Reproductive System

Overview Body system responsible for gamete formation (eggs and sperm) When gametes combine, offspring will result Existence & continuation of a species relies on this system! Sets apart males and females

Male Reproductive System Main function = produce & deliver sperm

Scrotum- sac containing –Testicles produce sperm –Epididymis- sperm mature here (store) Vas deferens (sperm duct) - tube coming from epididymis and merging with the urethra Preputial Gland –Produces seminal fluid Seminal vesicles - fluids produced here travel through vas deferens to carry sperm out of the body –Seminal fluid (lubricant/food for sperm) + sperm = semen Penis –Urethra- tube where semen exits the body Male Reproductive Organs

Life of a Sperm: Spermatogenesis & Ejaculation

Sperm Spermatogenesis- the production and development of new sperm Ejaculation- release of sperm from the body Between 50 and 130 MILLION sperm are present in 1 mL of semen

Female Reproductive System Main function- produce ova & provide nutrition and protection for developing offspring

Female Reproductive Organs Ovary –Stores ova (eggs) to be released during ovulation Fallopian Tube –Ova travel from ovaries through this to the uterus Uterus –Fertilized ova attach to the uterus –Embryo grows and develops into a baby Cervix –Outer end of the uterus Vagina –Canal leading from cervix to out of the body

Menstrual Cycle 28 day cycle of developing and releasing an ovum (1 egg) from the ovary and preparing the uterus for pregnancy If egg is unfertilized, it along with the lining of the uterus is expelled from the body Consists of 4 phases –Follicular- first 10 days: lining of uterus thickens; egg further develops in ovary –Ovulation- days 11-14: egg is released from ovary into fallopian tube –Luteal- overlaps with ovulation and continues if egg is fertilized, or until menstruation –Menstruation- days 21-28: if fertilization does not occur, lining of the uterus, blood, and unfertilized egg are discharged through the vagina

Fertilization Early Development Process of male and female gametes joining –Egg + Sperm = Zygote – n + n = 2n –Haploid + Haploid = Diploid –Sex cell + Sex cell = Somatic cell Almost always occurs during ovulation phase of the menstrual cycle Penis enters vagina, ejaculates sperm, sperm swim up through cervix, uterus, and into fallopian tube Millions of sperm try to fertilize one egg, but only ONE sperm is successful

Early Development After fertilization, zygote divides by mitosis until it forms a morula (solid ball of 64 cells) Morula transforms into a blastocyst (hollow ball of cells) Blastocyst implants itself on uterine wall where the baby can eventually form

Female Facts Females are born with all of the eggs they will ever have, no new eggs are formed after birth –Eggs become permanently mutated from drugs, alcohol abuse, excessive tanning, and as you age Females have 4 fluctuating reproductive hormones while males only have 1, so mood swings naturally occur more easily in females Menstrual cycles are not always regular, so pregnancy can be possible at almost any time especially in teens More STD’s show symptoms in females than males

Sexually Transmitted Diseases

Be Educated About STD’s! Most STD’s are transmitted because people don’t know enough about them Don’t be ignorant! All STD’s are 100% preventable!