OUR REPRODUCTIVE SYSTEMS MALE AND FEMALE ABOUT HUMAN

OUR REPRODUCTIVE SYSTEMS MALE AND FEMALE

ABOUT HUMAN REPRODUCTION • ALL LIVING THINGS REPRODUCE • REPRODUCTION - THE PROCESS BY WHICH ORGANISMS MAKE MORE ORGANISMS LIKE THEMSELVES • TWO KINDS OF SEX CELLS (GAMETES) ARE INVOLVED: • MALE GAMETE SPERM • FEMALE GAMETE EGG (OVUM) • THE SPERM AND THE EGG MUST MEET TO CREATE A NEW INDIVIDUAL

THE FEMALE REPRODUCTIVE SYSTEM UNLIKE THE MALE, THE HUMAN FEMALE HAS A REPRODUCTIVE SYSTEM LOCATED ENTIRELY INSIDE THE PELVIS

VULVA • THE EXTERNAL PART OF THE FEMALE REPRODUCTIVE ORGANS • MEANS “COVERING” • LOCATED BETWEEN THE LEGS, THE VULVA COVERS THE OPENING TO THE VAGINA AND OTHER REPRODUCTIVE ORGANS LOCATED INSIDE THE BODY

VULVA Vulva

MONS PUBIS • THE FLESHY AREA LOCATED JUST ABOVE THE TOP OF THE VAGINAL OPENING • PUBIC HAIR FORMS HERE

LABIA • TWO PAIRS OF SKIN FLAPS THAT SURROUND THE VAGINAL OPENING • SOFT OUTER LIPLIKE FOLDS OF TISSUE THAT SURROUND THE OTHER SEX ORGANS

CLITORIS • A SMALL SENSORY ORGAN THAT IS LOCATED TOWARD THE FRONT OF THE VULVA WHERE THE FOLDS OF THE LABIA JOIN

URETHRA • CANAL THAT CARRIES URINE FROM THE BLADDER TO OUTSIDE THE BODY • LOCATED BETWEEN THE LABIA

FEMALE REPRODUCTIVE ORGANS • VAGINA • UTERUS • FALLOPIAN TUBES • OVARIES

VAGINA • A MUSCULAR, HOLLOW TUBE THAT EXTENDS FROM THE VAGINAL OPENING TO THE UTERUS • ABOUT 3 TO 5 INCHES LONG IN A GROWN WOMAN • IT HAS MUSCULAR WALLS SO IT CAN EXPAND CONTRACT • THIS ABILITY TO BECOME WIDER OR NARROWER ALLOWS THE VAGINA TO ACCOMMODATE SOMETHING AS SLIM AS A TAMPON AND AS WIDE AS A BABY • THE VAGINA'S MUSCULAR WALLS ARE LINED WITH MUCOUS MEMBRANES, WHICH KEEP IT PROTECTED AND MOIST

VAGINA Vagina

THE VAGINA SERVES THREE PURPOSES 1. IT'S WHERE THE PENIS IS INSERTED DURING SEXUAL INTERCOURSE 2. IT'S THE PATHWAY THAT A BABY TAKES OUT OF A WOMAN'S BODY DURING CHILDBIRTH, CALLED THE BIRTH CANAL 3. IT PROVIDES THE ROUTE FOR THE MENSTRUAL BLOOD (THE PERIOD) TO LEAVE THE BODY FROM THE UTERUS

CERVIX • THE NARROW LOWER END OF THE UTERUS THAT OPENS INTO THE VAGINA • WHERE THE VAGINA CONNECTS WITH THE UTERUS • MEANS “NECK” • THE OPENING OF THE CERVIX IS VERY SMALL (NO WIDER THAN A STRAW), WHICH IS WHY A TAMPON CAN NEVER GET LOST INSIDE A GIRL'S BODY • DURING CHILDBIRTH, THE CERVIX CAN EXPAND TO ALLOW A BABY TO PASS

