Pelvis 1

Question 1

Where does the true pelvis exist? What is the false pelvis and what cavity is it apart of?

Answer 1

Question 2

What is the shape of the pelvic inlet (males vs females)?

What is the shape of the pelvic outlet?

Answer 2

Inlet males: Heart shaped.

Females: Oval (for giving birth).

Pelvic outlet: Diamond shape.

Question 3

Answer 3

Question 4

Answer 4

Question 5

Answer 5

Question 6

Explain the tilt of the pelvis

Answer 6

Pelvis actually lies in a tilted position.

In the coronal plane is the anterior supeior iliac spine and the pubic tubercle.

Question 7

Female vs male sex differences in pelvis

Answer 7

Female subpubic angle is obtuse.

In males it is V shaped (angled).

Plus pelvic inlet differences.

The sacrum in female is straighter as well as coccyx, in males it can be more curved (more concave).

From supeior aspect in the females it is more cylcindrical shape and doesn’t taper (the pelvic space).

Male bony structures are bigger bc of heavier loads.

Question 8

What are the 3 parts of the hip bone? How do they meet? When do they ossify?

Answer 8

Ileum (big one), Ischium and pubic bone.

Join in a Y shape suture in ascetabulum.

Completes ossification 22 years old (ascetabulum).

Question 9

Answer 9

Piriformis goes out via the greater trochanter to the greater trochanter of the femur.

Question 10

The two pelvid floor muscles: 1: _______ and 2: _________.

Muscle 1 can be split into 3: _________ , and 4: ________.

4: has different parts called _________ and ___________ / ____________.

Answer 10

1: Levator ani, 2: coccygeus (ischiococcygeus).
3: Illiococygeus, 4: pubococygeus.

called the puborectalis (not connected to the median raphe) and the pubovaginalis (which forms the sphincter of the vagina) /puboprostatis (wraps around the prostate).

Question 11

Answer 11

Pubococcygeus is separated further. Purple is the puborectalis, it does a turn around motion (doesn’t attach to median raphe), this helps with angulation between anus and rectum.

The part of the pubococcygeus part forms the pubovaginalis, this forms sphincter of vagina. In the males it goes around the prostate and is called the puboprostatis.

Question 12

What are the pelvic floor muscles innervated by?

Answer 12

Branches of pudendal nerve (S2-S4) - external anal sphincter - inferior rectal branch of pudendal.

Question 13

Answer 13

Question 14

What are the two sections of the perineum (anterior and posterior)?

Answer 14

Urogenital triangle and anal triangle.

Question 15

What are the contents of the pelvic cavity? (males vs females)

Answer 15

Question 16

Answer 16

Rectovesical pouch in males.

Females: Vesicouterine and rectouterine pouch (pouch of Douglas).

Vesicle = relating to bladder.

Question 17

Contents in the pelvis are ____peritoneal.

Answer 17

Infraperitoneal

Question 18

Answer 18

Question 19

Answer 19

Question 20

This is the ligamentous structures which the ovary is suspended, name the individual bits.

Answer 20

Question 21

Answer 21

Question 22

The bladder is _____ peritoneal.

The bladder is covered by the ____ muscle.

The smooth area of the bladder is called the ________. It has _ openings they are….

Answer 22

Retro.

Detrusor.

Trigone: 3 opennings, one for the internal urethral orifice, 2 for the ureteric orifaces.

Question 23

Explain the nerve supply to the muscle of the bladder.

Answer 23

Nerve supply motor by the parasympathetic nerves via pelvic splancnic nerves.

Sympathetic supplies the internal urethral sphincter and trigone from L1 and L2, this is more important in males because before ejaculation these will be closed off so that there is no retrograde ejaculation.

Question 24

What is the blood supply to the bladder?

Lymphatics?

Answer 24

Blood supply comes from superior and inferior vesical artereis - branches of internal iliac.

Lymphatics follow artereis (internal and external iliac nodes).

Question 25

Answer 25

Question 26

The bladder ______ is where the urethra starts. The ________ in males, or the _______ in females supports the neck of the bladder.

Answer 26

neck. pubovesicul ligament, puboprostatic.

Question 27

The ureter is crossed near the base of the bladder by the ________ \_\_\_\_\_\_\_\_\_ in men, and the _______ \_\_\_\_\_\_\_ in women. This can be remembered by the saying "\_\_\_\_\_\_\_ ______ \_\_\_\_\_\_ \_\_\_\_\_\_\_".

Answer 27

ductus deferens, uterine artery. "Water under the bridge".

Question 28

The male urethra is __ cm long with __ bends. Explain the 3 parts of the male urethra.

Answer 28

30cm with 2 bends. Prostatic (as it travels through the prostate), membranous and spongy (which is the longest as it travels through the corpus spongiosum and

Question 29

What is the function of the yellow bulbs?

Answer 29

In the external sphincter area there are bulbourethral glands which open in spongy urethra and lubricates urethra and neutralises acidity.

Question 30

How long is the female urethra? Where does it open?

Answer 30

Question 31

Is the rectum covered by peritoneum?

Answer 31

Upper 1/3 covered anteriorly and sides, middle 1/3 only anteriorly, lower 1/3 no peritoneum.

Question 32

How does the rectum differ from the rest of the colon?

Answer 32

No appendices epiploicae, no tinea coli, no mesentary.

Question 33

The __________ muscle must relax before defication to straighten out the _________ angle.

Answer 33

puborectalis, puborectal.

Question 34

How long is the rectum? How many curves does it have? What are rectal folds?

Answer 34

12 cm. 3 curves: upper and lower to the right, middle to the left. Transverse rectal folds formed by circular smooth muscles.

Question 35

What is the arterial supply to the rectum and the arteries origins?

Answer 35

Continuation of inferior mesenteric artery called the superior rectal artery.

Question 36

Explain the venous drainage of rectum? What are the clinical implications?

Answer 36

Same as the arteries. ## Footnote Venous drainage goes toward the abdomen (superior rectal vein or inferior mesenteric vein - this joins splanchnic to go to portal vein - this means it is to the portal system). Middle rectal means that the internal iliac vein goes to IVC - same as the inferior rectal. There are lot of anastomosis between all of these - a mixing of the portal and systemic veins. This is where shunts can occur.

Question 37

What is this fat?

Answer 37

In the perineum there is the ischioanal fossa with lots of fat.

Question 38

Continuation of the ___________ \_\_\_\_\_\_\_\_\_\_ into the ________ triangle deep to the perineal membrane.

Answer 38

Question 39

The upper \_/\_ of the anal canal has _______ which turn into \_\_\_\_\_\_. The _______ \_\_\_\_\_\_ delineates the superior part to the inferior part. What is the physiological significance of this deliniation?

Answer 39

2/3, columns which turn into valves. Pectinate line. Above = autonomic innervation and derived from endoderm, below = somatic innervation and derived from ectoderm.

Question 40

Answer 40

Question 41

Explain the difference between the internal anal sphincter and external anal sphincter.

Answer 41

Internal = smooth muscle, circular continuation, involuntary control. External = voluntary, attached anteriorly to perineal body, blends with puborectalis muscle.