PP3 - Male Genitalia (Neurovasculature & Lymphatics)

Question 1

which artery runs within the corpora cavernosa to supply erectile tissue?
A) superficial dorsal artery
B) deep dorsal artery
C) inferior vesical artery
D) deep artery of penis

Answer 1

D) deep artery of penis

Question 2

dorsal nerve is a branch of a) WHAT nerve & gives sensory innervation to B) WHAT

Answer 2

a) PUDENDAL nerve (dorsal nerve is a branch of the pudendal nerve)
b) PENIS (and clitoris in females)

Question 3

erection is under what sort of autonomic stimulation - parasympathetic or sympathetic?

Answer 3

parasympathetic

Question 4

how does parasympathetic stimulation influence the erectile tissues & cause erection?

Answer 4

parasympathetic innervation dilates arteries within corpora cavernosa & corpus spongiosum - increases blood flow to erectile arteries = erection

Question 5

what happens to the ischiocavernous & bulbospongiosus muscles that helps them maintain?

Answer 5

ischiocavernosus - compresses veins & nerves - prevents blood leaving penis, helps maintain erection

bulbospongiosus - compresses bulb, helps maintain erection

Question 6

what type of erectile tissue makes up the bulbospongiosus muscle in males?

Answer 6

corpus spongiosum

Question 7

what is the primary nerve source for erection? from what nerve & its nerve roots?

Answer 7

cavernous nerves (from pelvic splanchnic nerves; S2-4)

Question 8

what type of autonomic nerve control governs emission?

Answer 8

sympathetic

Question 9

what happens in the penis during emission?

Answer 9

semen is moved into the prostatic urethra through smooth muscle contractions in the prostate & seminal vesicles

Question 9

what prevents retrograde ejaculation during emission?

Answer 9

contraction of the internal urethral sphincter

Question 9

which nerve roots are involved in emission?

Answer 9

sympathetic fibres from T11-L2

Question 9

describe what happens during emission - innervation involved, muscle involvement, route

Answer 9

sympathetic innervation from sympathetic fibres (T11-L2) triggers smooth muscle contraction from prostate & seminal vesicles

semen moved from ejaculatory duct into prostatic urethra

Question 9

what happens in the penis during ejaculation?

Answer 9

semen is expelled from the external urethral meatus

Question 9

what two types of nerve control does ejaculation involve?

Answer 9

somatic
parasympathetic

Question 9

Which spinal cord segments are primarily responsible for the sympathetic control of emission?
A) S2–S4
B) T11–L2
C) L4–S1
D) C8–T1

Answer 9

B) T11–L2
- nerve roots for the sympathetic fibres involved in emission that contract smooth muscle to move semen into prostatic urethra

Question 9

what is the somatic nerve involved in ejaculation? what does it do?

Answer 9

pudendal nerve - contracts bulbospongiosus muscle, propels semen out of spongy urethra

Question 9

what is the parasympathetic role in ejaculation?

Answer 9

smooth muscle contractions along urethra to propel semen

Question 9

where is semen expelled from during ejaculation?

Answer 9

external urethral meatus - tip of penis

Question 9

The cavernous nerves involved in erection are primarily derived from:
A) Pudendal nerve
B) Hypogastric plexus
C) Pelvic splanchnic nerve
D) Ilioinguinal nerve

Answer 9

C) Pelvic splanchnic nerve - (S2-4), via prostatic plexus; parasympathetic

Question 9

what muscles are involved in ejaculation?

Answer 9

bulbospongiosus muscle
smooth muscle along the urethra

Question 10

Which phase of male sexual function involves contraction of the vas deferens and seminal vesicles?
A) Erection
B) Emission
C) Ejaculation
D) Detumescence

Answer 10

B) Emission

Question 11

The pudendal nerve contributes to which part of male sexual function?
A) Vasodilation during erection
B) Movement of semen into prostatic urethra
C) Expulsion of semen from the urethra
D) Contraction of internal urethral sphincter

Answer 11

C) Expulsion of semen from the urethra - pudendal nerve provides somatic innervation; contraction of bulbospongiosus muscle propels semen

Question 12

Which of the following is not part of the emission phase?
A) Contraction of smooth muscle in prostate
B) Vasodilation of helicine arteries
C) Seminal vesicle secretion
D) Internal urethral sphincter closure

Answer 12

B) Vasodilation of helicine arteries

Question 13

Failure of internal urethral sphincter contraction during emission may lead to:
A) Erectile dysfunction
B) Retrograde ejaculation
C) Priapism
D) Premature ejaculation

