Lower limb Flashcards
Describe the course of the ilioinguinal nerve?
Lies between internal oblique and transversus abdominus (supplies their lower fibres). Then pierces the internal oblique and passes deep to external oblique to emerge through superficial inguinal ring.
Supplies root of penis, anterior 1/3 of scrotum and a small area of the thigh below inguinal ligament
Origin and course of genitofemoral nerve
1st and 2nd lumbar nerves- only fibres from L1 pass into femoral branch. This branch is given off as it lies on psoas major. Runs with external iliac artery and passes beneath inguinal ligament into femoral sheath. Supplies skin over femoral triangle. Genital branch passes through deep ring with the spermatic cord
Key differences between medial femoral cutaneous nerve and intermediate femoral cutaneous nerve?
Medial: pierces the fascia lata at mid thigh and suppies medial side of the thigh
Intermediate: pierces sartorius and pierces fascia lata above medial and supplies front of thigh down to the knee
Both L2, L3
Course of lateral femoral cutaneous nerve
L2L3
Passes from lateral border of psoas major and lies behind the fascia iliaca, but then approaching the inguinal ligament it inclines forwards and is incorporated within iliac fascia. Pierces inguinal ligament a centimetre to the medial side of the ASIS.
Supplies posterolateral aspect of mid thigh
Can be compressed as passes through inguinal ligament causing meralgia parasthetica or through iliac fascia
What are the four superficial branches of the femoral artery found beneath the inguinal ligament?
Superficial circumflex iliac- lateral to saphenous opening
Superficial epigastric- through saphenous opening
Superficial external pudenal- through saphenous opening in front of spermatic cord to scrotum and penis
Deep external pudendal-pierces fascia lata behind spermatic cord
Course of long saphenous vein
Longest vein in body
Starts as medial marginal vein of the foot, passes up medially in front of medial malleolus and ends by passing through cribiform fascia covering saphenous opening (3cm below and lateral to pubic tubercle). Here it joins femoral vein.
Vein contains up to 20 valves.
Describe the lymphatics of the genitals
external genitalia (including lower vagina but excluding the testes) go to superficial inguinal nodes.
Glans penis/ clitoris go to deep inguinal nodes
Testes go to para-aortic nodes
Why can femoral hernias never grow very large?
Scarpas fascia from the abdomen fuses with fascia lata at the hip joint and extends laterally from the pubic tubercle below the inguinal ligament. Therefore a femoral hernia cannot get deep to scarpas fascia, it can only get into subcutaneous fat.
Where is the saphenous opening?
The gap in the fascia lata, attached laterally to the falciform edge and medially to the fascia lata where it lies over adducter longus
Pierced by great saphenous vein, its tributaries and efferent lymphatics- looks like sieve (called cribriform fascia)
Origin Insertion Action Nerve supply Special features Tensor fascia lata
External lip of iliac crest 5cm from ASIS to tubercle
Iliotibial band
Pull on iliotibial tract to assist GM in extending the knee and resists abduction in walking
Superior gluteal nerve (L4-5, S1)
Sup glut nerve ends in it
What does the iliotibial tract do?
It maintains the knee hyperextended while quadriceps is relaxed and patella freely mobile.
Inserts on Gerdy’s tubercle
Three quarters of glut max is inserted onto it.
What are the borders of the femoral triangle?
Lateral: sartorius
Medial: Adductor longus
Superior: inguinal ligament
What lies in the femoral triangle?
