Gluteal Region and Thigh (Week 4--Miller) Flashcards
Structures of gluteal region
Gluteal muscles (maximus, medius, minimus)
Superior and inferior gluteal vessels and nerves
Sciatic nerve
Posterior femoral cutaneous nerve
Muscles that laterally rotate the thigh (piriformis, superior/inferior gemilli, obturator internus, quadratus femoris)
Pudendal nerve
Internal pudendal vessels
Cluneal nerves
Cutaneous innervation of gluteal region
Superior cluneal: from dorsal rami of L1-3
Middle cluneal: from dorsal rami of S1-3
Inferior cluneal: from posterior femoral cutaneous nerve (which is a branch of sacral plexus, so ventral rami nerves)
Gluteal muscles
Gluteus maximus (superficial): inferior gluteal nerve; extention and lateral rotation of thigh
Gluteus medius (intermediate): superior gluteal nerve; abduction and medial rotation of thigh
Gluteus minimus (deep): superior gluteal nerve; (abduction and) medial rotation of thigh
Trendelenburg Test
Evaluates strength of gluteus medius as an abductor
Patient asked to stand on one leg
Point of reference is posterior superior iliac spines (PSIS)
Negative (normal): pelvis slightly elevates as gluteus medius contracts (abducts) on supported side
Positive: pelvis remains in position or descends (indicates weak or nonfunctioning gluteus medius on supported side)
Trochanteric bursa
Separates gluteus maximus from lateral side of greater trochanter of femur
Membranous sac containing synovial fluid to reduce friction
Sciatic nerve
Halfway between greater trochanter and ischial tuberosity, comes out below piriformis muscle
Largest branch of sacral plexus
Formed by ventral rami fibers from L4-S3
Two divisions: tibial division innervates hamstrings and posterior leg muscles and common peroneal (fibular) division innervates short head of biceps femoris and anterior and lateral compartment of leg muscles
Controls basically everything below gluteal region except for anterior compartment of thigh
Sacral plexus
Somatic nerve plexus formed by ventral rami fibers from L4-S4
Branches: sciatic nerve, superior/inferior gluteal nerves, posterior femoral cutaneous nerve, pudendal nerve, nerves to lateral rotator muscles of hip and levator ani
Part of lumbosacral plexus
Lumbosacral plexus
Sacral plexus plus lumbar plexus
Responsible for innervation of lower limb
Course of the sciatic nerve
Leaves pelvis to enter gluteal region
Courses inferiorly in posterior compartment of thigh
Divides in popliteal region into tibial nerve and common peroneal nerve
Safe area for intragluteal injections is upper outer (lateral) quadrant of gluteal region so don’t hit sciatic nerve
What exact movements does the sciatic nerve control?
Tibial nerve: controls posterior compartment of leg (plantar flexion) and all of the foot
Common peroneal nerve: controls anterior (dorsiflexion) and lateral (eversion) compartments of leg
Piriformis muscle
Laterally rotates and abducts the extended thigh
Right above piriformis muscle is superior gluteal vessels and nerves
Right below piriformis muscle is sciatic nerve and inferior gluteal vessels and nerve, and other muscles that laterally rotate thigh
Superior and inferior gluteal arteries
Branches of internal iliac artery
Originate in pelvis then reach gluteal region by going through greater sciatic foramen
Superior and inferior gluteal nerves
Branches of the sacral plexus
Originate in pelvis and reach gluteal region by going through greater sciatic foramen
Muscles that rotate the thigh laterally
Superior and inferior gemelli muscles
Obturator internus
Quadratus femoris
(Piriformis)
All are innervated by branches from sacral plexus
Greater sciatic foramen
Formed by greater sciatic notch, sacrospinous ligament and sacrotuberous ligament
Doorway from pelvis to gluteal region
Superior/inferior gluteal nerves and vessels, piriformis muscle comes out of it
Lesser sciatic foramen
Formed by sacrospinous and sacrotuberous ligaments
Doorway from gluteal region to perineum
Pudeneal nerve/vessels go from gluteal region to perineum
3 compartments of the thigh
Anterior (extensor): sartorius, iliopsoas, quadriceps; femoral nerve; femoral artery
Posterior (flexor): hamstrings; sciatic nerve; perforating branches of profunda femoris artery
Medial (adductor): adductors, gracilis, pectineus; obturator nerve; obrurator artery and profunda femoris artery
What separates the 3 compartments of the thigh?