Answer 13

B) Retrograde ejaculation

Question 14

Which nerve is primarily somatic and innervates the bulbospongiosus muscle involved in ejaculation? A) Hypogastric nerve B) Genitofemoral nerve C) Pudendal nerve D) Cavernous nerve

Answer 14

C) Pudendal nerve (S2-4) - contracts bulbospongiosus muscle during ejaculation, propels semen out of spongy urethra

Question 15

Parasympathetic innervation to penile erectile tissue is transmitted via: A) Hypogastric nerves B) Genital branch of genitofemoral nerve C) Pelvic splanchnic nerves (S2–S4) D) Dorsal nerve of penis

Answer 15

C) Pelvic splanchnic nerves (S2–S4)

Question 15

During which phase is the bulbospongiosus muscle most active? A) Erection B) Emission C) Ejaculation D) Flaccid state

Answer 15

C) Ejaculation

Question 16

The deep arteries of the penis, crucial for erection, are located within: A) Corpus spongiosum B) Superficial fascia C) Corpora cavernosa D) Urethral meatus

Answer 16

C) Corpora cavernosa

Question 17

the external iliac artery travels under the inguinal ligament and becomes WHAT artery

Answer 17

FEMORAL artery (entering the femoral triangle)

Question 18

what does the distal part of the umbilical artery become after birth?

Answer 18

median umbilical ligament

Question 19

what artery arises from the patent proximal part of the umbilical artery? what does it supply?

Answer 19

superior vesical artery - supplies superior bladder & vas deferens

Question 20

which artery accompanies the obturator nerve and vein through the obturator canal? what region does this artery supply?

Answer 20

obturator artery - supplies medial thigh

Question 21

which artery replaces the inferior vesical artery in females?

Answer 21

vaginal artery

Question 22

what does the inferior vesical artery supply in males?

Answer 22

base of bladder vas deferens prostate gland

Question 23

through which foramen does the inferior gluteal artery exit the pelvis?

Answer 23

greater sciatic foramen

Question 24

what muscles are supplied by the inferior gluteal artery?

Answer 24

gluteal muscles

Question 25

the internal pudendal artery loops around which bony landmark to reach the perineum?

Answer 25

ischial spine - reaches perineum & travels through Alcock's canal

Question 26

what are the 4 branches of the internal pudendal artery? what do they each supply?

Answer 26

1. inferior rectal artery = distal part of anus 2. perineal artery = structures of superficial perineal pouch, bulb of penis 3. deep artery of clitoris/penis = travels within and supplies corpora cavernosa (erectile tissue) 4. dorsal artery of penis/ clitoris = skin/dorsal penis/ clitoris

Question 27

which branch of the internal pudendal artery supplies the erectile tissues?

Answer 27

deep artery of the penis/clitoris

Question 28

Which of the following arteries is a continuation of the patent portion of the umbilical artery? A) Inferior vesical B) Perineal C) Superior vesical D) Dorsal penile

Answer 28

C) Superior vesical artery - supplies superior bladder & vas deferens

Question 29

In females, which artery is functionally equivalent to the inferior vesical artery in males? A) Obturator artery B) Internal pudendal artery C) Vaginal artery D) Uterine artery

Answer 29

C) Vaginal artery

Question 30

Which branch of the anterior internal iliac artery exits the pelvis via the greater sciatic foramen and enters the perineum via the lesser sciatic foramen? A) Inferior gluteal artery B) Obturator artery C) Internal pudendal artery D) Superior vesical artery

Answer 30

C) Internal pudendal artery

Question 31

The deep artery of the penis runs within which structure? A) Corpus spongiosum B) Urethra C) Corpora cavernosa D) Ischiorectal fossa

Answer 31

C) Corpora cavernosa

Question 31

Which artery is NOT derived from the anterior division of the internal iliac artery? A) Uterine artery B) Superior vesical artery C) Iliolumbar artery D) Internal pudendal artery

Answer 31

C) Iliolumbar artery

Question 32

Which artery supplies the anal canal below the pectinate line? A) Middle rectal B) Superior rectal C) Inferior rectal D) Internal pudendal

Answer 32

C) Inferior rectal

Question 33

What artery primarily supplies the erectile tissue of the penis or clitoris? A) Dorsal artery B) Superior vesical artery C) Deep artery of the penis/clitoris D) Perineal artery

Answer 33

C) Deep artery of the penis/clitoris

Question 34

which nerves carry sympathetic fibres to the pelvis? (nerve roots?)

Answer 34

sacral splanchnic nerves (from L1–L2/3 via the sympathetic chain)

Question 35

which nerves carry parasympathetic fibres to the pelvis? (nerve roots?)

