Pelvis and Contents

1. Pelvis and Contents Reproductive Organs

2. Pelvic / hip girdle Function: Attaches the lower limbs to spine Supports the viscera of the pelvis Transmits the weight of the upper body Contents: Paired hip bones (coxal bone) Unite with each other anteriorly and with the sacrum posteriorly Bony pelvis: Os coxae, sacrum and coccyx Bones of the Pelvis pg 366 Use lab work to learn bony landmarks of pelvis

3. Each pelvic bone during childhood: Ilium Superior region Ishium Posteroinferior region Pubis Anterior region Os Coxae pg 366, 381 pg 380

4. Separated by the pelvic brim False Pelvis Superior to the pelvic brim Iliac blades contains abdominal organs attachment for muscles and ligaments to body wall True Pelvis Inferior to the pelvic brim Space contains part colon rectum bladder uterus/ovaries (females) True and False Pelves pg 366

5. Pelvic Diaphragm levator ani and coccygeus muscles Supports pelvic organs Seals inferior opening of bony pelvis Lifts to help release feces during defecation pg 392

6. Males Cavity is narrow, deep Smaller inlet and outlet Bones heavier, thicker Pubic angle more acute Ischial tuberosities longer, face more medially Coccyx less moveable, more curved Females Tilted forward Cavity is broad, shallow Pelvic inlet oval and outlet round Bones are lighter, thinner Pubic angle larger Ischial tuberosities shorter, more everted Coccyx more moveable, straighter Sexual Dimorphism pg 386

7. Anus and external genitalia Diamond shaped Pubic symphysis anteriorly Ischial tuberosities laterally Coccyx posteriorly Females: External genitalia Anus Males: Scrotum Root of penis Anus Perineum pg 443-4

8. Embryonic Development of the Sex Organs • Begin at week 5 as masses of gonadal ridges • Develop into the gonads • Sexually indifferent! • Both ducts are present in embryo, but only one develops: • Male • Mesonephric (Wolffian) ducts • Vas deferens, epididymis • Female • Paramesonephric (Müllerian) ducts • Uterus, oviduct, vagina

9. External genitalia develops from same structures • Embryonic structure Male Female • Labioscrotal swelling Scrotum Labia major • Urethral folds Penile Urethra Labia minor • Genital tubercle Penis Clitoris www.bionalogy.com

10. Male Development: Testes partially descend at 3 months, finish at 7 months Enter the scrotum Vaginal process Outpocketing of the peritoneal cavity Eventually closes off Forms tunica vaginalis Gubernaculum Fibrous cord Extends from the testis to floor of scrotal sac Final teste descent: Shortening of gubernaculum Increase in intra-abdominal pressure Testosterone stimulation Descent of the Gonads

11. Descent of the Gonads • Female Development • Descend only into the pelvis • Broad ligament blocks further descent • Gubernaculum • Guides ovaries • Attached to labia major • Becomes: • Round ligament of the uterus (inferior portion) • Ovarian ligament (superior portion) • Vaginal process • Outpocketing of peritoneum guides descent

12. Puberty • Between ages 10 and 15 • Reproductive organs grow to their adult size • Reproduction becomes possible • Changes occur due to the increase in reproductive hormones in each individual • Testosterone in males • Estrogens in females

13. Males Age 13 Enlargement of the testes and scrotum Secondary sex characteristics Appearance of pubic, axillary, and facial hair Enlargement of larynx Oily skin Increase in body size and musculature Females Age 11 Budding of breasts Secondary sex characteristics Increase in subcutaneous fat (hips and breasts) Widening and lightening of the bones Oily skin Hair in pubic and axillary region Menarche Menstruation Happens 1-2 years later Dimporhism at Puberty

14. Overall function is to produce offspring Genitalia = sex organs Primary = Gonads Ovaries, testes Produce the sex cells / gametes Sperm, eggs Secrete sex hormones Secondary = Accessory Glands, ducts, external genitalia Nourish and transport of gametes Reproductive System

15. Primary sex organ Gonads = testes Lie in the scrotum Sperm-producing Secondary sex organs External Genitalia Penis Scrotum Ducts Epididymis Efferent ductules Duct of epididymis Vas deferens Ejaculatory duct Urethra Glands Seminal vesicle Prostate Bulbourethral Male Reproductive System pg 365

16. Sac of skin and fascia Hangs at the root of the penis Contains the testes Septum in midline divides right and left halves Muscles: Dartos Inside skin of scrotum Smooth muscle Responsible for wrinkling of scrotal skin (warms) Cremaster Extends into scrotum from spermatic cord Fibers from internal oblique Skeletal muscle Responsible for elevating and lowering the testes (warming and cooling) Scrotum pg 375

17. Lie within the scrotum Tunica vaginalis Light sac partly covering each testes Tunica albuginea Fibrous capsule of the testes Deep to tunica vaginalis Divides testes into lobules Lobules contain seminiferous tubules Testes pg 408

