Neurovasculature of the lower limbs

Last updated: September 18, 2023

Summary

The arteries of the lower limb arise from the external iliac artery, a branch of the common iliac branch of the abdominal aorta. Behind the inguinal ligament, the external iliac artery continues as the femoral artery, which is the main artery of the thigh. The femoral artery continues as the popliteal artery, which divides into the anterior tibial, posterior tibial, and fibular arteries, which supply the leg and foot. The venous system of the lower limbs consists of a superficial and a deep venous system. The long saphenous vein and the short saphenous vein comprise the superficial venous system, which drains into the deep venous system via perforator veins. The deep veins accompany the arteries of the lower limbs and drain into the external iliac veins, which drain into the inferior vena cava. The lower limbs are innervated by the nerves of the lumbosacral plexus, which is composed of the lumbar plexus (T12–L4) and the sacral plexus (L4–S4). The major motor nerves of the thigh are the femoral nerve, the obturator nerve, and the sciatic nerve. The tibial nerve and the common peroneal nerve are the major motor nerves of the leg. The lower limb receives cutaneous innervation from pure sensory nerves (e.g., saphenous nerve, sural nerve) as well as from mixed sensorimotor nerves (e.g., femoral nerve, tibial nerve, deep peroneal nerve).

Overview

Lower extremity (complete): interactive 3D Model

Arteries

Overview ^[1]

The lower limb is supplied by the femoral artery, which receives blood from the abdominal aorta via the external iliac artery.

Overview of arteries
Artery	Origin	Course	Branches and supply	Anatomical relations
Femoral artery	Continuation of the external iliac artery	Begins at the midinguinal point posterior to the inguinal ligament Descends along the anterior aspect of the thigh, within the femoral triangle Gives off the profunda femoris and continues as the superficial femoral artery Passes anteromedially to enter the adductor canal Continues as the popliteal artery by passing through the adductor hiatus into the popliteal fossa	Profunda femoris: muscles of the thigh (see below for further information) Descending genicular artery: knee joint (genicular anastomosis) External pudendal arteries (superficial and deep): perineum and scrotum or labia majora Superficial epigastric artery: skin over the lower abdomen Superficial circumflex iliac artery: skin over the anterior superior iliac spine	The femoral artery lies at the base of the femoral triangle, between the femoral nerve and the femoral vein.
Profunda femoris artery (deep femoral artery; deep artery of the thigh)	Main branch of the femoral artery	Arises from the posterolateral aspect of the femoral artery ∼ 4 cm below the inguinal ligament Descends in the medial compartment of the thigh Terminates by anastomosing with branches of the popliteal artery	Medial and lateral circumflex femoral arteries: femoral head and neck Numerous muscular branches: all muscular compartments of the thigh	The adductor longus lies between the profunda femoris and the femoral artery.
Popliteal artery	Continuation of the femoral artery	Begins at the adductor hiatus Descends almost vertically within the popliteal fossa Terminates at the inferior border of the popliteus by dividing into its terminal branches	Genicular branches: knee joint and popliteal fossa Terminal branches Anterior tibial artery (see below) Tibioperoneal trunk: divides into the posterior tibial and the peroneal artery (see below)	The tibial nerve, common peroneal nerve, and the popliteal vein lie superficial to the popliteal artery within the popliteal fossa.
Anterior tibial artery	A terminal branch of the popliteal artery	Begins at the inferior border of the popliteus muscle within the popliteal fossa Enters the anterior compartment of the leg through a gap in the upper part of the interosseous membrane Lies anteriorly on the interosseous membrane throughout its course Lies anteriorly between the two malleoli at the ankle joint Continues as the dorsalis pedis artery beyond the ankle joint (see below)	Muscular branches: muscles of the anterior compartment of the leg Anterior and posterior tibial recurrent arteries: anastomosis around the knee joint Medial and lateral malleolar branches: medial and lateral malleolar network	The deep fibular nerve crosses the anterior tibial artery from lateral to medial along its course in the leg.
Posterior tibial artery	A terminal branch of the tibioperoneal trunk of the popliteal artery	Begins at the inferior border of the popliteus muscle within the popliteal fossa Enters the posterior compartment of the leg by passing deep to the soleus muscle Passes under the flexor retinaculum of the ankle joint, below the medial malleolus Terminates just beyond the medial malleolus by dividing into the medial and lateral plantar arteries	A circumflex branch to the knee joint Muscular branches: muscles of the posterior compartment of the leg Medial and lateral plantar arteries: plantar aspect of the foot (sole) Medial malleolar and calcaneal branches	The tibial nerve courses behind the posterior tibial artery from medial to lateral in the lower half of the leg.
Fibular artery (peroneal artery)	A terminal branch of the tibioperoneal trunk of the popliteal artery	Begins at the inferior border of the popliteus muscle within the popliteal fossa Courses along the medial border of the fibula Terminates at the inferior tibiofibular joint by dividing into lateral calcaneal branches	Muscular branches: muscles of the lateral compartment of the leg and the deep flexor group of the posterior compartment of the leg Posterior lateral malleolar branch: contributes to the lateral malleolar vascular network Calcaneal branch: lateral aspect of the calcaneus and calcaneal tendon Perforating branches: anterior compartment of the leg, tarsus, and posterolateral skin of the leg Nutrient artery of the fibula: enters through the medial crest of the fibula	Courses within the flexor hallucis longus muscle Covered by the soleus muscle
Dorsalis pedis artery	A continuation of the anterior tibial artery	Begins at the ankle joint, in the anterior aspect of the 1^st intermetatarsal space Penetrates the 1^st dorsal interosseous muscle to enter the sole of the foot Terminates by anastomosing with the lateral plantar artery to form the plantar arch	1^st dorsal metatarsal artery: great toe and medial half of the 2^nd toe Tarsal arteries: muscles of the foot and the medial malleolus Arcuate artery: lateral 4 toes and the dorsal aspect of the foot	Lies lateral to the tendon of the extensor hallucis longus at the ankle joint (anteriorly)

