Anterior and Medial Compartments of the Thigh

Questions and Answers

What are the two main groups of inguinal lymph nodes?

Superficial and deep groups (correct)

Cranial and caudal groups

Anterior and posterior groups

Medial and lateral groups

Where do the superficial lymph vessels from the anterior abdominal wall primarily drain?

Into the thoracic duct

Directly into the superior vena cava

Into the deep inguinal lymph nodes

Into the horizontal group of superficial inguinal lymph nodes (correct)

The vascular lacuna contains which of the following structures?

Psoas major muscle

Lateral cutaneous nerve of thigh

Lymphatics and femoral branch of genitofemoral nerve (correct)

Femoral nerve

What is the position of the deep inguinal lymph nodes relative to the superficial nodes?

Medial to the superficial nodes Signup and view all the answers

The inguinal ligament is formed by the aponeurosis of which muscle?

External oblique muscle Signup and view all the answers

Which lymphatic vessels are excluded from the vertical group of superficial inguinal lymph nodes?

Lateral foot and lateral leg Signup and view all the answers

Which structure acts as a boundary between the abdomen and thigh?

Inguinal ligament Signup and view all the answers

What does the saphenous opening connect to?

Deep inguinal lymph nodes Signup and view all the answers

Which nerve is located in the muscular space of the inguinal region?

Femoral nerve Signup and view all the answers

What is the primary function of the superficial inguinal lymph nodes?

To receive superficial lymph vessels from the anterior abdominal wall and lower limb Signup and view all the answers

Which structures are contained within the vascular space of the inguinal region?

Femoral artery and vein along with lymphatics Signup and view all the answers

How are the superficial inguinal lymph nodes drained?

Via efferent vessels to deep inguinal lymph nodes Signup and view all the answers

Which anatomical feature helps to separate the muscular and vascular spaces in the inguinal region?

Interlacunar ligament Signup and view all the answers

What role does the inguinal ligament play in the anatomy of the abdomen and thigh?

It creates a separation between the abdomen and thigh Signup and view all the answers

What is the primary function of the horizontal group of superficial inguinal lymph nodes?

Receive lymph from the perineum and gluteal region Signup and view all the answers

Which of the following lymph vessels accompanies the small saphenous vein?

Lymphatic vessels from the lateral foot Signup and view all the answers

What is true about the draining process from superficial inguinal lymph nodes?

They pass through the saphenous opening to reach deep inguinal lymph nodes Signup and view all the answers

Which muscle is located in the muscular lacuna of the inguinal region?

Psoas major Signup and view all the answers

Where does the vertical group of superficial inguinal lymph nodes primarily receive lymph from?

Lower limb Signup and view all the answers

What forms the boundary between the abdomen and thigh?

Inguinal ligament Signup and view all the answers

Which anatomical feature does NOT contribute to the formation of the muscular and vascular spaces in the inguinal region?

Pubic tubercle Signup and view all the answers

What type of lymph nodes are located just below the inguinal ligament?

Superficial inguinal lymph nodes Signup and view all the answers

What is the function of the interlacunar ligament in the inguinal region?

To divide the space under the inguinal ligament into muscular and vascular lacunae Signup and view all the answers

Which of the following structures is located in the vascular space of the inguinal region?

Femoral branch of the genitofemoral nerve Signup and view all the answers

Which group of superficial inguinal lymph nodes primarily receives drainage from the gluteal region?

Horizontal group Signup and view all the answers

What connects the superficial inguinal lymph nodes to the deep inguinal lymph nodes?

Saphenous opening Signup and view all the answers

What anatomical structure does the inguinal ligament extend from?

Anterior superior iliac spine to pubic tubercle Signup and view all the answers

What is located medial to the interlacunar ligament in the inguinal region?

Femoral vein Signup and view all the answers

Which group of superficial inguinal lymph nodes receives lymph from the lower limb?

Vertical group Signup and view all the answers

What divides the space between the inguinal ligament and hip bone into muscular and vascular spaces?

Interlacunar ligament Signup and view all the answers

Which nerve is found within the vascular space of the inguinal region?

Femoral branch of genitofemoral nerve Signup and view all the answers

What anatomical space contains the psoas major and iliacus muscles?

Muscular lacuna Signup and view all the answers

What is the main role of the superficial inguinal lymph nodes?

To receive lymph from superficial areas Signup and view all the answers

What structure does the inguinal ligament extend from?

Anterior superior iliac spine (ASIS) Signup and view all the answers

Which area does the horizontal group of superficial inguinal lymph nodes primarily drain?

Anterior abdominal wall below the umbilicus Signup and view all the answers

Which nerve is NOT found in the muscular lacuna of the inguinal region?