18. Seminiferous tubules “sperm factories” Location of spermatogenesis Converge into……. Tubulus rectus Straight tube that conveys sperm into…. Rete testis Lead to the…… Efferent ductules Lead to epididymis …. Reproductive Duct System pg 408

19. Reproductive Duct System • Epididymis • Site of sperm maturation • Smooth muscle layer leads to ejaculation • Contains: • Head • Contain the efferent ductules • tube from rete testes to duct of epididymis • Ciliated simple columnar epithelium • Body and Tail • Duct of epididymis • Highly coiled • Leads into the vas deferens • Pseudostratified columnar epithelium with stereocilia • Resorb testicular fliud • Transfer nutrients and secretions to sperm stored in the epididymis

20. Reproductive Duct System • Vas Deferens (Ductus Deferens) • Stores and transports sperm during ejaculation • Runs from epididymis to ejaculatory duct • ED then runs within the prostate gland and empties into the prostatic urethra • Layers: • Pseudostratified epithelium • Lamina propria • Thick muscularis • Adventitia • Vasectomy • Cut vas deferns, close off ends • Sperm STILL produced, but cannot exit the body • Reversible sometimes! pg 365, 408 erl.pathology.iupui.edu

21. Spermatic Cord Collective name for structures associated with the scrotum Passes through inguinal canal Includes Vas Deferens Testicular arteries and veins (pampiniform plexus) Lymphatic vessels Cremaster muscle fibers Nerves Reproductive Duct System pg 235

22. Cell Division • Mitosis • Events in which replicated DNA of original cell is divided into 2 new cells • Cell division with chromosome duplication and division 2 daughter cells = parent • Have Diploid = 2n number of chromosomes • Occurs in body (somatic) cells • Meiosis = Reductional division • Events that reduce the number of chromosomes (1/2 of the parent) • Have Haploid = n number of chromosomes • Occurs in sex cells

23. Spermatogenesis faculty.sunydutchess.edu • Production of sperm • Stages: • Stem cells = Spermatogonia (2n) • Mitosis • Formation of 2 daughter cells • Type A become precursor cells (2n) • Type B become primary spermatocytes (2n) • Meiosis • Primary spermatocytes undergo Meiosis I • 2 secondary spermatocytes (n) • Secondary spermatocytes undergo Meiosis II • 4 spermatids (n) • Spermiogenesis • Spermatids differentiate into sperm • Sperm cell (spermatozoan) • Head (acrosome), tail and midpiece • Controlled by FSH (pituitary gland) and testosterone (testes)

24. Within Seminiferous Tubules • Sustentacular cells (Sertoli cells) • Surround the spermatogenic cells in the lumen • Provide nutrients to spermatogenic cells • Move cells toward tubule lumen • Secrete testicular fluid • Phagocytize cytoplasm shed by developing spermatids • Secrete Androgen-binding protein (concentrates testosterone) • Secrete Inhibin (hormone slows rate of sperm production) • Blood-testis barrier • In tight junctions between the sustentacular cells • Prevent escape of membrane antigens from sperm into the bloodstream

25. Within Seminiferous Tubules • Myoid cells • Layers of smooth muscle cells • Contract to squeeze sperm thru tubules and out of testis • Interstitial cells (Leydig cells) • Make and secrete male sex hormone (androgens) • In CT between tubules

26. Seminal Vesicles (2) Lie on posterior surface of the bladder Joins the vas deferens to form an ejaculator duct Contracts during ejaculation to empty Secretion contains: Fructose to nourish sperm Prostaglandins to stimulate contraction of the uterus Suppress immune response in females Sperm motility enhancers Enzymes that clot ejaculated semen in vagina, then liquefy it so sperm can swim out Accessory Glands pg 365

27. Prostate gland Inferior to bladder, anterior to rectum Encircles the first part of the urethra Contracts during ejaculation Secretion contains: Substances that enhance sperm motility Enzymes that liquefy ejaculated sperm Bulbourethral gland (2) Inferior to prostate gland Within urogenital diaphragm Empties into spongy urethra Produce a mucus Neutralize urine in urethra Lubricate semen for passage Accessory Glands pg 365

28. Male external genitalia Delivers sperm into the female reproductive tract Anatomy: Root Attached end Crura Anchored to pubic arch, covered by ischiocavernosus muscle Bulb Secured to urogenital diaphragm Body / Shaft Free; not attached Glans penis Enlarged tip Prepuce / Foreskin Loose cuff around glans Spongy urethra Tube within penis Penis pg 439

29. Erectile bodies 3 cylindrical bodies around the spongy urethra Thick tube covered by DCT Filled with smooth muscle, CT, and vascular spaces Corpus spongiosum Midventral erectile body Distally forms the glans penis Proximally forms the bulb of the penis Corpora cavernosa Paired, dorsal erectile bodies Proximal ends are the crura of the penis (crus) Covered by ischiocavernosus muscle Make up most of the mass of the penis Penis pg 439

