11 Reproductive System - Jaden Ross P.6

Major functions of the Reproductive system (male and female)

Form specialized cells for sexual reproduction call gametes

Bring gametes from male and female together through sexual intercourse

Combine genetic information contained within gametes through fertilization

  • Sperm – gametes in males
  • Ova(eggs) – gametes in females

Support development of fetus (gestation) and birth of baby (parturition)

Anatomy of male reproductive structures

Testes: sperm-producing male gonads that lie within the scrotum; surrounded by two tunics (Tunica vaginalis and Tunica albuginea)

Accessory sex glands: seminal glands, prostate, and bulbo-urethral glands

the scrotum: Hangs outside abdominopelvic cavity at root of penis

  • Sac of skin and superficial fascia

Accessory ducts carry sperm from testes to body exterior:

  1. epididymis: Sperm mature
  1. ductus deferens (vas deferens) During ejaculation, epididymis contracts, expelling sperm into this duct
  1. Joins duct of seminal vesicle to form ejaculatory duct
  1. Urethra: conveys both urine and semen(at different times)

Penis: male copulatory organ

External genitalia: scrotum and penis

Prepuce, or foreskin: cuff of loose skin covering glans

Seminal glands (seminal vesicles) :Produces viscous alkaline seminal fluid

Prostate: Encircles urethra inferior to bladder; Secretes milky, slightly acid fluid

Bulbo-urethral glands (Cowper’s gland) : Produce thick, clear mucus during sexual arousal

Semen: Milky-white mixture of sperm and accessory gland secretions

Anatomy of female reproductive structures

Internal Genitalia:

External Genitalia(aka vulva)

Ovaries: female gonads

  • Secrete female sex hormones, estrogen (estradiol, estrone, estriol), and progesterone
  • paired structures flank the uterus, are almond shaped and about twice as large

Mons pubis: fatty area overlying pubic symphysis

Labia majora: hair-covered, fatty skin folds

Labia minora: skin folds lying within labia majora

Vestibule: recess within labia minora

Clitoris: anterior to vestibule

Perineum:Diamond-shaped region between pubic arch and coccyx

Female Duct System:

Uterine Tubes(fallopian tubes or oviducts): eceive ovulated oocyte and are usual site of fertilization

  • Infundibulum: funnel-shaped opening into the peritoneal cavity
  • Margin contains ciliated projections called fimbriae that drape over ovary

The Uterus: Hollow, thick-walled, muscular organ

  • Function is to receive, retain, and nourish fertilized ovum
  • Body: major portion
  • Fundus: rounded superior region
  • Isthmus: narrowed inferior region
  • Cervix: narrow neck, or outlet; projects into vagina

Three layers of uterine wall

  • Perimetrium: outermost serous layer (visceral peritoneum)
  • Myometrium: bulky middle layer consisting of interlacing layers of smooth muscle
  • Endometrium: mucosal lining
    • Fertilized egg burrows into endometrium

The Vagina: Functions as birth canal, passageway for menstrual flow, and organ of copulation

Mammary Glands: Main function is milk production to nourish newborn

  • found in males and females but normally only functions in females

Methods and Classification of contraceptives

Most effective(99%):

Moderately effective:

Least Effective:

Female sterilization(surgical): tubal ligation in females; cutting the uterine tubes

male sterilization(surgical): vasectomy in males; removes small portion of the vas deferens

IUD(surgical): object implanted in the uterus ; either toxic to sperm and egg cells or prevents implantation of embryo by inhibiting growth of endometrium

Injectables: injection of a progesterone derivative; prevents follicle maturation and ovulation

Pill: contains estrogen and progesterone to prevent pregnancy; disrupts normal hormonal pattern

Diaphragm: put in vagina with spermicide; prevents sperm from entering vagina

Internal condom: put in vagina; prevents sperm from entering vagina

External condom: put over penis; prevents sperm from entering vagina

Fertility awareness: abstinence from sexual intercourse around time of ovulation

Withdrawal: withdrawal of penis from vagina before ejaculation

Spermicides: put in vagina; chemicals that kill sperm

Hormones of the reproductive system (male and female)

