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:
- epididymis: Sperm mature
- ductus deferens (vas deferens) During ejaculation, epididymis contracts, expelling sperm into this duct
- Joins duct of seminal vesicle to form ejaculatory duct
- 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
- 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
- Days 1–5: menstrual phase
- 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
- 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
- GnRH stimulates FSH and LH secretion
- FSH and LH stimulate follicles to grow, mature, and secrete sex hormones
- Negative feedback inhibits gonadotropin release
- Positive feedback stimulates gonadotropin release
- LH surge triggers ovulation and formation of the corpus luteum
- Negative feedback inhibits LH and FSH release