Anatomy Lectures 30/31

Front 1

What bones form the bony pelvis?

Back 1

Coxal bones (inominates/hip bones); Sacrum; Coccyx

Front 2

What three bones form the coxal bones?

Back 2

Ilium, ischium, and pubis

Front 3

What are the two joints of the pelvis?

Back 3

Symphysis pubis - fibrocartilaginous
sacroiliac - Synovial

Front 4

Describe the attachments of the sacrotuberous ligament.

Back 4

Fan shaped ligament, narrow portion attached to ischial tuberosity and broad attachment to sacrum.

Front 5

Describe the attachments and location of the sacrospinous ligament.

Back 5

Deep to sacrotubrous ligament, attaches to iscial spine and sacrum.

Front 6

What two notches become foramen after the attachment of the sacrotubrous and sacrospinous ligaments?

Back 6

Greater and lesser sciatic nothces.

Front 7

Describe the boundaries of the superior pelvic aperture and the structures it divides.

Back 7

Boundaries: promontory and alae of sacrum, arcuate line of ilium, pecten pubis, and pubic crest
superior pelvic aperture is the border between the false pelvis (pelvis major) and the true pelvis (pelvis minor).

Front 8

What are the contents of the pelvis major and minor?

Back 8

Pelvis major: abdominal viscera
Pelvis minor: pelvic viscera

Front 9

Describethe inferior pelvic aperture and its boundaries.

Back 9

Diamond shaped
Corresponds to perineum
Boundaries: coccyx, sacrotuberous ligaments, ischial tuberosities, conjoined rami, pubic symphysis.

Front 10

Describe the differences betwen the male and female bony pelvis.

Back 10

In female:
Sacrum - straighter tilted more posteriorly
conjoined rami - longer
ischial tuberosities - further apart
subpubic angle - greater in female (90 deg, 70 in male)
distance between ischial tuberosity and coccyx is larger
greater sciatic notch - larger (90 deg, 70 in male)
vertical height smaller
less robust
muscle markings less prominant
smaller weight bearing areas: lumbosacral IV disc, sacroiliac joint, acetabulum, pubic symphysis

Front 11

Describe the origin, insertion, innervation, and action of the piriformis.

Back 11

Origin: anterior surface of sacrum and capsule of sacroiliac joint.
Insertion: Greater Trochanter of femur.
Innervation: nerve to piriformis
Action: Laterally rotates thigh

Front 12

Describe the origin, insertion, innervation, and action of the obturator internus muscle.

Back 12

Origin: anterolateral wall of pelvis
Insertion: medial surface of the greater trocanter of the femur.
Innervation: nerve to obturator internus
Action: laterally rotates thigh

Front 13

Describe the course of the obturator internus to the femur.

Back 13

The muscle passes through the lesser sciatic foramen and the tendon makes a right angle bend to insert on femur.

Front 14

Describe the specialized features of the obturator fascia.

Back 14

Arcus tendineus: thickened section of the fascia extending from the pubis to ischial spine; contributes to pelvic diaphragm.
pudendal (Alcock's) canal: inferior portion of fascia splits to form a canal that lies inferior to the pelvic diaphragm.

Front 15

What muscles form the pelvic diaphragm?

Back 15

levator ani muscles and coccygeus muscles.

Front 16

What structures penetrate the fused levator ani musces in the male and female?

Back 16

male: urethra and anus
female: urethra, vagina, and anus

Front 17

Describe the three divsions of the levator ani muscle and their attachments.

Back 17

pubococcygeus: main portion; runs from pubis to coccyx
puborectalis: close to midsaggital plane, forms loop with puborectalis on opposite side, encircles anorectal junction
iliococcygeus: thin portion of pelvic diaphragm, from arcus tendineus

Front 18

What nerves supply the levator ani muscles?

Back 18

S3, S4, and inferior rectal

Front 19

Describe the actions of the levator ani muscles.

Back 19

- support pelvic viscera; resist inferior thrust from increased intraabdominal pressure
-raises pelvic floor (forced expiration, coughing, vomiting, urination, and lifting)
- pulls anorectal junction anteriorly (puborectalis); prevents passge of feces into anal canal relieving pressure on external anal sphincter

Front 20

Describethe origin, insertion, innervation and action of the coccygeus muscle.

Back 20

Origin: spine of ischium and sacrospinus ligament
Inserton: margin of coccyx and 5th sacral vertebra
Innervation: S4 and S5
Action: elevate pelvic floor, support coccyx, returns coccyx to anterior position, wags tail

Front 21

What ligament does the coccygeus muscle have the same attachemnts as? where does it lie in relation to the ligament?