CERVIX Cervix

UTERUS • SHAPED LIKE AN UPSIDE-DOWN PEAR • HAS A THICK LINING AND MUSCULAR WALLS • SOME OF THE STRONGEST MUSCLES IN THE FEMALE BODY • THESE MUSCLES ARE ABLE TO EXPAND CONTRACT TO ACCOMMODATE A GROWING FETUS AND THEN HELP PUSH THE BABY OUT DURING LABOR

UTERUS Uterus Uterine Cavity

FALLOPIAN TUBES • THERE ARE 2, EACH ATTACHED TO A SIDE OF THE UTERUS • THE NARROW TUBES THAT ARE PASSAGEWAYS FROM THE OVARIES TO THE UTERUS • ABOUT 4 INCHES LONG AND ABOUT AS WIDE AS A PIECE OF SPAGHETTI • WITHIN EACH TUBE IS A TINY PASSAGEWAY NO WIDER THAN A SEWING NEEDLE • WHEN AN EGG POPS OUT OF AN OVARY, IT ENTERS THE FALLOPIAN TUBE • ONCE THE EGG IS IN THE FALLOPIAN TUBE, TINY HAIRS IN THE TUBE'S LINING HELP PUSH IT DOWN THE NARROW PASSAGEWAY TOWARD THE UTERUS.

FALLOPIAN TUBES Fallopian Tubes

OVARIES • TWO OVAL-SHAPED ORGANS THAT LIE TO THE UPPER RIGHT AND LEFT OF THE UTERUS • THEY PRODUCE, STORE, AND RELEASE EGGS INTO THE FALLOPIAN TUBES IN THE PROCESS CALLED OVULATION • EACH OVARY MEASURES ABOUT 1½ TO 2 INCHES IN A GROWN WOMAN • PART OF THE ENDOCRINE SYSTEM • PRODUCE ESTROGEN AND PROGESTERONE

OVARIES Ovaries

THE FEMALE REPRODUCTIVE SYSTEM ENABLES A WOMAN TO: 1. PRODUCE EGGS (OVA) 2. HAVE SEXUAL INTERCOURSE 3. PROTECT AND NOURISH THE FERTILIZED EGG UNTIL IT IS FULLY DEVELOPED 4. GIVE BIRTH

GONADS • SEXUAL REPRODUCTION COULD NOT HAPPEN WITHOUT THE GONADS • BOTH SEXES HAVE GONADS! • MALES TESTICLES • FEMALES OVARIES • THE FEMALE GONADS PRODUCE FEMALE GAMETES • EGGS • THE MALE GONADS PRODUCE MALE GAMETES • SPERM • AFTER AN EGG IS FERTILIZED BY THE SPERM, THE FERTILIZED EGG IS CALLED THE ZYGOTE

FEMALES DURING PUBERTY • WHEN A BABY GIRL IS BORN, HER OVARIES CONTAIN HUNDREDS OF THOUSANDS OF EGGS, WHICH REMAIN INACTIVE UNTIL PUBERTY BEGINS • AT PUBERTY, THE PITUITARY GLAND, STARTS MAKING HORMONES THAT STIMULATE THE OVARIES TO PRODUCE FEMALE SEX HORMONES, INCLUDING ESTROGEN • THE SECRETION OF THESE HORMONES CAUSES A GIRL TO DEVELOP INTO A SEXUALLY MATURE WOMAN

MENSTRUATION • TOWARD THE END OF PUBERTY, GIRLS BEGIN TO RELEASE EGGS AS PART OF A MONTHLY PERIOD CALLED THE MENSTRUAL CYCLE • APPROXIMATELY ONCE A MONTH, DURING OVULATION, AN OVARY SENDS A TINY EGG INTO ONE OF THE FALLOPIAN TUBES • UNLESS THE EGG IS FERTILIZED BY A SPERM WHILE IN THE FALLOPIAN TUBE, THE EGG DRIES UP AND LEAVES THE BODY ABOUT 2 WEEKS LATER THROUGH THE UTERUS — THIS IS MENSTRUATION • BLOOD AND TISSUES FROM THE INNER LINING OF THE UTERUS COMBINE TO FORM THE MENSTRUAL FLOW • USUALLY LASTS FROM 3 TO 5 DAYS