NAVEL: Nerve, Artery, Vein, Empty space (femoral canal), and Lymphatics (order of the contents of the femoral triangle, from lateral to medial)

The sites where the peripheral pulses are best palpated:
Femoral artery: midinguinal point
Popliteal artery: within the popliteal fossa
Posterior tibial artery: between the Achilles tendon and the posterior border of the medial malleolus
Dorsalis pedis artery: against the navicular bone, just lateral to the extensor hallucis longus tendon

Arteries of the lower extremity Popliteal artery Dorsal arteries of the foot Anatomical structures of the dorsum foot

Veins

Overview ^[1]

The lower limbs have superficial and deep venous systems, both of which drain into the inferior vena cava.
The superficial veins lie within the subcutaneous tissues and drain into the deep venous system.
The deep veins lie deep to the deep fascia and drain into the inferior vena cava via the iliac veins.
Perforator veins are short horizontal or oblique veins that connect the superficial veins to the deep veins by piercing through the deep fascia.
Venous valves ensure the unidirectional flow of blood from the superficial to the deep venous system towards the heart.

Veins of the lower limbs

Major veins of the lower limbs

Overview of veins of the lower limbs
Veins	Superficial veins		Deep veins
Veins	Great saphenous vein (long saphenous vein)	Short saphenous vein (small saphenous vein)	Popliteal vein	Femoral vein	External iliac vein
Origin	Continuation of the medial marginal vein of the foot (medial end of the dorsal venous arch)	Continuation of the lateral marginal vein of the foot (lateral end of the dorsal venous arch)	Formed by the union of anterior tibial, posterior tibial, and fibular veins at the inferior border of the popliteus	Continuation of the popliteal vein at the adductor hiatus	Continuation of the femoral vein posterior to the inguinal ligament
Course	At the ankle: passes in front of the medial malleolus In the leg: ascends along the medial aspect of the shin At the knee: runs behind the medial condyles of the femur and tibia Thigh: medial aspect of the thigh	At the ankle: passes behind the lateral malleolus In the leg: ascends in the midline of the calf towards the popliteal fossa	Exits the popliteal fossa superiorly and ascends through the adductor hiatus	Begins at the adductor hiatus and accompanies the femoral artery throughout its course Continues as the external iliac vein as it passes posterior to the inguinal ligament	Begins at the inferior margin of the inguinal ligament Continues anteriorly towards the sacrum, where it joins with the internal iliac vein
Termination	Saphenofemoral junction (SFJ) The site at which the long saphenous vein passes through the saphenous opening in the deep fascia of the thigh to meet the femoral vein The position is fairly constant at 4 cm inferolateral to the pubic tubercle.	Saphenopopliteal junction (SPJ) The site at which the short saphenous vein drains into the popliteal vein Unlike the SFJ, the location of the SPJ is variable, lying within, proximal, or distal to the popliteal fossa.	At the adductor hiatus, continues as the femoral vein	Posterior to the inguinal ligament, continues as the external iliac vein	At the sacroiliac joint, forms the common iliac vein
Main tributaries	Short saphenous vein Superficial external pudendal vein Superficial epigastric veins Superficial circumflex iliac vein Lateral femoral cutaneous vein	Dorsal vein of the 5^th toe Dorsal venous arch	Short saphenous vein	Long saphenous vein Deep vein of the thigh Medial and lateral circumflex femoral veins	Inferior epigastric vein Deep circumflex iliac vein Pubic vein
Drains	The anteromedial aspect of the sole, leg, and thigh	The posterior and lower leg	The lower leg	The lower leg	The leg, pubic area, and anterior abdominal wall
Important relations	The saphenous nerve accompanies the long saphenous vein below the knee.	The sural nerve accompanies the short saphenous vein through most of its course.	The popliteal artery and popliteal nerve travel with the popliteal vein.	Runs within the femoral triangle	The internal iliac artery is found laterally. Crossed by the ureter and vas deferens in males Crossed by the ovarian artery and round ligament in females

