L7 Review - Gross Anatomy PDF

Lecture 7: Gross Anatomy - Male Reproductive Overview: glands for secretion (testis, seminal vesicle, prostate, bulbourethral gland), gonads for gametes (testis), ducts for transport (efferent ductules, epididymis, ductus deferens, urethra), penis for copulation Peritoneal coverings: continuous w/...

Lecture 7: Gross Anatomy - Male Reproductive Overview: glands for secretion (testis, seminal vesicle, prostate, bulbourethral gland), gonads for gametes (testis), ducts for transport (efferent ductules, epididymis, ductus deferens, urethra), penis for copulation Peritoneal coverings: continuous w/ abdominal peritoneum, covers superior part of bladder & part of seminal vesicles & ductus deferens, continues posterior to rectum; forms rectovesical pouch (b/w bladder & rectum) Testis: Tunica albuginea: white, smooth fibrous capsule which surrounds seminiferous tubules & mediastinum testis Tunica vaginalis: embryonic remnant of peritoneum which descended w/ testis; closed sac covering lateral & most of posterior parts of testis ​ Parietal layer: ext. layer separated by fluid Visceral layer: covers testis except at attachment of epididymis/ductus deferens Sinus epididymis: dead end recess of tunica vaginalis b/w body of epididymis & posterolateral surface of the testis Mediastinum testis: posterior region of testis not covered by tunica vaginalis, site of entry of vasculature, nerves, & lymphatics; site of exit of efferent ductules Septa: inward projections of tunica albuginea dividing the testis into lobules (200-300) 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 Blood supply: testicular a. (from aorta, supplies testis & epididymis), cremasteric a. (from inf. epigastric, supplies ductus deferens), deferential a. (from sup. or inf. vesical, supplies ductus deferens) Venous drainage: pampiniform plexus around testis & spermatic cord → testicular vv. ​ Varicocele: enlargement of the pampiniform plexus vessels, a main cause of male infertility Lymphatics: travels with testicular vessels and drains to lumbar/aortic nodes Innervation: derived from aortic and renal plexuses ​ Sympathetic efferents: vasomotor; follow arteries; cause testes to engorge during arousal ​ Visceral afferents: transmit pain; travel with sympathetics back to spinal cord Epididymis: system of tortuous tubules in which spermatozoa are stored and mature 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, lymphatics, innervation: same as testis Ductus (vas) deferens: transports mature spermatozoa to the ejaculatory duct Structure: thick smooth muscle walls, small lumen; acquires coverings of spermatic cord during descent of testis; expands to form ampulla posterior to bladder, joins seminal vesicle duct to form ejaculatory duct Course: travels superiorly posterior to bladder, crosses over ureter before entering deep inguinal ring Seminal vesicle & ejaculatory duct: Seminal vesicle: tightly coiled tube resembling the ampulla of ductus, lateral to ampulla of ductus; separated from rectum by rectovesical pouch & septum Ejaculatory duct: formed by convergence of duct of seminal vesicle & ductus; enters posterior surface of the prostate & opens into the posterior wall of prostatic urethra Prostate: largest accessory sex gland; produces prostatic fluid Base: superior portion in contact with bladder; prostatic urethra begins here Apex: inferior portion in contact with UGD; surrounded by EUS Posterior surface: related to seminal vesicles, ampullae of ductus and rectum, rectovesical septum Anterior surface: related to pubis and puboprostatic ligaments Urethral crest: elevated area of posterior prostatic urethra; widens into the seminal colliculus (where the openings of the ejaculatory ducts empty their secretions) Urethral sinuses: border the urethral crest/seminal colliculus; receive openings of prostatic glands Prostatic utricle: midline structure homologous to female uterus Zones: anterior (anterior to other zones; non glandular ), transitional (surrounds urethra, prone to benign prostatic hypertrophy), peripheral (most external; surrounds central zone; highest incidence of prostatic cancer), central (surrounds ejaculatory ducts) Blood supply, lymphatics, innervation (ductus deferens, prostate, seminal vesicle): Arterial supply: inferior vesical and middle rectal aa. Venous: 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: sympathetics from pelvic plexus supply their smooth muscle Bladder & urethra: hollow muscular bag located in the true pelvis for the storage of urine (highly distensible); separated from pubic bones by retropubic space Fundus/base: posteroinferior portion where ureters enter; related to ant. vaginal wall (F) or rectum (M) Apex: extends anteriorly toward the superior edge of pubic symphysis Body: extends from apex to fundus Neck: convergence of fundus and inferolateral surfaces; rests on prostate (M, transitions to prostatic urethra) or levator ani (F); held by pubovesical ligament (F) & puboprostatic ligament (M) Relationships (female): uterus (superior, vesico-uterine pouch b/w), vagina (posterior), pubis (anterior) Relationships (male): prostate (inferior), pubis (anterior), rectum (posterior, rectovesical pouch b/w) Detrusor muscle: main muscular component of bladder; several layers of SMC; parasympathetic control Internal urethral sphincter: surrounds internal urethral orifice; SMC under involuntary SANS control Ureteric orifices: enter bladder obliquely; slit-like so internal bladder pressure keeps them closed; connected by interureteric fold of mucus membrane Trigone: area b/w the three bladder orifices, mucus membrane is firmly attached (rest of the mucus membrane is loosely attached w/ numerous folds) Blood supply: sup/inf vesical & deferential aa. (M); superior vesical & vaginal aa. (F) Venous drainage: deep dorsal v. (penis)→ vesical & prostatic plexuses → internal Iliac & vertebral plexuses (M); dorsal v. (clitoris) → vesical plexus internal Iliac & vertebral plexuses (F) Lymphatic drainage: superior part to external iliac nodes; inferior part to internal iliac nodes Female urethra: shorter, passes from neck of bladder directly through deep perineal pouch & perineal membrane & empties via external urethral orifice; paraurethral (Skene’s) gland = “female prostate” Cystocele: pubocervical fascia is torn by childbirth → bladder herniates into vagina, often occurs w/ urethrocele Male urethra: preprostatic part (associated w/ IUS) → prostatic part (through prostate) → membranous part (associated w/ EUS & deep perineal pouch) → spongy (penile) part