Week 3 Quiz Flashcards
The bony pelvis is composed of what?
Os Coxae (Ilium, Ischium, Pubis)
Sacrum
Coccyx
Pubic symphysis
What are the boundaries of the pelvic cavity?
Pelvic inlet - superior opening
Pelvic outlet - enclosed by pelvic diaphragm inferiorly
Anterior pelvic wall - bodies of pubic rami and pubic symphysis
Lateral pelvic walls - hip bones and obturator internus muscle
Posterior pelvic wall - sacrum, coccyx, SI joint, associated ligaments
Describe the differences between the male and female pelvis.
Male
- general structure thick and heavy
- pelvic inlet heart shaped
- pelvic outlet small
- pubic arch narrow
- obturator foramen round
- acetabulum large
- subpubic angle < 70 degrees
Female
- general structure thin and light
- pelvic inlet oval and rounded
- pelvic outlet large
- pubic arch wide
- obturator foramen oval
- acetabulum smaller
- subpubic angle > 80 degrees
What makes up the pelvic floor?
Formed by the funnel shaped diaphragm and consists of Levator Ani and the coccygeus muscle
The diaphragm stretches anteroposteriorly from the pubis to the coccyx and laterally to the walls of the pelvis on either side
Describe the OINA of Levator Ani.
Consists of pubococcygeus, puborectalis, and iliococcygeus
Most important muscle in the pelvic floor
O: body of pubis, obturator fascia, Ischial spine
I: coccyx
N: nerve to levator ani (S3, S4)
A: forms muscular sling to support a abdominopelvic viscera, holds pelvic viscera in position to prevent sagging, assists with abdominopelvic cavity compression and is utilized with coughing, sneezing, vomiting, etc.
Describe the OINA for coccygeus.
AKA ischiococcygeus
O: Ischial spine
I: sacrum
N: nerve to levator ani (S3, S4)
A: supports pelvic viscera, forms part of diaphragm
What is the main blood supply to the pelvic region and what does it branch into?
Internal iliac artery, branches from the common iliac artery (which branches to internal and external iliac arteries, and from abdominal aorta)
Branches into anterior and posterior branches
Anterior branch branches into obturator artery, pudental artery, and inferior gluteal artery
Posterior branch branches into superior gluteal artery*, iliolumbar artery, and lateral sacral artery
What is the main supplier of blood for the muscles of the pelvic diaphragm? Describe it.
Inferior gluteal artery
Branches from the anterior branch of the internal iliac artery
Exits through the greater sciatic foramen to supply the gluteal region
What is the location of the femoral triangle? What are its boundaries and contents?
Located at the anterior thigh just inferior to the inguinal ligament
Superior boundary - inguinal ligament Lateral boundary - sartorius muscle Medial boundary - adductor longus muscle Roof - fascia lata Floor - iliopsoas and pectineus muscles
Contents - lateral femoral cutaneous nerve, femoral nerve, femoral artery and vein in femoral sheath, profunda femoris artery which gives rise to lateral and medial femoral circumflex arteries
Describe the profunda femoris artery including its location, function, and branching.
Located in the femoral triangle
Function: main supplier of blood to the thigh
Branches into lateral and medial femoral circumflex arteries, which are the main suppliers of blood to the head and neck of the femur
Describe the venous system of the lower extremity.
Dorsal venous arch to great saphenous vein with perforating branches
Blood flows from superficial veins to deep veins
Superficial veins have their own names, deep veins are named according to the artery they accompany
Venous valves are cup-like endothelial tissue that fill form above, prevent reflux of blood distally, and have a valve mechanism that allows blood to overcome gravitational force
Describe the location, function, and contents of the adductor canal. What are its other names?
