Reproductive Organs PDF

Reproductive Organs DPM PROGRAM 1. Describe the location of the testicles and muscles that move them. 2. Describe the layers of the testicles. 3. Describe the neurovasculature of the testicles. 4. Describe the vas deferens, seminal vesicles, and bulbourethral glands. 5. Describe the location featur...

Reproductive Organs DPM PROGRAM 1. Describe the location of the testicles and muscles that move them. 2. Describe the layers of the testicles. 3. Describe the neurovasculature of the testicles. 4. Describe the vas deferens, seminal vesicles, and bulbourethral glands. 5. Describe the location features of the prostate gland. 6. Describe the blood supply and lymphatic drainage to male internal genital organs. 7. Describe the female internal genitalia. 8. Describe the peritoneal reflections, pouches, and ligaments that form important support for the female pelvic organs. 9. Describe the female internal genitalia blood supply and lymphatic drainage. 1 SMU - Internal Data Describe the location of the testicles and muscles that move them. • The paired testes, or testicles, are located in the scrotum: a sac of skin and superficial fascia that hangs inferiorly external to the abdominopelvic cavity at the root of the penis • viable sperm cannot be produced at the core body temperature of 37o C, the scrotum’s superficial position provides an environment that is about 3o C cooler • the scrotum responds to changes in external temperature: • Under cold conditions, muscles contract, the testes are pulled up toward the warm body wall, and the scrotal skin wrinkles to increase its thickness and reduce heat loss. • Under hot conditions, muscles relax, the scrotal skin is flaccid and loose, and the testes hang low to increase the skin surface available for cooling (sweating); this also moves the testis farther away from the warm trunk. • These actions are performed by two muscles in the scrotum: • The dartos muscle: a layer of smooth muscle in the superficial fascia, is responsible for wrinkling the scrotal skin. • The cremaster muscles bands of skeletal muscle that extend inferiorly from the internal oblique muscles of the trunk, are responsible for elevating the testes. 2 SMU - Internal Data Describe the layers of the testicles. • The visceral & parietal layers of the thin serous membrane, the tunica vaginalis, forms the outermost covering of the testes. It is derived from the parietal peritoneum. • Deep to the tunica vaginalis is a tough fibrous outer surface called the tunica albuginia. The tunica albuginia thickens posteriorly, forming the mediastinum testis, which sends septa into the testes dividing them into lobes. • Lobes are filled with seminiferous tubules, where sperm are produced. Sperm lead from the seminiferous tubules, through straight tubules, toward the rete testis, located in the mediastinum testis. • Efferent ductules carry the sperm into the head & body of the epididymis. Sperm mature in the epididymis. • The body of the epididymis leads to its tail which is continuous with the ductus/vas deferens. • The testes are connected to the floor of the scrotum by a thin scrotal ligament – a remnant of the fetal gubernaculum. 3 SMU - Internal Data Describe the neurovasculature of the testicles. • The testes receive their arterial blood from the testicular arteries, which branch from the abdominal aorta around L1 vertebral level. • The testicular veins, arise from a venous network in the scrotum called the pampiniform plexus. The pampiniform plexus surrounds the testicular arteries, and absorbs heat from the arterial blood, cooling it before it enters the testes. The left testicular v. drains to the left renal v., the right testicular v. drains directly to the inferior vena cava. Urinary bladder Superficial inguinal ring Testicular artery Spermatic cord Ductus (vas) deferens Pampiniform venous plexus Cremaster muscle External spermatic fascia Superficial fascia Scrotum containing dartos muscle Skin SMU - Internal Data Epididymis Tunica vaginalis (from peritoneum) Tunica albuginea of testis Internal spermatic fascia 4 Describe the vas deferens, seminal vesicles, and bulbourethral glands. Vas Deferens This tube of about 18 inches in length transports sperm from