Download presentation
Presentation is loading. Please wait.
1
The Reproductive System
Chapter 28 The Reproductive System
2
The Reproductive Systems
Reproductive organs grouped by function Gonads - testes and ovaries produce gametes and secrete hormones production of gametes, fluid, discharge into ducts indicate exocrine glands production of hormones indicate endocrine glands Ducts - transport, store, receive gametes Accessory sex glands - gamete support Supporting structures - various reproductive roles
3
Male Reproductive System
Testes, system of ducts, accessory sex glands, several supporting structures (including penis)
4
Male Reproductive System
Scrotum 2 sacs that support testes muscle and connective tissue dartos muscle and fascia cremaster muscle location and temperature due to muscle contraction sperm production requires temp 3 C below body temp muscle contraction raises and lowers testes
5
Male Reproductive System
Testes - testicles paired oval glands 5 cm x 2.5 cm develop in abdomen begin to descend during 7th month of development cryptorchidism
6
Male Reproductive System
Testes surrounded by connective tissue covered by tunica vaginalis (serous membrane) from peritoneum more internal is tunica albuginea forms septa and lobules /testicle
7
Male Reproductive System
3 seminiferous tubules - each lobule Each tubule lined w/ spermatogenic cells in various developmental stages
8
Male Reproductive System
Spermatogonia to spermatazoa Sustentacular (Sertoli) cells blood-testis border mediate testosterone FSH effects phagocytize excess spermatid cytoplasm control movement and sperm release to tubule secrete fluid for sperm transport Interstitial endocrinocytes (interstitial cells of Leydig) located between tubules secrete testosterone
9
Male Reproductive System
Spermatogenesis occurs in seminiferous tubule production of haploid spermatozoa about 74 days in humans Spermatogonia diploid w/ mitosis some stay as stem cells some undergo developmental changes primary spermatocytes
10
Male Reproductive System
Reduction division secondary spermatocytes formed (haploid) equatorial division spermatids formed (haploid) sperm cells do not completely separate maintain cytoplasmic bridges due to incomplete nature of Y chromosome Spermiogenesis maturation of spermatids into spermatozoa 10-14 days for maturation in ductus epididymus
11
Male Reproductive System
Spermatozoa 300 million/day mature survive about 48 hrs following ejaculation structure head nuclear material acrosome - enzymes for penetration into egg midpiece - site of metabolism for tail tail - flagella
12
Male Reproductive System
Hormones of brain-testicular axis anterior pituitary drives changes during puberty begins to secrete FSH, LH controlled by GnRH from hypothalamus LH - Interstitial endocrinocytes testosterone DHT FSH - Sustentacular cells ABP Inhibin
13
Male Reproductive System
Development testosterone stimulates pattern development before birth (internal ducts) DHT external genitals estrogens from testes - brain development Puberty - testosterone, DHT stimulate enlargement of male sex organs and secondary sexual characteristics
14
Male Reproductive System
Testosterone - the gift that keeps on giving! 2 sex characteristics muscular, skeletal growth heavier, thicker muscle, bones in men than women also epiphyseal closure pubic, axillary, facial and chest hair oil gland secretion larynx enlargement sexual functions male sexual behavior and aggression spermatogenesis sex drive in both male and female metabolism - stimulates protein synthesis
15
Male Reproductive System
Ducts sperm and semen to lumen of seminiferous tubules straight tubules rete testis epididymis new sperm, fluid produce pressure to move things along fluid - androgens, estrogens, K+, glutamic acid, aspartic acid
16
Male Reproductive System
Epididymis posterior border of testes tightly coiled tube - head, body, tail 6 m long if uncoiled pseudostratified columnar epithelium microvilli reabsorb degenerated sperm ductus epididymis site of sperm maturation (10-14 days) - motility may remain in storage for a month, then reabsorbed
17
Male Reproductive System
Ductus (vas) deferens less convoluted, diameter ascends, enters pelvic cavity through inguinal canal loops up, over urinary bladder ends in ampulla
18
Male Reproductive System
Posterior View
19
