Anatomy of the Pelvic Floor

Question 1

Label the true and false pelvic cavity in the image below:

Answer 1

1 = true pelvic cavity
2 = false pelvic cavity

Question 2

Does the false or true pelvic cavity house the pelvic organs?

Answer 2

• true pelvis

Question 3

What name is given to the inferior lining of the pelvic cavity?

Answer 3

• pelvic floor muscles, also known as the pelvic diaphragm

Question 4

What name is given to the area below the pelvic floor that makes up the perineum?

Answer 4

• urogenital diaphragm

Question 5

The urogenital diaphragm is the area below the pelvic floor that makes up the perineum. It contains 2 triangles that are important, what are they called?

Answer 5

1 - anal triangle

2 - urogenital triangle

Question 6

Label the contents numbered 1-9 in the female pelvis using the labels below:

anal canal
anal aperture
rectum
fallopian tubes
uterus
ovary
vagina
bladder
urethra

Answer 6

Label the contents numbered 1-9 in the female pelvis using the labels below:

1 = fallopian tubes
2 = ovary
3 = uterus
4 = vagina
5 = bladder
6 = urethra
7 = rectum
8 = anal canal
9 = anal aperture

Question 7

Label the contents numbered 1-9 in the male pelvis using the labels below:

anal canal
anal aperture
rectum
seminal vesicles
ductus deferens
prostate
ejaculatory duct
bladder
urethra

Answer 7

1 = seminal vesicles
2 = ductus deferens
3 = prostate
4 = ejaculatory duct
5 = rectum
6 = anal canal
7 = anal aperture
8 = bladder
9 = urethra

Question 8

The pelvic floor is composed of muscles and fascia. What shape does it resemble?

Answer 8

• gutter

Question 9

Which somatic nerves, which is voluntary movement innervate the pelvic floor/diaphragm?

Answer 9

• S2-S5

Question 10

What 2 things penetrate the pelvic floor/diaphragm in men and women?

Answer 10

• men = rectum and ureter

- women = vagina, rectum and urethra

Question 11

What is the name given to the group of muscles that make up the pelvic floor/diaphragm?

Answer 11

• levator ani
• levator = greek for lifting up
• ani = anus

Question 12

The name given to the group of muscles that make up the pelvic floor/diaphragm is called the levator ani. This is muscles that arise laterally and meet in the middle of the pelvic forming a strong fibrous median in the floor of the pelvis, which extends between the coccyx and the margin of the anus. What is this called:

1 - Coccygeus
2 - Iliococcygeus
3 - Pubococcygeus
4 - Anococcygeal raphe

Answer 12

4 - anococcygeal raphe

Question 13

The levator ani is the group of muscles that make up the pelvic floor/diaphragm. The muscles arise laterally and meet in the middle of the pelvis forming a strong fibrous median in the floor of the pelvis, which extends between the coccyx and the margin of the anus and is called the anococcygeal raphe. Which muscles in the pelvis merge posteriorly with the levator ani to complete the pelvic floor/diaphragm?

1 - Coccygeus
2 - Iliococcygeus
3 - Pubococcygeus
4 - Anococcygeal raphe

Answer 13

1 - coccygeus muscle

Question 14

There are 3 origins of the levator ani, what are they?

Answer 14

1 - body of pubis
2 - spine of ischium
3 - ilium

Question 15

There are 3 key muscles that make up the levator ani? Label them in the image below using the labels below:

puborectalis
pubovaginalis
iliococcygeus

Answer 15

1 = pubovaginalis
2 = puborectalis
3 = iliococcygeus

Question 16

There are 3 key muscles that make up the levator ani:

puborectalis
pubovaginalis
iliococcygeus

Where does the pubovaginalis get its name from?

Answer 16

• pubo = attach to inside of pubic bones

- vaginalis = surround the vagina

Question 17

There are 3 key muscles that make up the levator ani:

puborectalis
pubovaginalis
iliococcygeus

Where does the puborectalis get its name from?

Answer 17

• pubo = attach to inside of pubic bones

- rectalis = surround the rectum

Question 18

There are 3 key muscles that make up the levator ani:

puborectalis
pubovaginalis
iliococcygeus

Where does the iliococcygeus get its name from?

Answer 18

• ilio = attach to inside of ilium

- coccygeus = attaches to coccyx

Question 19

When we look from superior to inferior through the pelvis we can see that there is a gap anteriorly where in the middle of the pubovaginalis muscles from the right and left sides. What is this gap called?

Answer 19

• urogenital diaphragm

- contains muscles of the perineum and perineum fascia

Question 20

The levator muscles have a number of functions including supporting the pelvic contents. What are the other 3 key functions of the pelvic floor/diaphragm?

