PELVIS INNERVATION + PERINEUM

Question 1

What nerve, when impinged leads to numbness and tingling of perineal region along with impotence and intermittent fecal incontinence? What is the significance of an anesthetic applied at this nerve?

Answer 1

Pudendal nerve;

A block at this nerve can provide temporary relief to pain in external hemorrhoids and external genitalia.

Question 2

What ligament in females passes through the inguinal canal? What is the male counterpart?

Answer 2

Round ligament of the uterus;

Gubernaculum

Question 3

Damage to the prostate nerve plexus can lead to what condition?

Answer 3

Erectile dysfunction.

Question 4

Preganglionic fibers of the pelvic splanchnic nerve synapse on what types of ganglia?

Answer 4

Ganglia in or near the viscera or on the pelvic plexus

Question 5

The parasympathetic fibers in the bladder wall cause what muscle to contract?

Answer 5

Detrusor muscle

Question 6

A slow growing tumor in the deep perineal space can endanger what male structures?

Answer 6

Bulbourethal glands, Membranous portion of urethra

Question 7

A culdocentesis or long needle inserted into a pregnant female to test for amniotic fluid would have to penetrate what structure?

Answer 7

Posterior fornix of the vagina

Question 8

The internal sphincter is ________ muscle of the anus that is controlled by _________. The external sphincter is _________, that is controlled by __________ innervation.

Answer 8

Internal anal sphincter = Smooth muscle = PSNS;

External anal sphincter = Skeletal muscle = Somatic NS

Question 9

Structures above the pectinate line of the perineum, are derived from the ________. Its sensory innervation is through _______ afferents to perceive _________.

Answer 9

Hindgut (endoderm-derived);
Visceral afferents;
Pressure “How much fecal matter is in rectum”

Question 10

Structure below the pectinate line are derived from the _____________. The sensory innervation is taken through the ___________ afferents to perceive ______.

Answer 10

Proctodeum (ectoderm-derived);
Somatic afferents;
Pain “External anal Hemorrhoids are covered by skin and painful”

Question 11

Structures of the hindgut, above the pectinate line, drain into _________ _______ nodes. This differs from structures of the proctodeum, below the pectinate line, that drain into the ___________ ______ nodes.

Answer 11

Above pectinate line = Internal Iliac nodes;

Below pectinate line = Superficial inguinal nodes

Question 12

What are structures of the deep perineal pouch in males?

Answer 12

Males: Membranous portion of urethra, bulbourethral glands, Sphincter Urethrae muscle, Deep Transverse Perineal muscle

Question 13

What structures are in the deep perineal pouch in females?

Answer 13

The Compressor urethrae muscle and Deep transverse perineal muscle, Urethra, Vagina, blood vessels and nerves

Question 14

The _________ _________ pouch is found between the deep fascia and perineal membrane. The _________ ________ pouch is found between the perineal membrane and superficial perineal fascia.

Answer 14

Deep perineal pouch;

Superficial perineal pouch

Question 15

What 3 skeletal muscles are contracting during an penile erection?

Answer 15

Ischiocavernous muscle, Bulbospongiosus muscle and Superior transverse perineal muscle

Question 16

What anatomical structures are found within the male superficial perineal pouch?

Answer 16

Superficial penile (over the penis), Dartos Fascia over the scrotum and Scarpa’s Fascia that covers the anterolateral abdominal wall

Question 17

Describe structure is damaged from a Straddle injury.

Answer 17

This is a tear in urethra below the floor commonly caused by falling on a bike and hit peddle. The blood/urine engorges around the penis, scrotum and lower abdominal wall.

Question 18

In females, the ________ _______ glands is in the superficial perineal pouch; whereas, in males the ___________ glands are found in the deep perineal pouch.

Answer 18

Greater Vestibular glands in female = Bulbourethral (Cowper’s) gland in males

Question 19

What is the clinical relevance and risk of an Episiotomy?

Answer 19

This is where a surgeon cuts through the perineum if a delivery of a baby is compromised by the size of his or her head. This can lead to future issues with the female’s bulbospongiosus muscle.

Question 20

What 3 muscles attach to the central common tendon in the superficial perineal pouch?

Answer 20

1. Superior transverse perineal muscle
2. Bulbospongiosus Muscle
3. Ischiocavernous Muscle

Question 21

What is the purpose of the Deep dorsal vein in regards to blood supply of the perineum?

Answer 21

Primary venous return for erectile tissues such as the clitoris and penis that passes through the opening in the UG diaphragm and pubis. It makes a venous plexus that covers the prostate in males and the urinary bladder in females.

Question 22

The _________ nerves are responsible for innervating the vasodilation that fills the erectile tissue with venous blood during an erection.

Answer 22

Cavernous nerves (PSNS innervation) = maintain erection

Question 23

The _________ nerves, responsible for the sympathetic innervation to the external genitalia, function during an penile ejaculation.

Answer 23

Pudendal nerves (SNS, L1-L2 + Somatic,S2-S4)

Question 24

Where would a gynecologist apply to anesthetic for female chronic perineum pain and what is the name of that nerve block?

Answer 24

Pudendal nerve block would be applied at the Ischial spine to deal with female chronic pain in the perineum.

Question 25

Benign Prostate Hypertrophy (BPH) is associated with enlargement of the _________ prostate lobe. What structure does this growth impede?

Answer 25

BPH = enlargement of middle prostate lobe which blocks the Prostatic urethra

Question 26

The anal canal as part of the proctodeum drains fluid into the what lymphatic node?

Answer 26

Structures below the pectinate line drain into the Superficial inguinal node. This also includes the thigh and gluteus muscles.

Question 27

A __________ _____ presents as colicky loin-to-groin pain.

Answer 27

Ureteric stone aka kidney stone

Question 28

This space is found between the posterior aspect of the pubic symphysis and the sacral promontory and is often used for measurement of the pelvic outlet during childbirth. What is this?

Answer 28

True conjugate

Question 29

Retrograde ejaculation involves a blow of semen into the _______, from an incompletely closed ________ ____ sphincter, often caused by a loss of ________ innervation that causes tonic contraction.

Answer 29

Bladder;
internal urethral sphincter;
Sympathetic (SNS)

Question 30

Describe what occurs if there is a tear in Buck’s Fascia

Answer 30

Extravasation of urine into the lower abdominal wall and scrotum.