Obturator nerve Signup and view all the answers

Where do the efferent vessels from superficial inguinal lymph nodes drain to?

Deep inguinal lymph nodes Signup and view all the answers

What is the primary function of the saphenous nerve?

To supply the skin of the medial aspect of the leg and foot Signup and view all the answers

What muscles are supplied by the anterior branch of the obturator nerve?

Adductor longus, adductor brevis, and gracilis Signup and view all the answers

Which structure does the obturator nerve pass through to enter the medial compartment of the thigh?

Obturator canal Signup and view all the answers

What is the primary area innervated by the posterior branch of the obturator nerve?

Medial thigh and hip joint Signup and view all the answers

Which artery does the obturator nerve accompany as it runs through the pelvis?

Obturator artery Signup and view all the answers

Which of the following structures does NOT receive innervation from the obturator nerve?

Sartorius Signup and view all the answers

What is the trajectory of the saphenous nerve after it becomes superficial on the medial side of the knee?

Descends along the medial side of the leg Signup and view all the answers

Which part of the lower limb does the saphenous nerve typically supply sensation to?

Ball of the great toe Signup and view all the answers

Which nerve division is responsible for supplying the knee joint?

Posterior branch of the obturator nerve Signup and view all the answers

What is the primary role of the saphenous nerve in the lower limb?

Provides sensation to the medial aspect of the leg and foot Signup and view all the answers

From which spinal nerves does the obturator nerve originate?

L2-L4 Signup and view all the answers

How does the obturator nerve enter the medial compartment of the thigh?

Through the obturator canal Signup and view all the answers

Which muscles are primarily supplied by the anterior branch of the obturator nerve?

Gracilis and adductor longus and brevis Signup and view all the answers

What is the trajectory of the saphenous nerve after it becomes superficial on the medial side of the knee?

Passes anterior to the medial malleolus and down the medial border of the foot Signup and view all the answers

What structures does the saphenous nerve commonly run alongside as it descends in the lower limb?

Great saphenous vein and femoral vessels Signup and view all the answers

What area does the posterior branch of the obturator nerve supply?

Adductor part of adductor magnus and knee joint Signup and view all the answers

Which of the following does NOT receive innervation from the obturator nerve?

Gluteus maximus Signup and view all the answers

What is the path taken by the obturator nerve in the pelvis?

Runs anteriorly on the medial wall of pelvis Signup and view all the answers

Which muscles are innervated by the anterior branch of the obturator nerve?

Adductor longus and gracilis Signup and view all the answers

Which structures does the obturator nerve accompany as it runs in the pelvis?

Obturator artery and vein Signup and view all the answers

What is the main sensory distribution area of the saphenous nerve?

Medial aspect of the leg and medial border of the foot Signup and view all the answers

Which of the following accurately describes the division of the obturator nerve within the obturator canal?

It separates into anterior and posterior branches Signup and view all the answers

What does the medial compartment of the femoral sheath contain?

Femoral canal Signup and view all the answers

Which nerve is located lateral to the femoral artery in the femoral triangle?

Femoral nerve Signup and view all the answers

What anatomical structure may lead to femoral hernias when abdominal contents protrude?

Femoral canal Signup and view all the answers

Which muscles receive innervation from the muscular branches of the femoral nerve?

Iliacus, sartorius, pectineus, and quadriceps femoris Signup and view all the answers

Where does the femoral nerve emerge from in the abdomen?

Lateral border of the psoas major Signup and view all the answers

What separates the three compartments of the femoral sheath?

Connective tissue tracts Signup and view all the answers

Which structure does NOT pass through the femoral sheath?

Femoral nerve Signup and view all the answers

What is the role of saphenous nerve in lower limb innervation?

To supply cutaneous sensation to the medial side of the leg and foot Signup and view all the answers

Which lymph nodes receive efferent vessels from deep inguinal lymph nodes?

External iliac lymph nodes Signup and view all the answers

What does the femoral sheath primarily surround?

Femoral vessels and lymphatics Signup and view all the answers

What structures does the saphenous nerve run along after it becomes superficial on the medial side of the knee?

With the great saphenous vein Signup and view all the answers

Which of the following muscles is NOT typically supplied by the anterior branch of the obturator nerve?

Semitendinosus Signup and view all the answers

Where does the obturator nerve enter the medial compartment of the thigh?

Via the obturator canal Signup and view all the answers

What is the primary function of the posterior branch of the obturator nerve?

To supply the knee joint Signup and view all the answers

Which area does the saphenous nerve primarily supply sensation to?

Skin of the foot's ball and medial border Signup and view all the answers

What branches does the obturator nerve divide into within the obturator canal?

Anterior and posterior branches Signup and view all the answers

What is the origin of the obturator nerve?

