PowerPoint ® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM 24 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Reproductive System PART 1

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Reproductive System  Primary sex organs  Testes  Ovaries  Accessory sex organs  Glands  External genitalia

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Male Reproductive System  The scrotum  Skin and superficial fascia surrounding the testes  Positioning provides an environment 3˚ cooler than body temperature  Dartos muscle – layer of smooth muscle  Cremaster muscle – bands of skeletal muscle surrounding the testes  Elevates the testes

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Male Reproductive System Figure 24.1

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Scrotum – Containing the Testes and Spermatic Cord Figure 24.2

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Testes  Are enclosed in a serous sac – the tunica vaginalis  Tunica albuginea – fibrous capsule of the testes  Divides each testis into 250 – 300 lobules  Lobules contain 1– 4 coiled seminiferous tubules  Epididymis  Comma-shaped structure on posterior testis

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Testes Figure 24.3a

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Seminiferous Tubules and Spermatogenesis  Seminiferous tubules  Separated by areolar connective tissue  Epithelium consists of  Spermatogenic cells – sperm-forming cells  Columnar sustentacular cells – support cells

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Spermatogenic Cells  Spermatogenesis  Sperm formation  400 million sperm formed per day  Begins at puberty  Process takes 75 days  Cells differentiate and move toward the lumen

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Spermatogenesis  Divided into three stages  Stage 1 – spermatogonia divide by mitosis  Type A – maintain the germ cells  Type B – differentiate into primary spermatocytes  Stage 2 – meiosis I and meiosis II  Meiosis I – forms two secondary spermatocytes  Meiosis II – each spermatocyte forms two spermatids

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Spermatogenesis  Stage 3 – spermiogenesis  The four spermatids differentiate into spermatozoa  Spermatozoa shed superfluous cytoplasm  Composed of  Head, midpiece, and tail

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.5

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Seminiferous Tubules and Spermatogenesis Figure 24.4b

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Spermatogenesis Figure 24.4c

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Sustentacular Cells  Surround spermatogenic cells  Extend from basal lamina to the lumen  Tight junctions between cells  Blood-testis barrier  Assist sperm production  Secret testicular fluid and androgen-binding protein

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Myoid Cells and Interstitial Cells  Myoid cells – surround seminiferous tubules  Contract rhythmically  Interstitial cells (Leydig cells)  Secrete testosterone  Secretion regulated by LH

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Epididymis  Duct of the epididymis is 6m long (when uncoiled)  Dominated by pseudostratified columnar epithelium  Bears tufts of stereocilia – immotile, long microvilli  20-day journey for sperm to move through  Gain the ability to swim and to fertilize an egg through the acrosomal reaction

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Epididymis Figure 24.3a

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Ductus Deferens  Stores and transports sperm  Hisotology of the ductus deferens  Epithelium – pseudostratified columnar  Thick muscularis  Adventitia

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.1 The Ductus Deferens  Trace the course of the ductus deferens

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Spermatic Cord  Contains  Ductus deferens  Testicular blood vessels  Nerves  Superior portion of ductus deferens  Runs through inguinal canal

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Spermatic Cord Figure 24.2

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Spermatic Cord in the Inguinal Canal Figure 24.7

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Urethra  Carries sperm from ejaculatory ducts to “outside”  Three parts of male urethra  Prostatic  Membranous  Spongy

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Urethra Figure 24.8a, b

PowerPoint ® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM 24 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Reproductive System PART 2

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Accessory Glands  The seminal vesicles  Lie on the posterior surface of the urinary bladder  Secretes about 60% of the volume of semen  Fluid contains  Fructose to nourish sperm  Substances to enhance sperm motility  Prostaglandins  Substances that suppress immune response against semen  Enzymes that clot and then liquify semen

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Accessory Glands  The prostate gland  Encircles the prostatic urethra  Consists of 20 – 30 compound tubuloalveolar glands  Secretes about 25 – 30% of seminal fluid  Contains substances that  Enhance sperm motility  Enzymes that clot and then liquify semen

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Accessory Glands Figure 24.9a, b

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Accessory Glands  The bulbourethral glands  Pea-sized glands inferior to the prostate gland  Produce a mucus  Mucus enters spongy urethra prior to ejaculation  Neutralizes traces of acidic urine  Lubricates urethra PLAY Male Reproductive Anatomy

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Penis  External anatomy  Shaft – body  Glans penis – distal expanded end  Prepuce – foreskin  Removed during circumcision

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Penis  Internal Anatomy  Three erectile bodies  One corpus spongiosum  Surrounds spongy urethra  Two coropora cavernosa  Contain sinuses, make up most of the penis

