L1 Defining the pelvic region

Question 1

What are the 4 bones that together make the pelvis?

Answer 1

• 2 innominate bones: ilium, ischium and pubis
• sacrum (formed by fusion of the 5 sacral vertebrae)
• coccyx (formed by 4 coccygeal vertebrae)

Question 2

What are the features of the innominate bones? (5)

Answer 2

iliac fossa

ischial spine

ischial tuberosity

inferior ramus of pubis bone

superior rams of pubis bone

Question 3

Components of the articulated pelvis (8)

Answer 3

L5

intervertebral disc

posterior sacral foramina

sacroiliac joint (under ligament)

sacrum

sacrococcygeal joint

coccyx

pubic symphysis (=interpubic disc + ligaments)

Question 4

Name the ligaments of the pelvis (3)

Answer 4

sacroiliac ligament

sacrotuberous ligament

sacrospinous ligament

Question 5

Ligaments of the pelvis: sacroiliac

Answer 5

between the sacrum and the ilium

has an anterior and posterior component

Question 6

Ligaments of the pelvis: sacrococcygeal

Answer 6

between the sacrum and the coccyx

Question 7

Ligaments of the pelvis: sacrocpinous

Answer 7

between the ischial spine and the sacrum/coccyx

Question 8

Ligaments of the pelvis: sacrotuberous

Answer 8

posterior to the sacrospinous

between the lateral aspect of the sacrum +coccyx onto medial margin of the ischial tuberosity

Question 9

Perineum

refers to what?

Answer 9

the space located at the pelvic outlet and inferior to the pelvic diaphragm (i.e. muscles of the pelvic floor)

Question 10

Perineum

what does it describe?

Answer 10

narrow region between the thighs

Question 11

Perineum

shape and boundaries?

Answer 11

diamond shaped surface extending from the mons pubis (in females) to the medial surface of the thighs and posteriorly to the gluteal folds

Question 12

Perineum

what splits it into two?

Answer 12

a transverse line joining the 2 ischial tuberosities

Question 13

Perineum

what are the 2 triangles called?

Answer 13

urogenital and anal triangles

Question 14

Perineum

what does the midpoint of the transverse line define?

Answer 14

the perineal body

Question 15

Perineum

what happens at the perineal body?

Answer 15

the convergence of several sphincter and perineal muscles

Question 16

Perineum

anatomy (9 labels)

Answer 16

pubic symphysis

inferior pubic ligament

ischial tuberosity

perineal membrane

deep perineal pouch

opening for urethra

pubic arch

obturator foramen

inf pubic ramus

Question 17

Perineum

what does the deep perineal pouch enclose? (4)

Answer 17

urethra

vagina, in females

glands, such as bulbourethral (Cowper) glands in males

perineal muscles that act as sphincters, such as compressor urethrae or urethrovaginal sphincter in females

Question 18

Perineum

what does the superficial perineal pouch enclose? (4)

Answer 18

urethra

vagina in females; root of penis in males

glands, such as Bartholin in females (the equivalent to Cowper glands in males)

perineal muscles that provide support to the external genitalia, such as the bulbospongiosus or ischiocavernosus muscles

Question 19

What is the pelvic brim formed by?

Answer 19

promontory and ala (wing) of sacrum

right + left linea terminals:

• arcuate line
• pectineal line

Question 20

What are the borders of the pelvic cavity?

Answer 20

posterior - sacrum/coccyx

anterior - pubic symphysis

inferior - pelvic floor

superior - pelvic brim

lateral - obturator internus m

Question 21

What are the contents of the pelvic cavity?

Answer 21

reproductive organs/tracts

bladder

rectum

Question 22

The pelvic musculature is composed of muscles that do what 2 things?

Answer 22

line the wall

line the floor

Question 23

Pelvic musculature

which line the wall?

Answer 23

piroformis

obturator internus

Question 24

Pelvic musculature

which line the floor?

Answer 24

coccygeus

levator ani (iliococcygeus, pubococcygeus and puborectalis)

Question 25

The pelvic wall Piriformis

Answer 25

from the anterior surface of the sacrum; through the greater sciatic foramen i.e. over the ischial spine; inserts onto the greater trochanter of femur

Question 26

The pelvic wall Obturator internus

Answer 26

from the internal surface of the obturator membrane; through the lesser sciatic foramen i.e. below the ischial spine; also inserts onto the greater trochanter of femur

Question 27

The pelvic floor - 1 (5 muscles)

Answer 27

puborectalis muscle pubococcygeus muscle iliococcygeus muscle coccygeus muscle piriformis muscle

Question 28

The pelvic floor - 2 Coccygeal

Answer 28

from the ischial spine to the inferior end of the sacrum + coccyx

Question 29

The pelvic floor - 2 Iliococcygeus

Answer 29

from the tendinous arch - a line extending from the ischial spine to the posterior aspect of the pubic bone - to the annococcygeal body

Question 30

The pelvic floor - 3 Pubococcygeus

Answer 30

from the posterior aspect of the pubic bone and inserting to the coccyx (lateral fibres) or merging with the contralateral fibres of the same named muscle (medial fibres)

Question 31

The pelvic floor - 3 Puborectalis

Answer 31

a continuous muscle that originates from the posterior aspect of the pubic bone and slings behind the rectum

Question 32

Blood supply & drainage Arteries

Answer 32

anterior division of internal iliac, providing several branches, e.g. uterine, vesical or internal pudendal Gonadal, from abdominal aorta, supplying the gonads

Question 33

Blood supply & drainage Veins

Answer 33

internal iliac, to common iliac veins gonadal, to IVC or L renal vein

Question 34

Nervous control Somatic plexuses (L4-Co)

Answer 34

subdivided into: lumbosacral (L4-S4 <=note: joined by lumbar L4/5) coccygeal (S4-Co) ``` function as motor or sensory e.g. sciatic nerve, sup/inf gluteal, pudendal nerve ```

Question 35

Nervous control Visceral plexuses

Answer 35

Paravertebral/Prevertebral sympathetic/parasympathetic/visceral fibres erection/ejaculation e.g. inf hypogastric plexus

Question 36

Lumbosacral trunk (4)

Answer 36

superior gluteal inferior gluteal sciatic pudendal

Question 37

Visceral plexuses: parasympathetic flow

Answer 37

pelvic splanchnic nerves (S2-4)

Question 38

Visceral plexuses: sympathetic flow

Answer 38

sacral sympathetic trunk superior and inferior hypogastric plexuses

Question 39

Posterior pelvis (gluteal) (3)

Answer 39

sciatic nerve pudendal nerve gluteal vessels - superior - inferior

Question 40

Pudendal nerve (diagram with 5 labels)

Answer 40

dorsal nerve of clitoris deep perineal nerve pudendal nerve sacrotuberous ligament