30. Arterial supply Branches of internal pudendal Innervation Branches of pudendal from sacral plexus provides sensory innervation Parasympathetic Engorgement of blood in erectile bodies = erection Sympathetic Contraction of smooth muscle in ducts and glands and bulbospongiosum muscle = ejaculation Autonomic from inferior hypogastric plexus Penis Innervation and Vasculature pg 449 pg 447

31. Primary Sex Organs Ovaries = gonads Secondary Sex Organs External Genitalia = vulva Labia major + minor Mons pubis Clitoris Ducts Uterine tube = oviducts Vagina Glands Greater vestibular gland Female Reproductive System pg 365

32. Ovaries (2) Produce and store ova (eggs) Produce estrogen Tunica albuginea Fibrous capsule that surrounds the ovary Germinal epithelium Covers the tunica albuginea Mesothelium Anatomy pg 365

33. Ovaries Surrounded by peritoneal cavity Ligaments Broad ligament Supports uterus and oviducts Suspensory ligament Attaches ovaries to lateral pelvic wall Ovarian ligament Anchors the ovary to the uterus medially Round ligament Part of broad ligament Attaches uterus to labia majorum Anatomy pg 365

34. Oogenesis: production of eggs (ova) • Stem cells = oogonia undergo Mitosis • All of female’s oogonia produced while fetus • Oogonia become oocytes • Oogonia begin Meiosis I are called primary oocytes (2n) • Meiosis I is stalled before birth and until ovulation • During ovulation, Meiosis I completed and Meiosis II begins • Once Meiosis II begins, primary oocytes now called secondary oocytes (n) • Meiosis II is completed when sperm penetrates plasma membrane of the egg • When Meiosis II is completed, secondary oocyte is now called ovum (egg) • Meiosis II results in 4 daughter cells • 1 ovum and 3 polar bodies (degenerate) www.cartage.org.lb

35. Also called oviducts, fallopian tubes Begins laterally near ovary and ends medially at uterus 3 parts: Infundibulum Lateral, funnel shaped portion Fimbrae on edges Ampulla Medial to infundibulum Expanded portion Site where fertilization occurs Isthmus Medial part of the tube Visceral Peritoneum, Smooth Muscle, Ciliated simple columnar epithelium Uterine Tubes pg 414

36. Through the oviduct Receives oocyte after ovulation Peristaltic waves Cilia lining tube Contains cells to nourish ova Ectopic pregnancy Implantation of embryo outside of the uterus Movement of Ova faculty.une.edu

37. Function: Receive, retain, nourish fertilized egg (=zygote) 3 layers of wall: Perimetrium (outer) Myometrium (middle) Endometrium (inner) Portions: Body Fundus Isthmus Location: Anterior to rectum Posterosuperior to bladder Uterus pg 414

38. Location: Below the isthmus of the uterus Considered the narrow neck of the uterus Projects into the vagina Function: Keeps uterus closed and fetus within it during pregnancy (collagen) Cervix pg 414

39. Location: Inferior to the uterus Anterior to the rectum Posterior to the urethra and bladder Birth canal 3 layers: Adventitia Muscularis Mucosa Rugae Vaginal orifice Hymen Extension of mucosa Incomplete wall / diaphragm Vagina pg 414

40. Mons pubis Rounded pad over the pubic symphysis Labia Major Fatty skin folds with hair Minor Smaller, hairless folds inside major 3 parts: Vestibule created by labia minor opening for urethra and vagina Central tendon Perineal body Fourchette Junction of labia minor Female External Genitalia = “Vulva” pg 443, 439

41. Clitoris Superior to vestibule Composed of erectile tissue Homologous to the penis Components: Crura Prepuce Corpus cavernosa No corpus spongiosum Bulbs of vestibule Engorge with blood to help grip the penis Greater vestibular glands Either side of vaginal opening Secrete mucus to make intercourse possible Female External Genitalia = “Vulva” pg 443, 439

42. Vasculature Uterine arteries from internal iliac and arcuate branches =uterus Ovarian arteries from abdominal aorta and ovarian branches of uterine arteries = ovaries Innervation Branches of Pudendal nerve (hypogastric plexus & pelvic splanchnic nerves) Vasculature and Innervation pg 317 pg 432

43. Fertilization: sperm meets egg Path of sperm: Seminiferous tubulestubulus rectus rete testisefferent ductules duct of epididymis vas deferens ejaculatory duct  urethrafemale’s vagina uterusoviduct Path of egg: ovaryperitoneal cavityinfundibulum (oviduct) oviduct The meeting: Sperm + egg meet in uterine tube sperm penetrates egg = fertilization Zygoteuterus for implantation in uterine wall