Pelvis Flashcards
Pelvic girdle
Hip Bones
- Ilium
- Ischium
-Pubis
Sacrum
Coccyx
Main joints of the pelvic Bones
Anterior: pubic symphysis
Posterior: sacroiliac
Pelvic Inlet Boundaries
- Pubic symphysis and posterior border of pubic crest
- Pecten pubis
- Arcuate line of the ilium
- Anterior border of ala of sacrum
- Sacral promontory
Pelvic outlet (pelvic diaphragm) Boundaries
- Inferior margin of the pubic symphysis
- Inferior rami of pubis and ischial bone
- Sacrotuberous ligaments
- Tip of the coccyx
Subpubic angle
Runs in the inferior border of the symphysis pubis
False (greater pelvis)
-Superior to the pelvic inlet
Boundaries:
- Anterior: abdominal wall
- Posterolateral: iliac fossae
- Posterior: L5-S1 vertebrae
Content of the greater (false) pelvis
Ileum and Sigmoid colon
True (lesser) pelvis
-Inferior to the pelvic inlet
Boundaries:
- Anterior: pubic symphysis
- Posterior: coccyx
- Inferior: pelvic outlet (pelvic diaphragm)
Contents of the true (lesser) pelvis
-Rectum, Urinary bladder, Reproductive Organs
Main Joints of Pelvis
- Lumbosacral Joints (L5-S1)
- Sacrococcygeal joint
- Sacroiliac joints
- Pubic symphysis
Lumbosacral joints (L5-S1) of the pelvis
- Determined by the intervertebral disk
- Iliolumbar ligament to the ilia and L5
Sacrococcygeal joint of the Pelvis
- Has both anterior and posterior ligaments
- Lateral ligaments at the posterior surface of the coccyx
Sacroliac joint of the Pelvis
- Presents several intraarticular joints between the articular surface of the ilium and sacrum
- Interosseous ligaments
- Sacroiliac ligaments (anterior and posterioror)
- Sacrotuberous ligaments (greater sciatic foramen)
- Sacrospinous ligaments (creates the lesser sciatic foramen)
Pubic symphysis of the Pelvis
- Presents a disk of cartilage that joins both pubic bones
Anterior pelvic wall
- Made up of pubic bones and the pubic symphysis
Lateral pelvic wall
- Hip bones (Ischium, Pubic, and part of ilum)
- Obturator canal (the connection between the lesser pelvis and the anteromedial surface of the thigh)
- Obturator internus muscle (tendon runs out of the greater sciatic foramen to the posterior thigh)
- obturator nerves and vessels (apart of the lumbar plexus)
Posterior pelvic wall
- Sacrum and coccyx
- Piriformis muscle
- Sacroiliac joint
- Sacral plexus
Pelvic floor (pelvic diaphragm)
- Levator ani muscle
- Puborectalis (runs from the posterior surface of the pubis and surround the rectum)
- Puboccygeus (runs from the posterior pubis and insert at the level of the tip of the coccyx)
- Iliococcygeus - Coccygeus muscle: part of the diaphragm of the pelvis
Pelvic Nerves (Plexus)
- Sacral (largest) and coccygeal nerves
- Autonomic nervous system (composed from sympathetic and parasympathetic nerves that came from the vertebrae bone)
- Piriformis and coccygeus: bed of the neurovascular structure of the pelvis
Pudendal Nerve; S2-S4 (Sacral plexus)
- ONLY nerve that runs from the lesser pelvis, exits out of the superior border of the sacrospinous ligament (greater sciatic foramen), makes a loop, and reenters the perineum via the lesser sciatic foramen
- MAIN INNERVATION OF THE PERINEUM IN BOTH MALES AND FEMALES!