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Penis Figure 24.8a, b

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Male Perineum  Contains – scrotum, root of penis, anus  Diamond-shaped area between  Pubic symphysis anteriorly  Coccyx posteriorly  Ischial tuberosities laterally

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Male Perineum Figure 24.10

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Female Reproductive System  Produces gametes (ova)  Prepares to support a developing embryo  Undergoes changes according to the menstrual cycle

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Female Internal Reproductive Organs Figure 24.11

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Female Reproductive System Figure 24.12a

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Ovaries  Small, almond-shaped organs  Produce ova  Held in place by ligaments and mesenteries  Broad ligament  Suspensory ligament  Ovarian ligament  Ovarian arteries – arterial supply

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Internal Structure of the Ovaries  Tunica albuginea  Fibrous capsule of the ovary  Covered in simple columnar epithelium  Ovarian cortex – houses developing oocytes  Follicles – multicellular sacs housing oocytes

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Structure of the Ovary Figure 24.13

PowerPoint ® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM 24 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Reproductive System PART 3

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Ovarian Cycle  Follicular phase  Days 1 – 13 of the ovarian cycle  6 – 12 primordial follicles stimulated to develop  Growth stimulated by FSH from anterior pituitary  Primordial follicle becomes a primary follicle  Zona pellucida – glycoprotein coat surrounding oocyte  Theca folliculi – internal layer secretes hormones

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Ovarian Cycle  Follicular phase (continued)  Antrum forms  A fluid filled cavity between granulose cells  Primary follicles become a secondary follicle  Corona radiata – coat of granulosa cells surrounding oocyte  Secondary follicle enlarges and becomes  Visicular (Graafian) follicle – ready to be ovulated

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Ovarian Cycle  Ovulation  Occurs about halfway through each ovarian cycle (Day 14)  One mature oocyte exits from one ovary  Enters peritoneal cavity  Swept into uterine tube  Sudden increase in LH is signal for ovulation PLAY Ovulation

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Ovarian Cycle  Luteal phase  Occurs after ovulation – days 15 – 28  Remaining follicle becomes a corpus luteum  Secretes progesterone  Acts to prepare for implantation of an embryo  If no implantation  Corupus luteum dies and becomes a corpus albicans

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Oogenesis  Takes many years to complete  Primordial follicles are arrested (stalled) in meiosis I  Surge of LH also causes primary oocyte to compete meiosis I

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Oogenesis  Oogenesis produces only one ovum and three polar bodies  Polar bodies do not contribute to developing embryo  Meiosis II is completed only is sperm penetration occurs

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Oogenesis Figure 24.15

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Uterine Tubes  Receive ovulated oocyte  Parts of the uterine tube  Infundibulum – distal end of uterine tube  Surrounded by fimbriae  Ampulla – middle third of uterine tube  Usual site of fertilization  Isthmus – medial third of uterine tube

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Uterine Tubes Figure 24.12

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Uterus  Lies anterior to rectum – posterior to bladder  Anteverted (anteflexed) usual position of uterus  Parts of the uterus  Fundus – rounded superior portion  Cervix – “neck” of uterus  Cervical canal – communicates with vagina inferiorly  Internal os – opening connecting with uterine cavity  External os – inferior opening of cervix

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Uterus Figure PLAY Female Reproductive Anatomy

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Uterine Wall Figure 24.18b

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Uterine Cycle  Series of cyclic phases of the endometrium  Phases coordinate with the ovarian cycle  Endometrial phases directed by FSH and LH  Phases of uterine cycle  Menstrual phase – days 1 – 5  Stratum functionalis is shed  Proliferative phase – days 6 – 14  Secretory phase – days 15 – 28

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Uterine Cycle  Series of cyclical changes to endometrium  The phases of uterine cycle  Menstrual phase (days 1– 5)  Proliferative phase (days 6 – 14)  Secretory phase (days 15 – 28)

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Menstrual Cycle Structural and hormonal changes Figure 24.19a, c

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Menstrual Cycle Figure 24.19b, d

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Vagina  Consists of three coats  Adventitia – fibrous connective tissue  Muscularis – smooth muscle  Mucosa – marked by transverse folds  Consists of lamina propria and stratified squamous epithelium  Hymen – an incomplete diaphragm  Fornix – recess formed at the superior part of the vagina

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Vagina Figure 24.12

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Vagina Figure 24.11

PowerPoint ® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM 24 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Reproductive System PART 4

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The External Genitalia and Female Perineum Figure 24.20a

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Deep Structures of the External Genitalia and Female Perineum Figure 24.20b

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Mammary Glands  Breasts – modified sweat glands  Glandular structure – undeveloped in non-pregnant women  Milk production – starts at or after childbirth

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Mammary Glands Figure 24.21a, b

