Perineum

Question 1

What is the perineum bounded by?

Answer 1

1. coccyx
2. Pubis
3. Ischial tuberosity

Question 2

What are the 2 divisions of the perineum?

Answer 2

1. anal triangle - posterior

2. urogenital triangle- anterior

Question 3

Describe the anal triangle

Answer 3

contains the anal canal that can be divided into upper and lower halves
contains the ischioanal fossae

Question 4

Characteristics of the ischioanal fossae

Answer 4

1. Full of fat for expansion and cushion

2. Pudendal canal for the pudendal nerve, internal pudendal artery and vein

Question 5

What are the branches of the pudendal nerve?

Answer 5

1. inferior rectal nerves

2. dorsal nerves of penis or clitoris

Question 6

What are the branches of the internal pudendal artery?

Answer 6

1. Inferior rectal artery

2. External genital artery

Question 7

Upper half of the anal triangle

Answer 7

Above the pectinate line

1. No pain receptors
2. Derived from endoderm
3. Anal columns present
4. Involuntary
5. Autonomic innervation
6. Superior rectal artery and middle rectal artery

Question 8

Lower half of the anal triangle

Answer 8

Below the pectinate line

1. Pain, stretch, and sensation receptors (clinically important for hemorrhoids)
2. Somatic innervation from inferior rectal branch of pudendal
3. Inferior rectal arteries

Question 9

Internal anal sphincter

Answer 9

Located next to anal canal

Involuntary

Question 10

External anal sphincter

Answer 10

Located next to levator ani muscle

Voluntary and innervated by inferior rectal nerve

Question 11

Male vs. Female urogenital triangle

Answer 11

1. Testes = ovaries
2. Body of penis = body of clitoris
3. Penile raphe and spongy urethra = labium minora
4. scrotum = labia majora
5. Bulbourethral gland = greater vestibular gland
6. Prostate gland = Paraurethral gland/lesser vestibule
7. Gubernaculum = round and ovarian ligament

Question 12

What are the parts to the root of the penis?

Answer 12

1. bulb

2. left and right crura

Question 13

What is the bulbospongiosus muscles job?

Answer 13

1. Covers the bulb

2. squeeze to keep the penis erect and empty the urethra

Question 14

What is the ischiocavernosus muscles job?

Answer 14

1. Covers the left and right crura

2. Squeeze to keep the penis erect and push blood distally

Question 15

What do the bulb and crura become?

Answer 15

Bulb = corpus spongiosum 
Crura = corpus cavernosum

Question 16

What does the body contain?

Answer 16

Three cylinders of erectile tissues

1. Corpus spongiosum
2. Corpus cavernosa x2

Question 17

What does the corpus spongiosum contain and do?

Answer 17

Contains the urethra and expands to form the glans

Fills with blood to keep the penis erect

Question 18

Characteristics of the superficial perineal pouch

Answer 18

1. Potential space
2. bounded laterally by ischiopubic rami
3. Proximal spongy urethra and root of penis here
4. 3 muscles connect here

Question 19

What are the 3 muscles of the superficial perineal pouch?

Answer 19

1. bulbospongiosus muscle
2. Ischiocavernous muscles x2
3. Superficial transverse perineal muscle

Question 20

What are all the muscles of the superficial pouch innervated by?

Answer 20

Perineal nerve of pudendal nerve

Question 21

Origin and insertion of the superficial transverse perineal muscle?

Answer 21

O: ischial tuberosity
I: perineal body

Question 22

Characteristics of deep perineal pouch

Answer 22

1. Includes fat filled ischioanal fossae
2. Contains intermediate urethra, bulbourethral glands
3. Sphincter urethrae- external
4. Deep transverse perineal muscle
5. Dorsal nerve of penis
6. Dorsal artery to bulb of penis
7. dorsal arteries of the penis

Question 23

Sphincter urethrae

Answer 23

1. external
2. voluntary- allows release of urine
3. Innervated by perineal branch of pudendal nerve

Question 24

Characteristics of deep perineal muscle

Answer 24

1. extends from ischial ramus to perineal body
2. Supports pelvic floor and expel residual semen and urine
3. innervated by perineal branch of pudendal nerve

Question 25

What does the dorsal nerve of the penis innervate?

