Human Reproduction MALE FEMALE Regents Biology

OBJECTIVES Upon completion of this unit students will be able to:   1. Explain the major functions of the following structures in the human female reproductive system: ovaries, oviduct (fallopian tube), uterus, cervix and vagina 2. Correctly identify the location of the organs in objective #1. 3. Define hormone and describe how hormone structure determines its function. 4. Explain the remarkable specificity displayed by hormones (Lock and Key Model). 5. State the functions of the following key reproductive hormones in females: progesterone, estrogen, FSH, and LH. 6. Define feedback mechanism. 7. List, in order, the stages of the menstrual cycle and discuss the major events of each stage. 8. Explain the major functions of the following structures in the human male reproductive system: penis, vas deferens, epididymis, testes, prostate, scrotum 9. Correctly identify the location of the organs in objective #8. KEY WORDS 1.    cervix 2.    epididymis 3.    estrogen 4.    follicle 5.    hormone   6.    menstruation 7.    ovaries 8.    oviduct (fallopian tube) 9.    ovulation 10.  penis 11.                       testes 12.                       testosterone 13.                       uterus 14.                       vagina 15.                       vas deferens

I. Female Reproductive System The female gonads are the OVARIES Ovaries produce ESTROGEN and PROGESTERONE Estrogen is the hormone responsible for secondary sex characteristics (breasts, pelvis, fat, menstruation) The path of eggs from the inside of the female to the outside of the female: OVARY  OVIDUCT UTERUS CERVIX VAGINA OUTSIDE When an egg matures, the FOLLICLE (egg sac) around it ruptures and the egg is released from the OVARY (ovulation)

OVIDUCT OVARY UTERUS VAGINA CERVIX URETHRA URINARY BLADDER RECTUM (Fallopian tube) OVARY URINARY BLADDER UTERUS URETHRA RECTUM VAGINA CERVIX

OVIDUCT UTERUS EGG OVARY CERVIX FOLLICLE SPERM VAGINA

FEMALE STRUCTURE FUNCTION OVARIES OVIDUCT (FALLOPIAN TUBES) UTERUS   OVARIES ·      MAKE EGGS ·      SECRETE ESTROGEN OVIDUCT (FALLOPIAN TUBES) ·      TUBE LINED WITH CILIA FOR EGG PASSAGE ·      FERTILIZATION OCCURS HERE UTERUS ·      THICK, MUSCULAR AND PEAR-SHAPED ·      FERTILIZED EGG DEVELOPS HERE CERVIX ·      NARROW OPENING TO THE UTERUS ·      EXPANDS DURING CHILDBIRTH BIRTH CANAL (VAGINA) ·      LEADS TO OUTSIDE OF THE BODY ·      BABY AND MENSTRUAL TISSUE EXIT HERE

II. The Menstrual Cycle Ovulation (egg-releasing) occurs approximately every 28 days If an egg is not fertilized, the UTERINE LINING breaks down; this, along with the EGG are discharged…this is menstruation The menstrual cycle begins at PUBERTY and stops during PREGNANCY (temporarily) and MENOPAUSE (permanently)   HORMONES HORMONES are protein chemicals that are produced by GLANDS and are carried by the BLOODSTREAM to SPECIFIC areas of the body where they perform certain functions.

FOLLICLE-STIMULATING HORMONE 1. Pituitary (Brain) Hormones   1 FOLLICLE-STIMULATING HORMONE (FSH) ·      SENDS MESSAGE TO THE OVARY ·      CAUSES FOLLICLES TO BEGIN DEVELOPING 2 LUTENIZING HORMONE (LH) ·      CAUSES EGG TO BE RELEASED FROM OVARY ·      CAUSES FOLLICLE TO FILL WITH CELLS FORMING A “YELLOW BODY”