Male Reproductive System
Spermatic cord - testicular artery, autonomic nerves, veins, lymphatic vessels, cremaster muscle ascend w/ vas deferens Enter body through inguinal canal Vasectomy - portion of each duct removed
20
Male Reproductive System
Ductus (vas) deferens pseudostratified columnar epithelium w/ heavy coat of muscle stores, conveys sperm from epididymis to urethra during ejaculation peristalsis
21
Male Reproductive System
Ejaculatory Ducts formed by ducts from seminal vesicle and ductus deferens move sperm into prostatic urethra before ejaculation
22
Male Reproductive System
Urethra terminal tract of urinary, reproductive systems 3 areas: prostatic urethra membranous urethra spongy (cavernous) urethra ends at external urethral orifice in bulb of penis
23
Male Reproductive System
Accessory sex glands secrete liquid portion of semen Seminal vesicles base of urinary bladder 60% of semen volume secrete alkaline viscous fluid containing: fructose, ascorbic acid prostaglandins vesiculase (coagulating enzyme)
24
Male Reproductive System
Prostate below bladder, around urethra secretes milky, slightly acidic fluid with: citrate enzymes Phosphatase Fibrinolysin Prostate specific antigen (PSA) Bulbourethral (Cowper's) glands beneath prostate gland at membranous urethra secrete: alkaline substance Mucous neutralize any acidic urine
25
Male Reproductive System
26
Male Reproductive System
Semen - mixture of sperm and secretions avg vol ml million sperm/ml below 20 million/ml infertility large numbers needed slightly alkaline ( ), milky and mucoid decreases acidity of vagina fructose for fuel prostaglandins decrease mucous viscosity and reverse peristalsis contains antibiotic coagulates after ejaculation into vagina different mechanism than blood clotting breaks down in 5-20 minutes
27
Male Reproductive System
Penis root (attachment) body (shaft) glans penis
28
Male Reproductive System
Root of penis - bulb (base of corpus spongiosum) Glans penis w/ outer corona terminal slitlike opening (external urethral orifice) covering is prepuce (foreskin)
29
Male Reproductive System
Body 3 cylindrical masses of tissue surrounded by tunica albuginea dorsolateral corpora cavernosa penis midventral corpus spongiosum penis w/ spongy urethra all surrounded by fascia and skin each have blood sinuses
30
Male Reproductive System
Erection arteries dilate w/ sexual stimulation - PNS reflex large quantities of blood enter sinuses compress superficial veins from sinuses trapped blood erection close bladder sphincter prevent urine flow prevent semen backflow Ejaculation sympathetic reflex peristalsis arterial vessels constrict, sinuses empty
31
Female Reproductive System
Ovaries, uterine (Fallopian) tubes, uterus, vagina, vulva, mammary glands
32
Female Reproductive System
Ovaries paired organs in pelvic cavity supported by several ligaments almond size homologous to testes
33
Female Reproductive System
Ovary Histology germinal epithelium around outside tunica albuginea - connective tissue stroma - connective tissue cortex - outer dense layer w/ ovarian follicles medulla - inner loose layer ovarian follicles vesicular ovarian (Graafian) follicle corpus luteum
34
Female Reproductive System
Oogenesis - formation of haploid ova in ovary Steps Reduction division - meiosis I starts during fetal development, pauses finishes after puberty Equatorial division - meiosis II pauses finishes after fertilization
35
Female Reproductive System
Uterine (Fallopian) tubes - oviducts extend laterally from uterus to carry ova from ovaries to uterus structure infundibulum with fimbriae ampulla isthmus
36
Female Reproductive System
Uterine tube histology - 3 cell layers internal mucosa - ciliated columnar epithelial cells and secretory cells middle muscularis inner thick circular layer of muscle outer thin longitudinal layer peristaltic contractions w/ cilia move secondary oocyte along outer serous membrane - serosa
37
Female Reproductive System
Once a month ovarian follicle ruptures releasing secondary oocyte (ovulation) oocyte swept into oviduct by fimbriae moves by peristalsis, cilia fertilization can occur any time in next 24 hours generally in ampulla becomes a zygote unfertilized oocytes disintegrate
38
Female Reproductive System
39
Female Reproductive System