Femoral nerve, artery and vein
Iliacus, psoas, pectineus and adductor longus lie in the floor
Origin Insertion Action Nerve supply Special features Sartorius
Immediately below ASIS
Upper medial surface of the tibia, in front of gracilis and semitendinosis
Flexes, abducts and laterally rotates the thigh at the hip. Flexes, medially rotates leg at the knee
Ant division of the femoral nerve L2-L4
Longest muscle in the body, parallel fibres. Pierces by intermediate femoral cutaneous nerve. Bursa lies between tendon and MCL
Origin Insertion Action Nerve supply Special features Iliacus
Iliac fossa
Lowermost surface of lesser trochanter of femur, in front of psoas tendon
Flexes the hip
Femoral nerve (L2-3)
Passes below inguinal ligament. Passes in front of the hip joint, may communicate with bursa in front of the hip joint
Origin Insertion Action Nerve supply Special features Psoas major
Transverse process of L1-5, bodies of T12-L5 and intervertebral discs below body of T12-L4
Lesser trochanter of femur
Flexes the hip
Anterior primary rami of L1-3 (mainly L2)
Passes below inguinal ligament. Passes in front of the hip joint, may communicate with bursa in front of the hip joint
Origin Insertion Action Nerve supply Special features Pectineus
Pectineal line of the pubis and superior pubic ramus below it
Vertical line behind and below lesser trochanter
Flexes and adducts the hip
Ant division of femoral nerve (L2-3) +/- obturator
Which layer of abdominal fascia becomes the femoral sheath?
Transversalis
Where does the femoral sheath fuse with the adventitia of the artery and vein?
3cm distal to inguinal ligament
How is the femoral neurovascular bundle ordered from lateral to medial?
Femoral nerve (outside femoral sheath)
Artery
Vein
Femoral canal
What are the four boundaries of the femoral ring?
Ant: medial part of inguinal ligament Med: lacunar ligament Post: pectineal ligament Lat: femoral vein Femoral canal contains 1 lymph node which drains directly from the clitoris
Describe the course and branches of the femoral artery
Enters thigh midpoint between ASIS and pubic symphysis (on top of psoas major tendon).
Profunda femoris branch comes off just below the femoral sheath. Passes between pectineus and adductor longus.
Lateral circumflex artery comes off profunda femoris (sometimes femoral).Lies deep to rectus femoris and sartorius. Becomes ascending, transverse and descending branches.
Medial circumflex comes off profunda femoris
Where does the ascending branch of the lateral circumflex artery run and why is it important?
Runs of the vastus lateralis, beneath sartorius and tensor fascia lata and passes on towards ASIS and anastomoses with the superficial and deep circumflex iliac (superior gluteal artery). Lies between between sartorius and tensor fasciae lata in the anterior approach to the hip
When does the femoral vein become the external iliac vein?
Receives profunda femoris vein just below the femoral sheath and the great saphenous vein joins it anteriorly, then in the sheath, passes under inguinal ligament becoming external iliac vein
What is the difference in the origins of the obturator vs femoral nerves?
Femoral: Posterior divisions of L2, 3, 4
Obturator: Anterior divisions of L2, 3, 4
Describe the course of the femoral nerve
Supplies iliacus in abdomen
Enters thigh between psoas and iliacus beneath the inguinal ligament
Enters femoral triangle, gives off branch to pectineus.
2 nerves to sartorius, 2 nerves to rectus femoris.
Nerve to vastus medialis (largest branch)
Nerve to vastus lateralis
Saphenous nerve leaves femoral angle and passes in front of femoral artery to reach medial side, passes between sartorius and gracilis
Origin Insertion Action Nerve supply Special features Rectus femoris
Straight head: AIIS above ileofemoral ligament
Reflected head: ilium above acetabulum
Quadriceps tendon to patella
Extends leg at the knee at flexes the thigh at the hip
Deep branch of femoral nerve (L3-4)
Posterior surface covered by glistening aponeurosis separating it from vastus intermedius
Origin Insertion Action Nerve supply Special features Vastus lateralis
Upper intertochanteric line, base of the trochanter and lateral lip of lateral linea aspera, lateral supracondylar ridge and lateral IM septum
Quads tendon to patella
Extends knee
Deep branch of femoral nerve (L3,4)
Descending branch of of lateral circumflex artery and nerve to vastus lateralis lies in gutter between of VL and VI
Origin Insertion Action Nerve supply Special features Vastus intermedius
Ant and lateral upper 2/3 of shaft of femur
Quads tendon to patella
Extends knee
Deep branch of femoral nerve L3,4
Origin Insertion Action Nerve supply Special features Vastus medialis
Lower intertrochanteric line and the medial lip of linea aspera and from tendon of adductor magnus below haitus for femoral vessels
Quads tendon to patella
Extends knee
Deep branch of femoral nerve L3,4
Most important muscle in stabilising patella
Where is the articularis genu?
