7/9/25 Perineum

Question 1

True or False: the pelvis is a stable structure with little movement between bones to support the body

Answer 1

True

Question 2

Pelvic bones surround the organs of the pelvic cavity in the false or true pelvis?

Answer 2

True pelvis

Question 3

Name the pelvic ligaments

Answer 3

Sacrospinous ligament
Sacrotuberous ligament

Question 4

What are the notches on the os coxa?

Answer 4

Greater sciatic notch
Ischial spine
Lesser sciatic notch
Ischial tuberosity

Question 5

What is the fxn of the pelvic ligaments?

Answer 5

Prevent movement between the sacrum and os coxa

Question 6

When the pelvic ligaments are in place, what do the greater and lesser sciatic notches become?

Answer 6

The greater and lesser sciatic foramen (muscles pass through these foramen IRL)

Question 7

Where are structures of the perineum found?

Answer 7

At or inferior to the pelvic outlet

Question 8

What is the anterior triangle of the perineum?

Answer 8

Urogenital triangle (urethra and genitals found here)

Question 9

Where is the posterior triangle of the perineum?

Answer 9

Anal triangle (anus found here)

Question 10

What 2 muscles make up the pelvic diaphragm?

Answer 10

Levator ani and coccygeus

Question 11

What muscle fibers make up the pelvic diaphragm?

Answer 11

Skeletal muscles

Question 12

What shape is the pelvic diaphragm?

Answer 12

bowl/funnel shaped

Question 13

What reinforces anal triangle the pelvic diaphragm inferiorly and laterally?

Answer 13

Ischioanal fossae (fat in the anal triangle)

Question 14

What is the hiatus in the pelvic diaphragm for the urethra and genitals called?

Answer 14

Urogenital hiatus

Question 15

What is the hiatus in the pelvic diaphragm for the external anal sphincter called?

Answer 15

Anal hiatus

Question 16

Where is the ischioanal fossa located?

Answer 16

In the anal triangle

Question 17

Fxn of the ischioanal fossa

Answer 17

Fat provides structural support and allows for expansion of the anal canal during defecation

Question 18

What makes up the boarders of the ischioanal fossa?

Answer 18

Pelvic diaphragm and external anal sphincter plus the obturator interus

Question 19

What causes pelvic organ prolapse (pelvic floor drops)?

Answer 19

Weakness of the pelvic diaphragm due to old age, history of constipation, chronic cough, and vaginal delivery

Loss of fat in the ischioanal fossa

Question 20

Which hiatus needs more reinforcement: urogenital or anal?

Answer 20

Urogenital

Question 21

What reinforces structures found in the urogenital triangle?

Answer 21

Urogenital diaphragm

Question 22

What does the perineal body do?

Answer 22

Acts as a connective tissue attachment point for diaphragms and other supporting muscles

Question 23

What are the 2 layers of the urogenital diaphragm?

Answer 23

Muscular layer (deep/superior)
Connective tissue layer (superficial/inferior)

Question 24

What kind of muscle fibers make up the muscular layer of the urogenital diaphragm?

Answer 24

Skeletal muscle

Question 25

The external urethral sphincter is part of what layer of the urogenital diaphragm?

Answer 25

Muscular layer

Question 26

What makes up the connective tissue layer of the urogenital diaphragm?

Answer 26

Perineal membrane

Question 27

What is the anterior opening in the perineal membrane for?

Answer 27

The passage of blood vessels and nerves

Question 28

What space/pouch in superior to the perineal membrane?

Answer 28

Deep space/pouch

Question 29

What space/pouch is inferior to the perineal membrane?

Answer 29

Superficial space/pouch

Question 30

What are vascular tissues surrounded by layers of connective tissue called?

Answer 30

Erectile tissue

Question 31

What do parasympathetics do to erectile tissue?

Answer 31

Leads to vasodilation so more blood can flow in

Question 32

What is the fxn of tunica albuginea?

Answer 32

Limits the degree of expansion when erectile tissue fills with blood

Question 33

What erectile tissue in males and females is paired and runs along the pubic bone to meet in the midline?

Answer 33

Corpora cavernosa

Question 34

Females have vestibular bulbs. What is the male equivalent?

