HBF-III LEC 07 Gross Anatomy Male Reproductive Notes 2025 PDF

Gross Anatomy: Male Reproductive System Page 1 of 16 Dr. Mark Ireland SESSION LEARNING OBJECTIVES By the end of this session, the student should be able to accurately: 1. Summarize the anatomy of the male reproductive system including glands for secret...

Gross Anatomy: Male Reproductive System Page 1 of 16 Dr. Mark Ireland SESSION LEARNING OBJECTIVES By the end of this session, the student should be able to accurately: 1. Summarize the anatomy of the male reproductive system including glands for secretion, gonads for gamete production, and ducts for transport. 2. Describe the peritoneal relationships of the male reproductive organs. 3. Describe the anatomy of the testis: functions, external and internal features, arterial supply, venous & lymphatic drainage, and innervation. 4. Describe the anatomy of the epidydimis: functions, structural features, arterial supply, venous & lymphatic drainage, and innervation. 5. Describe the anatomy of the ductus deferens: functions, structural features, course and organ relationships. 6. Describe the anatomy of the seminal vesicles and ejaculatory ducts. 7. Describe the anatomy of the prostate gland: functions, structural features and relationships, and zones. 8. Describe the arterial supply, venous & lymphatic drainage, and innervation of the prostate gland. 9. Describe the anatomy of the bladder and urethra: structural features, relationships to other structures, arterial supply, venous & lymphatic drainage, and innervation. Supplemental Reading: Gray’s Anatomy for Students, 4th Ed. (2020) Drake, Vogl, Mitchell (Elsevier) Chapter 5. Atlas of Human Anatomy, 7th Ed. (2019) Netter (Elsevier) Chapter 6. Gross Anatomy: Male Reproductive System Page 2 of 16 Dr. Mark Ireland SESSION OUTLINE I. Overview A. Glands for Secretion B. Gonads for Gamete Production C. Ducts for Transport II. Peritoneal Coverings III. Testis A. Functions B. External Structure C. Internal Structure D. Blood Supply, Venous Drainage, Lymphatic Drainage, Innervation IV. Epidydimis A. Functions B. Structure C. Blood Supply, Venous Drainage, Lymphatic Drainage, Innervation V. Ductus Deferens A. Functions B. Structure C. Course and Relationships VI. Seminal Vesicle and Ejaculatory Duct VII. Prostate A. Functions B. Parts and Relationships C. Zones VIII. Arterial Supply, Venous Drainage, Lymphatics, Innervation IX. Bladder and Urethra – Structure, Relationships, Vasculature, Lymphatics, Nerves Gross Anatomy: Male Reproductive System Page 3 of 16 Dr. Mark Ireland I. OVERVIEW (Fig 1 Gray’s 5.47A) Fig 1 Glands for secretion →testis →seminal vesicle →prostate →bulbourethral gland – located in UGD Gonads for gamete production – testis Ducts for transport →efferent ductules in the testis →epididymis – initial part of ductus deferens →ductus deferens →urethra Penis for copulation – already discussed Gross Anatomy: Male Reproductive System Page 4 of 16 Dr. Mark Ireland II. PERITONEAL COVERINGS (Fig 2 Gray’s 5.59B) Fig 2 Derivation and Extent continuous with the abdominal peritoneum; covers the superior surface of the bladder and part of the seminal vesicles and ductus deferens; continues posterior onto the rectum →rectovesical pouch →rectovesical septum pelvic fascia separating bladder and prostate from rectum Gross Anatomy: Male Reproductive System Page 5 of 16 Dr. Mark Ireland III. TESTIS Functions →produces spermatozoa in its seminiferous tubules →produces testosterone in its Leydig cells for reproductive functions and 2° sex characteristics →normally located in scrotum for proper temperature development of sperm; left testicle normally located slightly lower External structure (Fig 3 Gray’s 5.47B) Tunica albuginea – white, smooth fibrous capsule tunica vaginalis – Fig 3 embryonic remnant of peritoneum which descended with testis; closed sac covering the anterior, lateral and most of the posterior parts of the testis →parietal layer – external layer separated from visceral layer by fluid →visceral layer- covers the testis except at the attachment of epididymis/ductus →sinus epididymis – dead end recess of tunica vaginalis between the body of the epididymis and the posterolateral surface of the testis mediastinum testis – posterior region of testis not covered by tunica vaginalis; site of entry of vasculature, nerves and lymphatics; site of exit of efferent ductules carrying spermatozoa Internal structure (Fig 3) septa – inward projections of tunica albuginea dividing the testis into 200-300 lobules seminiferous tubules – 1-3 per lobule; site of spermatozoa development; end as straight tubules rete testis – convergence of straight tubules at the mediastinum testis efferent ductules – emerge from rete testis and enter the epididymis Gross Anatomy: Male Reproductive System Page 6 of 16 Dr. Mark Ireland Blood Supply →testicular a. – from aorta supplies testis and epididymis →cremasteric a. – from inferior epigastric also contributes; also supplies ductus deferens →deferential a. – from superior or inferior vesical; also supplies ductus deferens Venous drainage – pampiniform plexus forms around testis and spermatic cord to help cool arterial blood for proper sperm development; plexus eventually forms testicular vv.; varicocele is an enlargement of the pampiniform plexus vessels (similar to varicose veins); varicocele is one of the main causes of male infertility Lymphatic drainage – travels with testicular vessels and drains to lumbar/aortic nodes Innervation – derived from aortic and renal plexuses →sympathetic efferents – follow arteries; vasomotor; testes engorge with blood during sexual stimulation →visceral afferents – transmit pain; travel with sympathetics back to spinal cord IV. EPIDIDYMIS (Fig 4 Gray’s 5.47B) Function – system of tortuous tubules in which spermatozoa are stored and mature Fig 4 Structure (Fig. 5.47B) – approximately 4 cm long but contains about 6 m of tightly coiled ducts →head – located over superior pole of testis; receives the efferent ductules →body – located along posterior border of testis; contains convoluted ducts →tail – located at inferior pole of testis; continuous with ductus deferens Blood Supply, Venous Drainage, Lymphatics, Innvervation- same as testis Gross Anatomy: Male Reproductive System Page 7 of 16 Dr. Mark Ireland V. DUCTUS DEFERENS Fig 5 Function – transports mature spermatozoa to the ejaculatory duct Structure – thick smooth muscle walls surround a small lumen; acquires spermatic cord coverings during descent of testis; expands to form an ampulla posterior to bladder; ends by joining with the duct of the seminal vesicle to form the ejaculatory duct Course and Relationships (Fig 5 Gray’s 5.47A) – water under the bridge! Also known as vas deferens VI. SEMINAL VESICLE AND EJACULATORY DUCT (Fig 5, 6 Netter 366) –tightly coiled tube about 10-15 cm long resembling the ampulla of the ductus; located lateral to the ampulla of the ductus; upper part covered by peritoneum; separated from rectum by rectovesical pouch and rectovesical septum; its duct joins with that of the ductus to form the ejaculatory duct; the ejaculatory duct enters the posterior surface of the prostate and opens into the posterior wall of the prostatic urethra. Gross Anatomy: Male Reproductive System Page 8 of 16 Dr. Mark Ireland Fig 6 Gross Anatomy: Male Reproductive System Page 9 of 16 Dr. Mark Ireland VII. PROSTATE Fig 7 Function and General Description – largest accessory sex gland; produces prostatic fluid; invested in a thin, dense true fibrous capsule; the prostatic venous plexus is located between the true capsule and the false capsule derived from pelvic fascia. Parts and Relationships (Fig 7 Gray’s 5.59B) →base – superior portion in contact with bladder; prostatic urethra begins here →apex – inferior portion in contact with UGD; surrounded by external urethral sphincter →posterior surface – related to seminal vesicles, ampullae of ductus deferens and rectum and rectovesical septum; can be palpated per rectum →anterior surface – related to pubis and puboprostatic ligaments →prostatic urethra (Fig 8 Gray’s 5.45C) Gross Anatomy: Male Reproductive System Page 10 of 16 