What are the main functions of the male reproductive system? 1. Produce sperm 2. Deposit sperm into the female 3. Provide a pathway for the removal of urine Where is sperm produced? -In the 2 testes What is the optimal temperature for sperm production? -Less than normal body temperature
How is the temperature of sperm production regulated? -The scrotum ( a sac located just below the body cavity that allows the temperature to remain a few degrees cooler) Where does meiosis occur in males? -Inside the tubes of the testes **Remember the sole purpose for meiosis is to produce Gametes (sperm) When does sperm production occur? -It starts at puberty and continues on forever.. All the time (Average is about 30 million a day)
How many viable sperm cells does meiosis produce? -4 Structure of sperm: Head- Contains DNA (genetic material) Tail (Flagellum)- Allows sperm to swim to egg -Created in tubes of testes (where meiosis occurs) Immature sperm pushed into EPIDIDYMUS (Long tube found in each testis that stores immature sperm) (sperm remains here several weeks until mature)
Vas Deferens (Fluids added here to create semen) Urethra (Tube leading out of penis) Ejaculation (Process through which semen exits the penis) Testes Epididymus Vas deferens Urethra Ejaculation How many sperm cells are released in one ejaculation? -About 300 million (2-5 ml of liquid released)
What does semen consist of? 1. Sperm -Used to fertilize egg 2. sugar- Provides energy to swim 3. Prostaglandins- Chemicals that cause muscular contractions in the female reproductive tract to help sperm move toward the egg 4. Base- To neutralize the female reproductive tract
If so many sperm cells are released, why aren t eggs fertilized more frequently? -Eggs must be available (released into oviduct of female) -Sperm cells may die -Sperm cells may not be able to break through the egg -To deposit sperm into the female for fertilization to occur What tube runs through the center of the penis? -Urethra
What is the function of the urethra? 1. Pathway for urine to exit the body from the bladder 2. Pathway for sperm to exit the body Can a male urinate during sex? -No!! At the point of sexual excitement, a valve Closes that prevents the bladder from releasing urine How does an erection occur? -Blood rushes in and fills the empty spaces in the spongy tissue of the penis
Male Reproductive System- Front View Bladder Prostate Gland Vas deferens Urethra Testes Penis Epididymus scrotum
Bladder Prostate Gland Urethra Penis Vas deferens Epididymus Testes Scrotum
Scrotum- Testes- Sac surrounding testes Produce sperm cells and testosterone. Lay Outside of body. Temperature sensitive Epididymus- Tubes that store immature sperm cells, until mature. Located above testes. Vas deferens- Tube leading from testes to urethra. Carries sperm (When this is cut = Vasectomy) Prostate Gland- Secretes fluids to help sperm swim and survive Urethra- Tube leading out of the penis. Exit for both urine and semen Penis- Deposits sperm into female
What are the main functions of the female reproductive system? 1. Produce female gametes (eggs) 2. Provide pathway for sperm to reach egg 3. Provide temporary home for developing embryos Where are gametes produced? -Ovaries (egg production) When does egg production occur? -Before birth about 2 million egg cells have already Begun the first phase of meiosis
When do they continue meiosis? -Puberty How many eggs will the average woman use in her lifetime? -Around 500 (1 per cycle until menopause) How many egg cells survive meiosis? -1 egg cell (the larger egg feeds nutrients off the Other 3 and they eventually disappear) Fertilized Egg: -Egg produced in the ovary -During OVULATION, egg is swept into the oviduct (Fallopian Tube)
-Sperm fertilizes egg in the oviduct -Fertilized egg (zygote) travels to the uterus, attaches to the lining (implantation) and develops Unfertilized Egg: -Egg produced in ovaries -During OVULATION egg is swept into oviduct -If egg not fertilized within 48 hours of release Egg ruptures and exits body along with blood And tissue from the uterine lining (Period) Is the female excretory pathway the same? -No. The urethra ends at an opening near the vagina Can a female urinate during sex? YES
Ovary- Make eggs and hormones (estrogen/progesterone) Oviduct (Fallopian Tube)- Receives egg from ovaries. Fertilization MUST occur here Uterus- Muscular organ that provides temporary home to developing fetus Vaginal Canal- Pathway out of the body from the uterus Cervix- Opening to the uterus. Produces mucus. Must expand during labor to allow fetus to pass out of the uterus. Bladder- Stores urine Urethra- Tube leading from bladder to outside of body
