occur?
40-45 years
Higher rates of early/premature menopause and more severe vasomotor symptoms can be seen…
Black and Hispanic women
What happens during Ovarian aging that instigates Menopause?
- Declining follicles
- Decreased estradiol & inhibin B
- Increased FSH & LH
- Cessation of ovulation
What sort of menstrual changes occur that suggest Menopause?
Irregular cycles –> anovulation –> final cessation
What are some surgical or medical causes that can trigger menopause?
- Bilateral oophorectomy
- Chemotherapy
- Radiation
- Anti-estrogen therapy
What are some health risks to watch for after menopause?
Cardiovascular Disease: Increased risk due to lack of estrogen’s cholesterol-lowering effects.
Osteoporosis: Rapid bone density loss, leading to higher fracture risk.
What sort of treatment may be used to alleviate Menopause symptoms?
Hormone therapy (HT) involving synthetic estrogens and progestins.
In which of the following circumstances would menses be expected:
a) After egg implantation in the uterus
b) After menopause
c) With a sharp decrease of estrogen and progesterone
d) Pre-menarche
c) With a sharp decrease of estrogen and progesterone
Sex determination is primarily based on which chromosomes?
X and Y chromosomes
T or F: All fertilized eggs initially develop as female unless influenced by the Y chromosome.
True
Which gene triggers male development?
The SRY gene (Sex-determining Region of the Y chromosome)
What does the SRY gene lead to?
Male characteristics
What does the ABSENCE of the SRY gene lead to?
Female development
What are some chromosomal intersex variations?
XXY, XYY, XO
Both male and female embryos start with bipotential gonads, meaning what?
Bipotential tissue can develop into either male or female gonads
SRY gene recruit other genes to…
Develop testes and suppresses female development genes
Without the SRY gene, what forms?
Oogonia form and develop primordial follicles in the primitive ovary.
Differences of sex development (DSD) can be identified when?
At birth, during childhood, at puberty, or in adulthood.
What are some indications of DSD?
- The sex of a newborn’s genitals is not evident from their appearance
- Enlarged clitoris or small penis, absence of testes
- Infertility in adulthood
- Child does not go through puberty or menstruation does not start
- Mix of male and female reproductive parts
Testosterone influences the biopotential tissues to form which reproductive system?
Male reproductive system
E.g., glans penis develops from bipotential cells exposed to testosterone; without testosterone, these cells become the clitoris
Internal reproductive structures (uterus, uterine tubes, vagina, etc.) form from which two rudimentary duct systems?
Müllerian duct (FEMALE development).
Wolffian duct (MALE development).
What happens in MALES to the Müllerian duct?
Sustentacular cells secrete substances that degrade the Müllerian duct
What happens to the Wolffian duct in FEMALES?
Without sustentacular cell secretion, the Müllerian duct develops and the Wolffian duct degrades
What is the role of testosterone in duct development?
Testosterone stimulates development of the male tract (Wolffian duct); Absence of testosterone leads to degradation of the Wolffian duct, and the Müllerian duct develops instead.
Proper development of either the Wolffian or Müllerian duct is essential for what?
Reproductive function in adulthood
What is Puberty?
The stage when individuals reach sexual maturity, and although the outcomes differ between males and females, the hormonal control processes are quite similar.
How does Puberty begin?
Puberty begins with the release of gonadotropin-releasing hormone (GnRH) from the hypothalamus, which then triggers the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the anterior pituitary.
What does the release of these hormones (GnRH, LH, FSH) at the beginning of Puberty do?
These hormones drive the gonads (testes in males, ovaries in females) to produce testosterone or estrogen, leading to the maturation of the reproductive system and the development of secondary sex characteristics (such as breast development in females, or facial hair in males).
What are the 2 phases of Puberty?
- Initial changes
- Changes in sensitivity
What occurs during the Initial changes phase of Puberty?
Around ages 8-9, the production of LH becomes detectable; This phase is marked by a slow increase in LH and FSH, which precedes the physical changes of puberty by several years.
What occurs during the Changes in sensitivity phase of Puberty?
- Hypothalamus and Pituitary Sensitivity: Before puberty, these structures have high sensitivity to negative feedback, so small amounts of sex hormones effectively suppress LH and FSH production; now more sex hormones are needed to suppress LH and FSH.
- Gonad Sensitivity: The gonads become more responsive to LH and FSH, leading to the production of higher levels of sex hormones, which triggers spermatogenesis in males and folliculogenesis (maturation of eggs) in females.
What are some of the factors that influence the timing of puberty?
Genetics
Environmental influences
Psychological stress
Nutrition
What is Leptin and how is it used in Puberty?
Leptin, a hormone produced by adipose (fat) tissue, plays a key role in signaling the body to begin puberty.
What are some of the changes MALES experience during puberty?
- Increased larynx size and deepening of the voice
- Increased muscular development
- Growth of facial, axillary, and pubic hair, and increased growth of body hair
What are some of the changes FEMALES experience during puberty?
- Deposition of fat, predominantly in breasts and hips
- Breast development
- Broadening of the pelvis and growth of axillary and pubic hair
What are the 4 stages of Female Puberty?
- Breast development
- Hair growth
- Growth spurt
- Menarche
What are the 3 stages of Male Puberty?
- Growth (occurs later than in females)
- Voice changes
- Fertile ejaculation
How do Growth Spurts differ between Males and Females?
Females generally experience their growth spurt earlier, starting around ages 9-11, while males experience theirs around ages 11-13.
How do Physical Signs differ between Males and Females?
In females, breast development and menarche are the most notable early signs of puberty.
In males, it is the growth of the testes and penis.
How do Voice and Hair Changes differ between Males and Females?
Males experience the growth of facial and body hair, along with a deepening of the voice, which occurs later in puberty compared to the breast development and hair growth seen in females.
How does Duration of Puberty differ between Males and Females?
Puberty in males can continue into the early 20s, while females generally complete the process by their late teens.
Which of the following best describes the roles of LH and FSH in sexual development?
A) They trigger testosterone production in the testes and estrogen production in the ovaries
B) They stimulate the development of male secondary sex characteristics
C) They stimulate the development of female secondary sex characteristics
D) They trigger the production of gonadotropin-releasing hormone
A) They trigger testosterone production in the testes and estrogen production in the ovaries
