The pelvic floor Flashcards
what resides within the pelvic cavity?
The pelvic viscera, (bladder, rectum, pelvic genital organs and terminal part of the urethra)
what is the pelvic cavity also known as?
true pelvis
where is the pelvic cavity located within?
within the lesser part of the pelvis, beneath the pelvic brim
which muscles help make up the lateral walls of the pelvic cavity?
the obterator internus and the pirformis muscle
which muscle helps make up the posterior walls of the pelvic cavity?
piriformis
what is the pelvic floor also known as?
the pelvic diaphragm
what is the pelvic floor?
a funnel-shaped musculature structure
what does the pelvic floor attach to?
walls of the lesser pelvis
what does the pelvic floor separate?
the pelvic cavity from the inferior perineum
what does the inferior perineum contain?
genitalia and anus
what are the gaps within the pelvic floor and what is their purpose?
In order to allow for urination and defecation:
urogenital hiatus
rectal hiatus
what is the urogenital hiatus and where is it?
An anteriorly situated gap, which allows passage of the urethra (and the vagina in females)
where is the rectal hiatus and what is it’s function?
A centrally positioned gap, which allows passage of the anal canal
what lies between the urogenital hiatus and the anal canal?
a fibrous node known as the perineal body
what does the perineal body join?
the pelvic floor to the perineum
what are the roles of the muscles in the pelvic floor?
Support of abdominopelvic viscera through their tonic contraction
Resistance to increases in intra-pelvic/abdominal pressure
Urinary and fecal continence
what are examples of abdominopelvic viscera organs?
bladder, intestines, uterus etc.
when would there be increases in intra-pelvic/abdominal pressure?
during activities such as coughing or lifting heavy objects.
what is the role of the pelvic floor in Urinary and fecal continence?
The muscle fibers have a sphincter action on the rectum and urethra. They relax to allow urination and defecation
how many components are there to the pelvic floor and what are they?
Levator ani muscles (largest component)
Coccygeus muscle
Fascia coverings of the muscles
what is the levator ani muscle innervated by?
Innervated by branches of the pudendal nerve
what are the roots of the pudendal nerve?
S2, S3, S4
what shape is the levator ani?
a broad sheet of muscle
what is the levator ani composed of?
three separate paired muscles, called the pubococcygeus, puborectalis and iliococcygeus
what is the anterior attachment of the levator ani to the pelvis?
The pubic bodies of the hip bone
what is the lateral attachment of the levator ani to the pelvis?
Thickened fascia of the obturator internus muscle, known as the tendinous arch
what is the posterior attachment of the levator ani to the pelvis?
The ischial spines of the hip bone
what is the puborectalis?
The puborectalis muscle is a U-shaped sling
where does the extend from?
extending from the bodies of the pubic bones, past the urogenital hiatus, around the anal canal
what type of contraction does the puborectalis carry out?
tonic contraction
what happens during the tonic contraction of the puborectalis? what is created?
Its tonic contraction bends the canal anteriorly, creating the anorectal angle
where does the anorectal angle occur?
anorectal junction
what is the anorectal junction?
where the rectum meets the anus
what is the angle of the anorectal angle?
90 degrees
what is the main function of the puborectalis?
The main function of this thick muscle is to maintain faecal continence
what happens during defecation?
the puborectalis relaxes
what is the function of the pubococcygeus?
The muscle fibres of the pubococcygeus are the main constituent of the levator ani
where does the pubococcygeus arise from?
arise from the body of the pubic bone and the anterior aspect of the tendinous arch
what do the fibres of the pubococcygeus travel?
travel around the margin of the urogenital hiatus and run posteriomedially
what do the pubococcygeus fibres attach to once it runs posteriomedially?
the coccyx and anococcygeal ligament
where do the fibres of the pubococcygeus run?
As the fibres run inferiorly and medially
as the fibres of the pubococcygeus run inferiorly and medially, what does this mean happens to some fibres in males?
some fibres divide and loop around the prostate in males (levator prostatae)
as the fibres of the pubococcygeus run inferiorly and medially, what does this mean happens to some fibres in females?
some fibres divide and loop around the vagina in females (pubovaginalis). Some also terminate in the perineal body
what happens to the fibres of pubococcygeus which do not loop around the prostate or the vagina?
terminate in the perineal body
what type of muscle fibres does the iliococcygeus have?
The iliococcygeus has thin muscle fibres
where does the iliococcygeus begin?
start anteriorly at the ischial spines and posterior aspect of the tendinous arch
where does the iliococcygeus attach?
attach posteriorly to the coccyx and the anococcygeal ligament
what is the coccygeus innervated by?
Innervated by the anterior rami of S4 and S5
what is the coccygeus?
the smaller, and most posterior, pelvic floor component
what is situated anterior to the coccygeus?
The levator ani muscles situated anteriorly
where does the coccygeus originate from?
the ischial spines
where does the coccygeus travel to?
the lateral aspect of the sacrum and coccyx, along the sacrospinous ligament