Lumbar plexus Signup and view all the answers

Which muscle does the posterior branch of the obturator nerve NOT typically innervate?

Rectus femoris Signup and view all the answers

What is the general pathway of the saphenous nerve after it passes the medial malleolus?

Travels medially along the foot to the first metatarsophalangeal joint Signup and view all the answers

What anatomical structure does the obturator nerve pass through to enter the pelvis?

Obturator canal Signup and view all the answers

The Gracilis muscle is the only muscle of the medial compartment that crosses the knee joint.

True Signup and view all the answers

Study Notes

Anterior Compartment Muscles

Sartorius: A narrow, strap-like muscle originating at the anterior superior iliac spine (ASIS) and attaching to the upper part of the tibial shaft. Innervated by the femoral nerve, it facilitates flexion, abduction, and lateral rotation of the thigh, as well as flexion and medial rotation of the leg.
Pectineus: A flat, quadrangular muscle arising from the pectineal line of the pubis and inserting on the femur's pectineal line. Supplied by the femoral nerve, it performs thigh flexion and adduction.
Quadriceps Femoris: Comprising four muscles (rectus femoris, vastus medialis, vastus intermedius, vastus lateralis), it originates from various points on the hip and femur, converging into the quadriceps tendon. Innervated by the femoral nerve, it extends the leg at the knee; rectus femoris also flexes the thigh at the hip.
Iliopsoas: Formed by iliacus and psoas major, it attaches to the lesser trochanter of the femur. Psoas major originates from lumbar vertebrae, while iliacus comes from the iliac fossa. Innervated by lumbar spinal nerves and the femoral nerve, it facilitates thigh flexion and trunk flexion when the femur is fixed.

Medial Compartment Muscles

Gracilis: A long, slender muscle from the pubis to the upper medial tibia, part of the pes anserinus. Innervated by the obturator nerve, it adducts the thigh and assists in flexion and medial rotation of the leg.
Adductor Longus: The anterior adductor muscle, it originates from the pubis and inserts into the middle third of the linea aspera. Supplied by the obturator nerve, it adducts and flexes the thigh.
Adductor Brevis: Situated posterior to adductor longus, originating from the pubis and attaching to the femur's posterior surface. Innervated by the obturator nerve, it aids in thigh adduction and flexion.
Adductor Magnus: The largest adductor, originating from the ischiopubic ramus and ischial tuberosity. It has two parts: the adductor part (innervated by the obturator nerve) and the hamstring part (innervated by the tibial sciatic nerve). It adducts and extends the thigh at the hip. Has an adductor hiatus for vessel passage.
Obturator Externus: Deep muscle that rotates the thigh laterally, originating from the obturator membrane and inserting on the greater trochanter. Innervated by the obturator nerve.

Deep Fascia of the Thigh (Fascia Lata)

Envelops the thigh, resembling a stocking, with a thickened lateral aspect forming the iliotibial tract, associated with gluteus maximus.
Saphenous Opening: An opening in the fascia lata transmitting the great saphenous vein, superficial branches of femoral vessels, and efferent lymph vessels from inguinal lymph nodes.

Inguinal Lymph Nodes

Divided into superficial and deep groups; superficial nodes lie in superficial fascia.
Superficial Inguinal Lymph Nodes:
- Horizontal group below the inguinal ligament, receiving lymph from the lower abdomen, perineum, and gluteal region.
- Vertical group alongside the great saphenous vein, draining lymph from the lower limb (except lateral foot and leg).
Efferent vessels from superficial inguinal lymph nodes pass through the saphenous opening into deep nodes.

Spaces Under the Inguinal Ligament

Inguinal Ligament: Connects ASIS to the pubic tubercle, forming a boundary between the abdomen and thigh.
The space beneath the inguinal ligament is split into muscular and vascular lacunae by the iliac fascia.
Muscular Lacuna: Contains psoas major, iliacus, femoral nerve, and lateral cutaneous nerve of the thigh.
Vascular Lacuna: Contains the femoral artery, vein, lymphatics, and the femoral branch of the genitofemoral nerve.

Anterior Compartment Muscles

Sartorius: A narrow, strap-like muscle originating at the anterior superior iliac spine (ASIS) and attaching to the upper part of the tibial shaft. Innervated by the femoral nerve, it facilitates flexion, abduction, and lateral rotation of the thigh, as well as flexion and medial rotation of the leg.
Pectineus: A flat, quadrangular muscle arising from the pectineal line of the pubis and inserting on the femur's pectineal line. Supplied by the femoral nerve, it performs thigh flexion and adduction.
Quadriceps Femoris: Comprising four muscles (rectus femoris, vastus medialis, vastus intermedius, vastus lateralis), it originates from various points on the hip and femur, converging into the quadriceps tendon. Innervated by the femoral nerve, it extends the leg at the knee; rectus femoris also flexes the thigh at the hip.
Iliopsoas: Formed by iliacus and psoas major, it attaches to the lesser trochanter of the femur. Psoas major originates from lumbar vertebrae, while iliacus comes from the iliac fossa. Innervated by lumbar spinal nerves and the femoral nerve, it facilitates thigh flexion and trunk flexion when the femur is fixed.