Dr. Mark Ireland Fig 8 →urethral crest – elevated area of posterior prostatic urethra; widens into the seminal colliculus (where the openings of the ejaculatory ducts empty their secretions) →urethra sinuses – border the urethral crest/seminal colliculus; receive the openings of the prostatic glandular tissue →prostatic utricle – mid-line structure homologous to female uterus Gross Anatomy: Male Reproductive System Page 11 of 16 Dr. Mark Ireland →zones (Fig 9 Gray’s 5.48) →anterior – anterior to other zones; nonglandular →transitional – surrounds urethra, prone to benign prostatic hypertrophy (BPH) →peripheral – most external; surrounds central zone. Highest incidence of prostatic cancer →central – surrounds ejaculatory ducts; Fig 9 VIII. ARTERIAL SUPPLY TO PROSTATE AND SEMINAL VESICLE – inferior vesicle and middle rectal aa. Gross Anatomy: Male Reproductive System Page 12 of 16 Dr. Mark Ireland VENOUS DRAINAGE (Fig 10 Gray’s 5.67A) AND LYMPHATIC DRAINAGE – lymph drains to internal iliac nodes→common iliac nodes→aortic nodes Fig 10 The deep dorsal vein of the penis passes inferior to the pubic symphysis before emptying into the prostatic plexus; many interconnections between prostatic, vesical and rectal plexuses INNERVATION OF DUCTUS DEFERENS, PROSTATE AND SEMINAL VESICLE – sympathetics from pelvic plexus supply their smooth muscle Gross Anatomy: Male Reproductive System Page 13 of 16 Dr. Mark Ireland IX. BLADDER & URETHRA General Considerations – a hollow muscular bag located in the true pelvis for the storage of urine; highly distensible, may rise to the level of the umbilicus when full; separated from pubic bones by retropubic space External Structure and Relations (Fig 11 Gray’s 5.41A) fundus or base - posteroinferior portion; Fig 11 related in female to anterior vaginal wall and in the male to the rectum; where the ureters enter apex – extends anterior toward the superior edge of pubic symphysis body – extends from apex to fundus neck – convergence of fundus and inferolateral surfaces; rests on the prostate in the male and is the site of the junction of the bladder lumen and the prostatic urethra; rests on the levator ani in the female pubovesical and puboprostatic ligaments (female and male, respectively) (Fig 12 Gray’s 5.42) Fig 12 Gross Anatomy: Male Reproductive System Page 14 of 16 Dr. Mark Ireland Relationships of Female Bladder (Fig 13 Gray’s 5.59A) Fig 13 Relationships of Male Bladder (Fig 14 Gray’s 5.59B) Fig 14 Gross Anatomy: Male Reproductive System Page 15 of 16 Dr. Mark Ireland Internal Structure (Fig 15 Gray’s 5.41B) Fig 15 →detrusor muscle – main muscular component; smooth muscle arranged in several layers; parasympathetic control →internal urethral sphincter – surrounds internal urethral orifice; smooth muscle under involuntary sympathetic control →ureteric orifices – enter bladder obliquely; slit-like so internal bladder pressure keeps them closed; connected by interureteric fold of mucus membrane →trigone – area between the three orifices where mucus membrane is firmly attached; the rest of the mucus membrane is loosely attached and thrown into numerous folds Blood Supply – superior vesical, inferior vesical and deferential in males; superior vesical and vaginal in females Venous Drainage (Fig 10 Gray’s 5.67A) – in males the vesical and prostatic venous plexuses communicate with deep dorsal vein of the penis, internal iliac veins and vertebral venous plexus; in females the vesical venous plexus communicates with the dorsal vein of the clitoris, the vaginal venous plexus, internal iliac veins and vertebral venous plexus Lymphatic Drainage – superior part to external iliac nodes; inferior part to internal iliac nodes Gross Anatomy: Male Reproductive System Page 16 of 16 Dr. Mark Ireland URETHRA Female (Fig 16 Gray’s 5.45A) Fig 16 (female prostate) A cystocele occurs when the tough fibrous wall between a woman's bladder and her vagina (the pubocervical fascia) is torn by childbirth, allowing the bladder to herniate into the vagina. Urethroceles often occur with cystoceles. Male (Fig 17 Gray’s 5.45B) Fig 17