LH: triggers ovulation

FSH: Helps control the menstral cycle and stimulates the growth of eggs in the ovaries

GnRH: released from the hypothalamus; helps the pituitary gland make and secrete the hormones LH and FSH; in males it causes testicles to make testosterone

Estrogen: helps i the development of the mammary gland and secretion of milk; female sex hormone that triggers uterine lining to thicken

Progesterone: helps with growth of endometrium ; promotes implantation

Disorders associated with the reproductive system (including STI’s)

Syphilis: sexually transmitted infectionthat causes fever , sores, and rashes; treated with antibiotics

Genital Herpes: and STD caused by the herpes simplex viruses types one and two; causes blisters around the genitals, rectum, or mouth; no cure

Chlamydia: common STD effects men and women and can cause permanent reproductive damage; can cause abnormal discharge in man and women and burning sensation when peeing ; can be treated with prescribed meds

Gonorrhea:an STD in men and women causes infections of the genitals, rectum, and throat; ; can cause burning while peeing ; treated by prescribed meds

trichomonasis: common STD that is caused by infection with a protozoan parasite called trichomonas vahinalis

AIDS/HIV: HPV weakens a persons immune system by destroying important cells that fight disease and infection ;can cause night sweats, rash, and fever

PID: an infection of women's reproductive organs; complication often caused by STD's like chlamydia and gonorrhea; treated with antibiotics

HPV:most common STI many types of HPV mostly effect teens and early twenties; can causes genital warts and cancer

Testosterone:helps in the production of sperm

Events of the female hormonal cycles (be sure to include all categories)

The Ovarian Cycle

1. Follicular phase: period of vesicular follicle growth (days 1–14)

3. Luteal phase: period of corpus luteum activity (days 14–28)

During follicular phase, several vesicular (antral) follicles become sensitive to FSH and are stimulated to grow

FSH levels drop around middle of follicular phase

dominant follicle outcompetes other follicles and is only one to continue on then secondary oocyte is formed when the dominant follicle goes through meiosis I

  1. Ovulation: Ballooning ovary wall ruptures, expelling secondary oocyte with its corona radiata into peritoneal cavity

After ovulation, ruptured follicle collapses

Remaining cells form corpus luteum

Corpus luteum secretes progesterone and some estrogen

If no pregnancy occurs, corpus luteum degenerates into corpus albicans

If pregnancy occurs, corpus luteum produces hormones that sustain pregnancy until placenta takes over

The Uterine (Menstrual) Cycle

  1. Days 1–5: menstrual phase
  1. Days 6–14: proliferative (preovulatory) phase

Ovarian hormones are at lowest levels

Gonadotropin levels are beginning to rise

Stratum functionalis detaches from uterine wall and is shed
– Menstrual flow of blood and tissue lasts 3–5 days

By day 5, growing ovarian follicles start to produce more estrogen

Rising estrogen levels prompt generation of new stratum functionalis layer

Estrogen also increases synthesis of progesterone receptors in endometrium

Thins out normally thick, sticky cervical mucus to facilitate sperm passage

Ovulation occurs at end of proliferative phase on day 14

  1. Days 15–28: secretory (postovulatory) phase

Endometrium prepares for embryo to implant

If fertilization does not occur:

  • Corpus luteum degenerates toward end of secretory phase; progesterone levels fall
  • Blood vessels fragment, and functional layer sloughs off and uterine cycle starts all over again on first day of menstruation

Hormonal interaction during ovarian cycle

  1. GnRH stimulates FSH and LH secretion
  1. FSH and LH stimulate follicles to grow, mature, and secrete sex hormones
  1. Negative feedback inhibits gonadotropin release
  1. Positive feedback stimulates gonadotropin release
  1. LH surge triggers ovulation and formation of the corpus luteum
  1. Negative feedback inhibits LH and FSH release