cocks and dicks

Male Reproductive System Overview

• The male reproductive system encompasses primary and accessory reproductive organs
• Key organs include the scrotum, testes, epididymis, vas deferens, seminal vesicles, prostate gland, and bulbourethral glands
• Spermatogenesis, factors affecting spermatogenesis, and cryptorchidism are central topics.

Divisions of Male Genital Organs

• External Genital Organs:
• Penis: Provides passage for urine and semen.
• Scrotum: Contains testes and epididymis.
• Internal Genital Organs:
• Testis: Male gonad, homologous to female ovaries.
• Epididymis: Stores and matures sperm.
• Vas Deferens: Transports sperm.
• Accessory Glands:
• Seminal Vesicles: Contribute to seminal fluid.
• Prostate Gland: Produces a component of seminal fluid.
• Bulbourethral Glands: Produce pre-ejaculate.

Male Reproductive System - Components

• Testis: Gonad
• Epididymis: Duct
• Vas Deferens: Duct
• Ejaculatory Duct: Duct
• Urethra: Duct
• Seminal Vesicles: Accessory Gland
• Prostate: Accessory Gland
• Bulbourethral Gland: Accessory Gland
• Scrotum: External Genitalia
• Penis: External Genitalia

Medial Section of Male Pelvis

• Structures include ureters, peritoneum, urinary bladder, seminal vesicle, ejaculatory duct, prostate, corpus cavernosum, corpus spongiosum, urethra, glans penis, navicular fossa, urethral opening (meatus), bulb of penis, epididymis, testis, scrotum, rectum, and anus.

Male Copulatory Organ - The Penis

• Function: Passageway for both urine and semen.
• Parts:
• Root/Radix (attached portion)
• Body/Corpus (free portion)
• Glans (tip)

Root of Penis

• Ischiocavernosus muscle covers the crus and beginning of corpus cavernosum
• Bulbospongiosus muscle covers the bulb of the penis

Body of Penis

• Contains two corpora cavernosa and one corpus spongiosum.
• Corpora cavernosa expand and fill with blood during erection.
• Corpus spongiosum surrounds the urethra.
• The crus and bulb are part of the root of penis.

Blood Supply of Penis

• Cavernous artery (deep artery of penis) supplies the corpora cavernosa
• Dorsal artery supplies blood to the dorsal surface of the penis
• Circumflex artery supplies outer regions
• Bulbourethral artery supplies the corpus spongiosum
• Veins drain blood from the penis: deep dorsal vein, superficial dorsal vein, and crural veins (crural arteries and vein support erection)

Nerve Supply of Penis

• Pudendal nerve
• Dorsal nerve of penis
• Deep perineal nerve
• Superficial perineal nerve
• Posterior scrotal nerves
• Sacral spinal nerves

Clinical Anatomy - Hypospadias/Epispadias

• Hypospadias: Urethral opening is on the underside of the penis.
• Epispadias: Urethral opening is on the top surface of the penis.
• These are congenital conditions.

Phimosis & Paraphimosis

• Phimosis: Foreskin cannot be retracted.
• Paraphimosis: Foreskin becomes trapped behind the glans penis. These are conditions where a tight foreskin prevents it from being drawn back over the gland.

Scrotum

• Contains testes, epididymis, and lower parts of spermatic cords
• Layers: skin, dartos muscle, external spermatic fascia, cremasteric muscle, and fascia, internal spermatic fascia
• Blood supply includes common iliac artery, external iliac artery, internal iliac artery, external pudendal artery, dorsal artery, deep artery, posterior scrotal artery, and anterior scrotal artery.
• Nerve supply from ilioinguinal nerve, genital branch of genitofemoral nerve, and posterior scrotal branches of perineal nerve.

Testes

• Male gonads, homologous to ovaries
• Suspended in scrotum by spermatic cord
• Upper pole tilted forward and laterally
• Location: within the scrotum
• External features: poles (upper and lower), borders (anterior and posterior), surfaces (medial and lateral)

Coverings of Testes

• Tunica vaginalis (parietal and visceral layers)
• Tunica albuginea (capsule)

Structure of Testes

• Lobules containing seminiferous tubules
• Tubuli recti, rete testis, vasa efferentia
• Head, body, and tail of the epididymis

Blood Supply of Testes

• Testicular artery
• Pampiniform plexus

Nerve Supply of Testes

• Sympathetic: Pre-ganglionic fibres (T10 & T11), Post-ganglionic fibres (renal & aortic plexuses)
• Sensory & vasomotor nerves
• Pain referred to umbilicus

External Features of Epididymis

• Head, body, and tail

Descent of Testes

• Develops in relation to segments T10 to T12
• Descend into scrotum in the 2nd month of intrauterine life
• Stages: reaches iliac fossa, deep inguinal ring, traverses inguinal canal, superficial inguinal ring. Reaches bottom of the scrotum in the 9th month

Cryptorchidism/Undescended Testes

• Undescendent testes remain in the abdominal cavity instead of descending into the scrotum
• Ectopic testes are located outside the normal scrotum location

Varicocele

• Varicose veins in the spermatic cord.

Tumors of Testes

• Types/distribution (statistics are provided)

Vas Deferens (Ductus Deferens)

• Location within the male reproductive system
• Transports sperm from the epididymis to the ejaculatory duct
• Arterial supply: branch of superior vesical artery
• Venous drainage: Pampiniform plexus
• Nerve supply: testicular plexus

Vasectomy

• Surgical procedure to prevent pregnancy

Ejaculatory Duct

• Formed by the union of the vas deferens and the seminal vesicle duct
• Empties into the prostatic urethra.

Seminal Vesicles

• Paired lobulated sacs between the bladder and rectum
• Secrete a component of seminal fluid; contains vesiculase (coagulating enzyme)

Bulbo-Urethral Glands

• Located in the deep perineal pouch on either side of the membranous urethra
• Secrete pre-ejaculate.

Prostate

• Accessory gland, located in the lesser pelvis
• Contains fibromuscular stroma with embedded glandular elements
• Shape: inverted cone
• Gross features: apex, base, anterior surface, posterior surface, inferolateral surface.
• Lobes: Anterior, Posterior, Median/middle/prespermatic lobe.

Capsules of Prostate

• True capsule (formed by condensation of peripheral part of the gland, fibromuscular)
• False capsule (lies outside true capsule, Anteriorly continuous with puboprostatic ligaments, Posteriorly forms by rectovesical fascia of Denonvillier's)
• Contains no venous plexus

Structures within Prostate

• Prostatic urethra
• Prostatic utricle
• Ejaculatory duct
• Urethral crest
• Colliculus seminalis
• Prostatic sinus
• Opening of prostatic ducts

Blood Supply & Venous Drainage of Prostate

• Inferior vesical arteries
• Superior (central) prostatic pedicle
• Inferior (capsular) prostatic pedicle
• Middle rectal artery
• Apical prostatic-rectal anastomoses
• Venous drainage: venous plexus

Nerve Supply of Prostate

• Inferior mesenteric plexus
• Hypogastric nerve
• Pelvic plexus (inferior hypogastric plexus)
• Pelvic nerves (parasympathetic)

Age Changes of Prostate

• Prostate gradually increases in size from adolescence to older adulthood
• Typical size at different ages (walnut, golf ball, lemon, cricket ball)
• Symptoms associated with age-related prostate enlargement: urinary frequency, urgency, hesitancy

Clinical Anatomy of Prostate

• Benign Prostatic Hyperplasia (BPH): Enlargement of prostate causing urinary problems
• Prostate cancer: presence/detection/metastatic spread