A narrow fascial tunnel in the anterior thigh that allows passage for the femoral vessels to the popliteal fossa
Location - begins at the point where the sartorius passes over the adductor longus, and ends at the adductor hiatus in the tendon of the adductor magnus
Contents
- femoral artery and vein enter the adductor canal - as the femoral artery and vein exit through the adductor hiatus they change names to the popliteal artery and vein - saphenous nerve (cutaneous branch of femoral nerve) accompanies the femoral artery and vein into the canal
AKA Hunter’s canal or the Subsartorial canal
Describe the components of the thigh and their innervations.
Divided into 3 compartments by extensions of the deep fascia lata called intermuscular septa
Anterior compartment - knee extensors, innervated by the femoral nerve
Medial compartment - hip adductors, innervated by the obturator nerve
Posterior compartment - knee flexors and hip extensors, innervated by sciatic nerve
Describe the cutaneous innervation of the thigh.
Subcostal nerve (T12) - supplies lateral aspect of the thigh anterior to greater trochanter
Iliohypogastric (L1) - divides into lateral (supplies skin over superolateral buttock) and anterior (supplies skin superior to pubis) branches
Ilioinguinal - travels through superficial inguinal ring to innervate inferior pelvis. Also travels to proximal medial thigh
Genitofemoral- innervates skin of thigh inferior to inguinal ligament on the medial aspect
Lateral femoral cutaneous - innervates lateral and anterior parts of skin of thigh, passes under lateral aspect of inguinal ligament, extends laterally and distally from the greater trochanter to the area just proximal to the knee
Femoral nerve - innervates skin of anterior and medial thigh
Anterior femoral cutaneous - arises from femoral nerve in the femoral triangle, runs along sartorius muscle path and innervates skin of anterior, medial aspect of thigh
Name the muscles of the anterior component of the thigh.
Quadriceps femoris - rectus femoris - vastus intermedius - vastus lateralis - vastus medialis Sartorius Iliopsoas
Describe OINA for rectus femoris.
O: AIIS and rim of acetabulum
I: tibial tuberosity via the patellar ligament
N: femoral nerve
A: hip flexion, knee extension
Describe OINA for vastus intermedius.
O: anterior surface of femur
I: tibial tuberosity via patellar ligament
N: femoral nerve
A: knee extension
Describe OINA for vastus lateralis.
O: lateral surface of femur
I: tibial tuberosity via patellar ligament
N: femoral nerve
A: knee extension
Describe OINA for vastus medialis.
O: medial surface of femur and tendon of adductor magnus.
I: tibial tuberosity via patellar ligament
N: femoral nerve
A: knee extension and controls tracking of patella
Describe OINA for sartorius.
O: ASIS
I: superior end of medial surface of tibia via the Pes Anserine tendon
N: femoral nerve
A: hip flexion and lateral rotation; weak hip abduction and weak knee flexion
Name the muscles of the medial compartment of the thigh.
Pectineus Gracilis Adductor longus Adductor magnus Adductor brevis
Describe OINA for pectineus.
O: Pectineal line of the superior ramus of pubis
I: Pectineal line of femur
N: femoral nerve and obturator nerve
A: hip flexion and adduction
Describe OINA for adductor longus.
O: body of pubis
I: distal 2/3 of the linea aspera
N: obturator nerve
A: hip flexion and adduction
Describe OINA for gracilis.
O: inferior ramus of pubis
I: medial surface of tibia, inferior to the condyle via Pes Anserine tendon
N: obturator nerve
A: hip adduction, knee flexion
Describe OINA for adductor magnus.
O: tuberosity and ramus of ischium
I: linea aspera and adductor tubercle
N: obturator nerve and tibial portion of sciatic nerve
A: hip flexion and adduction, weak hip extension
Describe OINA for adductor brevis.
O: inferior ramus of pubis
I: femur
N: obturator nerve
A: hip flexion and adduction
Describe the boundaries of the gluteal region.
Superior boundary - crest of ilium
Medial boundary - sacrum and coccyx
Inferior boundary - sacrotuberous ligament and Ischial tuberosity
Lateral boundary - greater trochanter
Describe the cutaneous innervation of the gluteal region.