Medial Compartment Muscles

Gracilis: A long, slender muscle from the pubis to the upper medial tibia, part of the pes anserinus. Innervated by the obturator nerve, it adducts the thigh and assists in flexion and medial rotation of the leg.
Adductor Longus: The anterior adductor muscle, it originates from the pubis and inserts into the middle third of the linea aspera. Supplied by the obturator nerve, it adducts and flexes the thigh.
Adductor Brevis: Situated posterior to adductor longus, originating from the pubis and attaching to the femur's posterior surface. Innervated by the obturator nerve, it aids in thigh adduction and flexion.
Adductor Magnus: The largest adductor, originating from the ischiopubic ramus and ischial tuberosity. It has two parts: the adductor part (innervated by the obturator nerve) and the hamstring part (innervated by the tibial sciatic nerve). It adducts and extends the thigh at the hip. Has an adductor hiatus for vessel passage.
Obturator Externus: Deep muscle that rotates the thigh laterally, originating from the obturator membrane and inserting on the greater trochanter. Innervated by the obturator nerve.

Deep Fascia of the Thigh (Fascia Lata)

Envelops the thigh, resembling a stocking, with a thickened lateral aspect forming the iliotibial tract, associated with gluteus maximus.
Saphenous Opening: An opening in the fascia lata transmitting the great saphenous vein, superficial branches of femoral vessels, and efferent lymph vessels from inguinal lymph nodes.

Inguinal Lymph Nodes

Divided into superficial and deep groups; superficial nodes lie in superficial fascia.
Superficial Inguinal Lymph Nodes:
- Horizontal group below the inguinal ligament, receiving lymph from the lower abdomen, perineum, and gluteal region.
- Vertical group alongside the great saphenous vein, draining lymph from the lower limb (except lateral foot and leg).
Efferent vessels from superficial inguinal lymph nodes pass through the saphenous opening into deep nodes.

Spaces Under the Inguinal Ligament

Inguinal Ligament: Connects ASIS to the pubic tubercle, forming a boundary between the abdomen and thigh.
The space beneath the inguinal ligament is split into muscular and vascular lacunae by the iliac fascia.
Muscular Lacuna: Contains psoas major, iliacus, femoral nerve, and lateral cutaneous nerve of the thigh.
Vascular Lacuna: Contains the femoral artery, vein, lymphatics, and the femoral branch of the genitofemoral nerve.

Anterior Compartment Muscles

Sartorius: A narrow, strap-like muscle originating at the anterior superior iliac spine (ASIS) and attaching to the upper part of the tibial shaft. Innervated by the femoral nerve, it facilitates flexion, abduction, and lateral rotation of the thigh, as well as flexion and medial rotation of the leg.
Pectineus: A flat, quadrangular muscle arising from the pectineal line of the pubis and inserting on the femur's pectineal line. Supplied by the femoral nerve, it performs thigh flexion and adduction.
Quadriceps Femoris: Comprising four muscles (rectus femoris, vastus medialis, vastus intermedius, vastus lateralis), it originates from various points on the hip and femur, converging into the quadriceps tendon. Innervated by the femoral nerve, it extends the leg at the knee; rectus femoris also flexes the thigh at the hip.
Iliopsoas: Formed by iliacus and psoas major, it attaches to the lesser trochanter of the femur. Psoas major originates from lumbar vertebrae, while iliacus comes from the iliac fossa. Innervated by lumbar spinal nerves and the femoral nerve, it facilitates thigh flexion and trunk flexion when the femur is fixed.

Medial Compartment Muscles

Gracilis: A long, slender muscle from the pubis to the upper medial tibia, part of the pes anserinus. Innervated by the obturator nerve, it adducts the thigh and assists in flexion and medial rotation of the leg.
Adductor Longus: The anterior adductor muscle, it originates from the pubis and inserts into the middle third of the linea aspera. Supplied by the obturator nerve, it adducts and flexes the thigh.
Adductor Brevis: Situated posterior to adductor longus, originating from the pubis and attaching to the femur's posterior surface. Innervated by the obturator nerve, it aids in thigh adduction and flexion.
Adductor Magnus: The largest adductor, originating from the ischiopubic ramus and ischial tuberosity. It has two parts: the adductor part (innervated by the obturator nerve) and the hamstring part (innervated by the tibial sciatic nerve). It adducts and extends the thigh at the hip. Has an adductor hiatus for vessel passage.
Obturator Externus: Deep muscle that rotates the thigh laterally, originating from the obturator membrane and inserting on the greater trochanter. Innervated by the obturator nerve.

