Pelvis Anatomy Flashcards
What is the pelvis compromised of
3 bones
Sacrum
Left and right hip bones (innominate) bones
What is the hip bone compromised of
3 smaller bones that fuse together
Ilium
Ischium
Pubis
How many articulations does the bony pelvis have
5
What are the names of the articulations of the bony pelvis
Hip joint
Sacroiliac joint
Pubic symphysis
Lumbosacral joint
Sacrococcygeal joint
What is the hip joint
Head of the femur and the acetabulum (socket) of the pelvis
Where is the sacroiliac joint
Between sacrum and ilium of the hip bone
What are the features of the sacroiliac joint
Very stable and strong
Supported by many ligaments
Where is the pubic symphysis
Between the two pubic bones
What are the features of the pubic symphysis
Almost no movement is permitted at the pubic symphysis
Where is the lumbosacral joint
Between the 5th lumbar vertebrae and the sacrum (an intervertebral disc lies between the two)
Where is the sacrococcygeal joint
Between the sacrum and coccyx
Where is the most anterior point of the ilium
Anterior superior iliac spine
Where is the most lateral point of the ilium
Iliac tubercule
What does the line drawn between each iliac tubercles mark
Division of the lower third of the abdomen from the middle third
Delineating the suprapubic region from the umbilical and the iliac fossae from the flanks
What is the intertubercular line
A line drawn between each iliac tubercle
What is the most medial point of the pubic bone
Pubic tubercle
Where does the inguinal ligament run
Runs from the anterior superior iliac spine to the pubic tubercle
What is the mid-inguinal point
Mid-point of a line drawn from the anterior superior iliac spine to the pubic symphysis
Where is the femoral artery palpable
Mid-inguinal point
What organs does the pelvis contain
Gastrointestinal and genitourinary system
What is the arterial supply of the pelvis
Left and right iliac arteries
What do the iliac arteries give rise to branches which supply
Pelvic viscera
What are the key branches of the internal iliac arteries
Vesical arteries
Uterine and vaginal arteries (female)
Middle rectal artery
Internal pudendal artery
Superior and inferior gluteal arteries
What does the middle rectal artery supply
Rectum
What does the internal pudendal artery supply
Exits the pelvis to supply the perineum
What do the superior and inferior gluteal arteries supply
Exit the pelvis to supply the gluteal (buttock) region
What drains the pelvic organs
Several venous plexuses
What do the venous plexuses unite and drain into
Mostly the internal iliac vein
What type of nerves supply the pelvis
Somatic
Sympathetic
Parasympathetic
What are they key nerves from the sacral plexus
Sciatic nerve
Pudendal nerve
Superior and inferior gluteal nerves
Pelvis splanchnic nerves
What is the sciatic nerve formed by
By lumbar and sacral nerves
L4-S3
Where does the sciatic nerve exit and what does it supply
Exits pelvis
Supplies lower limb
What is the pudendal nerve formed by
Spinal nerves S2-4
Where does the pudendal nerve exit and what does it supply
Exits pelvis
Major nerve of the perineum
Where does the superior and inferior gluteal nerves exit and what do these innervate
Exits the pelvis
Innervate gluteal region
What do pelvic splanchnic nerves carry
Parasympathetic fibres from S2-S4 spinal cord segments
Where do splanchnic nerves travel
Pelvic viscera
Where are sympathetic nerves that innervate the pelvic viscera derived from
Lumbar splanchnic nerves
What is the pelvic floor
Collective name for several muscles that support the pelvic organs from below
What are the three primary functions of the pelvic floor
Prevent herniation - pelvic organs inferiorly, out of the pelvis
Control continence of urine and faeces - provide a sphincter action of urethra and rectum respectively
Aid in increasing intra-abdominal pressure
What are the muscles which make up the pelvic floor
Levator ani
Coccygeus
What is the levator ani composed of
Puborectalis
Pubococcygeus
Iliococcygeus
Where is the perineum
Immediately superficial and inferior to the pelvic floor
Where is the superficial region of the perineum
Between the pubic symphysis and coccyx and medial surfaces of the thighs
When viewed from above what shape is the perineum
Diamond shaped
What can the perineum be split into
2 triangles
What are the names of the two triangles the perineum can be split into
Anal triangle (posteriorly)
Urogenital triangle (anteriorly)
What does the anal triangle contain
The opening of the anus and the external anal sphincter
How many layers does the urogenital triangle have
5
What are the layers if the urogenital triangle
Skin
Perineal fascia
Superficial perineal pouch
Perineal membrane
Deep perineal pouch
What opens out through the skin in the pelvis
Urethra and vagina
What is the perineal fascia
Continuation of the fascia overlying the abdominal wall muscles
What is the superficial perineal pouch
Potential space which contains the erectile tissues of the penis or clitoris
How many muscles does the superifical perineal pouch contain
3
What are the names of the three muscles in the superficial perineal pouch
Ischiocavernosus
Bubospongiosus
Superficial transverse perineal muscles
What is the perineal membrane
A strong fibrous membrane that provides support for attachment of the ischiocavernosus and bulbospongiosus
What foes the perineal membrane have
Specific holes in for the urethra and vagina
What is the deep perineal pouch
Potential space between the perineal membrane and the pelvic floor muscles
What does the deep perineal pouch contain
Parts of the vagina, urethra and the external urethral sphincter
What sits between the two triangles of the perineum
Perineal body
What is the perineal body
Dense mass of fibrous tissue and muscle
Acts as an attachment for almost all perineal and pelvic floor muscles