Fascial (intermuscular) septa that attach from linea aspera of femur to fascia lata of thigh
Fascia lata
Fascial sleeve of deep fascia that completely surrounds all of muscles of lower limb like a sock
In the thigh, is called fascia lata and is continuous with inguinal ligament (above)
In the leg, it is called crural fascia
Posterior compartment of the thigh
Hamstring muscles (biceps femoris, semitendinosus, semimembranosus) to flex knee and extend hip
Sciatic nerve (tibial division except short head of biceps femoris)
Perforating branches of profunda femoris (deep femoral artery)
3 muscles of the hamstrings (posterior thigh)
To be a true hamstring muscle must be innervated by tibial division of sciatic nerve and must attach to ischial tuberosity
Semitendinosus: medial; superficial to semimembranosus;
Semimembranosus: medial; deep to semitendinosus
Biceps femoris: lateral; 2 heads; long head is true hamstring but short head is NOT true hamstring because innervated by common peroneal division of sciatic nerve and attaches to linear aspera!
Anterior compartment of the thigh
Femoral triangle
Adductor canal
Sartorius, iliopsoas, quadriceps
Femoral nerve
Femoral artery
Cutaneous innervation of anterior and medial thigh
Femoral nerve
Obturator nerve
Lateral femoral cutaneous nerve
Also subcostal, iliohypogastric, ilioinguinal nerves
Great saphenous vein
From dorsal venous arch of foot –> anterior to medial malleolus –> medial aspect of leg and thigh –> dives through saphenous opening in fascia lata –> femoral vein
Note: use graft of portion of great saphenous vein to do bypass for CAD caused by atherosclerosis but have to put the vein graft in reverse so valves don’t obstruct blood flow!
Saphenous opening
Opening in fascia lata that allows the great saphenous vein to pass through and drain into femoral vein
Muscles of the anterior compartment
Iliopsoas
Sartorius
Quads: rectus femoris, vastus lateralis, vastus medialis, vastus intermedius
Femoral triangle
In anterior compartment of thigh
Contains femoral nerve, artery, vein, inguinal lymph nodes
Adductor canal
In anterior compartment of thigh
Deep to sartorius, between anterior and medial compartment muscles
“Tunnel-like” space also known as subsartorial canal or Hunter’s Canal
Contains 2 nerves and 2 vessels: saphenous nerve, nerve to vastus medius, femoral artery, femoral vein
Femoral vein
Popliteal vein –> crosses adductor hiatus to become femoral vein –> travels superiorly through adductor canal then femoral triangle –> crosses inguinal ligament to become external iliac vein
Medial to femoral artery
Catheter inserted here used when rapic access to large veing is needed, but because of high incidence of thrombosis and pulmonary embolism, remove catheter ASAP
Femoral artery
External iliac artery –> crosses inguinal ligament to become femoral artery –> travels inferiorly through femoral triangle then adductor canal –> crosses adductor hiatus to become popliteal artery
Lateral to femoral vein
Catheter inserted here is used to image SMA, IMA, celiac artery, renal arteries, aorta, everything
Catheter inserted here is used to take pressure recordings through aortic valve into left ventricle
Boundaries that form femoral triangle
Sartorius (lateral)
Adductor longus (medial)
Inguinal ligament (superior)
Muscles that make up floor of femoral triangle
Adductor longus (medial compartment)
Pectineus (medial compartment)
Iliopsoas (anterior compartment)
Where is the femoral artery within the femoral triangle?