Deep Fascia of the Thigh (Fascia Lata)

Envelops the thigh, resembling a stocking, with a thickened lateral aspect forming the iliotibial tract, associated with gluteus maximus.
Saphenous Opening: An opening in the fascia lata transmitting the great saphenous vein, superficial branches of femoral vessels, and efferent lymph vessels from inguinal lymph nodes.

Inguinal Lymph Nodes

Divided into superficial and deep groups; superficial nodes lie in superficial fascia.
Superficial Inguinal Lymph Nodes:
- Horizontal group below the inguinal ligament, receiving lymph from the lower abdomen, perineum, and gluteal region.
- Vertical group alongside the great saphenous vein, draining lymph from the lower limb (except lateral foot and leg).
Efferent vessels from superficial inguinal lymph nodes pass through the saphenous opening into deep nodes.

Spaces Under the Inguinal Ligament

Inguinal Ligament: Connects ASIS to the pubic tubercle, forming a boundary between the abdomen and thigh.
The space beneath the inguinal ligament is split into muscular and vascular lacunae by the iliac fascia.
Muscular Lacuna: Contains psoas major, iliacus, femoral nerve, and lateral cutaneous nerve of the thigh.
Vascular Lacuna: Contains the femoral artery, vein, lymphatics, and the femoral branch of the genitofemoral nerve.

Anterior Compartment Muscles

Sartorius: A narrow, strap-like muscle originating at the anterior superior iliac spine (ASIS) and attaching to the upper part of the tibial shaft. Innervated by the femoral nerve, it facilitates flexion, abduction, and lateral rotation of the thigh, as well as flexion and medial rotation of the leg.
Pectineus: A flat, quadrangular muscle arising from the pectineal line of the pubis and inserting on the femur's pectineal line. Supplied by the femoral nerve, it performs thigh flexion and adduction.
Quadriceps Femoris: Comprising four muscles (rectus femoris, vastus medialis, vastus intermedius, vastus lateralis), it originates from various points on the hip and femur, converging into the quadriceps tendon. Innervated by the femoral nerve, it extends the leg at the knee; rectus femoris also flexes the thigh at the hip.
Iliopsoas: Formed by iliacus and psoas major, it attaches to the lesser trochanter of the femur. Psoas major originates from lumbar vertebrae, while iliacus comes from the iliac fossa. Innervated by lumbar spinal nerves and the femoral nerve, it facilitates thigh flexion and trunk flexion when the femur is fixed.

Medial Compartment Muscles

Gracilis: A long, slender muscle from the pubis to the upper medial tibia, part of the pes anserinus. Innervated by the obturator nerve, it adducts the thigh and assists in flexion and medial rotation of the leg.
Adductor Longus: The anterior adductor muscle, it originates from the pubis and inserts into the middle third of the linea aspera. Supplied by the obturator nerve, it adducts and flexes the thigh.
Adductor Brevis: Situated posterior to adductor longus, originating from the pubis and attaching to the femur's posterior surface. Innervated by the obturator nerve, it aids in thigh adduction and flexion.
Adductor Magnus: The largest adductor, originating from the ischiopubic ramus and ischial tuberosity. It has two parts: the adductor part (innervated by the obturator nerve) and the hamstring part (innervated by the tibial sciatic nerve). It adducts and extends the thigh at the hip. Has an adductor hiatus for vessel passage.
Obturator Externus: Deep muscle that rotates the thigh laterally, originating from the obturator membrane and inserting on the greater trochanter. Innervated by the obturator nerve.

Deep Fascia of the Thigh (Fascia Lata)

Envelops the thigh, resembling a stocking, with a thickened lateral aspect forming the iliotibial tract, associated with gluteus maximus.
Saphenous Opening: An opening in the fascia lata transmitting the great saphenous vein, superficial branches of femoral vessels, and efferent lymph vessels from inguinal lymph nodes.

Inguinal Lymph Nodes

Divided into superficial and deep groups; superficial nodes lie in superficial fascia.
Superficial Inguinal Lymph Nodes:
- Horizontal group below the inguinal ligament, receiving lymph from the lower abdomen, perineum, and gluteal region.
- Vertical group alongside the great saphenous vein, draining lymph from the lower limb (except lateral foot and leg).
Efferent vessels from superficial inguinal lymph nodes pass through the saphenous opening into deep nodes.