Back 21

- sacropinus ligament
- lies immediately deep to it

Front 22

Where is the location of potential herniation in the pelvic diaphragm and how does the body compensate?

Back 22

- the midline gape, where the pelvic viscera exit the pelvis, is a weak area of the diaphragm
- the pelvis compensates with a urogenital diaphragm

Front 23

Describe the attachments of the urogenital diaphragm.

Back 23

attached to conjoined rami on either side of midline
- small gap between anterior edge and pubic symphysis
- posterior edge lies at level of ischial tuberosities

Front 24

What are the muscles that form the urogenital diaphragm and what are their attachments?

Back 24

deep transverse perineal muscle: runs from ischial ramus to meet muscle from other side of midline
sphincter urethrae muscle: encircles urethra, located anteriorly

Front 25

What is the innervation of the muscles of the urogenital diaphragm?

Back 25

perineal branch of pudendal nerve

Front 26

Describe he inferior and superior fascias of the urogenital diaphragm.

Back 26

Inferior: aka perineal membrane, thic connective tissue, courses between rami.
Superior: merges with inferior fascia of pelvic diaphragm close to midline.

Front 27

Describe the boundaries of the perineum.

Back 27

Coccyx, sacrotuberous ligament, ischial tuberosities, conjoined rami, and pubic symphysis

Front 28

Describe the two regions that are formed by an imaginary line between the ischial tubeosities.

Back 28

Anal triangle: posterior portion, contains terminal portion of anal canal
urogenital triangle: contains external urogenital organs

Front 29

What is the fibromuscular mass at the center of the imaginary line between the anal and urogenital triangle?

Back 29

central tendon of the perineum or perineal body.

Front 30

What is the lithotomy position?

Back 30

prone with feet in stirrups

Front 31

Describe the anal orifice.

Back 31

opening of the anal canal that is surrounded by pigmented skin.

Front 32

Describe the location, fiber orientation, innervation and action of the external anal sphincter.

Back 32

Location: surrounds the anal orifice external to levator ani
Fiber orientation: inner cicular layer, outer elliptical layer from perineal body to anococcygeal ligament
Innervation: S4 and inferior rectal nerves
Action: closes and draws anal canal forward to prevent defecaion

Front 33

Describe the ishioanal fossa and their boundaries.

Back 33

Paired wedge shaped spaces on either side of the anal canal and rectum
Boundaries:
- apex: line where levator ani originates from arcus tendineus
- base: skin of buttocks
- lateral wall: fascia of the medial side of the obturator internis muscle
- medial wall: inferior fascia of levator ani and external anal sphincter
- anterior wall: base of urogenital diaphragm
- posterior wall: gluteus maximus and sacrotuberous ligament.

Front 34

What structures are contained within the pudendal canal?

Back 34

Pudendal nerve and internal pudendal vessels

Front 35

What structures are contained within the ischioanal fossae?

Back 35

- fibrous bands and septa supporting anal canal
- inferior rectal nerves an vessels

Front 36

What nerves and vessels do the inferior rectal nerves and vessels arise from?

Back 36

The pudendal nerves and inernal pudendal vessels

Front 37

Describe the course of the inferior rectal branches of the pudendal nerves and vessels.

Back 37

They cross the fat of the ischioanal fossae to reach anus and rectum.

Front 38

What pathology can occur at the site of the ischioanal fossa?

Back 38

An infection can occur leading to an abscess which can extend to the other side by crossing the anococcygeal ligament.

Front 39

What is the continuation of Scarpa's fascia into the urogenital triangle?

Back 39

superficial perineal (Colles') fascia.

Front 40

Describe the attachments of Colles' fascia.

Back 40

Inguinal ligaments, conjoined rami, and posterior border of urogenital diaphragm

Front 41

What is the space between te Colles' fascia and the infrior fascia of the urogenital diaphragm and what does it contain?

Back 41

Superficial perineal space contains the erectile bodies of the male and female genitalia, their associated muscles, nerves, and blood vessels

Front 42

What is tespace between the two fascias of the urogenital diaphragm and what does it contain?

Back 42

Deep perineal space contains the muscles of te urogenital diaphragm, nerves, blood vessels, and glands

Front 43

What are the surface or external features of the urogenital triangle in the male and female?

Back 43

Male: Penis and scrotum
Female: mons pubis, labia majora, labia minor, and clitoris

Front 44

Describe the structure of the body or shaft of the penis.

