Reproductive Health Quiz

Reproductive System Overview

• Reproduction is the process by which organisms create descendants.
• This trait distinguishes living things from nonliving things.
• The reproductive system is essential for the continuation of a species but not for individual survival.
• It is not essential for homeostasis.

Function of Reproductive System

• Reproduction (perpetuation of species)
• Gametogenesis (formation of sperm and egg cells)
• Transport and sustenance of gametes
• Nurturing of developing offspring
• Endocrine function (synthesis of sex hormones)
• Sexual pleasure (coitus, coupling)

Sex Determination

• Primitive gonadal cells (PGCs) appear during the 7th week of intrauterine life.
• PGCs have both Mullerian and Wolffian ducts.
• Mullerian duct develops into female accessory sex organs (vagina, uterus, fallopian tubes) if the sex chromosome is XX.
• Wolffian duct develops into male accessory sex organs (epididymis, vas deferens, seminal vesicles) if the sex chromosome is XY.
• The sex of an individual is determined by the short arm of the Y chromosome (Sex-determining Region of Y chromosome).

Sex Determination (Continued)

• A Y chromosome in the sperm fertilizing the ovum results in an XY zygote developing into a genetic male.
• Male cells (XY) contain an X and a Y chromosome
• An X chromosome in the sperm results in an XX zygote, which develops into a genetic female.
• Female cells (XX) contain two X chromosomes.
• In the absence of a Y chromosome, primitive gonadal cells develop into ovaries.
• In the absence of functioning testes and testosterone, the Wolffian duct regresses.
• The Mullerian duct develops into female internal genitalia (fallopian tubes, uterus, upper vagina).
• The urogenital slit remains open.

Embryonic Sexual Development Regulation

• TDF (Testis-Determining Factor) initiates the development of testes.
• Testosterone triggers the development of male reproductive structures.
• Mullerian-inhibiting factor (MIF) causes the Mullerian duct to regress.
• Sex of the fetus is identifiable by ultrasound at 16 weeks of gestation.

Male Reproductive System

• The main difference between male and female reproductive systems lies in the Y chromosome and the pair of gonads (testes in males and ovaries in females).
• Functions of the male reproductive system include: Production of male gametes (sperm) Synthesis of male sex hormones, such as androgens and testosterone Delivering sperm into the female reproductive tract

Male Reproductive System Structures

• 1. Gonads (testes)
• Primary male sex structures Function: Spermatogenesis (sperm formation), endocrine function (producing testosterone, inhibin, estrogen);
• 2. Accessory Tubular/duct/structures (genital tracts): involved in transporting sperm.
• Epididymis: storage and maturation of sperm.
• Vas deferens: connects the epididymis to the ejaculatory duct.
• Ejaculatory duct: connects the vas deferens to the urethra.

Accessory Glands

• Provide a fluid medium for sperm protection and nourishment.
• Seminal vesicle: secretes fluids containing fructose (energy for sperm), prostaglandins (alter the uterine environment for sperm passage), and coagulating enzyme (turns semen into a bolus).
• Prostate gland: makes up 30% of the seminal plasma, contains citrate (food source for sperm) and prostate-specific antigen (liquefies semen and allows sperm to swim freely).
• Bulbourethral (Cowper's) glands: secrete a fluid similar to the prostate gland's.
• Prostate produces alkaline mucus after erection for urethra neutralization and gland lubrication.

Supporting Structures

• Penis: supports the urethra.
• Scrotum: supports the testes and epididymis.
• Spermatic cord: contains blood vessels, nerves, and lymphatics.

External Structure of the Penis

• Spongy erectile tissue; Gland penis; Prepuce (foreskin)
• Male circumcision has significant positive health benefits.

The Testis

• Made up of seminiferous tubules (contain spermatogenic epithelium that gives rise to spermatozoa, Leydig cells [secrete testosterone], Sertoli cells [support spermatogenesis])
• Seminiferous tubules account for about 90% of testicular mass

Spermatogenesis

• Production of sperm cells
• Primitive germ cells (spermatogonia) mature into primary spermatocytes (A and B) via mitosis.
• Primary spermatocytes undergo two meiotic divisions.
• Spermatids mature into spermatozoa (sperms).
• In humans, it takes an average of 74 days.