MENSTRUAL CYCLE • IT CAN TAKE UP TO 2 YEARS FROM MENARCHE (A FEMALES FIRST PERIOD) FOR A GIRL'S BODY TO DEVELOP A REGULAR MENSTRUAL CYCLE • DURING THAT TIME, HER BODY IS ADJUSTING TO THE HORMONES PUBERTY BRINGS • ON AVERAGE, THE MONTHLY CYCLE FOR AN ADULT WOMAN IS 28 DAYS, BUT THE RANGE IS FROM 23 TO 35 DAYS

THE MALE REPRODUCTIVE SYSTEM UNLIKE THE FEMALE, WHOSE SEX ORGANS ARE LOCATED ENTIRELY WITHIN THE PELVIS, THE MALE HAS REPRODUCTIVE ORGANS, OR GENITALS, THAT ARE BOTH INSIDE AND OUTSIDE THE PELVIS

THE MALE GENITALS • THE TESTICLES • THE DUCT SYSTEM, WHICH IS MADE UP OF THE EPIDIDYMIS AND THE VAS DEFERENS • THE ACCESSORY GLANDS, WHICH INCLUDE THE SEMINAL VESICLES AND PROSTATE GLAND • THE PENIS

SCROTUM • A SAC-LIKE POUCH THAT HOLDS THE TESTES AND EPIDIDYMIS • THIS POUCH HELPS TO REGULATE THE TEMPERATURE OF THE TESTES, WHICH NEED TO BE KEPT COOLER THAN BODY TEMPERATURE TO PRODUCE SPERM • CHANGES SIZE TO MAINTAIN THE RIGHT TEMPERATURE • COLD – SHRINKS AND BECOMES TIGHTER TO HOLD IN BODY HEAT • WARM – BECOMES LARGER AND MORE FLOPPY TO GET RID OF EXTRA HEAT • HAPPENS UNCONSCIOUSLY • THE BRAIN AND THE NERVOUS SYSTEM GIVE THE SCROTUM THE CUE TO CHANGE SIZE

SCROTUM Scrotum

TESTICLES / TESTES • IN A MALE WHO HAS REACHED SEXUAL MATURITY, THE TWO TESTICLES, OR TESTES, PRODUCE AND STORE MILLIONS OF TINY SPERM CELLS • THE TESTICLES ARE OVAL-SHAPED AND GROW TO BE ABOUT 2 INCHES IN LENGTH AND 1 INCH IN DIAMETER • THE TESTICLES ARE ALSO PART OF THE ENDOCRINE SYSTEM BECAUSE THEY PRODUCE HORMONES, INCLUDING TESTOSTERONE • TESTOSTERONE IS THE HORMONE THAT CAUSES BOYS TO DEVELOP DEEPER VOICES, BIGGER MUSCLES, AND BODY AND FACIAL HAIR, AND IT ALSO STIMULATES THE PRODUCTION OF SPERM

TESTES / TESTICLES Testes

EPIDIDYMIS • A SET OF COILED TUBES (ONE FOR EACH TESTICLE) THAT CONNECTS TO THE VAS DEFERENS • SPERM IS STORED HERE

EPIDIDYMIS Epididymis

VAS DEFERENS • A MUSCULAR TUBE THAT PASSES UPWARD ALONGSIDE THE TESTICLES AND TRANSPORTS THE SPERMCONTAINING FLUID CALLED SEMEN • WHERE SPERM TRAVEL AFTER LEAVING THE EPIDIDYMIS ON THEIR WAY TO THE URETHRA

VAS DEFERENS Vas Deferens

SEMINAL VESICLES • SAC-LIKE STRUCTURES ATTACHED TO THE VAS DEFERENS TO THE SIDE OF THE BLADDER • PROVIDE FLUIDS (SEMEN) THAT LUBRICATE THE DUCT SYSTEM AND NOURISH THE SPERM

