Visceral Anatomy - Pelvic Floor

greater pelvis

What is another name for the false pelvis?

lesser pelvis

What is another name for the true pelvis?

pelvic cavity

the space in which organs (including reproductive and urinary), muscles, vessels, nerves, and other structures are housed

perineum

• a diamond-shaped region comprised of soft tissue that seals the pelvic cavity outlet

urogenital triangle and anal triangle

Name the 2 triangles that make up the perineum

pubic symphysis

• a partially moveable cartilaginous joint

• bony components: 2 pubic bones

• articular surfaces of each pubic bone are covered with hyaline cartilage

• interpubic disc: fibrocartilaginous

superior pubic ligament, anterior pubic ligament, posterior pubic ligament, and inferior pubic ligament

Name the 4 static stabilizers of the pubic symphysis

adductors, rectus abdominis, transversus abdominis, ischiocavernosus, bulbocavernosus, pubococcygeus, and puborectalis

Name the dynamic stabilizers of the pubic symphysis

superior pubic ligament

anterior pubic ligament

posterior pubic ligament

inferior pubic ligament

arcuate pubic ligament

What is another name for the inferior pubic ligament?

rectus abdominis

transversus abdominis

sacroiliac joint

• synovial, irregular plane joint

• bony components and articular surfaces: auricular surfaces of ilium and sacrum

auricular surface of ilium

• covered with fibrocartilage

auricular surface of sacrum

• covered with hyaline cartilage

interosseous sacroiliac ligaments, iliolumbar ligaments, anterior sacroiliac ligaments, posterior sacroiliac ligaments, sacrospinous ligament, and sacrotuberous ligament

Name the 6 static stabilizers of the SI joint

interosseous sacroiliac ligaments

iliolumbar ligaments

anterior sacroiliac ligaments

posterior sacroiliac ligaments

sacrospinous ligament

sacrotuberous ligament

body of pubis

superior pubic ramus

inferior pubic ramus

obturator internus

piriformis

• ischiocavernosus

• bulbocavernosus

• superficial transverse perineum

• external anal sphincter

Name the 4 muscles of pelvic floor: layer 1

levator ani and coccygeus

Name the 2 muscles that make up the pelvic diaphragm

layer 3

The pelvic diaphragm is which layer of the pelvic floor muscles?

layer 1 and layer 2

Which 2 layers of the pelvic floor muscles make up the perineum?

male ischiocavernosus

female ischiocavernosus

male bulbocavernosus

female bulbocavernosus

superficial transverse perineum

external anal sphincter

male external urethral sphincter

female external urethral sphincter

compressor urethrae

sphincter urethrovaginalis

deep transverse perineum

perineal membrane

levator ani

pubococcygeus

• main part of levator ani

• arises from the posterior aspect of body of the pubis

• runs posteromedial to insert into the coccyx and anococcygeal ligament

• encircles the urethra, vagina, and anus

• forms the bulk of the levator ani complex (located between the puborectalis and iliococcygeus muscles within the pelvic floor)

anococcygeal ligament

• the median fibrous intersection of the pubococcygeus muscles

puborectalis

• arises from the pubis, posterior aspect of body

• U-shaped muscular sling

• surrounds anorectal junction (junction between anus and rectum)

• most important of the levator ani group for maintaining fecal continence

iliococcygeus

• arises from the ATLA and the ischial spine

• attaches to the coccyx and anococcygeal ligament

nerve to levator ani, inferior anal nerve, and coccygeal plexus

innervation of levator ani

coccygeus

• triangular sheet of muscle

• lies against the posterior part of the iliococcygeus muscle

pelvic surface of ischial spine and sacrospinous ligament

lateral/proximal attachment of coccygeus

inferior end of sacrum (S5 vertebra) and lateral margin of coccyx

medial/distal attachment of coccygeus

nerve to coccygeus (branches of S4 and S5 spinal nerves)

innervation of coccygeus