Uterus site of menstruation, implantation, fetal development, labor between urinary bladder and rectum size, shape of inverted pear
40
Female Reproductive System
3 parts of Uterus fundus body - isthmus
41
Female Reproductive System
cervix narrow portion that opens into vagina produces cervical mucous; (20-60 ml/day) more receptive to spermatazoa at or near ovulation otherwise mucous plug cervix, mucus protect spermatazoa provide nutrients role in capacitation Cervical canal in cervix internal os external os
42
Female Reproductive System
Uterus bends between body and cervix Uterus enters vagina at right angle
43
Female Reproductive System
Ligaments provide stability broad ligaments uterosacral ligaments cardinal ligaments round ligaments
44
Female Reproductive System
3 uterine layers Perimetrium - visceral peritoneum Myometrium 3 layers of smooth muscle thickest in fundus thinnest in cervix expulsion
45
Female Reproductive System
Endometrium highly vascular surface layer simple columnar epithelium ciliated, secretory cells uterine (endometrial) glands
46
Female Reproductive System
Endometrium - divided into 2 layers: stratum functionalis (functional layer) - shed during menstruation stratum basalis (basal layer) - gives rise to stratum functionalis
47
Female Reproductive System
Blood supply from uterine arteries arcuate arteries - circular around myometrium radial arteries penetrate into myometrium w/ 2 branches: straight arterioles terminate in basilis supply materials to regenerate functionalis spiral arterioles penetrate functionalis change during menstruation Drained by uterine veins
48
Female Reproductive System
Endoparasitic expulsion
49
Female Reproductive System
Vagina Tubular, fibromuscular organ with mucous membrane Between bladder, rectum superiorly attached to uterus recess (fornix) around attachment to cervix Several functions passage for menstrual flow, childbirth receives semen
50
Female Reproductive System
Vagina histology Mucosa continuous w/ uterus non-keratinized stratified squamous epithelium and connective tissue in folds (rugae) mucosal cells have large stores of glycogen upon decomposition produce organic acids - lo pH dendritic (APC) cells - AIDS? Muscularis smooth muscle - outer circular, inner longitudinal stretches to receive penis and for childbirth Adventitia - areolar connective tissue
51
Female Reproductive System
Vulva - pudendum Female external genitalia Mons pubis Anterior to vaginal, urethral openings Adipose tissue covered by skin, hair Labia majora Lateral skin folds (adipose tissue) with sebaceous and sudoriferous glands Homologous to scrotum Labia minora Smaller, medial folds with sebaceous glands Homologous to spongy urethra this is a test
52
Female Reproductive System
Clitoris Anterior junction of labia majora Small cylindrical mass of erectile tissue, nerves Plays a role in sexual excitement Homologous to glans penis
53
Female Reproductive System
Vestibule Region between labia minora Mostly vaginal orifice w/ hymen (if present) Bulb of vestibule 2 elongated masses of tissue filled w/ blood during sexual arousal narrows vaginal orifice pressure on penis homologous to corpora spongiosum and bulb of penis
54
Female Reproductive System
External urethral orifice Anterior to vaginal orifice, posterior to clitoris Exterior opening of the urinary tract
55
Female Reproductive System
Accessory glands Paraurethral (Skene's) glands either side of ext. urethral orifice in uterine wall secrete mucous homologous to prostate gland Greater vestibular (Bartholin's) glands open between area of hymen, labia minora mucous secretion during sexual intercourse also, some lesser vestibular glands homologous to bulbourethral (Cowper's) gland
56
Female Reproductive System
Mammary Glands Modified sudoriferous (sweat) glands that produce milk along with adipose tissue Anatomy over pectoralis major, serratus anterior muscles attached to muscles by connective tissue suspensory ligament of breast run between skin and deep fascia support breast, may stretch with age/time
57
Female Reproductive System
Mammary Glands Nipple exterior pigmented projection many closely spaced openings - lactiferous ducts Areola surrounding pigmented area modified sebaceous (oil) glands
58
Female Reproductive System