Sciatic Nerve (L4-S3) ; Sacral Plexus
- The largest nerve of the body
- Runs in the posterior aspect of the leg after it exits the pelvis via the greater sciatic foramen
Quadratus femoris and inferior gemellus nerve; L4-S1 (Sacral plexus)
- Innervated the quadratus femoris and inferior gemellus muscles
Posterior femoral cutaneous nerve; S2-S3 (Sacral Plexus)
- Sensorial nerve to the posterior aspect of the thigh
- Runs through the inferior border of the gluteus maximus
Superior gluteal nerve; L4-S1 (Sacral Plexus)
- Corresponds to the posterior aspect of the sacral plexus
- Exits the pelvis via the greater sciatic foramen
- Innervates: Gluteus medius, Gluteus minimus and tensor fascia lata
- Posterior divisions
Inferior gluteal nerve; L4-S2(Sacral plexus)
- Exits pelvis via the greater sciatic foramen
- Innervates the gluteus meximus muscle
- Posterior divisions
Pelvic Nerves (Sacral Plexus)
- Nerve to piriformis muscle (S1-S2)
- Nerve to obturator internus and superior gemellus muscles (L5-S2)
- Levator ani / coccygeus nerve (S3-S4)
- Perineal branch nerve (cutaneous to the perineal region)
- Perforating cutaneous nerve (additional cutaneous nerves of the perineum)
Coccygeal plexus
- Ventral rami S4-S5 and the coccygeal nerve
- Anococcygeal nerve
- Innervation to: Coccygeaus muscle, Part of the Levator ani, and Sacrococcygeal joint
Autonomic System
- Responsible for the autonomic functions of the pelvis, inferior limb, and part of the external genitalia
Sacral sympathetic trunk
- Runs in two chains parallel to the backbone and at the end of the pelvis it presents 4 sympathetic ganglia
- Coccygeal ganglion (anterior to coccyx)
- Gives fibers to the Sacral Nerve, Coccygeal Nerve, Median Sacral Artery, and inferior hypogastric plexus
- Gives Postsynaptic fibers to the sacral plexus for sympathetic innervation of lower limbs (vasomotor, pilomotor, and sudomotor)
Hypogastric Plexus
Superior
- Inferior to bifurcation of aorta
- Receives L3-L4 splanchnic nerves (sympathetic chain)
- Descends to the pelvis as the left and right hypogastric nerves
Inferior (pelvic plexus)
- To prostate gland, seminal vesicles, bladder, cervix, and lateral fornices of the vagina
Parasympathetic Component of the pelvic Nerves
- S2-S4 (Nervi erigentes: gives innervation for the parasympathetic component)
- Nervi erigentes nerves are inferior to the hypogastric plexus
- Gives multiple branches to the Subplexus
- Subplexus surrounds the rectal, visceral, and uterovaginal structures
Arteries entering the pelvis
- Internal iliac artery (MAIN ARTERY OF THE PELVIS)
- Ovarian artery (orginates from the aorta)
- Medial sacral artery
- Superior rectal artery
Internal iliac artery (L5-S1)
- Close to the areas of the ureter
- Ends at the superior border of the greater sciatic foramen
Umbilical Artery (Anterior Division of the Internal Iliac Artery)
- In adults, the umbilical artery is called the Superior Vesical artery
- It continues as the medial peritoneal ligament
Obturator Artery (Anterior Division of the internal Iliac Artery)
- Travels in the obturator canal at the lateral wall of the pelvis
- Ends at the anterior medial aspect of the thigh
Inferior Vesical Artery (Anterior Division of the Internal iliac Artery
- ONLY IN MALES
- Supplies the prostate, bladder, seminal vesicles, ureter (distal)
- Branches: vas deferens and prostatic artery
Middle Rectal Artery (Anterior Division of the Internal Iliac Artery)
- Supplies the mid portion of the rectum, vagina (proximal), prostate gland, and seminal vesicles
Uterine Artery (Anterior Division of the Internal Iliac Artery)
- ONLY in females
- Runs in the root of the broad ligament
- Travels up to the lateral margin of the uterus
- Branch: vaginal artery (male= Inf. Vesical)
- Anterior and superior to the ureter (during hysterectomy physicians has to be aware of the uterine artery when you have to occlude the artery)
- Anastomose with ovarian artery
Internal pudendal artery (Anterior Division of the Internal iliac artery
- Exits via the greater sciatic foramen
- Goes through the ischioanal fossa via the lesser sciatic foramen
- Supplies the Perineum
Inferior Gluteal Artery (Anterior Division of the Internal iliac artery)
- Larger artery
- Exits via the greater sciatic foramen
- Located inferior to the piriformis muscle
- Will supply the inferior aspect of the gluteal region
Superior Gluteal Artery (Posterior Division)
- Exits via the greater sciatic foramen
- Located superior to the piriformis muscle
- Supplies the superior aspect of the thigh
Iliolumbar Artery (Posterior Division of the Internal Iliac Artery)
- Branches: Iliac and lumbar branches
- Supplies the iliac muscle and the ilium
- Also supplies the psoas major and the quadratus lumborum
Lateral sacral artery (Posterior Division of the Internal Iliac Artery)
- The main artery to the spinal meninges located inside of the vertebral canal
- Erector spinae and skin and supplied by the lateral sacral artery
Median Sacral Artery (Pelvic Vessels)
- Posterior surfaces of the abdominal aorta
- Anterior to the bodies of L4-L5, sacrum, and coccyx
Braches:
- 5th lumbar arteries
- Lateral sacral arteries
- Rectal arteries (posterior)
Superior Rectal Artery (Pelvis Vessels)
- the terminal branch of the inferior mesenteric artery
Ovarian Artery (Pelvis Vessels)
- Branches directly from the abdominal aorta
Pelvic Veins
All veins runs parallel at the level of the arteries
Superior gluteal veins
- Greater tributary of the internal iliac, except in pregnancy (uterine vein)
Internal iliac veins
Joins with the external iliac vein and from the common iliac veins
Common iliac veins
Iliolumbar veins