Maturation of Spermatid to Spermatozoa

• Golgi apparatus forms the acrosome vesicle.
• Centrioles form the flagellum.
• Mitochondria collect to form the midpiece.

Mature Sperm Cell

• Contains head, neck and tail.
• Acrosome contains enzymes (hyaluronidase or proteases) for egg penetration during fertilization.
• Maturation occurs in the epididymis and requires testosterone.

Hormones for Spermatogenesis

• Testosterone: crucial for testicular germinal cell growth and division.
• Luteinizing hormone (LH): stimulates Leydig cells to secrete testosterone.
• Follicle-stimulating hormone (FSH): stimulates spermatids' conversion to sperm through spermiogenesis.
• Growth hormone, T3/T4, and prolactin are vital for controlling testicular metabolic functions.

Semen

• fluid ejaculated during the male sexual act
• Made of spermatozoa and seminal plasma
• The resultant product of testis, epididymis, seminal vesicles and prostate
• An average volume per ejaculation is 2–5 ml with 108 sperms/ml.
• Sperm count <20x10^6/ml = infertile or sterile.

Hormonal Regulation of Male Reproduction

-GnRH from hypothalamus stimulates LH (ICSH) and FSH secretion by pituitary.

• LH stimulates interstitial cells to secrete androgens (primarily testosterone).
• FSH stimulates meiosis in primary spermatocytes to form immature sperm cells.

Function of Testosterone

• Develops primary and secondary sexual characteristics during puberty.
• Stimulates the brain to develop male sexual behavior.
• Stimulates spermatogenesis and sperm maturation.
• Is an anabolic protein hormone increasing muscle mass and bone matrix.
• Facilitates fusion of epiphyseal plates of bone.
• Increase Basal Metabolism
• Increase RBC
• Increase reabsorption of Na+ in distal tubules of kidneys, resulting in increased blood and extracellular fluid volumes after puberty, 5-10%.

Male Sexual Act

• Has 3 stages: Erection, Emission, and Ejaculation.

Erection Mechanism

• Parasympathetic stimulation dilates penile arteries.
• Large volume of blood enters the arteries.
• Veins compress.
• Erectile tissue stiffens.

Orgasm

• Ejection of seminal plasma (spermatozoa) from the male ductal system.
• Sympathetic stimulation of the smooth muscles in the epididymis, vas deferens, seminal vesicles, and prostate.

Ejaculation

• Ejaculation propels sperm from the epididymis to vas deferens.
• Vas deferens runs from scrotum and behind the urinary bladder.
• Each vas deferens joins with a duct from seminal vesicle to form ejaculatory duct.
• Ejaculatory ducts open into the urethra.
• Urethra drains excretory and reproductive systems.

Resolution

• Reversion of erection; sympathetic stimulation constricts arteries.
• Blood leaves erectile tissues; penis becomes flaccid

Testicular Problems

• Testicular trauma: severe pain, bruising, swelling after impact.
• Varicocele: abnormally swollen testicular vein (commonly develops during puberty and is usually harmless).
• Testicular cancer: abnormal cell division forming a tumor; curable if detected early.
• Epididymitis: inflammation of the epididymis (often caused by sexually transmitted infections).
• Hydrocele: fluid collections in membranes surrounding the testes; usually painless.
• Disorders of the Penis:
  • Inflammation of the penis, redness, itching, and swelling.
• Hypospadias: urethra opens underneath the penis' tip.
• Phimosis: tightness of the foreskin.
• Paraphimosis: boy's uncircumcised penis is retained but cannot return to unrestricted position.
• Ambiguous genitalia: unclear male or female genitals at birth.
• Micro penis: significant smaller than average penis.