the epididymis & testis to the ejaculatory duct of the urethra. Ureter Seminal vesicle It begins at the tail of the epididymis, travels in the spermatic cord through the inguinal canal, then crosses the ureter to reach the posterior aspect of the bladder. At its distal end, it becomes dilated to form an ampulla, then narrows to join the duct of the seminal vesicle, here forming the ejaculatory duct. Seminal vesicles A highly coiled tubular gland, the secretions of the seminal vesicles contribute nutrients to the liquid portion of semen. The walls of the seminal vesicles contract during ejaculation and their secretory product is released into the ejaculatory duct. Bulbourethral (Cowper’s) glands These small glands located in the deep perineal pouch of males also contribute to semen (they drain into the spongy portion of the urethra) Prostate Ampulla of vas deferens Vas Deferens Ureter Seminal vesicle Bulbourethral gland SMU - Internal Data Posterior view 5 Describe the location features of the prostate gland. Ejaculatory duct Features of the prostate: -secretions play a role in the activation of sperm -situated inferior to the neck of the bladder -the apex of the gland, which points inferiorly, is supported inferiorly by the muscles of the deep perineal space -The base of the gland is closely related to the neck of the bladder -The ejaculatory ducts pierce the posterior surface of the prostate and open into the prostatic urethra. Lobes: • Anterior/Isthmus (anterior to urethra; fibromuscular) • (Infero)posterior (post. To urethra & inf. To ejaculatory ducts) • Right & Left Lateral (lateral to urethra) • Middle (between urethra and ejaculatory ducts, primary source of benign hypertrophy of the prostate - BHP) Internal urethral sphincter Lateral lobes Anterior lobe urethra Middle lobe Posterior lobe SMU - Internal Data Ejaculatory ducts Ejaculatory ducts External urethral sphincter 6 Describe the blood supply and lymphatic drainage to male internal genital organs. Deferential a. Ureteric a. Deep dorsal v. of penis Prostatic Venous plexus SMU - Internal Data Prostatic branches off Inferior Vesical a. (the inferior vesical a. also supplies the seminal vesicals, the ductus deferens and the inferior part of the ureters) -Venous drainage is via the prostatic plexus which drains to either the internal iliac v. or internal vertebral plexus via the lateral sacral v -Lymph drains to the lymph nodes around the internal and common iliac arteries to reach the para-aortic nodes. - Carcinoma of the prostate spreads by both hematogenous and lymphatic routes. The tumor spreads through the pelvic lymphatics to the lymph nodes around the internal and common iliac arteries and the aorta (para-aortic nodes). Hematogenous spread via the pelvic veins occurs late in the disease and produces systemic metastases. Generally, prostatic carcinoma shows a tendency to cause bony metastases because there are many connections between the prostatic venous plexus and the internal vertebral veins. 7 Describe the female internal genitalia. Vagina: - musculomembranous tube between vestibule and cervix - The vaginal fornix is a recess within the superior end of the vagina, around the inferior end of the cervix. It has anterior, posterior and lateral parts. The posterior fornix is the deepest. - Anteriorly, the vagina is related to the urethra and bladder. Posteriorly it is related to the anal canal, rectum and rectouterine pouch Uterus: - parts: -body (with its rounded fundus) -Isthmus (constriction) -cervix, inferior third of uterus which extends into the upper part of the vagina. The cervical canal opens into the vagina at the external os and into the uterus at the internal os - normal position is anteflexed (uterine body is bent anteriorly relative to the axis of the cervix) and anteverted (the cervix is tipped anteriorly relative to the axis of the vagina) Uterine tubes transport the ovum and zygote from the ovary towards the uterine cavity. They are subdivided into four parts: 1. infundibulum, with its fimbriae, capture ovulated gametes 2. ampulla: the widest and longest part, where fertilization typically occurs 3. isthmus: narrow, thick-walled part 4. uterine (intramural) part that passes through the wall of