Answer 20

1 - compress urethra and vagina (maintain position and support)
2 - maintain anorectal angle (maintain anorectal angle)
3 - during childbirth, levator ani muscles support foetal head

Question 21

If there is an increased pressure within the abdominal cavity what can this do to the pelvic floor/diaphragm?

Answer 21

• compresses pelvic organs into the pelvic diaphragm

- can stretch and damage the pelvic floor muscles

Question 22

The aorta bifurcates at what vertebral level into what just above the pelvic?

Answer 22

• bifurcates at L4

- bifurcates into common iliac artery

Question 23

The common iliac artery bifurcates into what 2 arteries, and what is the anatomical landmark where this occurs?

Answer 23

• bifurcates into internal and external iliac

- bifurcates at level of sacroiliac joint

Question 24

The internal iliac artery bifurcates into 2 further arteries, what are these called and what do they supply?

Answer 24

1 - anterior = urethra, uterus, vagina

2 - posterior = muscles of thigh and hips

Question 25

Using the labels below, label the arteries from the internal anterior iliac artery: ``` anterior trunk of internal iliac artery superior vesical artery obturator artery uterine artery umbilical artery vaginal artery ```

Answer 25

``` 1 = anterior trunk of internal iliac artery 2 = uterine artery 3 = umbilical artery 4 = vaginal artery 5 = obturator artery 6 = superior vesical artery ```

Question 26

What 2 veins from the pelvic merge to form the inferior vena cava and at what vertebral level does this occur?

Answer 26

- left and right common iliac veins | - merge at L5

Question 27

Where do the left and right gonadal veins drain?

Answer 27

- left = left renal vein (important as renal problems can cause problems such as hydroseal) - right = inferior vena cava

Question 28

What part of the sympathetic and parasympathetic nervous system innervate the pelvis viscera (organs)?

Answer 28

- sympathetic = T12-L2 | - parasympathetic = S2-S4

Question 29

Which key nerve innervates the pelvic floor/diaphragm and where does this originate from in the vertebrae?

Answer 29

- pudendal nerve | - arises from S2-S4

Question 30

The pudendal nerve innervates the pelvic floor/diaphragm and originates from S2-S4 vertebrae. This then bifurcates into 3 other nerves after passing through pudendal canal. Using the labels below label the 3 other nerves involved: perineal nerve inferior rectal nerve pudendal nerve

Answer 30

``` 1 = inferior rectal nerve 2 = pudendal nerve 3 = perineal nerve ```

Question 31

During pregnancy or surgery on the perineum, the pudendal nerve will need to be anaesthetised. What landmark on the hip bones is used to identify the location of the pudendal nerve?

Answer 31

- ischial spine

Question 32

Where does the majority of lymph from the pelvic cavity drain into?

Answer 32

- common iliac lymph nodes

Question 33

The majority of lymph from the pelvic cavity drains into the common iliac lymph nodes. However, some genital structures also drain into deep lymph nodes. Which lymph nodes are these?

Answer 33

- deep inguinal lymph nodes

Question 34

What is the perineum?

Answer 34

- anatomical region in the pelvis between the thighs | - most inferior part of the pelvic outlet

Question 35

What separates the perineum from the pelvic cavity superiorly?

Answer 35

- pelvic floor/diaphragm

Question 36

The perineum is divided into the anterior and posterior triangle. What other names do we use for the anterior and posterior triangles?

Answer 36

- anterior = urogenital triangle | - posterior = anal triangle

Question 37

What forms the inferior and superior borders of the perineum?

Answer 37

- superior = urogenital and anal triangles | - inferior = skin

Question 38

The inferior and superior borders of the perineum are formed by skin and urogenital and anal triangles, respectively. What is the name given to the 2 spaces between the inferior and superior borders?

Answer 38

- deep and superficial perineal space

Question 39

The superficial perineal space is what lies inferior to the deep perineal space. What part of the male and female reproductive organs is contained within the superficial perineal space?

Answer 39

- external genitalia

Question 40

The superficial perineal space is what lies inferior to the deep perineal space. The male and female external genitalia are located in this space. What 3 main things are located in this space in females?

Answer 40

- clitoris - vestibule bulbs (erectile tissue close to the inferior side of the clitoris) - ischocavernosus (inserts on ischium)

Question 41

The superficial perineal space is what lies inferior to the deep perineal space. The male and female external genitalia are located in this space. What 3 main things are located in this space in males?