2. Ovarian Hormones   3 Progesterone ·      CAUSES GROWTH OF UTERINE LINING ·      PREVENTS FORMATION OF MORE THAN ONE EGG FOLLICLE AT A TIME ·      CONSTANTLY SECRETED DURING PREGNANCY 4 Estrogen ·      REGULATES CYCLE ·      STIMULATES UTERINE LINING TO THICKEN W/MUCUS & BLOOD VESSELS

HORMONAL FEEDBACK MECHANISMS A feedback mechanism involves a CHANGE in which the STIMULUS of a process “feeds back” to either REINFORCE or OPPOSE the resulting action taken by that process. Feedback mechanisms help to maintain HOMEOSTASIS   1.  POSITIVE FEEDBACK – REINFORCES ORIGINAL CHANGE 2. NEGATIVE FEEDBACK - OPPOSES ORIGINAL CHANGE

STAGES OF THE MENSTRUAL CYCLE 1. Follicle Stage (lasts about 10 days) FSH produced by the PITUITARY GLAND stimulates the growth of the egg sac or FOLLICLE in the ovary. The growing follicle inside the OVARY produces ESTROGEN which causes the wall of the muscular UTERUS to grow and thicken.   2. Ovulation (lasts 1 day) ESTROGEN produced by the ovary is carried by the BLOODSTREAM and is detected by the brain. The PITUITARY GLAND inside the brain DECREASES its production of FSH and INCREASES its production of LH. This sudden INCREASE of LH causes the OVARY to release an EGG in the process of OVULATION.

 3. Corpus Luteum (lasts about 14 days) LH causes the now empty FOLLICLE to turn into the CORPUS LUTEUM or “yellow body”. The corpus luteum amazingly changes into an OVARIAN CYST and is now capable of producing and secreting the hormone PROGESTERONE PROGESTERONE maintains the thick wall of theUTERUS. Progesterone is of ten called the “HORMONE of PREGNANCY”   4. Menstruation (lasts about 4 days) If FERTILIZATION does NOT occur, secretion of LH decreases and the UTERINE LINING breaks down. NO corpus luteum means NO PROGESTERONE. NO progesterone means NO more maintenance of the newly formed thickened wall of the UTERUS The thick muscular wall of the uterus starts to break down and, along with the UNFERTILIZED EGG and small amounts of BLOOD is discharged through the birth canal or VAGINA. The discharge is called the woman’s PERIOD or MENSTRUATION

III. Male Reproductive System The male gonad is the TESTES Testes produce SPERM and TESTOSTERONE Testosterone is the HORMONE responsible for secondary sex characteristics (hair, muscles, voice change) The testes are located in the SCROTUM (proper temperature!) The path of the sperm from the inside to the outside of the male:       TESTES  EPIDIDYMIS VAS DEFERENS URETHRA PENIS OUTSIDE THE BODY  Before ejaculation, the URETHRA blocks the opening from the urinary bladder SPERM

URINARY BLADDER COWPER’S GLAND PROSTATE GLAND URETHRA PENIS RECTUM SEMINAL VESICLES EPIDIDYMIS TESTES VAS DEFERENS SCROTUM

COWPER’S GLAND, PROSTATE GLAND, MALE STRUCTURE FUNCTION   PENIS ·       TRANSFERS SPERM TO THE FEMALE TESTES ·       MAKE SPERM AND TESTOSTERONE SCROTUM ·   KEEPS TESTES @ LOWER TEMPERATURE OUTSIDE THE BODY URETHRA ·   CARRIES SEMEN AND URINE THROUGH THE PENIS TO THE OUTSIDE  COWPER’S GLAND, PROSTATE GLAND, SEMINAL VESICLES ·   SECRETE FLUIDS INTO THE URETHRA TO NOURISH AND PROTECT SPERM EPIDIDYMIS ·       STORES IMMATURE SPERM FOR 18 HOURS UNTIL THEY MATURE VAS DEFERENS ·       TUBE THAT LEADS SPERM FROM EPIDIDYMIS TO THE URETHRA