Spaces Under the Inguinal Ligament

Inguinal Ligament: Connects ASIS to the pubic tubercle, forming a boundary between the abdomen and thigh.
The space beneath the inguinal ligament is split into muscular and vascular lacunae by the iliac fascia.
Muscular Lacuna: Contains psoas major, iliacus, femoral nerve, and lateral cutaneous nerve of the thigh.
Vascular Lacuna: Contains the femoral artery, vein, lymphatics, and the femoral branch of the genitofemoral nerve.

Anterior Compartment Muscles

Sartorius: A narrow, strap-like muscle originating at the anterior superior iliac spine (ASIS) and attaching to the upper part of the tibial shaft. Innervated by the femoral nerve, it facilitates flexion, abduction, and lateral rotation of the thigh, as well as flexion and medial rotation of the leg.
Pectineus: A flat, quadrangular muscle arising from the pectineal line of the pubis and inserting on the femur's pectineal line. Supplied by the femoral nerve, it performs thigh flexion and adduction.
Quadriceps Femoris: Comprising four muscles (rectus femoris, vastus medialis, vastus intermedius, vastus lateralis), it originates from various points on the hip and femur, converging into the quadriceps tendon. Innervated by the femoral nerve, it extends the leg at the knee; rectus femoris also flexes the thigh at the hip.
Iliopsoas: Formed by iliacus and psoas major, it attaches to the lesser trochanter of the femur. Psoas major originates from lumbar vertebrae, while iliacus comes from the iliac fossa. Innervated by lumbar spinal nerves and the femoral nerve, it facilitates thigh flexion and trunk flexion when the femur is fixed.

Medial Compartment Muscles

Gracilis: A long, slender muscle from the pubis to the upper medial tibia, part of the pes anserinus. Innervated by the obturator nerve, it adducts the thigh and assists in flexion and medial rotation of the leg.
Adductor Longus: The anterior adductor muscle, it originates from the pubis and inserts into the middle third of the linea aspera. Supplied by the obturator nerve, it adducts and flexes the thigh.
Adductor Brevis: Situated posterior to adductor longus, originating from the pubis and attaching to the femur's posterior surface. Innervated by the obturator nerve, it aids in thigh adduction and flexion.
Adductor Magnus: The largest adductor, originating from the ischiopubic ramus and ischial tuberosity. It has two parts: the adductor part (innervated by the obturator nerve) and the hamstring part (innervated by the tibial sciatic nerve). It adducts and extends the thigh at the hip. Has an adductor hiatus for vessel passage.
Obturator Externus: Deep muscle that rotates the thigh laterally, originating from the obturator membrane and inserting on the greater trochanter. Innervated by the obturator nerve.

Deep Fascia of the Thigh (Fascia Lata)

Envelops the thigh, resembling a stocking, with a thickened lateral aspect forming the iliotibial tract, associated with gluteus maximus.
Saphenous Opening: An opening in the fascia lata transmitting the great saphenous vein, superficial branches of femoral vessels, and efferent lymph vessels from inguinal lymph nodes.

Inguinal Lymph Nodes

Divided into superficial and deep groups; superficial nodes lie in superficial fascia.
Superficial Inguinal Lymph Nodes:
- Horizontal group below the inguinal ligament, receiving lymph from the lower abdomen, perineum, and gluteal region.
- Vertical group alongside the great saphenous vein, draining lymph from the lower limb (except lateral foot and leg).
Efferent vessels from superficial inguinal lymph nodes pass through the saphenous opening into deep nodes.

Spaces Under the Inguinal Ligament

Inguinal Ligament: Connects ASIS to the pubic tubercle, forming a boundary between the abdomen and thigh.
The space beneath the inguinal ligament is split into muscular and vascular lacunae by the iliac fascia.
Muscular Lacuna: Contains psoas major, iliacus, femoral nerve, and lateral cutaneous nerve of the thigh.
Vascular Lacuna: Contains the femoral artery, vein, lymphatics, and the femoral branch of the genitofemoral nerve.

Cutaneous Innervation of the Thigh

Anterior surface innervation begins below the inguinal ligament, from lateral to medial with:
- Lateral cutaneous branch of subcostal nerve
- Femoral branch of genitofemoral nerve
- Ilioinguinal nerve
Lateral cutaneous nerve of thigh supplies lateral thigh skin.
Anterior cutaneous nerves of thigh are branches of the femoral nerve, innervating anterior and medial thigh skin.
Posterior surface of thigh is innervated by the posterior cutaneous nerve of thigh.

