Unit 4: Lecture 6 (Finish Perineum & Pelvic Neurovasculature, Start and Finish Pelvic Urinary Organs, & Start Male Internal & External Genitalia)

True

(T/F) The pelvic cavity is predominantly innervated by the sacral and coccygeal nerves.

Lumbosacral trunk

What is formed by anterior rami of L4 and L5?

Sacral plexus

What does the lumbosacral trunk join, which includes S1-S4 and part of S5?

Coccygeal plexus

What is formed by ventral rami of S4, S5, and coccygeal nerve (Co1)?

Pedendal nerve (S2-S4)

What is the main somatic nerve of the perineum; carries motor and sensory fibers?

Pudendal Nerve (S2-S4)

What nerve Exits pelvis through greater sciatic foramen, loops around sacrospinous ligament, and re-enters through lesser sciatic foramen?

External anal sphincter and peri-anal skin.

What does the inferior rectal nerve innervate?

Superficial and deep branches to urogenital triangle muscles

and skin.

What do the perineal nerves innervate in females?

Terminal sensory branch to clitoris

What does the dorsal nerve of clitoris innervate in females?

Superficial and deep branches to urogenital triangle muscles

and skin, and superficial branches innervate scrotum.

What do the perineal nerves innervate in males?

Primary sensory input to penis

What does the dorsal nerve of penis innervate?

Internal iliac artery

What is the principal vascular supply to the pelvic viscera, perineum, pelvic walls, and gluteal region?

Internal iliac artery

What artery branches from the common iliac artery opposite the lumbosacral joint (L5-S1) and divides into anterior and posterior divisions?

Internal iliac artery

What artery supplies blood to pelvic organs, pelvic walls, gluteal muscles, perineum, and

medial thigh?

Anterior Division of Internal Iliac Artery

What artery primarily supplies visceral structures—urinary bladder, rectum, reproductive organs and contributes to perineal, gluteal, and medial thigh supply?

Umbilical, obturator, inferior vesicle (males), vaginal (females), uterine (females), middle rectal, internal pudendal, and inferior gluteal arteries.

What are the key branches of the anterior division of internal iliac artery?

Umbilical artery

What branch off of the anterior division of internal iliac artery gives off superior vesical arteries before becoming the medial

umbilical ligament?

Obturator artery

What branch off of the anterior division of internal iliac artery supplies pelvic muscles and medial thigh; anastomoses with external iliac via pubic branch?

Inferior vesical artery (in males)

What branch off of the anterior division of internal iliac artery supplies bladder, seminal vesicles, and prostate?

Vaginal artery (in females)

What branch off of the anterior division of internal iliac artery is homologous to inferior vesical; supplies vagina and base of bladder?

Uterine artery

What branch off of the anterior division of internal iliac artery courses medially in the cardinal ligament; supplies uterus and anastomoses with ovarian artery?

Middle rectal artery

What branch off of the anterior division of internal iliac artery anastomoses with superior and inferior rectal arteries?

Internal pudendal artery

What branch off of the anterior division of internal iliac artery exits greater sciatic foramen and re-enters via lesser

sciatic foramen?

Inferior gluteal artery

What branch off of the anterior division of internal iliac artery often shares a trunk with internal pudendal; supplies gluteus maximus and lateral rotators?

Inferior rectal artery, perineal arteries (superficial and deep), dorsal artery of penis/clitoris, and deep artery of penis/clitoris.

What are the branches of the internal pudendal artery?

Middle and inferior rectal arteries

What two arteries does the superior rectal artery anastomosis with to provide collateral circulation to the rectum and is clinically relevant in colorectal surgery?

Iliolumbar, lateral sacral, and superior gluteal arteries.

What are the key branches of the posterior division of internal iliac artery?

Urinary bladder

What is a hollow muscular organ that temporarily stores urine prior to micturition?

Posterior to pubic symphysis and anterior to rectus

Where does the urinary bladder lie in males?

Anterior to uterus and vagina

Where does the urinary bladder lie in females?

Mucosa (Transitional epithelium), lamina propria, submucosa, detrusor muscle, and adventitia

What are the layers of the urinary bladder?

Mucosa (Transitional epithelium)

What layer of the urinary bladder allows for expansion; lines the bladder and ureters?

Detrusor muscle

What layer of the urinary bladder is smooth muscle responsible for bladder contraction?

Adventitia (or serosa on superior surface)

What layer of the urinary bladder is the outer fibrous covering?

Sympathetic (T11-L2 via hypogastric nerves)

What promotes detrusor relaxation and internal sphincter contraction—facilitates urine storage?

Parasympathetic (S2-S4 via pelvic splanchnic nerves)

What stimulates detrusor contraction and

internal sphincter relaxation—initiates micturition (urination)?

