1.2 - Muscles and Walls of the Pelvic Cavity Flashcards
What walls does the pelvic cavity have?
Antero-inferior wall 2 lateral walls Posterior wall
What is the anterior inferior wall of the pelvis formed by?
The bodies and rami of the pubic bones and the pubic symphysis
Which muscle/structures occupy the lateral pelvic wall? (5)
Pelvic outermost layer of hip bone below pelvic inlet Obturator membrane Sacrotuberous & sacrospinous ligaments OBTURATOR INTERNUS muscle (& it’s fascia)
What muscle comprises the posterior wall of the pelvis? And what nerve network lies on this muscle?
Piriformis Sacral plexus
What are the 2 hiatuses found in the pelvic floor?
Urogenital Rectal
What are the 2 ‘bodies’ found in the pelvic floor?
Perineal Anococcygeal
What is the perineal body?
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)
What is the anococcygeal body?
Fibrous median raphe extending between coccyx and margin of anus Location of meeting between levator ani, external anal sphincter and fibrous connective tissue
What are the 2 major parts of the pelvic floor?
Levator ani muscles Coccygeus muscle
What are the levator ani muscles?
Puborectalis Pubococcygeus Ileococcygeus
Give the 3 main functions of the pelvic floor
- Support of abdominopelvic viscera - Resistance to increase in intra-pelvic/abdominal pressure - Urinary and faecal continence
Innervation to pelvic diaphragm/floor?
Levator ani = anterior rami of S4 and branches of pudendal nerve (S2, 3 and 4)
Coccygeus = anterior rami of S4 and S5 nerves
What is a cystocele?
Bladder pushes against weakened tissue in vagina and drops down into the vagina
What is a rectocele?
Rectum bulges into vagina
Why is injury to the pelvic floor during childbirth common and potentially damaging?
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
Why may an episiotomy during childbirth minimise long-term damage?
Helps prevent uncontrolled tearing of perineal muscles
Why is a mediolateral episiotomy preferable to a midline episiotomy?
So that the tear does not extend into the anus
What are the main pelvic viscera present in males and females as part of the urinary system?
Pelvic ureter Urinary bladder Urethra
What are the main pelvic viscera present in the reproductive system of males?
Ductus deferens Seminal vesicles Prostate gland
What are the main pelvic viscera present as part of the reproductive system in females?
Ovaries Uterine tubes Uterus Vagina
What are the main pelvic viscera present as part of the alimentary system in males and females?
Pelvic colon Rectum Anal canal
Name the structures you might be able to palpate in a DRE of a male
Prostate gland Seminal vesicles Sacrum
Name the structures you might be able to palpate in a DRE of a female
Cervix Sacrum
