Pelvis and perineum

Question 1

Label

Answer 1

Question 2

What are the anterior, posterior and lateral boundries of the pelvic outlet?

Answer 2

Anterior= pubic arch

Posterior= Tip of the coccyx

Lateral= ischial tuberosities

Question 3

Which parts of the pelvis are termed the true and false pelvis?

Answer 3

Question 4

What type of joint is the sacroiliac joint?

Answer 4

Synovial plane joint

Question 5

What type of joint is the pubic symphysis

Answer 5

Secondary cartilagenous joint

Question 6

Identify male vs female pelvis

Answer 6

Question 7

Fill in the differences of male vs female pelvis

Answer 7

Question 8

What 2 muscles make up the majority of the pelvic floor

Answer 8

1. Levator ani
2. Coccygeus

Question 9

Through which foramina does obturator internus leave the pelvis through?

Answer 9

Lesser sciatic forament

Question 10

Which pelvic floor muscle is made of 3 separate muscles & name these muscles

Answer 10

Levator ani

1. Puborectalis
2. Iliococcygeus
3. Pubococcygeus

Question 11

Give two functions of the pelvic diaphragm/ floor:

Answer 11

Support of abdominopelvic viscera (bladder, intestines, uterus etc.) through their tonic contraction.

Resistance to increases in intra-pelvic/abdominal pressure during activities such as coughing or lifting heavy objects.

Urinary and faecal continence.The muscle fibres have a sphincter action on the rectum and urethra. They relax to allow urination and defecation.

Question 12

What is the innervation of the pelvic diaphragm/ floor?

Answer 12

Anterior rami of S4/5…… branches of the pudendal nerve (roots S2, S3 and S4).

2,3 and 4 to keep poo of the floor

Question 13

What is a cystocele

Answer 13

Anterior vaginal prolapse

Supportive tissues around the bladder and vaginal wall weaken and stretch, allowing the bladder and vaginal wall to fall into the vaginal canal. Usually, the muscles and connective tissues that support the vaginal wall hold the bladder in place.

Question 14

What is a rectocele

Answer 14

Posterior vaginal prolapse

Supportive wall of tissue between a woman’s rectum and vaginal wall weakens. Without the support of these pelvic floor muscles and ligaments, the front wall of the rectum sags and bulges into the vagina, and in severe cases, protrudes out of the vaginal opening.

Question 15

Why is injury to the pelvic floor damaging

Answer 15

Weakening of the levator ani & pelvic fascia may decrease support for the vagina, bladder, uterus, or rectum or alter the position of the neck of the bladder and the urethra. These changes may cause urinary stress incontinence,

Question 16

What is an episotomy

Answer 16

An episiotomy is a cut made along your perineum by your doctor during labor. Your doctor may need to cut your vaginal opening to allow more room for your baby to be born safely and without harm.

Question 17

Which part(s) of the rectum drain(s) into the portal circulation?

Answer 17

..Upper one third of rectum: drained by superior rectal vein….

Question 18

Which part(s) of the rectum drain(s) into the systemic circulation?

Answer 18

.. Lower ⅔rds rectum & anus, draining into the middle & inferior rectal veins ..

Question 19

Why might haemorrhoids be associated with cirrhosis of the liver?

Answer 19

A back up of blood flow to the liver due to liver cirrhosis, leads to a backup of draining veins which will dilate, thus causing haemorrhoids…

Haemorrhoids= swollen/dilated veins in the anus

Question 20

With which venous plexus does the prostatic venous plexus communicate with on its posterior side?

what is the clinical significance of this

Answer 20

Internal vertebral venous plexus..

This means that prostate cancer can spread easily to the vertebrae

Question 21

What structure(s) in the male are supplied by the genital branch of the genitofemoral nerve & what is its clinical significance

Answer 21

Cremaster muscle & anterior scrotal skin..

Question 22

The pudendal nerve arises from the sacral plexus and follows the course of the pudendal artery to innervate the skin and the muscles of the perineum.

From which segmental level(s) does the pudendal nerve arise?

Answer 22

S2-S4

Question 23

What bony landmarks are used when performing a pudendal nerve block during labour?

Answer 23

Ischial spine

Question 24

Label

Answer 24

Question 25

Label the 3 muscles that form levator ani

Answer 25

Question 26

What does the perineal nerve innervate & what is it a branch of

Answer 26

Branch of peudendal nerve

Innervates the levator ani muscles & external urethral sphincter

Question 27

Function of the pedudendal nerve

Answer 27

voluntary/somatic control of faecal and urinary continence

Question 28

What is the autonomic nerve supply to the pelvis?

Answer 28

Originates from the pelvic plexus (or inferior hypogastric)

Question 29

Where does the sympathetic supply of the pelvis originate from

Answer 29

L1 & L2 via the hypogastric nerve & terminal aspect of the sympathetic trunk

→ provide sympathetic supply to all internal pelvic organs.

In a male they supply the vas deferens, seminal vesicles, prostate and epididymis.

In a female they supply the ovaries, uterus, fallopian tubes and vagina.

Question 30

Where does the parasympathetic supply of the pelvis originate from?

Answer 30

Pelvic splanchnic nerves (S2 to S4).

Question 31

What do the hypogastric and pelvic splanchnic nerves merge to form

Answer 31

Inferior hypogastric plexuses, which consists of both sympathetic and parasympathetic nerve fibres.

Question 32

In the thorax the greater, lesser and least splanchnic nerves are sympathetic/parasympathetic

Answer 32

Sympathetic nerves

Question 33

In the pelvis the pelvic splanchnic nerves are sympathetic/parasympathetic

Answer 33

Parasympathetic nerves

Question 34

After rectal surgery, why are some men unable to ejaculate?

Answer 34

The bulbocavernosus muscle is responsible for ejaculation. This muscle resides in the area between the anus and the genitals, hence during rectal surgery it is at risk of damage..

The perineal nerve has been damaged

Question 35

What are the four primary lymph nodes of the pevlis

Answer 35

External iliac lymph nodes

Internal iliac lymph nodes

Sacral lymph nodes

Common iliac lymph nodes

Question 36

What does the External iliac lymph nodes drain

Answer 36

Pelvic viscera, especially the superior parts of the middle to anterior pelvic organs and inguinal lymph nodes..

Question 37

What does the internal iliac lymph nodes drain

Answer 37

Gluteal region, deep perineum and inferior pelvic visera

Question 38

Where do the sacral lymph nodes drain

Answer 38

Postero-inferior pelvic viscera and drain either to internal or common iliac nodes.

Question 39

Where do the common iliac lymph nodes drain

Answer 39

Drainage from the three main groups: external, internal and sacral lymph nodes

Question 40

What type of muscle is the internal urethral sphincter

Answer 40

Smooth muscle

> involuntary

Question 41

What type of muscle is the external urethral sphincter

Answer 41

Skeletal muscle

> voluntary control

Question 42

What structures pass through the greater sciatic foramen

Answer 42

• Superior gluteal artery and vein
• Superior gluteal nerve
  
  • Sciatic nerve
  • Pudendal nerve
  • Inferior gluteal artery and vein
  • Inferior gluteal nerve
  • Posterior femoral cutaneous nerve
  • Nerve to obturator internus
  • Nerve to quadratus femoris

Question 43

What structures pass through the lesser sciatic foramen

Answer 43

• Internal pudendal artery and vein
• Pudendal nerve (note the pudendal nerve first leaves the pelvis via the greater sciatic foramen, and then re-enters via the lesser sciatic foramen)
• Obturator internus tendon
• Nerve to obturator internus