Answer 35

pelvic splanchnic nerves (S2-4)

Question 36

what effect do the sacral splanchnic nerves (L1-2/3) have on the internal urethral & anal sphincters?

Answer 36

contraction - prevents retrograde transport of sperm and maintains continence

Question 37

what effect do the pelvic splanchnic nerves (S2-4) have on the internal urethral & anal sphincters?

Answer 37

inhibit contraction - allow for urination and defectation

Question 38

what nerve fibres cause contraction of the internal urethral sphincter during emission? - sympathetic, parasympathetic, somatic? (+ nerve)

Answer 38

sympathetic - sacral splanchnic nerve (L1-2/3)

Question 39

what type of autonomic nerve control is involved in erection? what nerve fibres are involved?

Answer 39

parasympathetic - pelvic splanchnic nerves (S2-4)

Question 40

what nerve type causes relaxation of the internal anal and urethral sphincters?

Answer 40

parasympathetic - pelvic splanchnic nerves (S2-4)

Question 41

what are the functions of sympathetic innervation in the pelvis? (3)

Answer 41

1. *emission* - contract smooth muscle of vas deferens, prostate & seminal vesicles to propel semen to prostatic urethra 2. contract internal urethral & anal sphincters - prevent semen retrograde transport & maintain continence 3. reproductive gland secretion for reproductive fluid

Question 42

which plexus integrates both sympathetic and parasympathetic pelvic innervation?

Answer 42

inferior hypogastric plexus

Question 43

where do pelvic splanchnic nerves arise from?

Answer 43

ventral rami S2-4

Question 44

what is the main somatic nerve of the pelvis and perineum?

Answer 44

pudendal nerve (S2-4)

Question 45

where do most pelvic organs drain lymphatically? where do they then drain?

Answer 45

internal & external iliac LNs > pre-aortic LNs

Question 46

where do the testes drain lymphatically?

Answer 46

para-aortic (lumbar) LNs

Question 47

what nerves stimulate secretion from reproductive glands?

Answer 47

sympathetic nerves - sacral splanchnic sympathetic fibres (L1-2/3)

Question 48

Which nerve fibers are responsible for relaxing the internal anal sphincter during defecation? A) Somatic motor B) Sympathetic C) Parasympathetic D) Sacral splanchnic

Answer 48

C) Parasympathetic

Question 49

A 27-year-old man presents with erectile dysfunction. Neurological testing reveals damage to pelvic splanchnic nerves (S2–S4). Which of the following components of the sexual response is most likely impaired? A) Emission of semen into the prostatic urethra B) Erection due to impaired vasodilation of erectile tissues C) Ejaculation due to impaired contraction of bulbospongiosus D) Contraction of internal urethral sphincter preventing retrograde ejaculation E) Secretory activity of the seminal vesicles

Answer 49

B) Erection due to impaired vasodilation of erectile tissues - pelvic splanchnic nerves (S2–S4) carry parasympathetic fibres = responsible for erection via vasodilation of erectile tissue

Question 50

A patient has normal erection and ejaculation but no emission phase. Which autonomic pathway is likely impaired? A) Parasympathetic from pelvic splanchnic nerves B) Somatic pudendal nerve C) Sympathetic from sacral splanchnic nerves (L1–L2) D) Hypogastric nerve (afferent) E) Ilioinguinal nerve

Answer 50

C) Sympathetic from sacral splanchnic nerves (L1–L2)

Question 51

Which of the following BEST explains the sequential order of events in the male sexual response? A) Sympathetic → Parasympathetic → Somatic B) Parasympathetic → Sympathetic → Somatic C) Somatic → Sympathetic → Parasympathetic D) Somatic → Parasympathetic → Sympathetic E) Sympathetic → Somatic → Parasympathetic

Answer 51

B) Parasympathetic → Sympathetic → Somatic Erection: Parasympathetic (S2–S4, pelvic splanchnic) Emission: Sympathetic (L1–L2, sacral splanchnic) Ejaculation: Somatic (pudendal)

Question 52

A 35-year-old man has an injury to the deep perineal pouch, affecting the bulbospongiosus muscle. Which function is most impaired? A) Initiation of erection B) Vasodilation of corpora cavernosa C) Compression of the deep dorsal vein to maintain erection D) Propulsion of semen through the penile urethra E) Prevention of retrograde ejaculation

Answer 52

D) Propulsion of semen through the penile urethra - bulbospongiosus muscle (somatically innervated by pudendal nerve) contracts during ejaculation to expel semen from the spongy urethra