Mammary Glands lobes internally separated by adipose tissue (determine size, shape) Lobes separated into lobules w/ milk secreting glands, alveoli milk (when being produced) passes from alveoli secondary tubes mammary ducts when approaching nipple ducts expand to form lactiferous sinus (storage) open to nipple
59
Female Reproductive System
Mammary Gland Development Develop in puberty due to estrogen, progesterone Ducts develop, fat deposition occurs Areola, nipple grow, become pigmented Further development occurs following ovulation and corpus luteum formation Mammary Gland Physiology Primary function is milk synthesis Secretion, ejection together known as lactation Primary stimulus for production is prolactin Stimulus for release is oxytocin from ant. pit. in response to suckling
60
Female Reproductive Cycle
Two parts in two different areas Ovarian cycle - events in ovary Uterine (menstrual) cycle - endometrial changes Controlled by varying levels of several hormones from many sites Anterior Pituitary Ovarian follicles Corpus luteum Hormones act on several sites Ovary Uterus
61
Female Reproductive Cycle - Hormones
62
Female Reproductive Cycle
Normally days in length Anterior Pituitary hormones act on ovary Ovarian hormones act on uterus
63
Female Reproductive Cycle
3 Phases of Reproductive cycle Day menstrual phase 1. Day preovulatory (proliferative) phase 2. Day postovulatory (secretory) phase 3.
64
Female Reproductive Cycle
Menstrual Phase ml of blood, tissue fluid, mucus, epithelial cells from endometrium levels of estrogen/progesterone - negative feedback uterine spinal arteries constrict ischemic tissue entire stratum functionalis sloughs off Ovaries FSH levels rise (from day 25 of cycle) stimulate primordial follicles to develop into primary follicles By day four 20 develop into secondary (growing) follicles granulosa cells surround zona pellucida between oocyte, granulosa secretes follicular fluid forces oocyte to follicle edge and fills follicular cavity All follicles release low levels of estrogen
66
Female Reproductive Cycle
Preovulatory Phase - lasts 6-13 days Menstrual and Preovulatory phase together known as Follicular phase By day 6 of cycle one follicle outgrows others low estrogen levels from all follicles causes negative feedback inhibition of GnRH, FSH and LH all other follicles stop growing and degenerate, atresia dominant follicle secretes enough estrogen to survive estrogen levels increase due to single follicle Dominant follicle matures vesicular ovarian (Graafian) follicle (mature follicle) blisterlike bulge on surface of ovary
68
Female Reproductive Cycle
Preovulatory Phase Follicle continues to secrete estrogen Early FSH is dominant Close to ovulation, LH takes over Estrogen stimulates endometrial repair stratum basilis mitosis create new stratum functionalis endometrial glands develop arterioles coil, lengthen
70
Female Reproductive Cycle
Ovulation Rupture of vesicular ovarian follicle and release into pelvic cavity occurs around day 14 Secondary oocyte surrounded by cells, corona radiata secondary oocyte in metaphase II Fimbrae become more active, create currents in fluid to carry oocyte into uterus Changes in body temperature (estrogen) and cervical mucous (more stringy)
71
Female Reproductive Cycle
Ovulation Prior to ovulation high estrogen exerts positive feedback on FSH, LH suddern surge of LH releases oocyte LH surge measurable Following ovulation follicle collapses becoming corpus hemorrhagicum follicle cells then enlarge, change character, form corpus luteum under influence of LH to secrete estrogen and progesterone
73
Female Reproductive Cycle
Postovulatory Phase Most constant in duration, lasts for 14 days, from ovulation to next menses LH stimulates corpus luteum (luteal phase) development which secretes levels of estrogen and progesterone Progesterone prepares endometrium to receive fertilized ovum growth, coiling of endometrial glands vascularization of surface endometrium endometrial thickening tissue fluid secretory phase of endometrial glands
74
Female Reproductive Cycle
Postovulatory Phase If no fertilization estrogen and progesterone inhibit GnRH and LH corpus luteum degenerates (no LH) corpus albicans levels of estrogen and progesterone stop endometrial development stimulate next menstruation stimulates anterior pituitary hormones If fertilization occurs corpus luteum maintained until placenta takes over maintained by hCG (human chorionic gonadotropin) produced by chorion home pregnancy test placenta produces estrogen, progesterone
