Gross Anatomy- Anterior Thigh Muscles Flashcards
Decsribe the Anterior Thigh Muscles
- Generally innervated by femoral n.
- Contains flexors of hip and extensors of knee
- Includes pectineus, iliopsoas, sartorius and quadriceps femoris mm.
Describe the Pectineus m.
- Flat quadrangular muscle
- Composed of two layers, innervated by different nerves
- Transitional muscle between anterior and medial compartments
• O: Superior pubic ramus
* *I:** Pectineal line of femur, inferior to lesser trochanter * *A:** ADD and flexion of thigh; assists with MR * *N:** Femoral n. (L2, L3); may receive a branch from obturator n. * *B:** Anterior branch obturator a.
Describe the Iliopsoas m.
- Chief flexor of thigh
- Composed of iliacus and psoas major mm.
• O: Iliacus – Iliac crest and fossa, ala of sacrum, anterior sacroiliac ll.
* *Psoas major** – Sides of T12-L5 vertebrae and IVD; TPs of all lumbar vertebrae * *I:** **Iliacus** – Tendon of psoas major, lesser trochanter and femur distal to it * *Psoas major** – Lesser trochanter * *A:** Flexion of thigh or trunk; stabilize hip joint * *N:** **Iliacus** – Femoral n. (L2, L3) * *Psoas major** – Ventral rami of L1, L2 * *B:** Femoral and medial femoral circumflex aa.
• Capable of moving trunk if thigh is fixed
o Bilateral contraction initiates flexion of trunk
• Postural muscle
o Active during standing in maintaining lumbar lordosis
o Resists hyperextension of hip
Describe the Sartorius m.
- “Tailors muscle”
- Long and ribbon-like
- Longest muscle in body
- Passes from lateral to medial
- Is a pes anserinus m.
- Superficial in anterior compartment
- Acts on two joints
• O: ASIS and superior part of notch inferior to it
- I:** Superior part medial surface of tibia (pes anserinus)
- *A:** Flexion, ABD, and LR of thigh; flexion of leg; MR leg when knee is flexed
- *N:** Femoral n. (L2, L3)
- *B:** Femoral a.
- Actions bring lower limb into cross-legged sitting position
- Mainly a synergist
Describe the Quadriceps Femoris m.
• Forms main bulk of anterior compartment
• Composed of:
o Rectus femoris
”Kicking muscle”
Crosses hip and knee joints
Ability to extend knee, limited when in flexion
O: AIIS and ilium superior to acetabulum
I: Tibial tuberosity via patellar tendon
A: Extension of leg; flexion of thigh; steadies hip joint
** N:** Femoral n. (L2, L3, L4)
B: Femoral a.
o Vastus lateralis
O: Greater trochanter and lateral lip linea aspera
** I:** Tibial tuberosity via patellar tendon
A: Extension of leg
N: Femoral n. (L2, L3, L4)
B: Femoral and profunda femoris aa.
o Vastus intermedius
O: Anterior and lateral surfaces of shaft of femur
** I:** Tibial tuberosity via patellar tendon
A: Extension of leg
N: Femoral n. (L2, L3, L4)
B: Femoral and profunda femoris aa.
o Vastus medialis
O: Intertrochanteric line and medial lip of linea aspera
I: Tibial tuberosity via patellar tendon
** A:** Extension of leg
N: Femoral n. (L2, L3, L4)
** B:** Femoral and profunda femoris aa.
• Vastus lateralis and medialis mm. attach independently to patella
• Form aponeuroses, medial and lateral patellar retinacula
o Reinforce joint capsule of knee joint on each side of patella
o Play a role in keeping patella aligned over patellar surface of femur
Describe a test for the Quadriceps Femoris m.
• To test the quadriceps femoris m.:
o Person is supine with knee partly flexed
o Extends knee against resistance
o Normally, muscle should be observable and palpable
o Tests integrity of femoral n.
Describe the Medial Thigh Muscles
- Comprises the adductor group
- Includes adductor longus, adductor brevis, adductor magnus, gracilis and obturator externus mm.
- All supplied by obturator n., except hamstring part of adductor magnus m.
Describe the Adducttor Longus m.
- Large, fan-shaped muscle
- Most anteriorly placed
- Covers anterior aspect of adductor brevis and adductor magnus mm.
• O: Body of pubis inferior to pubic crest
* *I:** Middle 1/3 of linea aspera * *A:** ADD thigh * *N:** Anterior division, obturator n. (L2, **L3**, L4) * *B:** Anterior branch obturator a.
Describe the Adductor Brevis m.
- Lies deep to pectineus and adductor longus mm.
- Two divisions of obturator n. pass anterior and posterior to muscle
• O: Body and inferior ramus of pubis
* *I:** Pectineal line and proximal part of linea aspera * *A**: ADD and limited flexion of thigh * * N:** Anterior division, obturator n. (L2, **L3**, L4) * *B:** Anterior branch, obturator a.
Describe the Adductor Magnus m.