Somatic (S2-S4 via pudendal nerve)

What controls external urethral sphincter—voluntary control of urination?

True

(T/F) Spinal cord injuries above the sacral level can disrupt parasympathetic innervation, leading to neurogenic bladder dysfunction.

Within true pelvis and is pyramidal.

What is the position of the urinary bladder when empty?

Rises into the abdominal cavity and becomes ovoid.

What is the position of the urinary bladder when distended?

400-600 mL

What is the typical capacity of the urinary bladder?

Urethra

What serves as the terminal pathway for urine to exit the bladder and the body?

Urethra

What passes from the internal urethral orifice in the bladder through the pelvic floor to the external urethral orifice located in the vestibule, between the labia minora?

Internal urethral sphincter

Which urethral sphincter is smooth muscle?

External urethral sphincter

Which urethral sphincter is skeletal muscle?

True

(T/F) The shorter female urethra contributes to a higher incidence of urinary tract infections due to proximity to the anus and vaginal opening.

Prostatic, membranous, and spongy (penile) urethra

What are the three sections of the male urethra?

Membranous urethra

What is the shortest segment of the male urethra that traverses the deep perineal pouch and external sphincter?

Spongy (penile) urethra

What is the longest portion of the male urethra; runs within the corpus spongiosum; opens at external urethral orifice at the glans penis?

Seminiferous tubules, rete testis, efferent ductules, epididymis, ductus (vas) deferens, ejaculatory ducts, urethra

What is the pathway of sperm?

False

(T/F) Sperm passes through the seminal vesicles.

False

(T/F) Sperm passes through the internal urethral sphincter.

Seminiferous tubules

What is the site of spermatogenesis within the testis?

Rete testis

What is the network of tubules within the mediastinum testis?

Efferent ductules

What is the transport system to the epididymis?

Epididymis

What is the site of sperm maturation and storage?

Sperm

What are male reproductive cells produced in the seminiferous tubules of the testes?

Seminal fluid

What are the combined secretions from the accessory glands (seminal vesicles, prostate, bulbourethral glands)?

Semen

What is the suspension of sperm in seminal fluid; the complete ejaculate?

Utricular glands

What is the seminal vesicles homologus to in females?

Seminal vesicles

What secretes a viscous fluid rich in fructose (energy source), prostaglandins (stimulate smooth muscle contractions), and bicarbonate (neutralizes acidic urethra)?

Seminal vesicles

What is responsible for 60% of ejaculate volume?

Prostate gland

What secretes thin, milky fluid containing citric acid (metabolic substrate), enzymes, and seminalplasmin (antimicrobial protein)?

Skene's glands (paraurethral glands)

What is the prostate gland homologus to in females?

Prostate glands

What is responsible for 20-30% of semen?

Bulbourethral (Cowper's) Glands

What secretes a clear, alkaline mucus that lubricates the urethra and neutralizes

residual acidity from urine and is responsible for trace amounts of ejaculate?

Greater vestibular (Bartholin's) glands

What are the Bulbourethral (Cowper's) Glands homologous to in females?

Prostate cancer

What is a malignant neoplasm arising from the glandular epithelium of the prostate, most often in the peripheral zone?

Prostate cancer

What is the most common non-cutaneous cancer and the second leading cause of cancer-related death among men in many developed countries?

False

(T/F) Prostate cancer is often symptomatic in early stages.

True

(T/F) Most prostate cancers are adenocarcinomas.

True

(T/F) The lumbosacral trunk is not a nerve.

Digital rectal exam, serum prostate-specific antigen, transrectal ultrasound with biposy, and MRI

What are the ways to diagnose prostate cancer?

Active surveillance for low-risk cases, radical prostatectomy, radiation therapy (external beam or brachytherapy), hormonal (androgen deprivation) therapy, chemotherapy for metastatic disease

What are the treatment options for prostate cancer?

True

(T/F) Localized prostate cancer has an excellent prognosis (5-year survival >99%).

True

(T/F) Far more things exit through the greater sciatic foramen than the lesser sciatic foramen.

Benign prostatic hyperplasia

What is is a non‑cancerous enlargement of the prostate gland, usually involving the transitional zone around the prostatic urethra?

Sleep disturbance from nocturia or falls from urgent

nighttime voiding

What secondary effects of benign prostatic hyperplasia may PT/OT encounter in patients?

Median umbilical ligament

What structure on the anterior portion of the bladder is a remnant of the urachus?

Top portion

What part of the bladder is serosa rather than adventitia?

Internal urethra sphincter

What closes during ejaculation to prevent backflow into the urinary bladder?

Sperm

What are the smallest cells in the body?