Perineum

Question 1

What are the boundaries of the perineum

Answer 1

inferior to pelvic diaphragm, bound by inferior pelvic aperture

Question 2

What happens if you draw a line between the ischial tuberosities

Answer 2

You divide the perineum into the urogenital triangle, and anal triangle

Question 3

What are the sischioanal fossae

Answer 3

fat filled spaces on either side of the anal canal that allow the anal canal to expand if necessary

Question 4

What are the lateral walls of the fossae formed by

Answer 4

obturator internus and ischial tuberosity

Question 5

What are the medial walls of the fossae formed by

Answer 5

External anal sphincter

Question 6

What does each fossa project anteriorly into

Answer 6

The UG triangle, formin anterior recesses, allowing for easy spread of infection between UG and anal triangle

Question 7

What is the importance of the ischioanal fossa communicating posteriorly

Answer 7

Allows for spread of infection between left and right sides of anal triangle

Question 8

Where does the anal canal begin

Answer 8

At the anorectal flexure (held up by puborectalis)

Question 9

What allows the anus to close off when not in use

Answer 9

anal columns and anal valves

Question 10

What is the line where external tissue meets internal tissue in the anal canal

Answer 10

Pectinate line (inferior to anal valves

Question 11

What supplies/drains anal canal superior to pectinate line

Answer 11

superior rectal vessels (IMA) with aid from middle rectal vessels

Question 12

Where does lymph superior to pectinate line drain

Answer 12

internal iliac nodes

Question 13

What innervation does superior to pectinate line receive

Answer 13

Parasympathetic and Sympathetic (similar to hindgut)
Visceral sensory (stretch, ischemia)

Question 14

What supplies/drains inferior to the pectinate line

Answer 14

inferior rectal vessels (to pudendal, to internal iliac)

Question 15

Where does lymph drain inferior to the pectinate line

Answer 15

superficial inguinal nodes

Question 16

What innervation does inferior to pectinate line receive

Answer 16

Somatic via inferior rectal nerve (pain, temp, touch)

Question 17

What anastomoses happens in the anal canal

Answer 17

Superior rectal vein (proximal, portal) with Inferior rectal vein (distal, caval)

Question 18

What are external hemorrhoids indicative of

Answer 18

portal hypertension

Question 19

What is the internal anal sphincter made of

Answer 19

smooth muscle

Question 20

What effect does innervation have on the internal anal sphincter

Answer 20

Sympathetic- stimulates contraction, prevents defecation

Parasympathetic- relaxes, allowing defecation

Question 21

What is the external anal sphincter made of

Answer 21

Skeletal muscle, receiving somatic motor innervation

Question 22

What does “potty training” involve

Answer 22

learning to control the external anal sphincter

Question 23

What is SF fatty layer of SF perineal fascia continuous with

Answer 23

camper fascia

Question 24

What is deep membranous layer of SF perineal fascia continuous with

Answer 24

Scarpa fascia (dartos fascia in men, colles fascia in women)

Question 25

What separates superficial and deep muscles on the perineum (UG triangle)

Answer 25

Perineal membrane (openings for vagina and urethra)

Question 26

What does the perineal membrane provide

Answer 26

attachment for erectile tissue and muscles of UG triangle

Question 27

What is an episiotomy

Answer 27

incision made through, or lateral to the perineal body during child birth to minimize tearing

Question 28

What are the external female genitalia

Answer 28

Mons pubis, labia majora, labia minora (prepuce), vestibule (hymen)

Question 29

What is the erectile tissue in women

Answer 29

``` Corpora cavernosa (paired)- crus, body, and glans Bulbs of the vestibule ```

Question 30

What muscles cover erectile tissue

Answer 30

Crura covered by ischiocavernosus | Bulbs covered by bulbospongiosus

Question 31

What are the erectile tissues in men

Answer 31

``` Corpora cavernosa (paired)- crura Corpus spongiosum (unpaired)- glans, bulb ```

Question 32

What covers the glans of the penis

Answer 32

The prepuce (foreskin)

Question 33

What is the purpose of ischiocavernosus

Answer 33

aid in erection by compressing veins of corpora cavernosa and maintaining blood

Question 34

What is the purpose of bulbospongiosus

Answer 34

aid in erection and expel semen during ejaculation

Question 35

What muscle runs along the inferior border of the UG triangle

Answer 35

Superficial Transverse Perineal, helps stabilize perineal body

Question 36

What are the deep perineal muscles

Answer 36

Deep transverse perineal (smooth and skeletal in females) | External urethral sphincter (surrounds membranous urethra in men)

Question 37

What innervation does the external urethral sphincter receive

Answer 37

Somatic motor- stimulating contraction may help prevent urination

Question 38

What are the levels of urethra in men

Answer 38

Prostatic, membranous, penile (spongy)

Question 39

What are the glands of the female UG triangle

Answer 39

``` Bartholin glands (great vestibular), infection and cysts can occur open into vestibule, secrete mucus for lubrication ```

Question 40

What are the glands of the male UG triangle

Answer 40

Bulbourethral (cowper) glands | empty into penile urethra

Question 41

What spinal levels contribute to the sacral plexus

Answer 41

``` Ventral rami of L4-S4 Lumbosacral trunk (L4-L5) and ventral rami of S1-S4 go through piriformis ```

Question 42

What levels contribute to the Pudendal nerve

Answer 42

S2-S4, keep your junk off the floor

Question 43

What is the path of the pudendal nerve

Answer 43

Exits pelvic cavity through greater sciatic foramen, inferior to piriformis Goes around ischial spine Enters perineum through lesser sciatic foramen Enters pudendal canal

Question 44

What are the branches of the pudendal nerve after entering pudendal canal

Answer 44

Inferior rectal nerves Perineal nerves Dorsal nerve of penis or clitoris

Question 45

What is a pudendal nerve block

Answer 45

used to anesthetize the perineum by directing the needle towards the ischial spine

Question 46

What does parasympathetic do to sexual function

Answer 46

Helps achieve erection by closing off anastomoses to help blood pool in penis

Question 47

How does Sympathetic innervation control sexual function

Answer 47

helps achieve emission by peristalsis of ductus deferens, and contracting internal urethral sphincter to prevent sperm back flow into bladder

Question 48

What is the primary source of blood to the perineum

Answer 48

Internal pudendal artery

Question 49

What are the branches of the internal pudendal artery

Answer 49

inferior rectal artery, perineal arteries, dorsal artery of the penis or clitoris, deep artery of the penis or clitoris

Question 50

What do veins of perineum accompany

Answer 50

arteries of the perineum. | Except: superficial and dip dorsal veins of the penis

Question 51

Where does lymph from SF perineum drain

Answer 51

superficial inguinal nodes

Question 52

Where does lymph from deep perineum drain

Answer 52

internal iliac nodes