Advanced Perineal Muscles Quiz

Q1. A lesion of the deep branch of the perineal nerve would most directly weaken which pair of superficial perineal muscles?

• Bulbospongiosus and ischiocavernosus
• Gluteus maximus and gluteus medius
• Puborectalis and iliococcygeus exclusively
• Piriformis and obturator internus

Q2. Damage to the inferior rectal nerves would most directly compromise which voluntary action?

• Voluntary contraction of the external anal sphincter
• Contraction of the urinary bladder detrusor
• Autonomic contraction of the internal anal sphincter
• Peristalsis of the sigmoid colon

Q3. A tear involving the perineal body during childbirth can disrupt several muscular attachments. Which muscle is among those commonly associated with this structure?

• Bulbospongiosus
• Gluteus medius
• Obturator externus
• Iliacus

Q4. Why can damage to the perineal body impair pelvic support?

• It forms the entire pelvic diaphragm
• It is the primary attachment of the femoral nerve
• It serves as an attachment point for multiple supporting muscles
• It contains the main arterial supply to both lower limbs

Q5. Which action of bulbospongiosus in the male assists during ejaculation?

• Relaxation of the internal anal sphincter
• Rhythmic compression of the bulb and spongy urethra
• Contraction of the urinary bladder wall
• Elevation of the testis by the cremaster

Q6. In the female, injury to bulbospongiosus would most directly affect which function?

• Contraction of the uterine myometrium
• Compression of the bulbs of the vestibule and constriction of the vaginal opening
• Movement of the ovum through the uterine tube
• Relaxation of the urinary bladder

Q7. A patient retains autonomic function of the internal anal sphincter but loses voluntary anal closure. Which muscle is most likely dysfunctional?

• Obturator internus
• External anal sphincter
• Internal anal sphincter
• Ischiocavernosus

Q8. Which functional relationship best explains the role of ischiocavernosus during erection?

• Contraction relaxes the external anal sphincter
• Contraction moves the testis through the inguinal canal
• Contraction opens the urethral lumen for urination
• Compression of the crus helps maintain pressure within erectile tissue

Q9. A pudendal nerve injury affecting motor branches in the perineum could produce which combination of deficits?

• Paralysis of the abdominal diaphragm
• Loss of hip extension only
• Loss of detrusor smooth muscle only
• Impaired voluntary continence and weakened perineal muscle function

Q10. Which statement best integrates the functions of the perineal muscles?

• They contribute to perineal support, continence, and sexual and urogenital functions
• They function only in hip movement
• They consist entirely of involuntary smooth muscle
• Their only function is to support the rectum