76
Female Reproductive Cycle
77
Female Reproductive Cycle
79
Physiology of Sexual Intercourse
Male Reproductive Act Erection may be initiated by anticipation, memory, visual sensation or reflex from stimulation PNS stim causes vasodilation, compression of veins, erection Lubrication PNS stimulates bulbourethral and urethral glands secrete mucus for lubrication
80
Physiology of Sexual Intercourse
Male Reproductive Act (cont.) Orgasm tactile stimulation causes ejaculation intense stimulation causes rhythmic sympathetic impulses causing peristaltic contractions of ducts propelling spermatazoa into urethra simultaneous stimulation of seminal vesicles and prostate add fluid to spermatazoa also rhythmic stimulation of skeletal muscle at base of penis for rhythmic contraction to help expel semen, ejaculation sensory input including HR, BP, RR, pleasurable sensations along w/ ejaculation define an orgasm Followed by a refractory period
81
Physiology of Sexual Intercourse
Female Reproductive Act Arousal – mediated by PNS stimulation of breasts, genitalia, especially the clitoris, generates arousal Clitoris, vaginal mucosa and breasts engorge with blood Lubrication - secretion of mucous from epithelium of the cervical mucosa Orgasm (climax) - maximal tactile stimulation of genitalia results in orgasm, SNS driven perineal muscle contract rhythmically, general in muscle tension, rhythmic contractions of uterus engorgement of clitoris, breasts HR, RR, BP intense pleasurable sensations
82
Female Reproductive System
Breast Cancer 1/9 women will have breast cancer Early detection the most important aspect Each month after menstrual period breasts should be examined for lumps, puckering of skin or nipple retraction or discharge
83
Female Reproductive System
Breast Cancer Risk factors family history no child or first child after 34 previous cancer in breast exposure to ionizing radiation (x-rays) excess fat and alcohol intake, cigarette smoking Detection - mammogram, flattening the key Treatment lumpectomy (removal of tumor and surrounding tissue) radical mastectomy (breast, pectoral muscles, axillary lymph nodes)
84
Birth Control Sterilization Vasectomy
Tubal ligation (uterine tubes cut and tied)
85
Birth Control Hormonal methods Oral contraceptives
generally hi progesterone and low estrogen negative feedback inhibition of FSH, LH and GnRH preventing follicular development and ovulation also alter cervical mucous and make endometrium less receptive to implantation allows for regulation of length of menstrual cycles, menstrual flow, and prevention of ovarian cysts not good for women w/ clotting problems, cerebral blood vessel damage, hypertension, liver malfunction or heart disease also risk in women who smoke and drink for heart attack and stroke
86
Birth Control Hormonal methods Intrauterine devices Norplant
surgical implants under skin of progestin prevents ovulation and thickens cervical mucus no longer in widespread use Depo-provera – IM injection every 3 months of progestin (similar to progesterone) No male oral contraceptive currently available Intrauterine devices Small plastic, copper or stainless steel device inserted into uterine cavity to prevent implantation Danger of pelvic inflammatory disease, infertility and excess menstrual bleeding and pain
87
Birth Control Barrier methods Condom Diaphragm
nonporous elastic (latex) preventing mechanical barrier to sperm deposition reliable and prevents STD's when used correctly both male and female (vaginal pouch) Diaphragm rubber dome-shaped device over cervix w/ spermicide to stop sperm passage toxic shock syndrome and frequent urinary tract infections possible does not prevent STD's
88
Birth Control Spermicides Physiological methods
Make vagina more inhospitable to sperm, inactivate HIV, decrease incidence of gonorrhea More successful when used with barrier method Physiological methods Rhythm method abstention 3 days before and after ovulation oocyte only viable for 24 hours after ovulation Sympto-thermal method - abstention when signs of ovulation are present Coitus interruptus (withdrawal)
89
Birth Control Induced abortion RU486
blocks progesterone preventing proper endometrial development menstruation occurs
Similar presentations
