Reproductive System Chapter

A. Meiosis Halves the chromosome number Occurs during the formation of eggs and sperm-forms gametes Provides for variability Consists of two cell division

B. Male Reproductive System Male reproductive organs 22-2

Male Reproductive Organs posterior view 22-3

1. Functions Produce and maintain male gametes Transport the sperm and supporting fluids to the female reproductive tract Secrete male hormones

2.Testes a. Descent of 22-4 gubernaculum inguinal canal spermatic cord

b. Structure of the Testis 22-5 tunica albuginia seminiferous tubules rete testis

c. Spermatogenesis 22-6

Spermatogenesis 22-7

Structure of a Sperm Cell 22-10

3. Male Internal Accessory Organs epididymis vas deferens seminal vesicle prostate gland bulbourethral glands 22-11

a. Epididymis tightly coiled tube connected to ducts within testis promote maturation of sperm cells 22-12

b. Vas Deferens muscular tube about 45 cm lined with pseudostratified coumnar epithelium near end it enlarges to form the ampulla extends from epididymis to ejaculatory duct Sperm remain viable for several months 22-13

c. Seminal Vesicle paired glands attached to vas deferens near base of bladder secretes alkaline fluid secretes fructose and prostaglandins contents empty into ejaculatory duct 22-14

d. Prostate Gland surrounds beginning of urethra ducts of gland open into urethra secretes a thin, milky, alkaline fluid secretion enhances fluid mobility of sperm composed of tubular glands in connective tissue also contains smooth muscle 22-15

e. Bulbourethral Gland paired glands inferior to the prostate gland secrete mucus-like fluid fluid released in response to sexual stimulation 22-16

f. Semen sperm cells secretions of seminal vesicles, prostate gland, and bulbourethral glands slightly alkaline prostaglandins nutrients million sperm cells per milliliter 22-17

4. Male External Reproductive Organs scrotum penis 22-18

a. Scrotum pouch of skin and subcutaneous tissue dartos muscle – smooth muscle in subcutaneous tissue; contracts to cause wrinkling of the scrotum medial septum divides scrotum into two chambers each chamber lines with a serous membrane each chamber houses a testis and epididymis 22-19

b. Penis 22-20

Penis prepuce glans penis corpus spongiosum corpora cavernosa penile urethra

c. Erection, Orgasm, and Ejaculation Erection parasympathetic nerve impulses blood accumulates in erectile tissues Orgasm culmination of sexual stimulation accompanied by emission and ejaculation Ejaculation emission is the movement of semen into urethra ejaculation is the movement of semen out of the urethra largely dependent on sympathetic nerve impulses 22-22

Mechanism of Penile Erection 22-23

Mechanism of Emission and Ejaculation 22-24

5. Hormonal Control of Male Reproductive Functions hypothalamus controls maturation of sperm cells and development of male secondary sex characteristics negative feedback controls concentration of testosterone 22-25

Actions of Testosterone increased growth of body hair sometimes decreased growth of scalp hair enlargement of larynx and thickening of vocal cords thickening of skin increased muscular growth thickening and strengthening of the bones 22-26

C. Female Reproductive System 22-27

Transverse Section of Female Pelvic Cavity 22-28

1. Functions Produce and maintain eggs Transport eggs to the site of fertilization Provide a proper environment for the developing fetus Move the offspring to the outside of the body Produce female sex hormones

2.Ovary a. Attachments broad ligament suspensory ligament ovarian ligament

b. Descent develop as masses inferior to the parietal peritoneum descend into the pelvic cavity descend similar to the testis

c. Structure covered by germinal epithelium tunica albuginea lies inferior to germinal epithelium two regions –medulla contains blood vessels, lymph vessels, and nerves –cortex contains ovarian follicles

d. Primordial Follicles before birth, cells located in the cortex develop into primordial follicles one million at birth, number declines, at puberty 400,000 consist of large cell called primary oocyte surrounded by epithelial cells called follicular cells begin meiosis, halted at Prophase I, remain until puberty no new oocytes formed

e. Oogenesis 22-30

f. Follicle Maturation 22-33

Follicle Maturation primary follicle –primary oocyte –granulosa cells –zona pellucida –corona radiata –thecal cells –antrum secondary follicle –primary oocyte Graafian follicle –requires days to develop –secondary oocyte

Follicle Maturation Mammalian Ovary Graffian Follicle 22-31

Follicles 22-32

g. Ovulation 22-34

Ovulation luteinizing hormone causes the mature follicle to swell and the wall to weaken secondary oocyte and several layers of surrounding cells are expelled from the ovary usually drawn into fallopian tubes corpus luteum develops from old follicular cells –secretes estrogen and progesterone –if no fertilization, disintegrates and forms the corpus albicans

3. Female Internal Accessory Organs uterine tubes uterus vagina 22-35

a. Uterine Tubes fallopian tubes oviducts infundibulum fimbriae

Lining of Uterine Tubes 22-37

b. Uterus broad ligament round ligament fundus body cervix

Uterine Wall 22-39

Vagina vaginal orifice hymen

Vagina rectouterine pouch fornix

4. Female External Reproductive Organs vulva labia majus mons pubis labia minus clitoris glans corpora cavernosa vestibule

Erection, Lubrication, and Orgasm 22-42

5. Hormonal Control of Female Reproductive Functions Estrogen –ovaries secrete at puberty –causes maturation of the female reproductive system –development of the secondary sex characteristics development of breasts and ductile system of the mammary glands increased adipose tissue in breasts, thighs, and buttocks increases vascularization of skin Progesterone –monthly cycle

b. Female Reproductive Cycle Menarche Menopause

Female Reproductive Cycle 22-46

Female Reproductive Cycle 1.Hypothalamus secretes gonadotropin releasing hormone 2.GnRH stimulates anterior pituitary to release follicle stimulating hormone and luteinizing hormone 3.FSH causes maturation of ovarian follicle

Female Reproductive Cycle 4.Surge LH stimulates ovulation-Day 14 5.Corpus luteum-secretes estrogen and progesterone 6.Corpus albicans 7.Estrogen and progesterone fall 8.Hypothalamus no longer inhibited, GnRh release, LH, FSH

Menopause usually occurs in late 40s or early 50s reproductive cycles stop ovaries no longer produce as much estrogens and progesterone some female secondary sex characteristics may disappear may produce hot flashes and fatigue hormone therapy may prevent effects on bone tissue 22-47

6. Mammary Glands areola alveolar glands lactiferous duct

7. Birth Control coitus interruptus rhythm method mechanical barriers condom diaphragm cervical cap spermicidal foams or jellies chemical barriers spermicides oral contraceptives hormonal injectable contraception hormonal contraceptive implants hormonal intrauterine devices surgical methods vasectomy tubal ligation 22-49

Surgical Methods of Birth Control 22-50

8. Sexually Transmitted Diseases silent infections most are bacterial and can be cured herpes, warts, and AIDS are viral and cannot be cured many cause infertility AIDS causes death symptoms of STDs include burning sensation during urination pain in lower abdomen fever or swollen glands discharge from vagina or penis pain, itch, or inflammation in genital or anal area sores, blisters, bumps or rashes itchy runny eyes 22-51

Clinical Application Prostate Enlargement benign prostatic hypertrophy occurs in most men over 50 BPH causes frequent urination risk factors include a fatty diet, having had a vasectomy, or exposure to certain environmental factors treatments include surgical removal, drugs, insertion of balloon into urethra, freezing of tumor, or insertion of stent between lobes of prostate to relieve pressure on urethra 22-52