Advanced Ischiocavernosus Muscle Quiz

Q1. A lesion of the deep branch of the perineal nerve would most directly impair which action of ischiocavernosus?

• Relaxation of the internal anal sphincter
• Compression of the crus during erection
• Contraction of the detrusor
• Peristalsis of the rectum

Q2. Which hemodynamic effect most directly results from ischiocavernosus contraction?

• Complete closure of the internal pudendal artery
• Increased venous drainage from the corpora cavernosa
• Increased intracavernosal pressure with reduced venous outflow
• Reduced arterial inflow to all pelvic organs

Q3. A patient can expel residual urine normally but has weakness in voluntary compression of the penile crura. Which muscle is most specifically affected?

• Puborectalis
• External anal sphincter
• Ischiocavernosus
• Bulbospongiosus

Q4. Why does contraction of ischiocavernosus primarily affect the corpora cavernosa rather than the corpus spongiosum?

• The corpus spongiosum is located in the pelvic cavity
• The corpus spongiosum lies inside the ischial tuberosity
• Each crus is the proximal attached part of a corpus cavernosum
• The corpora cavernosa form the urethral wall

Q5. A pudendal nerve lesion proximal to the origin of the perineal nerve could weaken ischiocavernosus because the muscle depends primarily on which type of neural control?

• Sympathetic motor control only
• Visceral sensory control only
• Parasympathetic motor control only
• Somatic motor control

Q6. Which finding would best distinguish isolated ischiocavernosus weakness from isolated bulbospongiosus weakness in a male?

• Impaired expulsion of residual urine from the spongy urethra
• Reduced voluntary compression of the crura
• Loss of detrusor contraction
• Loss of voluntary anal closure

Q7. Which anatomical relationship permits ischiocavernosus to exert mechanical pressure directly on erectile tissue?

• It surrounds the urinary bladder
• It directly overlies the crus along the ischiopubic ramus
• It forms the pelvic diaphragm
• It lies within the corpus spongiosum

Q8. In a female, contraction of ischiocavernosus has its most direct mechanical effect on which structure?

• Crus of the clitoris
• External anal sphincter
• Greater vestibular gland
• Uterine cervix

Q9. Erection begins through autonomic vascular mechanisms, but ischiocavernosus contributes mechanically during erection. Which statement best describes this distinction?

• Autonomic nerves have no role in erection
• Ischiocavernosus alone initiates all arterial dilation in erectile tissue
• Autonomic activity initiates vascular engorgement, while ischiocavernosus mechanically reinforces rigidity
• Ischiocavernosus is autonomic smooth muscle

Q10. Which statement best integrates the anatomy and function of the ischiocavernosus muscle?

• It is a deep hip muscle responsible primarily for lateral rotation of the femur
• It is a superficial perineal skeletal muscle that covers the crus and helps maintain erection by compressing erectile tissue
• It is a smooth muscle sphincter that surrounds the urethra and controls urination
• It is a pelvic diaphragm muscle responsible primarily for fecal continence