Oviduct Ovary Cervix Uterus Vaginal Canal
Oviduct Ovary Uterus Bladder Cervix Urethra Vaginal Canal
Hypothalamus stimulates the pituitary gland to produce: 1. FSH (Follicle Stimulating Hormone): Males- Stimulates testes to increase testosterone production and begin producing sperm (spermatogenesis) Females- Stimulates the maturation and release of egg from the ovaries and production of estrogen Receptor in Ovary or Testes
-Development of male sex organs before and after birth (without presence of testosterone fetus will develop into a female) -At puberty testosterone levels increase and Sperm production begins. Penis and testes mature -Secondary sex characteristics develop (pubic hair, Under arm hair, increase in muscle tissue, voice Deepens) -Development of female sex organs at puberty (increased hormone levels, uterus, vagina, and ovaries mature) -Secondary sex characteristics develop (pubic hair, breast development, hips widen,) -Menstrual Cycle begins
-Maintains uterine lining for implantation of embryo -Sustains pregnancy and milk production ( Pregnancy Hormone ) What is the menstrual cycle? -Series of changes in the female that includes producing An egg and preparing the uterus for receiving How long does it last? -About 28 days
1. Follicle Stage: (About 6-10 days) -Follicle develops around egg -High levels of estrogen -Uterus lining thickening 2. Ovulation: (occurs about day 14) -Sharp increase in LH -Low FSH -Follicle ruptures and egg released (if not fertilized within 48 hours egg ruptures)
3. Corpus Luteum Stage: (About 14 days) -High progesterone levels (to maintain uterine lining) -FSH and LH slow down (negative feedback) If NO fertilization occurs: -progesterone and estrogen decrease and uterine lining sheds If fertilization DOES occur: -Progesterone level remains high (uterine lining begins secreting a fluid rich in nutrients for the embryo) 4. Menstruation (Flow Phase): (About 4-5 days) -Menstrual flow begins as uterine lining sheds and ruptured egg leaves body -Contractions of the uterine muscle can cause discomfort
How long can sperm survive inside the female body? -About 72 hours When can fertilization occur? -If intercourse occurs any where from a few days BEFORE ovulation to a couple of days AFTER ovulation -About a 5-6 day window
Rebuilding -thickest -uterine lining shedding
Ovulation: Oviduct Uterus Cervix Ovary Follicle Egg Vaginal Canal Sperm
24 Weeks -Response to light and sound from outside the uterus -End of 2 nd trimester
32 Weeks (8 months) 3 rd trimester: -Mass more than triples -During 8 th month Eyes open/close -Fully mature at 35 Weeks (20 ) -Perfect hearing
What are some of the first signs of birth? - water breaks (Amniotic sac breaks and fluid is released Into the vagina) -Muscular contractions cause cervix to widen (dilate) -Baby moves further from the uterus towards the vagina What is afterbirth? -The placenta separates from the uterus and exits through the vaginal canal What are some dangers facing a fetus? -Radiation (X-rays)- may stop cell division -Genetic mutations (chromosome #) -Infectious Illness (can lead to brain damage, miscarriage)
-Inadequate Diet -Harmful Lifestyle- (smoking, drugs, alcohol, std s) may lead to still birth, brain damage, low birth weight, mental retardation, learning disabilities Artificial Insemination- -Donor sperm is inserted into vaginal canal of female during ovulation and internally fertilizes the egg in the oviduct -Baby contains ½ of mother s DNA and ½ from the donor In Vitro Fertilization- -Sperm and egg are combined EXTERNALLY -Embryo implanted into female s uterus for development
Amniocentesis- -Technique used to extract fetal cells and examine DNA for possible genetic defects (can be risky) Cloning- -Technique in which the nucleus is removed from a Normal body cell and used to replace the nucleus of An egg cell -Egg is implanted into female s uterus for development -Offspring is IDENTICAL to parent (no variation) -Offspring ages faster than normal -Not successful in humans as to date (moral and ethical issues involved)
Stem Cell Research- -UNDIFFERENTIATED embryonic cells are removed (around day 5) and treated with chemicals to develop into specific tissues and organs -Moral and ethical debates -Belief is that this technique can be used to cure many diseases and disorders