Superior cluneals come from dorsal rami of L1-L3
Middle cluneals come from dorsal rami of S1-S3
Inferior cluneals come from posterior femoral cutaneous nerve
Branches of the subcostal, iliohypogasric, and lateral femoral cutaneous nerve may also reach the area
Innervation of the gluteal region generally comes from what?
Superior and inferior nerves and smaller branches of the lumbosacral plexus
Describe the ligaments of the gluteal region, including their insertions and function.
Sacrotuberous ligament - extends from PIIS, sacrum, and coccyx to the Ischial tuberosity
Sacrospinous ligament - extends from the sacrum and coccyx to the Ischial spine. Lies anteriorly to the sacrotuberous ligament
These two ligaments transform the greater and lesser sciatic notches into foramina.
Describe OINA for gluteus maximus.
O: ilium posterior to posterior gluteal line, sacrum, sacrotuberous ligament
I: gluteal tuberosity and ITB
N: inferior gluteal nerve
A: hip extension and lateral rotation; used for running, climbing, STS
Describe OINA for piriformis.
O: pelvic surface of the sacrum
I: greater trochanter
N: nerve to piriformis
A: hip extension and lateral rotation
Describe OINA for gluteus medius.
O: ilium between iliac crest and superior gluteal line
I: greater trochanter
N: superior gluteal nerve
A: hip abduction and IR
Describe OINA for obturator internus.
O: obturator membrane
I: greater trochanter
N: nerve to obturator internus
A: hip extension and lateral rotation
Describe OINA for superior gemellus.
O: Ischial spine
I: greater trochanter
N: nerve to obturator internus
A: hip extension and lateral rotation
Describe OINA for quadratus femoris.
O: Ischial tuberosity
I: intertrochanteric crest
N: nerve to quadratus femoris
A: hip extension and lateral rotation
Describe OINA for gluteus minimus.
O: ilium between superior and inferior gluteal lines
I: greater trochanter
N: superior gluteal nerve
A: hip abduction and IR
Describe OINA for obturator externus.
O: obturator membrane
I: Trochanteric fossa
N: obturator nerve
A: hip adduction and lateral rotation
Describe OINA for TFL.
O: iliac crest
I: ITB
N: superior gluteal nerve
A: hip flexion and abduction
Describe the superior and inferior gluteal nerves and arteries.
Superior gluteal nerve and vessels pass through greater sciatic foramen superior to the piriformis and provide superficial branches to the gluteus maximus, medius, and minimus, and pass through medius and minimus to reach the TFL
Inferior gluteal nerve and vessels exit the greater sciatic foramen inferior to the piriformis and enter the deep surface of the gluteus maximus
Describe the sciatic nerve and vessels. What runs medially to the sciatic nerve?
Sciatic nerve and vessels pass through the greater sciatic foramen inferior to the piriformis and descend posterior to the obturator internus, gemelli, and quadratus femoris to enter the thigh
The posterior femoral cutaneous nerve runs medial to the sciatic nerve and supplies cutaneous information to the posterior thigh.
Describe the nerve to the obturator internus.
Exits greater sciatic foramen and passes immediately into the lesser sciatic foramen
Supplies motor innervation to the obturator internus and superior gemellus muscles
Describe the pudental nerve and vessels.
Exit through the greater sciatic foramen and pass immediately into the lesser sciatic foramen just medial to the nerve to the obturator internus
Describe the nerve to the quadratus.
Exits the greater sciatic foramen inferior to the piriformis and descends anterior to the obterator internus and gemelli muscles
Innervates the inferior gemellus and quadratus femoris muscles
Describe potential sciatic nerve alternatives.
Normally, both tibial and common fibular components of sciatic nerve run under the piriformis (about 87% of the time)
About 12% of the time, the tibial nerve runs through the piriformis and the common fibular nerve runs under it.
0.5% of the time, the tibial nerve runs above the piriformis and the common fibular nerve runs under it.
NEVER does the common fibular nerve run over or through the piriformis