5th quadricep muscle Arises from the lower 1/3 of femur and inserts on suprapatellar bursa, deep to vastus intermedius
What are the boundaries of the adductor canal?
Lies between vastus medial and adductors
Roof: fascia and sartorius
Floor: adductors
Contains femoral artery, vein, saphenous vein and nerve to vastus medialis and subsartorial plexus (medial cutaneous nerve, saphenous nerve and ant division of obturator nerve)
Origin Insertion Action Nerve supply Special features Gracilis
Inferior ramus of pubis and ischial ramus
Upper medial shaft of tibia behind sartorius
Adducts hip, flexes knee and medially rotates flexed knee.
Anterior division of the obturator nerve L2-3
Blood supply is medial circumflex, profunda and femoral arteries
Origin Insertion Action Nerve supply Special features Adductor longus
Body of pubis inferior and medial to pubic tubercle
Lower 2/3rd medial linea aspera
Adducts the hip
Anterior division of the obturator L2-3
Most superficial adductor
Origin Insertion Action Nerve supply Special features Adductor brevis
Inferior ramus and body of pubis, deep to pectineus and adductor longus
Upper 1/3 of linea aspera
Adducts hip
Anterior division of obturator nerve L2-3
Anterior division of obturator nerve passes in front of muscle, posterior obturator nerve passes behind
Origin Insertion Action Nerve supply Special features Adductor magnus- adductor part
Ischiopubic ramus
Lower tuberosity and linea aspera
Adducts hip
Posterior division of the obturator L2-3
Horizontal upper border is edge to edge with quadratus femoris. Medial circumflex femoral artery runs between the two
Origin Insertion Action Nerve supply Special features Adductor magnus- hamstring part
Lower outer quadrant of posterior surface of the ischial tuberosity
Adductor tubercle of femur and medial supracondylar line
Extends hip
Tibial part of sciatic nerve L2-3
4 openings for profunda femoris alone linea aspera. Opening for adductor hiatus above medial supracondylar line.
Origin Insertion Action Nerve supply Special features Obturator externus
Obturator membrane and anterior border of obturator foramen
Trochanteric fossa on medial side of greater trochanter
Laterally rotates hip
Posterior division of the obturator L3-4
Part of the posterior capsule deficient where the tendon crosses the neck of femur. Muscle passes posterior lateral to NOF
How does the obturator artery supply the hip joint?
Obturator artery enters thigh through obturator foramen. Divides into anterior and posterior branches which then anastomose with medial circumflex artery. From posterior branch- articular twig to hip joint
What do the anterior and posterior branches of obturator nerve supply?
Anterior:Hip joint, adductor longus, gracilis and subsartorial plexus
Posterior: obturator externus, passes on adductor magnus and gives a terminal branch which runs with femoral artery through hiatus in muscle to supply capsule of knee joint
Describe the spinal origins of the sensation of skin of buttock
Central -coccygeal
Anus-S5/S4
S3 beyond anus
S2 central buttock and down medial posterior leg
S1 lateral buttock and posterior lateral leg and lateral foot
Origin Insertion Action Nerve supply Special features Gluteus maximus
Outer surface of ilium behind posterior gluteal line and posterior 1/3 of iliac crest, lumbar fascia, lateral mass of the sacrum and ST ligament
Deepest 1/4 into gluteal tuberosity of the femur. Remaining 3/4 into the IT tract.
Extends and laterally rotates hip, supports knee extension through ITT
Inferior gluteal nerve (L5, S1, 2) only muscle by this nerve
Largest muscle in the body- 3 bursae-ischial tuberosity, GT and ITT
Origin Insertion Action Nerve supply Special features Gluteus medius
Gluteal surface of the ilium between posterior and middle gluteal lines
Posterolateral surface of greater trochanter of femur
Abducts and medially rotates the hip. Tilts pelvis on walking.