Answer 41

``` 1 = bulb and cura of penis 2 = ischocavernosus muscle 3 = bulbospongiosus muscle ```

Question 42

What muscle is located in both males and females in the urogenital space that crosses the majority of the perineal space?

Answer 42

- transverse perineal muscles

Question 43

The deep perineal space, also referred to as the perineal membrane is a layer of dense connective tissue. Which parts of the hip bones does this membrane attach to?

Answer 43

- along the ischiopubic rami

Question 44

There is a small opening in the perineal membrane directly posterior to the pubic symphysis. What is the purpose of this opening?

Answer 44

- allows transit for veins from penis and clitoris to pass through

Question 45

Label the 4 muscles that contribute to the make up of the superficial perineal space using the labels below: transverse perineal ischiocavernosus bulbocavernosus perineal body

Answer 45

``` 1 = perineal body 2 = ischiocavernosus 3 = bulbocavernosus 4 = transverse perineal ```

Question 46

What is the perineal body, also referred to as the central tendon of the perineum?

Answer 46

- a fibro-muscular structure | - located in the midline of the perineum between anus and urogenital triangle

Question 47

What is the importance of the perineal body?

Answer 47

- critical for maintaining the integrity of the pelvic floor, especially in females

Question 48

The perineal body is critical for maintaining the integrity of the pelvic floor, especially in females. During pregnancy what can happen to the perineal body?

Answer 48

- can rupture during vaginal birth - widens the gap between the anterior free borders of levator ani muscle of both sides - increases risk of prolapse of the uterus, rectum, or even the urinary bladder

Question 49

What is an episiotomy?

Answer 49

- epi = greek for pubic region - otomoy = greek for operation - perineal body between anus and vagina is cut to increase opening size

Question 50

In female and males what important pelvic organs are covered by the peritoneum?

Answer 50

- females = bladder, uterus and rectum | - males = bladder and rectum

Question 51

The peritoneum comes down and covers the bladder, uterus and rectus forming 1 pouch in males and 2 pouches in females. What are these pouches called?

Answer 51

- females = rectouterine/douglas pouch (between rectum and uterus) = vesicouterine pouch (between bladder and uterus) - males = retrovesicle pouch (between rectum and bladder

Question 52

The peritoneum comes down and covers the bladder, uterus and rectus forming 1 pouch in males and 2 pouches in females. - females = rectouterine/douglas pouch (between rectum and uterus) = vesicouterine pouch (between bladder and uterus) - males = retrovesicle pouch (between rectum and bladder In males there is only one, so this is the lowest pouch, but which pouch is lower in females?

Answer 52

- rectouterine/douglas pouch (between rectum and uterus) | - the lowest pouch in male and females is where fluid can collect from abdomen

Question 53

The folds of the peritoneum encapsulate the majority of the uterus, ovaries and fallopian tubes. What is the name of the ligament that covers the majority of the uterus?

Answer 53

- broad ligament

Question 54

The folds of the peritoneum encapsulate the majority of the uterus, ovaries and fallopian tubes providing support and holding the female reproductive organ in place. What is the name of the ligament that helps maintain the ovaries position?

Answer 54

- ovarian ligament | - suspensory ligament

Question 55

The folds of the peritoneum encapsulate the majority of the uterus, ovaries and fallopian tubes providing support and holding the female reproductive organ in place. The ovarian and suspensory ligaments helps maintain the ovaries position. Which of these ligaments also has another crucial role?

Answer 55

- suspensory ligament | - contains the ovarian artery, vein and nerve plexus

Question 56

The folds of the peritoneum encapsulate the majority of the uterus, ovaries and fallopian tubes providing support and holding the female reproductive organ in place. What ligament contributes to maintaining the anteverted position (pointing towards the vagina) of the uterus?

Answer 56

- round ligament | - attaches to uterus, through inguinal canal and to the labium majora

Question 57

The cervical ligaments of the pelvis are important ligaments that are located where?

Answer 57

- inferior border of the broad ligament | - house the uterine artery and uterine veins

Question 58

The cervical ligaments of the pelvis are important ligaments that are located on the inferior border of the broad ligament and house the uterine artery and uterine veins. Where do these ligaments originate from?

Answer 58

- cervix and lateral fornix of the vagina

Question 59

The cervical ligaments of the pelvis are important ligaments that are located on the inferior border of the broad ligament and house the uterine artery and uterine veins that arise from the cervix and lateral fornix of the vagina and are important for maintaining the uterus position. Label the 3 key ligaments using the labels below: Pubocervical Transverse cervical/cardinal Uterosacral

Answer 59

``` 1 = Pubocervical 2 = Transverse cervical/cardinal 3 = Uterosacral ```

Question 60

The cervical ligaments of the pelvis are important ligaments that are located on the inferior border of the broad ligament and house the uterine artery and uterine veins that arise from the cervix and lateral fornix of the vagina and are important for maintaining the uterus position. What can happen if these ligaments are weak or damaged?

Answer 60

- prolapse of pelvic organs