Superficial Veins

Superficial veins are located in the superficial fascia.
Great saphenous vein:
- Originates from the medial end of the dorsal venous arch.
- Ascends along the medial aspect of the leg, passing posterior to the knee and drains into the femoral vein.
- Linked with deep veins via perforating veins, which may cause varicosity if valves fail.
Small saphenous vein:
- Originates from the lateral end of the dorsal venous arch, passes posterior to the lateral malleolus.
- Drains into the popliteal vein and is accompanied by the sural nerve.

Femoral Triangle

Triangular area in the upper anterior thigh with boundaries:
- Superior: inguinal ligament
- Lateral: medial border of sartorius
- Medial: medial border of adductor longus or lateral border of adductor longus
Contains the lateral cutaneous nerve of thigh, femoral nerve and artery, femoral vein, and lymph nodes.
Roof formed by fascia lata, floor consists of iliopsoas, pectineus, and adductor longus muscles.

Adductor Canal (Hunter's Canal)

Intermuscular space in the medial aspect of the middle thigh.
Extends from the apex of the femoral triangle to the adductor hiatus.
Triangular cross-section with walls formed by sartorius (medial), vastus medialis (anterior), and adductor muscles (posterior).
Contains femoral artery, femoral vein, saphenous nerve, and nerve to vastus medialis.

Deep Inguinal Lymph Nodes

Located along the medial upper part of the femoral vein.
Receive lymph from superficial inguinal nodes and deep tissues of the lower extremity.
Lymph from structures above the knee drains directly into these nodes; below the knee first drains into popliteal lymph nodes.

Femoral Sheath

Formed from the endoabdominal fascia, extending into the thigh.
Surrounds femoral vessels and lymphatics, not the femoral nerve.
Contains three compartments:
- Lateral: femoral artery
- Intermediate: femoral vein
- Medial (femoral canal): lymph vessels, often housing a deep inguinal lymph node; site of potential femoral hernias.

Femoral Nerve

Largest branch of the lumbar plexus (L2-L4 spinal nerves).
Emerges from the psoas major and descends between psoas major and iliacus.
Located lateral to the femoral artery within the femoral triangle.
Terminates into branches innervating iliacus, sartorius, pectineus, quadriceps, and provides sensory supply to thigh skin.

Saphenous Nerve

Longest branch of the femoral nerve, following a course inferiorly and medially.
Becomes superficial at the medial knee, covering the medial leg and foot up to the ball of the great toe.
Supplies skin along the medial aspect of the leg and foot.

Obturator Nerve

A lumbar plexus branch formed by L2-L4 spinal nerves.
Emerges from the medial border of psoas major, entering the thigh via obturator canal.
Divides into anterior and posterior branches:
- Anterior branch innervates adductor muscles and skin on medial thigh.
- Posterior branch supplies obturator externus and part of adductor magnus.

Cutaneous Innervation of the Thigh

Anterior thigh innervation below the inguinal ligament includes the lateral cutaneous branch of the subcostal nerve, femoral branch of the genitofemoral nerve, and ilioinguinal nerve.
Lateral cutaneous nerve of the thigh supplies skin along the lateral aspect; anterior cutaneous nerves (branches of the femoral nerve) supply anterior and medial aspects.
Posterior cutaneous nerve of thigh innervates the posterior surface; anterior branch of the obturator nerve serves a small area of the medial thigh.

Superficial Veins

Superficial veins are located in the superficial fascia.
Great saphenous vein originates from the dorsal venous arch of the foot, ascends along the medial aspect, and drains into the femoral vein after passing through the saphenous opening.
Small saphenous vein originates from the lateral aspect of the foot, ascends to the popliteal vein, and is accompanied by the sural nerve.

Femoral Triangle

Triangular area located in the upper anterior thigh, bordered by the inguinal ligament, medial border of sartorius, and medial border of adductor longus.
Continuous with the adductor canal, with a floor comprised of iliopsoas, pectineus, and adductor longus muscles.
Contains femoral nerve, artery, and vein, lymphatics, and the lateral cutaneous nerve of the thigh.

Adductor (Subsartorial, Hunter’s) Canal

Intermuscular space on the medial aspect of the middle third of the thigh.
Begins at the apex of the femoral triangle and ends at the adductor hiatus.
Surrounded by sartorius (medial wall), vastus medialis (anterior wall), and adductor longus/magnus (posterior wall). Contains the femoral artery, vein, saphenous nerve, and genicular nerve branch.

Femoral Artery

Main arterial supply to the lower limb, beginning at the inguinal ligament as a continuation of the external iliac artery.
Ends at the adductor hiatus and continues into the popliteal fossa as the popliteal artery.
Supplies the inferior part of the abdominal wall and external genitalia through branches such as the superficial epigastric and deep external pudendal arteries.