Back 44

3 erectile bodies or corpora covered by thin skin and fat-free fascia
- erectile tissue is spongy
- cavernous spaces lined by endothelium and continuous with venous system

Front 45

Describe the glans of the penis.

Back 45

- tightly adherent skin
- prepuce (foreskin) i redundant skin over glans connected to glans by frenulum (small fold of skin)

Front 46

Describe the fascia of the penis.

Back 46

Superficial: oontinuation of Colle's fascia
Deep: Buck's fascia

Front 47

Describe the ventral and dorsal surfaces of the penis

Back 47

Dorsal: side that faces poteriorly when erect.
Ventral: side that faces anteriorly when erect.

Front 48

Which porton of the penis lies within the superficial perineal space?

Back 48

The root of the penis.

Front 49

What is the mons pubis?

Back 49

The fat pad over the pubis.

Front 50

What male structure is the labia majora homologus to?

Back 50

The scrotum

Front 51

Describe the location and structure of the labia majora.

Back 51

- Fat-filled folds
- continuous with mons pubis anteriorly
- lateral to labia minora.

Front 52

Describe the structure and location of the labia minor.

Back 52

- folds of skin and fat free fascia
- connected anteriorly to prepuce and frenulum of the clitoris
- space between labia minara is vestibule

Front 53

What structures open into the vestibule?

Back 53

Urethra, vagina, and greater vestibular or Bartholin's glands

Front 54

Describe the contents of the superficial perineal space in the male and female.

Back 54

Male: erectile bodies of the penis and associated muscles
Female: erectile tissue of the clitori, bulb of the vestibule, associated muscles, greater vestibular gland

Front 55

Describe the structure of the corpora cavernosa in the male.

Back 55

- Paired (left and right)
- surrounded by thick tunica albuginea
- Body: external to superficial perineal space, fuses with corpus cavernosum, separated by incomplete median septum
Root: corpus cavernosa separates and form the right and left crura, crura attatched to perineal membrane and conjoined rami

Front 56

Describe the structure of the corpus spongiosum.

Back 56

- unpaired
- contains urethra
- has thin tunica albuginea
- Body: forms part of body of penis and all of the glans
- root: enlarges to form bulb of penis, attached to perineal membrane in midline.

Front 57

What are the three muscles associated with the root of the penis in the superficial perineal space and what are they innervated by?

Back 57

Ischiocavernosus, bulbospongiosus, and superficial transverse perineal muscles
Innervated by the perineal branch of the pudendal nerve.

Front 58

Describe the location, attachment, and function of the ischiocavernosus muscles in the male.

Back 58

- surround the crura of the corpus cavernosum
- attach to perineal membrane, conjoined rami, and deep fascia of the penis
- function: enhancement of erection by constriction of the venous outflow corpora cavernosa

Front 59

Describe the location, attachments, and function of the bulbospongiosus muscles in the male.

Back 59

- Covers the bulb of the penis
- formed by two muscles united by median raphe
- attached to perineal body
- function: forms a sphincter that compresses the bulb and urethra, empties urethra of residual urine and semen, assists with erection.

Front 60

Describe the structure and function of the superficial transverse perineal muscles.

Back 60

Structure: slender transverse strips from ischial tuberosity to perineal body
Function: fix position of perineal body

Front 61

What male structure is the clitoris homologus to?

Back 61

The penis (sans urethra)

Front 62

Describe the body and glans of the clitoris.

Back 62

Corpora cavernosa (body): similar to male, but smaller; seperate in superficial perineal space into right and left crura that attach to perineal membrane and conjoined rami
Glans: Caps fused corpora cavernosa

Front 63

What forms the prepuce, or hood, of the clitoris? What forms the frenulum?

Back 63

the meeting of the labia minora anteriorly over the glans forms the prepuce
The meeting of the labia minora posteriorly forms the frenulum

Front 64

Describe the structure of the bulb of the vestibule.

Back 64

- Two elongated masses of erictile tissue lying on either side of vaginal orifice.
- pear shaped: larger part posterior

Front 65

How is the bulb of the vestibule connected to the clitoris?

Back 65

Via a fibrous band to the glans of the clitoris.

Front 66

Describe the structure, location, and opening of the greater vestibular glands.

Back 66

- paired, pea-sized
- posterolateral to vaginal orifice
- may lie deep to posterior edge of bulb
- duct opens into vestibule

Front 67

Describe the secretion of the greater vestibular glands.

Back 67

Mucous secretion, lubricates vaginal orifice

Front 68

What is a potential pathogenic organism that can infect the greater vestibular glands?

Back 68

Gonorrhea and more...
Possible site for culture

Front 69

Describe the structure and function of the ischiocavernosus muscles in the female.