Answer 34

Corpus spongiosum

Question 35

Vestibular bulbs and corpus spongiosum location

Answer 35

Surround the outlet of the urinary and reproductive tracts (but the corpus spongiosum fuses midline in males)

Question 36

Both sets of erectile tissue makes up what in females? Males?

Answer 36

Females: Clitoris Males: Penis

Question 37

What do the penis and clitoris both have structurally?

Answer 37

Bulb(s), crura, body, and glans

Question 38

What part of the erectile tissue is the crura?

Answer 38

Erectile tissue that is anchored to bone (corpora cavernosa)

Question 39

Where are the bulbs anchored?

Answer 39

To the perineal membrane

Question 40

Superficial Perineal Muscles: What muscle fiber type covers erectile tissue and the UG diaphragm superficially (not on the phallus)?

Answer 40

Skeletal muscle

Question 41

What 2 superficial perineal muscles assist in the sexual response?

Answer 41

Ischiocavernosus Bulbospongiosus

Question 42

What superficial perineal muscle assists with structural support of the UG diaphragm and perineal body?

Answer 42

Superficial transverse perineal

Question 43

How does the perineum get its blood supply?

Answer 43

The internal pudendal leaves the pelvis and branches into inferior rectal, perineal, and dorsal arteries of the penis/clitoris

Question 44

What are the paired arteries that bring blood to erectile tissue?

Answer 44

Dorsal artery of the penis/clitoris

Question 45

What is the unpaired vein that returns blood to the pelvis from erectile tissue?

Answer 45

Deep dorsal vein of the penis/clitoris

Question 46

What kind of nerve fibers does the pudendal nerve supply to the perineum skeletal muscle and skin?

Answer 46

Somatosensory, somatomotor, and sympathetics

Question 47

Where does the pudendal nerve start?

Answer 47

At spinal nerves S2-4, but is NOT the same as pelvic splanchnics

Question 48

What does the pudendal nerve innervate?

Answer 48

Leaves the pelvis to innervate perineal structures from posterior to anterior

Question 49

True or False: Branches of the pudendal nerve have the same names as the branches of the internal pudendal artery

Answer 49

True

Question 50

What type of innervation causes excitement in females and erection in males?

Answer 50

Parasympathetic (pelvic splanchnics and cavernous nerves) Leads to vasodilation of erectile tissue and secretion of glands

Question 51

What type of innervation causes orgasm in females and emission in males?

Answer 51

Sympathetic (lumbar and sacral splanchnics) Cause contraction of smooth muscles in the reproductive tract and secretion of glands

Question 52

What type of innervation causes orgasm in females and ejaculation in males?

Answer 52

Somatomotor (pudendal) Causes contraction of skeletal muscles in the perineum

Question 53

What is the portion of the pelvic plexus that crosses the prostate called?

Answer 53

Cavernous nerves (contain parasympathetics and stimulate erection)

Question 54

What nerves are at risk during prostate procedures?

Answer 54

Cavernous nerves. If they are damaged, men will have issues with erections

Question 55

What is the female equivalent to the cavernous nerves?

Answer 55

Uterovaginal plexus

Question 56

What innervation relaxes internal sphincters (involuntary)?

Answer 56

Parasympathetic (smooth muscle)

Question 57

What type of innervation contracts internal sphincters (involuntary)?

Answer 57

Sympathetic (smooth muscle)

Question 58

What type of innervation has voluntary control over external sphincters?

Answer 58

Somatomotor

Question 59

What is another word for the female perineum?

Answer 59

Vulva

Question 60

What makes up the skin of the perineum in females?

Answer 60

Labia majora and labia minora

Question 61

Where is the vestibule located in females?

Answer 61

Between the labia minora

Question 62

Where do the orifices for urethral and vagina open into?

Answer 62

Vestibule

Question 63

What is the skin of the perineum innervated by?

Answer 63

Pudendal nerve

Question 64

What skin in the male is homologous to the labia majora in females?

Answer 64

Scrotal skin

Question 65

What does the midline fusion of the scrotal skin create?

Answer 65

Raphe

Question 66

Urogenital triangle from deep to superficial

Answer 66

Peritoneum Pelvic organs Pelvic diaphragm Urogenital diaphragm Erectile tissue Superficial perineal muscle Skin

Question 67

Anal triangle from deep to superficial

Answer 67

Peritoneum Pelvic organs Pelvic diaphragm Ischioanal fossa Skin