Profunda Femoris (Deep Femoral) Artery

Largest branch of the femoral artery; chief blood supply to thigh muscles.
Originates in the upper part of the femoral triangle, passing posteriorly to the femoral artery.
Terminates as the 4th perforating artery and gives off medial and lateral circumflex femoral arteries.

Femoral Sheath

Fascia extending from the abdominal wall into the upper thigh, surrounding femoral vessels and lymphatics.
Contains three compartments: lateral for femoral artery, intermediate for femoral vein, and medial (femoral canal) for lymph vessels.
Femoral canal is a potential site for femoral hernias.

Femoral Nerve

Largest lumbar plexus branch, formed from L2-L4 spinal nerves.
Emerges from the psoas major and enters the thigh below the inguinal ligament, located lateral to the femoral artery.
Branches supply iliacus, sartorius, quadriceps femoris, and provide cutaneous innervation to the thigh's anterior and part of the medial surface.

Saphenous Nerve

Longest branch of the femoral nerve, runs with the great saphenous vein.
Supplies skin of the medial aspect of the leg and foot, extending to the ball of the great toe.

Obturator Nerve

Branch of the lumbar plexus formed from L2-L4 spinal nerves.
Emerges from the psoas major, runs with the obturator artery and vein, and enters the medial thigh via the obturator canal.
Divides into anterior and posterior branches, supplying various adductor muscles and skin of the medial thigh.

Cutaneous Innervation of the Thigh

Anterior surface innervation includes various nerves below the inguinal ligament:
- Lateral cutaneous branch of the subcostal nerve
- Femoral branch of the genitofemoral nerve
- Ilioinguinal nerve
Lateral cutaneous nerve of the thigh supplies the lateral aspect of the thigh.
Anterior cutaneous nerves of the thigh, branches of the femoral nerve, supply the anterior and medial aspects.
Anterior branch of the obturator nerve provides sensory innervation to a small area on the medial thigh.
The posterior surface is innervated by the posterior cutaneous nerve of the thigh.

Superficial Veins

Superficial veins are located in the superficial fascia of the thigh.
Great saphenous vein:
- Originates from the medial end of the dorsal venous arch of the foot, ascends along the leg, and drains into the femoral vein after passing through the saphenous opening.
- Connects to deep veins via perforating veins; in case of valvular incompetence, it can lead to varicose veins.
Small saphenous vein:
- Originates from the lateral end of the dorsal venous arch, traverses posterior to the lateral malleolus, and drains into the popliteal vein.
- Accompanies the sural nerve and connects to deep veins.

Femoral Triangle

A triangular area in the upper anterior thigh with distinct boundaries:
- Superior: inguinal ligament
- Lateral: medial border of sartorius
- Medial: medial border of adductor longus
Continuous with the adductor canal inferiorly.
Floor consists of iliopsoas, pectineus, and adductor longus muscles from lateral to medial.
Roof formed by the fascia lata; contains important structures like the femoral nerve, artery, vein, and lymph nodes.

Adductor (Subsartorial, Hunter’s) Canal

An intermuscular space on the medial aspect of the middle third of the thigh.
Begins at the apex of the femoral triangle and ends at the adductor hiatus.
Triangular cross-section with three walls:
- Medial: sartorius
- Anterior: vastus medialis
- Posterior: adductor longus and adductor magnus
Contains femoral artery and vein, saphenous nerve, and a nerve to the vastus medialis.

Femoral Artery

The primary arterial supply for the lower limb; begins at the inguinal ligament as a continuation of the external iliac artery.
Terminates at the adductor hiatus, continuing as the popliteal artery.
Descends through the femoral triangle and adductor canal.
Lies between the femoral nerve (lateral) and vein (medial) in the upper triangle; anterior to the vein in the lower part.
Branches supply the abdominal wall, external genitalia, and muscles of the thigh.

Profunda Femoris (Deep Femoral) Artery

The largest branch of the femoral artery, crucial for supplying thigh muscles.
Originates from the femoral artery in the upper femoral triangle, descending behind it.
Terminates as the fourth perforating artery and branches include medial and lateral circumflex femoral arteries, supplying surrounding muscles and joints.

Deep Inguinal Lymph Nodes

Located along the medial side of the upper femoral vein.
Drain lymph from superficial inguinal lymph nodes and deep tissues of the lower extremity.
Structures above the knee drain directly, while those below first drain into popliteal lymph nodes.

Obturator Nerve

A branch of the lumbar plexus from L2-L4 spinal nerves.
Emerges at the psoas major, travels laterally, exits the pelvis via the obturator canal.
Divides into anterior and posterior branches within the canal:
- Anterior branch supplies adductor longus, brevis, gracilis, and part of the hip joint.
- Posterior branch supplies obturator externus and part of adductor magnus, along with the knee joint.