Answer 25

skin of penis and glans of the penis

Question 26

What does the dorsal artery to the bulb of the penis supply?

Answer 26

1. posterior corpus spongiosum | 2. bulbourethral gland

Question 27

What do the dorsal arteries of the penis supply?

Answer 27

fibrous tissue around corpora and skin

Question 28

What do the deep arteries of the penis supply?

Answer 28

1. Fill crura and corpus cavernosa with blood | 2. Aid in erection

Question 29

Parts of the vagina

Answer 29

1. Vestibule 2. Labia majora 3. Labia minora 4. Mons pubis 5. Clitoris

Question 30

Characteristics of the clitoris

Answer 30

1. Root 2. Erectile tissues present covered by bulb of vestibule, left and right crura 3. Body- Corpus cavernosa x2 and slender erectile body from the bulb

Question 31

Female superficial perineal pouch contents

Answer 31

1. clitoris 2. Bulbospongiosus muscle 3. Ischiocavernosus muscle 4. Greater vestibule glands 5. Paraurethral glands/ lesser vestibular glands 6. Superficial transverse perineal muscles

Question 32

Characteristics of female bulbospongiosus muscle

Answer 32

1. covers bulb of vestibule and greater vestibular glands 2. constrict vagina 3. Innervated by perineal nerve of pudendal nerve

Question 33

What nerve innervates the female superficial perineal pouch?

Answer 33

Perineal nerve of pudendal nerve

Question 34

What does the ischiocavernosus muscle do in females?

Answer 34

assists in erection of the clitoris

Question 35

What do the greater vestibular glands do?

Answer 35

Secrete lubricating mucus during sexual arousal

Question 36

What do the paraurethral/lesser vestibular glands do?

Answer 36

secrete fluid into vestibule for distribution to labia

Question 37

What do the female superficial transverse perineal muscles do?

Answer 37

support/fix perineal body to support pelvic viscera and resist increased intra-abdominal pressure

Question 38

What is an episiotomie?

Answer 38

Cut perineal body before child birth and causes the need to strengthen the perineal muscles Don't strengthen the muscles risk of uterine prolapse occurring

Question 39

Contents of female deep perineal pouch

Answer 39

1. part of urethra 2. part of vagina 3. sphincter urethrae 4. deep transverse perineal muscles 5. posterior labial branches of internal pudendal artery 6. artery to bulb of vestibule 7. Deep artery of clitoris 8. Dorsal artery of clitoris 8. Dorsal nerves of clitoris

Question 40

Characteristics of deep transverse perineal muscles

Answer 40

1. located on internal surface of ischiopubic ramus and ischial tuberosity to perineal body 2. Same action as superficial transverse perineal muscles = support/fix perineal body to support pelvic viscera and resist increased intra-abdominal pressure

Question 41

What do the posterior labial branches of the internal pudendal artery supply?

Answer 41

skin of labia majora and minora

Question 42

What does the deep artery of the clitoris supply?

Answer 42

erectile tissues of the clitoris

Question 43

What does the dorsal artery of the clitoris supply?

Answer 43

1. deep perineal pouch | 2. erectile tissues of clitoris

Question 44

What are somatic nerves roles within the pelvic region?

Answer 44

1. voluntary control 2. Come out via pudendal nerve (S2-S4) 3. Present in pelvic floor muscles and external sphincter (both) 4. Sensory fibers- know when you have a bladder infection

Question 45

What are sympathetic nerve roles in the pelvic region?

Answer 45

1. Involuntary 2. T11-L2 3. Contracts internal anal sphincter and male internal urethral sphincter 4. Contracts ductus deferens, seminal vesicles, and prostatic muscles 4. Sensory fibers but poorly localized- no pain receptors

Question 46

What are parasympathetic nerve roles in the pelvic region?

Answer 46

1. Involuntary 2. S2-S4 3. Contracts detrusor and rectal muscles 4. Sensory- how you know you have to go to the bathroom