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Pregnancy  Events leading to fertilization  Sperm binds to the zona pellucida  Undergoes the acrosomal reaction  Release of enzymes to form a slit in the zona pellucida  Fusion of oocyte and sperm plasma membranes  Cortical reaction  Enzymes prevent any other sperm from binding to the egg  Fertilization – chromosomes of male and female gametes join

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Events Leading to Fertilization Figure 24.22

PowerPoint ® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM 24 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Reproductive System PART 5

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Implantation  Blastocyst begins implantation  About six days after conception  Blastocyst consists of  An inner cell mass and outer trophoblast  Trophoblast forms two layers  Cytotrophoblast – inner layer  Syncytiotrophoblast – outer layer

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Implantation Figure 24.23

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Implantation Figure 24.24a–c

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Formation of the Placenta  Embryonic and maternal tissues contribute to the placenta Figure 24.24d

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Anatomy of the Placenta  Exchanges across the chorionic villi between maternal and fetal blood  Provide fetus with nutrients and oxygen  Dispose of its wastes  Allow hormonal signals to be sent to the mother  By week 13 the placenta is fully formed

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Anatomy of the Placenta Figure 24.24f, g

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Anatomy of the Placenta  Placental barrier consists of  All three layer of the chorionic villi  Sugars, fats, and oxygen diffuse from mother to fetus  Urea and carbon dioxide diffuse from fetus to mother  Syncytiotrophoblast – secretes substances that regulate events of pregnancy  Maternal antibodies transported across placenta  Viruses, alcohol, and heroin cross the placental barrier

PowerPoint ® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM 24 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings The Reproductive System PART 6

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.25a, b Childbirth  Parturition – 266 days after fertilization  Labor – events that expel the infant from the uterus

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Childbirth Figure 24.25c, d

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Reproductive System Cancers in Males  Testicular cancer  Affects 1 of 50,000 males  Commonly from early-stage spermatogenic cells  Increase of 50% from 1974 – 1990  Cured in 95% of cases

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Reproductive System Cancers in Males  Prostate cancer  Slow-growing – arises from peripheral glands  Risk factors  Fatty diet  Genetic predisposition

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Reproductive System Cancers in Females  Ovarian cancer – arises from cells in the germinal epithelium  Endometrial cancer – arises from the endometrium of the uterus  Cervical cancer – slow-growing, arises from epithelium at the tip of the cervix

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Reproductive System Cancers in Females  Breast cancer – Second most common cause of cancer deaths in women  97% occurs in women over 50  Treatment  Surgical removal of the mass (lumpectomy)  Radiation therapy  Administration of selected hormones  Chemotherapy

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Embryonic Development of the Sex Organs  5 – 6 week embryo is sexually indifferent  Mesonephric ducts – future male ducts  Paramesonephric ducts – future female ducts

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Embryonic Development of the Sex Organs  Development of the internal reproductive organs Figure (1 of 3)

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Embryonic Development of the Sex Organs  Male embryos – sexual differentiation begins in week seven  Mesonephric duct becomes  Epididymis  Ductus deferens  Ejaculatory duct  Paramesonephric ducts degenerate

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Embryonic Development of the Sex Organs  Female embryos – sexual differentiation begins in week eight  Cortical portion of immature ovaries form ovarian follicles  Paramesonephric duct becomes  Uterus  Uterine tubes  Superior part of vagina  Mesonephric ducts degenerate

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Embryonic Development of the Sex Organs Figure (2 of 3)

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Embryonic Development of the Sex Organs Figure (3 of 3)

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Embryonic Development of the Sex Organs  Development of the external genitalia Figure 24.27a

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Embryonic Development of the Sex Organs Figure 24.27b, c

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Decent of the Gonads Figure 24.28a–c

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Puberty  Period of life between ages 10 – 15  Reproductive organs grow to their adult size  Events of puberty occur in the same sequence in all individuals  Age at which events of puberty occur varies widely

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Puberty  Male secondary sex characteristics  Enlargement of the scrotum and testes (about age 13)  Appearance of pubic, axillary, and facial hair  Lengthening of vocal folds – deepening voice  Musculoskeletal system increases in mass  Sexual maturation – mature sperm in semen

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Puberty  Female secondary sex characteristics  Budding breasts (around age 11)  Menarche – the first menstruation  Other estrogen-induced secondary sex characteristics  Increase in subcutaneous fat  Widening and lightening of the bones of the pelvic girdle  Appearance of axillary and pubic hair  Estrogen-induced growth spurt from age 12 – 17

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Menopause  Female reproductive peak – late 20s  Around age 35 – rate of follicle degeneration increases  Ovulation and menstruation cease – age 46 – 54  Ovaries stop secreting estrogen  Reproductive organs and breasts begin to atrophy