SEMINAL VESICLES Seminal Vesicles

PROSTATE GLAND • SURROUNDS THE EJACULATORY DUCTS AT THE BASE OF THE URETHRA, JUST BELOW THE BLADDER • PROVIDE FLUIDS THAT LUBRICATE THE DUCT SYSTEM AND NOURISH THE SPERM • SECRETES A CLEAR FLUID WHICH MAKES UP ABOUT 1/3 OF THE FLUID IN AN EJACULATION

PROSTATE GLAND Prostate Gland

URETHRA • THE CHANNEL THAT CARRIES THE SEMEN TO THE OUTSIDE OF THE BODY THROUGH THE PENIS • ALSO PART OF THE URINARY SYSTEM BECAUSE IT IS ALSO THE CHANNEL THROUGH WHICH URINE PASSES AS IT LEAVES THE BLADDER AND EXITS THE BODY

URETHRA Urethra

COWPER’S GLAND • PRODUCES A CLEAR STICKY FLUID (PRE-EJACULATE) WHEN THE MALE SEXUALLY IS EXCITED • THE SECRETIONS PRODUCED BY THE COWPER’S GLANDS HELP TO PROTECT SPERM AS IT PASSES THROUGH THE URETHRA DURING EJACULATION. IN RESPONSE TO SEXUAL STIMULATION PRIOR TO EJACULATION, THE COWPER’S GLANDS BEGIN PRODUCING AN ALKALINE MUCOUS SECRETION KNOWN AS

COWPER’S GLAND Cowper’s Gland

PENIS • MADE UP OF 2 PARTS: • SHAFT – MAIN PART OF THE PENIS • GLANS – TIP • AT THE END OF THE GLANS IS A SMALL OPENING, WHICH SEMEN AND URINE EXIT THE BODY THROUGH THE URETHRA • THE INSIDE OF THE PENIS IS MADE OF A SPONGY TISSUE THAT CAN EXPAND CONTRACT

PENIS Shaft Glans

PUBERTY • DURING THE FIRST STAGE OF MALE PUBERTY, THE SCROTUM AND TESTES GROW LARGER • NEXT, THE PENIS BECOMES LONGER, AND THE SEMINAL VESICLES AND PROSTATE GLAND GROW • HAIR BEGINS TO APPEAR IN THE PUBIC AREA AND LATER IT GROWS ON THE FACE AND UNDERARMS. DURING THIS TIME, A MALE'S VOICE ALSO DEEPENS. • BOYS ALSO UNDERGO A GROWTH SPURT DURING PUBERTY AS THEY REACH THEIR ADULT HEIGHT AND WEIGHT.

SPERM • A MALE WHO HAS REACHED PUBERTY WILL PRODUCE MILLIONS OF SPERM CELLS EVERY DAY • EXTREMELY SMALL – 1/1600 OF AN INCH • DEVELOP IN THE TESTICLES WITHIN A SYSTEM OF TINY TUBES CALLED THE SEMINIFEROUS TUBULES • EACH SPERM CONTAINS A HEAD AND A SMALL TAIL • THE HEAD CONTAINS THE GENETIC MATERIAL • THEY USE THEIR TAILS TO PUSH THEMSELVES INTO THE EPIDIDYMIS WHERE THEY COMPLETE DEVELOPMENT • IT TAKES SPERM ABOUT 4 TO 6 WEEKS TO TRAVEL THROUGH THE EPIDIDYMIS

SPERM

SPERM & THE PENIS • NEXT, THE SPERM GOES TO THE VAS DEFERENS, OR SPERM DUCT. • THE SEMINAL VESICLES AND PROSTATE GLAND PRODUCE A WHITISH FLUID CALLED SEMINAL FLUID, WHICH MIXES WITH SPERM TO FORM SEMEN WHEN A MALE IS SEXUALLY STIMULATED