- Largest, most powerful and most posterior of adductor group
- Triangular muscle
- Has adductor part and hamstring part
• O: Adductor part – Inferior ramus of pubis, ramus of ischium
Hamstring part – Ischial tuberosity
I: Adductor part – Gluteal tuberosity, linea aspera, medial supracondylar line
Hamstring part – Adductor tubercle
A: ADD thigh; Adductor part – flexes thigh; Hamstring part extends thigh
N: Adductor part – Posterior division, obturator n. (L2, L3, L4)
Hamstring part – Tibial division of sciatic n. (L4)
B: Anterior branch obturator and perforating aa.
What is the Adductor hiatus?
o Opening between distal attachments of two adductor magnus parts
Located just lateral and superior to adductor tubercle
o Transmits femoral a. and v. to/from adductor canal to/from popliteal fossa
Does not contain saphenous n.
Describe the Gracilis m.
- Long, strap-like muscle
- Most medial of adductor group
- Weakest member
- Crosses hip and knee joints
• Joins with two other two-joint muscles from two different compartments:
o Semitendinosus and sartorius mm.
o Have common tendinous insertion the pes anserinus (goose’s foot)
On superior part of medial surface of tibia
• O: Body and inferior ramus of pubis
- I:** Superior part of medial surface of tibia (pes anserinus)
- *A:** ADD thigh, flexes leg; MR of leg
- *N:** Anterior division, obturator n. (L2, L3)
- *B:** Anterior branch obturator a.
- Synergist in ADD of thigh, flexing knee and rotating leg medially
- With two other pes anserinus muscles, it adds stability to extended knee
Describe the Obturator Externus m.
• Flat, small fan-shaped muscle
• Obturator canal exits superior to muscle
• Deep in superomedial part of thigh
o Deep to adductor longus and pectineus mm.
• Tendon passes directly under acetabulum and neck of femur
• O: Margins of obturator foramen and obturator membrane
* *I:** Trochanteric fossa of femur * *A**: LR of thigh; steadies femoral head * *N:** Posterior division, obturator n. (L3, **L4**) * *B:** Anterior branch obturator a.
Describe how to test the Medial Thigh m.
• To test medial thigh muscles:
o Person lies supine with knee extended and thigh is ADD against resistance o Normally, proximal ends of gracilis and adductor longus are easily palpated o Tests integrity of obturator n.
Desribe the Vasculature of the Anterior and Medial Thigh
• Arteries –
o Femoral a. – direct continuation of external iliac a. distal to inguinal l.
Primary a. of lower limb
One of the four places to take a pulse
Passes through femoral triangle lateral to femoral v.
Superficial circumflex iliac a. –
• Parallels inguinal l. towards ASIS
Superficial epigastric a. –
• Runs subcutaneously towards umbilicus
Superficial and deep external pudendal aa. –
• To skin of scrotum/labia majora
Profunda femoris a. (deep a. of thigh) –
• Chief a. of thigh
• From lateral or posterior side of femoral a.
• Gives off 3 perforating aa., terminating in a 4th
o Supply all 3 compartments of thigh
o 1st participates in cruciate anastomosis
• Medial femoral circumflex a. –
o Supplies most blood to head and neck of femur
Via cruciate anastomosis
• Lateral femoral circumflex a. –
o Mainly supplies lateral thigh muscles
o Divides into the following branches:
Anterior – cruciate anastomosis
Transverse – cruciate anastomosis
Descending – genicular anastomosis
Traverses adductor canal
• Descending genicular a. –
o Branches off just before femoral a. passes through adductor hiatus
o Participates in genicular anastomosis
Terminates as it traverses adductor hiatus
• Becomes popliteal a.
o Obturator a. – from internal iliac a. (usually)
20% branch from inferior epigastric a.
• Accessory or replacement obturator aa.
Divides into:
• Anterior branch of obturator a.
• Posterior branch of obturator a.
o Acetabular branch –
Supplies head of femur
Found in ligament to head of femur
What are the 3 Veins in the Anterior and Medial Thigh and describe them.
o Great saphenous v. – from medial aspect of dorsal venous arch
Ascends anterior to medial malleolus
Passes posterior at medial femoral condyle
Found in subcutaneous tissue of medial thigh
Traverses saphenous opening
Drains into femoral v.
o Accessory saphenous v. – joining of medial and posterior thigh tributaries
When present, main communication between saphenous vv.
o Femoral v. – direct continuation of popliteal v. as it traverses adductor hiatus
Ascends through adductor canal
Enters femoral sheath lateral to femoral canal
Becomes external iliac v. posterior to inguinal l.
Describe the Lymphatics of the thigh.
o Pass to superficial inguinal nodes then to external iliac nodes
Explain Intermittent Claudication and its symptons
• Due to obstruction of femoral, popliteal or posterior tibial aa.
o Blockage can occur at any of these aa.
o Most commonly occurs at adductor hiatus
• Causes ischemia (decreased blood flow) to muscles during exercise
• Symptoms:
o Pain in calf and foot when walking
Pain usually disappears with rest
o May show decreased pulse below blockage
Explain what Saphenous Vein grafts are
• Great saphenous v. is sometimes used for coronary artery bypass grafts (CABG)
o It is readily accessible
o Usable lengths can be harvested
o Walls contain higher percentage muscular and elastic fibers
• Used to bypass blocked arteries
• Vein is inverted so valves don’t block blood flow
• Rarely produces problems as superficial leg veins are plentiful
o As long as deep veins are intact