Halfway between pubic tubercle and ASIS, along inguinal ligament
Femoral nerve
From ventral rami of L2-4
Branch of lumbar plexus
Mixed nerve: sensory, motor, symp post (to blood vessels, glands)
Nerve of the anterior compartment of thigh and innervates all anterior muscles
Participates in innervation of hip and knee joints
Femoral sheath
Derived from transversalis fascia
Contains femoral vein and femoral artery (NOT femoral nerve–that is lateral to femoral sheath)
Divided into 3 compartments: lateral (artery), intermediate (vein), medial (aka femoral canal, which connects to abdominopelvic cavity and can get femoral hernias here)
Inguinal lymph nodes
Lie in superficial fascia of femoral triangle region
If enlarged, may be sign of infection ascending from lower extremity, or local pelvic problem
Medial compartment of thigh
Adductor compartment with 3 muscles:
Gracilis
Pectineus
3 adductor muscles: adductor longus, adductor brevis, adductor magnus
Obturator nerve
Obturator artery, profunda femoris artery
3 layers of adductor muscles
Superficial: adductor longus
Intermediate: adductor brevis
Deep: adductor magnus
Adductor hiatus
Formed by split tendon of adductor magnus
Between adductor part (innervated by obturator nerve) and hamstring part (innervated by sciatic nerve) of adductor magnus
Doorway from anterior thigh to popliteal region
Femoral vessels pass through here
Obturator nerve
From ventral rami of L2-4 (smooth obturator…)
Branch of lumbar plexus
Mixed nerve: sensory, motor, symp post (to blood vessels, glands, etc)
Nerve of the medial compartment and innervates medial compartment muscles
Participates in innervation of hip and knee joints
Blood supply of medial compartment of thigh
Profunda femoris artery (branch of femoral artery)
Obturator artery (branch of internal iliac artery)
Popliteal fossa
Diamond-shaped region on back of knee
Contains fat, blood vessels, lymphatic vessels and nerves
Boundaries of popliteal fossa
Superior: hamstrings (biceps femoris laterally; semitendinosus/semimembranosus medially)
Inferior: heads of gastrocnemius
Contents of the popliteal fossa
2 vessels and 2 nerves:
Popliteal artery, popliteal vein (both continuations of femoral vessels)
Tibial nerve, common peroneal nerve (both divisions of sciatic nerve)
3 pelvic girdle joints
1) Sacroiliac joint: synovial joint, between sacrum and lilum
2) Pubic symphysis: cartilagenous joint (fibrocartilagenous disc between 2 bones), between 2 pubic bones
3) Hip joint: synovial joint (ball and socket), reinforced by 3 ligaments (iliofemoral, pubofemoral, ischiofemoral ligaments), innervated by femoral, obturator, sciatic and superior gluteal nerves
Knee joint
Synovial joint (hinge type)
Largest joint in the body
Strengthened by 5 intrinsic ligaments/external ligaments (thickenings of fibrous joint capsule)
Cruciate ligaments/internal ligaments (intracapsular and extrasynovial)
Menisci
5 intrinsic ligaments of the knee joint
All help strengthen knee joint and are thickenings of fibrous joint capsule
1) Patellar ligament
2) Fibular (lateral) collateral ligament (LCL)
3) Tibial (medial) collateral ligament (MCL)
4) Oblique popliteal ligament
5) Arcuate popliteal ligament
Cruciate ligaments of the knee joint
Intracapsular and extrasynovial
1) Anterior cruciate ligament (ACL): weaker; from anterior intercondylar area of tibia to lateral condyle of femur; prevents posterior displacement of femur on tibia and hyperextension; when joint flexed at right angle, tibia can’t be pulled anteriorly because held by ACL
2) Posterior cruciate ligament (PCL): stronger; from posterior intercondylar area of tibia to medial condyle of femur; prevents anterior displacement of femur on tibia/posterior displacement of tibia, and hyperflexion
Menisci of knee joint
Crescentic plates of fibrocartilage on articular surface of tibia
Shock absorbers that deepen articular surfaces of tibia where they articulate with femoral condyles
Medial meniscus attached firmly to MCL
Lateral meniscus
Unhappy triad
Medial meniscus
MCL
ACL
“Clipping” injuries to the knee (hit knee from lateral side) involve these
Blood supply to knee joint
10 vessels that form geniculate anastomosis
Includes branches of femoral artery, popliteal artery, anterior tibial artery
Innervation of knee joint
Branches of femoral nerve, obturator nerve, tibial nerve, common peroneal nerve
Muscles that attach at pes anserine (medial condyle of tibia)
Say Grace at Tea
Sartorius
Gracilis
Semitendonosus and Semimembranosus