the uterus Ovaries: - female gonads - Embryological gubernaculum is divided into 2 by the uterus: 1. (Proper) ovarian ligament: between ovary & lateral angle of the uterus 2. Round ligament of the uterus: between uterus and labium majus - through the inguinal canal 8 SMU - Internal Data Body Fundus Cervix Isthmus Posterior fornix External os Ampulla Uterine part Isthmus Infundibulum Fimbriae Isthmus Ovarian ligament Lateral fornices SMU - Internal Data 9 Describe the peritoneal reflections, pouches, and ligaments that form important support for the female pelvic organs. -The peritoneum drapes over the pelvic viscera and creates two inferior extensions of the peritoneal cavity on either side of the uterus: -The rectouterine pouch: most inferior point of the peritoneal cavity in females -The vesicouterine pouch: between the bladder and the uterus -The peritoneum hangs over the ovarian vessels creating the suspensory ligament of the ovary Note: The ovaries are also connected to the angle of the uterus by the proper ovarian ligament. The proper ovarian ligament is continuous with the round ligament of the uterus. Both of these structures are adult derivatives of the embryological gubernaculum. -The broad ligaments consist of double folds of peritoneum that extend from the lateral wall of the pelvis to enclose the uterus, uterine tubes and ovaries. -Posteriorly, three parts of the broad ligament are visible: Mesometrium: major part of the broad ligament, inferior to the mesosalpinx and mesovarium Mesosalpinx: mesentery of the uterine tube Mesovarium: mesentery of the ovaries 10 SMU - Internal Data rectouterine pouch (of douglas) Suspensory ligament of the ovary SMU - Internal Data vesicouterine pouch Mesosalpinx POSTERIOR VIEW Mesovarium Mesometrium 11 Rectovesical pouch Rectouterine pouch Pararectal fossa Vesicouterine pouch MALE FEMALE -The kidneys and suprarenal glands are all retroperitoneal -the peritoneum of the abdominopelvic cavity covers the superior surfaces of the pelvic viscera, therefore, most pelvic viscera are considered subperitoneal -of all the pelvic viscera, only the uterine tubes are completely covered by peritoneum, have a mesentery (part of the broad ligament of the uterus), and are considered to be intraperitoneal (a misnomer, as they are not derived from the gut tube) SMU - Internal Data 12 The uterus is stabilised by condensations of the pelvic fascia that form ligaments. The pelvic fascia is connective tissue that occupies the space inferior to the peritoneum and within the muscular pelvic walls and floor. It is an inferior continuation of the transversalis fascia that lines the abdominal wall. Pubocervical ligament - between cervix and pubis Uterosacral ligament - between cervix and sacrum Transverse cervical (Cardinal ) ligament - between cervix and lateral pelvic walls. 13 SMU - Internal Data Describe the female internal genitalia blood supply and lymphatic drainage. Ovarian a. Uterine a. ureter Vaginal a. Internal pudendal a. BLOOD SUPPLY: Uterine a. - direct branch off the internal iliac. Courses in the base of the broad ligament, OVER the ureters, to reach the cervix. Major blood supply to the uterus and anastomoses with the ovarian a. (from abdominal aorta) and the vaginal a. Ovarian a. - direct branch off the abdominal aorta. Creates a fold of peritoneum called the suspensory ligament of the ovary. Supplies the ovaries and the fundus of the uterus. Vaginal a. -either a direct branch off the internal iliac or a branch off the uterine a. Supplies parts of vagina and often gives off an artery to the inferior aspect of the bladder Internal pudendal a. - supplies the most inferior part of the vagina LYMPHATICS: Lymphatics of uterus: Fundus near uterine tubes - along round ligament of uterus to the superficial inguinal nodes Lymph from the remainder of the Uterus and the ovaries drains deeply. Lymphatics from the vagina: The Vestibule & the inferiormost one-quarter of the vagina (same region that receives somatic innervation from a branch of the pudendal nerve and blood supply/drainage from branches of the internal pudendal vessels) also drains to the superficial inguinal nodes Lymph from the remainder of the vagina drains deeply. SMU - Internal Data 14