Superior gluteal nerve above piriformis (L4-5, S1)
Bursa over lateral GT. Posterior 1/3 covered by gluteus maximus, anterior 2/3 by thick fascia
Origin Insertion Action Nerve supply Special features Gluteus minimus
Gluteal surface of ileum between posterior and anterior gluteal lines
Posterolateral surface of greater trochanter of femur
Abducts and medially rotates the hip. Tilts pelvis on walking.
Superior gluteal nerve (L4-5, S1)
Bursa over anterior GT
Superior gluteal nerve superficial. Opposite side contracts to prevent pelvis sagging to unsupported side
Origin Insertion Action Nerve supply Special features Piriformis
Arises 2,3,4 costotransverse bars of the anterior sacrum between sacral foramina
Anterior part of medial aspect of greater trochanter of femur
Laterally rotates and stabilises the hip
Anterior rami of S1, 2
Passes through greater sciatic foramen
Upper border: superior gluteal a/n
Lower border: inferior gluteal a/n, pudendal a/n, obturator int n, sciatic n, post femoral cutaneous n, quadratus femoris n
Origin Insertion Action Nerve supply Special features Obturator internus
Inner surface of obturator membrane and rim of pubis and ischium
Middle part of medial greater trochanter
Hip stabiliser, lateral rotator of extended thigh, abductor of flexed thigh
Nerve to obturator internus (ant divisions L5, S1-2)
Passes through lesser sciatic foramen. Bursa at lesser sciatic notch
Describe the borders of the lesser sciatic foramen and the contents
Superior: Sacrospinous ligament
Posterior: sacrotuberous ligament
Anterior: ischial spine, lesser sciatic notch and ischial tuberosity
Contains: pudendal nerve, tendon of obturator internus, internal pudenal artery and vein, nerve to obturator internus
Origin Insertion Action Nerve supply Special features Superior gemellus
Spine of ischium
Middle part of medial greater trochanter
Hip stabiliser, lateral rotator of extended thigh, abductor of flexed thigh
Nerve to obturator internus L5-S2
Sciatic nerve passes down posterior surface
Origin Insertion Action Nerve supply Special features Inferior gemellus
Upper border of ischial tuberosity
Middle part of medial trochanter
Hip stabilisers, lateral rotation of hip in extension and abductor of flexed thigh
Nerve to quadratus femoris (ant divisions L4, 5 S1)
Origin Insertion Action Nerve supply Special features Quadratus femoris
Lateral border of sichial tuberosity
Quadrate tubercle of femur
Hip stabiliser, lateral rotation of the hip in extension, abductor of flexed thigh
Nerve to quadratus femoris (ant L4,5, S1)
Separated from NOF by tendon of obturator extensor, border of adductor magnus lies below
Which muscles do the gluteal nerves emerge in between?
Superior gluteal: emerges between piriformis and runs between gluteus minimus and medius
Inferior gluteal: emerges beneath piriformis and disappears into gluteus maximus
Which vessels form the trochanteric anastomosis?
Descending branch of superior gluteal artery
Ascending branch of lateral and medial circumflex arteries (from profunda femoris)
Describe the course of the sciatic nerve (L4, 5, S1-3)
Emerges below piriformis (more laterally than inf gluteal and pudendal)
Lies on the ischium, in contact with bone at a point 1/3 of the way up from ischial tuberosity to the PSIS (the surface marking for entry into gluteal region).
Passes down posterior surface of obturator internus and quadratus femoris. Crossed posteriorly by long head of biceps femoris. Separates into tibial (L4, 5 S1-S3) and common peroneal (L4, 5 S1, 2) nerves at the popliteal fossa. Can occasionally separate early- in which case common peroneal pierces the piriformis and tibial emerges beneath piriformis
Why is the posterior femoral cutaneous nerve relevant to pelvic pain?
Distribution is S1-3. S2,3 segments supply pelvic parasympathetic nerves. Pain from pelvic disease may be referred to distribution of posterior femoral cutaneous nerve ( down posterior thigh and upper calf)