Disorders of the Male Sexual Act

• Impotence: inability to produce or maintain an erection.
• Hypogonadism: lack of function of the gonads in regards to hormones or gamete production.
• Hypoactive sexual desire: low level of sexual desire and interest.
• Premature ejaculation: lack of voluntary control over ejaculation.
• Periapism: persistent undesired erection.
• Absence of emission

Causes of Male Sterility

• Congenital absence of testes
• Cryptorchidism (hidden testes)
• Sexually transmitted infections
• Seminiferous tubule destruction
• Radiation
• Oligospermia, azoospermia, asthenospermia
• Drugs, alcohol, smoking.
• Impotence
• Hypogonadism
• Genetic defects
• Functional disorders of prostate and seminal vesicles.
• Genital tract obstruction
• Spermatogenesis arrest due to hypovitaminosis
• Testicular failure

Physiology of the Female Reproductive System

• Production of female gametes (ova), female sex hormones (estrogens and progesterone).
• Reception and maintenance of a developing embryo and fetus.
• Feeding of the new-born with milk (lactation).

Female Reproductive System Structures

• 1. Gonads (ovaries): - The gametogenic potential is established early in fetal development; the endocrine role is established during puberty.

• Medullary part (central portion): contains blood vessels, connective tissues (elastin and collagen).

• Cortical part (peripheral portion): contains actively proliferating ovarian follicles.

• 2. Oviduct/fallopian tubes/uterine tubes:

• Paired organs, approximately 4 inches long.

• Connect the ovary to the uterine cavity. – Four parts: - Infundibulum– Ampulla--Isthmus–Intra mural part

• Function: Site of fertilization; transport of ovum and sperm; move zygote to implantation; receive ovum from ovary; secretory function.

• 3. Uterus (womb):

• Hollow, pear-shaped organ with thick muscular walls.

• About 3 inches long, 2 inches wide, and 2 inches thick.

• Divided into 3 parts: Fundus, Body, Cervix.

• Function: site of pregnancy, embryo and fetal growth, menstrual cycle, and childbirth.

• 3 layers: perimetrium (outer layer), myometrium (middle layer), endometrium (inner layer).

• 4. Vagina (birth canal):

• Thin-walled tube between the bladder and rectum that extends from the cervix to the body exterior.

• Contains mucosa and smooth muscle

• Lined with non-keratinized stratified epithelium

• Glands secrete glycogen and lactate, harbors Lactobacillus species that maintains acidic vaginal pH.

• Copulatory organ of the female

• Birth canal

• Allows passage of menstruation

Female External Genitalia (Vulva)

• Clitoris: homologous to the penis, sensitive to tactile stimuli, involved in sexual arousal.
• Labia majora: outer folds of tissue surrounding the vaginal and urinary openings.
• Labia minora: inner folds of tissue on each side of the vestibule.
• Mons pubis: fatty tissue covering the pubic bone.
• Vestibule of vagina: area enclosed by the labia, including the openings of the vagina and urethra.

The Ovaries

• Secrete four hormones
• Estrogen (E1 = estrone, E2 = estradiol, E3 = estriol)
• Progesterone
• Androgens
• Inhibin

Progesterone

• Source: corpus luteum, follicular cells, adrenal cortex, placenta, and testes
• Rate of secretion: 1 mg/day (early follicular phase), 4 mg/day (before ovulation), 25 mg/day (mid-luteal phase)
• Function: prepares the uterus for pregnancy; inhibits FSH and LH release; increases uterine blood flow; stimulates secretion of thick cervical mucus; promotes breast development.

Estrogen

• Source: ovarian follicular cells, corpus luteum, adrenal cortex, placenta, and testes
• Rate of secretion varies throughout the menstrual cycle; high in mid-luteal phase.
• Function: develops primary and secondary sex characteristics; enhances bone ossification and protein anabolism, lowering cholesterol, retains salt and water.

Pregnancy and Fertilization

• Ovum released from Graafian follicle of ovary into abdominal cavity at ovulation.
• Sperm and ovum unite in fallopian tube.
• Zygote develops into a blastocyst, implants in uterine wall.
• Placenta forms from trophoblast cells.

