1.2 - Muscles and Walls of the Pelvic Cavity

Question 1

What walls does the pelvic cavity have?

Answer 1

Antero-inferior wall 2 lateral walls Posterior wall

Question 2

What is the anterior inferior wall of the pelvis formed by?

Answer 2

The bodies and rami of the pubic bones and the pubic symphysis

Question 3

Which muscle/structures occupy the lateral pelvic wall? (5)

Answer 3

Pelvic outermost layer of hip bone below pelvic inlet Obturator membrane Sacrotuberous & sacrospinous ligaments OBTURATOR INTERNUS muscle (& it’s fascia)

Question 4

What muscle comprises the posterior wall of the pelvis? And what nerve network lies on this muscle?

Answer 4

Piriformis Sacral plexus

Question 5

What are the 2 hiatuses found in the pelvic floor?

Answer 5

Urogenital Rectal

Question 6

What are the 2 ‘bodies’ found in the pelvic floor?

Answer 6

Perineal Anococcygeal

Question 7

What is the perineal body?

Answer 7

Fibrous node which joins the pelvic floor and perineum Found at the junction of the rectal/anal and urogenital hiatuses Location where various ligaments/structures/muscles meet (Muscles = anterior levator ani, bulbospongiosus, external anal sphincter, superficial transverse perineal)

Question 8

What is the anococcygeal body?

Answer 8

Fibrous median raphe extending between coccyx and margin of anus Location of meeting between levator ani, external anal sphincter and fibrous connective tissue

Question 9

What are the 2 major parts of the pelvic floor?

Answer 9

Levator ani muscles Coccygeus muscle

Question 10

What are the levator ani muscles?

Answer 10

Puborectalis Pubococcygeus Ileococcygeus

Question 11

Give the 3 main functions of the pelvic floor

Answer 11

• Support of abdominopelvic viscera - Resistance to increase in intra-pelvic/abdominal pressure - Urinary and faecal continence

Question 12

Innervation to pelvic diaphragm/floor?

Answer 12

Levator ani = anterior rami of S4 and branches of pudendal nerve (S2, 3 and 4)

Coccygeus = anterior rami of S4 and S5 nerves

Question 13

What is a cystocele?

Answer 13

Bladder pushes against weakened tissue in vagina and drops down into the vagina

Question 14

What is a rectocele?

Answer 14

Rectum bulges into vagina

Question 15

Why is injury to the pelvic floor during childbirth common and potentially damaging?

Answer 15

Levator ani muscles are involved in supporting the foetal head during cervix dilation in childbirth; during 2nd phase of childbirth, levator ani muscles and/or the pudendal nerve are at high risk of damage (pubococcygeus and puborectalis are the most prone to injury due to them being situated most medially) Due to their role in supporting the vagina, urethra and anal canal, injury to these muscles can lead to a number of problems - primary problems include urinary stress incontinence and rectal incontinence

Question 16

Why may an episiotomy during childbirth minimise long-term damage?

Answer 16

Helps prevent uncontrolled tearing of perineal muscles

Question 17

Why is a mediolateral episiotomy preferable to a midline episiotomy?

Answer 17

So that the tear does not extend into the anus

Question 18

What are the main pelvic viscera present in males and females as part of the urinary system?

Answer 18

Pelvic ureter Urinary bladder Urethra

Question 19

What are the main pelvic viscera present in the reproductive system of males?

Answer 19

Ductus deferens Seminal vesicles Prostate gland

Question 20

What are the main pelvic viscera present as part of the reproductive system in females?

Answer 20

Ovaries Uterine tubes Uterus Vagina

Question 21

What are the main pelvic viscera present as part of the alimentary system in males and females?

Answer 21

Pelvic colon Rectum Anal canal

Question 22

Name the structures you might be able to palpate in a DRE of a male

Answer 22

Prostate gland Seminal vesicles Sacrum

Question 23

Name the structures you might be able to palpate in a DRE of a female

Answer 23

Cervix Sacrum