Back 69

- cover the crura of the corpora cavernosa
- impede venus flow to maintain erecton

Front 70

Describe the structure and function of the bulbospongiosus muscles in the female.

Back 70

- cover lateral surface of bulbs of vestibule and greater vestibular glands
- attachments: perineal body, clitoris, ischiocavernosus mm.
- fxn: compress bulb and constrict vaginal orifice, releases contents from glands

Front 71

What fascias are the boundaries of the deep perineal space?

Back 71

Suprior and inferior perineal fascias.

Front 72

What are the general contents of the deep perineal space in the male and female?

Back 72

Male: muslces, bulbourethral glands, and the urethra
Female: muscles, urethra, and vagina.

Front 73

Describe the course of the deep transverse perineal muscles.

Back 73

They run from the conjoined rami to the deep transverse perineal muscle on the other side.

Front 74

Describe the sphincter urethrae muscle in the male and female.

Back 74

Male: surrounds urethra in U-G diaphragm
Female: same as in male, also encircles vagina

Front 75

What nerve innervates the muscles of te deep perineal space?

Back 75

the perineal branch of the pudendal nerve

Front 76

Describe the structure and function of the bulbourethral (Cowper's) glands.

Back 76

- pea shaped
- mucous secreteing
- duct opens into spongy urethra

Front 77

Describe the portion of the urethra that's contained in he deep perineal space of the male.

Back 77

Short, membranous. About 1 cm

Front 78

What structure does the urethra open into in the female?

Back 78

The Vestibule

Front 79

What structure in the male is surrounded by the sphincter urethrae other than the urethra?

Back 79

Prostate gland.

Front 80

What arteries supply the perineum?

Back 80

Internal and external pudendal.

Front 81

What artery does the internal pudendal artery branch from?

Back 81

Internal Iliac Artery

Front 82

Describe the course of the inernal pudendal artery.

Back 82

exits pelvis through greater sciatic foramen, crosses ischial spine, reenters pelvis through the lesser sciatic foramen, enters pudendal canal

Front 83

What ar the two branches of the internal pudendal artery in the pudendal canal?

Back 83

Inferior rectal and Perineal

Front 84

What branches do the perineal arteries give off?

Back 84

Posterior scrotal/labial branches

Front 85

What are the branches of the internal pudendal artery in the UG diaphragm and what do they supply?

Back 85

Artery to the bulb - supplies bulb of penis/clitoris
Deep artery of the penis/clitoris - supplies corpus cavernosum (courses with)
Dorsal artery of the penis/clitoris - main supply to distal penis/clitoris

Front 86

What artery does the external pudenda artery branch from?

Back 86

Femoral arteries

Front 87

Describe the venous drainage of the penis/clitoris.

Back 87

Superficial dorsal vein of the penis/clitoris - drains to external pudendal vein

Deep dorsal vein of the penis/clitoris - Drains to rostatic or veinous plexus

Front 88

What vein is a possible route for cancer metastasesto the internal pelvic structures and vertebrae?

Back 88

Deep dorsal vein of the penis/clitoris

Front 89

Describe the course of the pudendal nerve.

Back 89

branches from sacrel plexus -> exits pelvis through greater sciatic foramen -> crosses iscial spine -> enters pelvis through lesser sciatic foramen -> enters pudendal canal

Front 90

What are the three branches of the pudendal nerve?

Back 90

Inferior rectal
Perineal
Dorsal nerve of the penis/clitoris

Front 91

What does the inferior rectal branch of the pudendal nerve supply?

Back 91

skeletal muscle of external anal sphincter - destruction leads to incontinence

Front 92

Descrbe the branching and innnervation of the perineal branch of the pudendal nerve.

Back 92

uperficial branch of the perineal nrve - supplies muscles of superficial space and gives of posterior scrotal/labial

Deep branch of perineal nerve - supplies muscles of UG diaphragm

Front 93

What does the dorsal nerve of the penis/clitoris supply?

Back 93

carries SENSORY fibers to the penis/clitoris

Front 94

Describe the arangement of the nerves, artery and vein of the penis/clitoris.

Back 94

NAVAN:

Right dorsal NERVE, Right dorsal ARTERY, Dorsal VEIN, Left dorsal ARTERY, Left dorsal NERVE

Front 95

What is a pudendal block?

Back 95

An injection made close to the ischial spine where the pudendal nerve crosses it, used to anesthetize the perineum

Front 96

What is an episiotomy?

Back 96

An inscision made at the distal end of the vagina during birth to enlarge the birth canal to avoid tearing