Cleavage and Blastocyst Formation

• Zygote divides in fallopian tube or uterine wall by mitosis.
• Blastocyst forms.

Implantation

• Zygote travels through the fallopian tube to the uterus.
• Zygote (develops into blastocyst) remains freely in the uterine cavity for 2-4 days prior to implantation.
• Implantation takes about 1 week after fertilization.

Development of Placenta & Embryo

• A cavity in the morula develops.
• A blastocyst develops on the wall; blastocyst is the initial stage for embryo development.
• Trophoblast cells and other underlying cells proliferate to form the placenta.

Placenta Structure

• Maternal blood; Syncytiotrophoblast; Cytotrophoblast; Connective tissue stroma of villus; Fetal blood vessels.

Amniotic Fluid

• Clear, slightly yellowish fluid surrounding the fetus
• Produced by mother's placenta (first trimester and early second trimester).
• Baby swallows and excretes fluid to maintain circulation
• Filtered by mother's kidneys.

Amniotic Fluid Function

• Protective cushion for the fetus
• Allows fetal movement
• Stabilizes fetal temperature
• Permits proper lung development
• Exchange of water and chemicals
• Uniform growth of baby's body parts and organs
• Proper bone and muscle development

Abnormalities of Amniotic Fluid

• Too much = polyhydramnios, possibly due to abnormal digestive system or CNS issues.
• Too little = oligohydramnios, possibly due to abnormal urinary system.

Puberty, Menarche, Menopause

• Puberty: period (typically between ages 10 and 15) of reproductive system growth.
• Menarche: first menstrual period.
• Menopause: cessation of menstruation between ages 46 and 54
• Hormonal changes include decrease in estrogen, progesterone, and release in FSH and LH.

Menopause Symptoms

• Vaginal dryness.
• Genital atrophy.
• Hot flushes.
• Psychological and emotional symptoms.
• Decrease in bone density; fractures (osteoporosis)
• Increased incidence of cardiovascular disease

Birth Control

• Regimen of actions, devices, or medications to prevent pregnancy.
• Contraception: methods that reduce the likelihood of sperm fertilizing ovum.
• Birth control methods include:
  • Intrauterine devices
  • Contraceptive pills
  • Progestin implant (under skin)
  • Safe period (natural family planning)
  • Postcoital contraceptives (large dose)
  • Barrier methods (including vaginal diaphragm, and condoms), surgical methods like vasectomy (surgical interruption of the vas deferens)

Twin Pregnancy

• Pregnancies with two or more fetuses.
• Non-identical twins or Dizygotic Twins:
• Spontaneous release from two seperate ova
• Have two placentas and separate amniotic cavities
• Identical Twins or Monozygotic Twins:
• A single fertilized egg splits into two identical structures.
• Always of the same sex

Classification of Twin Pregnancy

• Number of fetuses.
• Number of fertilized eggs.
• Number of placentas (chorionicity).
• Number of amniotic cavities (amniocity).

Ectopic Pregnancy

• Fertilized egg doesn't travel to the uterus, it implants in the fallopian tube.
• Surgery required.

Ovarian Cysts

• Noncancerous sacs filled with fluid.
• Common but can cause pain if large
• Most pass on their own, but surgery may be required.

Polycystic Ovarian Syndrome

• Hormone disorder causing enlarged ovaries and fluid-filled cysts
• Often appears in teenage years.
• Treated with hormones to restore balance

Menstrual Abnormalities

• Anovulatory Cycle: no ovulation in a menstruating woman (infertility).
• Dysmenorrhea: painful periods.
• Menorrhagia: excessive menstrual bleeding.
• Oligomenorrhea: infrequent or absent menstrual periods
• Amenorrhea: absence of menstruation.
• Hypomenorrhea: scanty flow.

Test your knowledge on the physiology and functions of the uterus, menstrual abnormalities, and related conditions. This quiz covers important topics such as ovarian hormones, pregnancy roles, and common reproductive health issues. Perfect for students studying human biology or reproductive health.