Pelvic floor muscles Flashcards
what are the 3 muscular components of the pelvic floor?
Levator ani muscles
Coccygeus muscle
Fascia coverings of the muscles
which is the largest muscular component of the pelvic floor?
Levator ani muscles
what are the levator ani muscles innervated by? nerve roots?
Innervated by branches of the pudendal nerve, roots S2, S3 and S4
what is the levator ani muscle?
a broad sheet of muscle
what is the levator ani muscle composed of?
three separate paired muscles, called the pubococcygeus, puborectalis and iliococcygeus
where do the levator ani muscles have attachments?
Anterior
Laterally
Posteriorly
what is the anterior attachment of the levator ani muscle?
The pubic bodies of the hip bone
what is the lateral attachment of the levator ani muscle?
Thickened fascia of the obturator internus muscle, known as the tendinous arch
what is the posterior attachment of the levator ani muscle?
The ischial spines of the hip bone
what is the puborectalis muscle?
a U-shaped sling
where does the puborectalis muscle extend?
from the bodies of the pubic bones, past the urogenital hiatus, around the anal canal
what does tonic contraction of the puborectalis muscles lead to?
bends the canal anteriorly, creating the anorectal angle at the anorectal junction
what is the anorectal junction?
where the rectum meets the anus
what is the anorectal angle?
90 degrees
what is the main function of the puborectalis muscle?
The main function of this thick muscle is to maintain faecal continence
what happens to the puborectalis muscle during defecation?
muscle relaxes
what are the muscle fibres of the pubococcygeus muscle the main constituent of?
of the levator ani
where do the muscle fibres of the pubococcygeus muscle arise from?
from the body of the pubic bone and the anterior aspect of the tendinous arch
where do the muscles fibres of the pubococcygeus muscle travel?
The fibres travel around the margin of the urogenital hiatus and run posteriomedially
where do the muscle fibres of the pubococcygeus muscle attach to?
attaching at the coccyx and anococcygeal ligament
what happens to the muscle fibres of the pubococcygeus muscle as it travels inferiorly and medially?
some fibres divide and loop around the prostate in males and around the vagina in females
where do some fibres of the pubococcygeus muscle terminate?
in the perineal body
what are the muscle fibres of the pubococcygeus muscle called as it loops around the prostate in males?
levator prostatae
what are the muscle fibres of the pubococcygeus muscle called as it loops around the vagina in females?
pubovaginalis
what does the iliococcygeus muscle contain?
has thin muscle fibres, which start anteriorly at the ischial spines and posterior aspect of the tendinous arch
where do the thin muscle fibres of the iliococcygeus muscle begin?
start anteriorly at the ischial spines and posterior aspect of the tendinous arch
where do the thin muscle fibres of the iliococcygeus muscle attach?
They attach posteriorly to the coccyx and the anococcygeal ligament
what is the Coccygeus muscle innervated by?
Innervated by the anterior rami of S4 and S5
what is the coccygeus muscle?
the smaller, and most posterior, pelvic floor component
where are the levator ani muscles situated?
The levator ani muscles situated anteriorly
where do the levator ani muscles originate from?
It originates from the ischial spines
where do the levator ani muscles travel to?
to the lateral aspect of the sacrum and coccyx, along the sacrospinous ligament