Veins of the leg (ventral aspect) Veins of the leg (dorsal aspect) Saphenofemoral junction

Veins of the leg

Superficial veins: long and short saphenous veins (see the table “Overview of veins of the lower limbs” above)
Deep veins
- Anterior tibial vein
  - Arises from venae comitantes of the dorsalis pedis artery
  - Accompanies the anterior tibial artery
  - Drains the anterior aspect of the leg and foot
- Posterior tibial vein
  - Arises from the medial and lateral plantar veins
  - Accompanies the posterior tibial artery
  - Drains the posterior aspect of the leg and foot
- Fibular veins (peroneal veins)
  - Arise from the medial and lateral plantar veins
  - Accompany the fibular artery
  - Drain the lateral aspect of the leg

Veins of the foot

Superficial veins
- Dorsal venous arch of the foot
  - Lies on the dorsal aspect of the heads of the lateral four metatarsal bones
  - Tributaries: Dorsal digital veins unite to form dorsal metatarsal veins that drain into the dorsal venous arch.
  - Termination: continues as the medial and lateral marginal veins
- Marginal veins
  - Medial marginal vein continues as the long saphenous vein
  - Lateral marginal vein continues as the short saphenous vein
Deep veins
- Plantar venous arch of the foot
  - Lies on the plantar aspect of the lateral four metatarsal bones
  - Tributaries: Plantar digital veins unite to form metatarsal veins that drain into the deep plantar venous arch.
  - Termination: continues as the medial and lateral plantar veins
- Medial and lateral plantar veins: drain into the posterior tibial vein

Nerves

Overview

The lower limb is innervated by branches of the lumbosacral plexus.
Lumbosacral plexus: a network of nerves composed of two distinct plexuses
- The lumbar plexus: formed by the subcostal nerve (T12) and first four lumbar nerves (L1–L4)
- The sacral plexus: formed by the last two lumbar nerves (L4–L5) and the first four sacral nerves (S1–S4)
Lumbosacral trunk
- Formed by the fusion of lumbar nerves L4 and L5
- Contributes to the sacral plexus

Innervation of the lower extremity (ventral view)

Lumbar plexus

Definition: a neural network formed by the subcostal and first four lumbar nerves
Nerve roots: anterior (ventral) divisions of T12–L4
Anatomical location: : anterior to the transverse processes of the lumbar vertebrae, within the psoas major muscle ^[2]
Supply
- Motor innervation
  - Lower abdominal muscles: external oblique, internal oblique, and transversus abdominis
  - Pelvic muscles: Iliacus, pectineus, cremaster
  - Muscles of the anterior and medial compartments of the thigh
- Sensory innervation
  - Lower abdomen
  - Lateral gluteal region
  - External genitalia
  - Thigh
  - Medial aspect of the leg (via the saphenous nerve)

Nerves of the lumbar plexus
Nerve	Nerve root	Important characteristics	Course	Motor innervation	Sensory innervation
Iliohypogastric nerve	T12–L1	Mixed sensorimotor nerve	Emerges from the lateral border of the psoas major Courses dorsal to the psoas major and quadratus lumborum muscles, posterior to the kidney Pierces the transversus abdominis and internal oblique muscles Courses parallel to the inguinal ligament from lateral to medial Terminates by piercing through the external oblique muscle ∼ 3 cm proximal to the superficial inguinal ring	Transversus abdominis muscle Internal oblique muscle Conjoint tendon	Suprapubic region Lateral aspect of the gluteal region
Ilioinguinal nerve	T12–L1	Mixed sensorimotor nerve	Emerges from the lateral aspect of the psoas major muscle Courses dorsal to the psoas major and quadratus lumborum muscles Pierces the transversus abdominis and the internal oblique muscles Terminates by emerging from the superficial inguinal ring	Transversus abdominis muscle Internal oblique muscle	Proximal medial aspect of the thigh Mons pubis (women) or root of penis (men)
Genitofemoral nerve	L1–L2	Sensorimotor nerve	Pierces the psoas major and courses over its dorsal surface Divides into two branches just above the inguinal ligament: Genital branch: traverses the inguinal canal and emerges from the superficial inguinal ring Femoral branch: courses beneath the inguinal ligament to enter the femoral triangle, lateral to the femoral artery	Genital branch: cremaster muscle	Genital branch: labia majora (in women) or scrotum (in men) Femoral branch: anteromedial thigh
Lateral cutaneous nerve of thigh (lateral femoral cutaneous nerve) ^[3]	L2–L3	Pure sensory nerve	Courses dorsal to the psoas major and iliac muscles toward the anterior superior iliac spine Passes deep to the inguinal ligament to enter the thigh Courses through the muscular space	None	Skin over the anterolateral aspect of thigh (up to the knee)
Femoral nerve	L2–L4 (dorsal branches)	Sensorimotor nerve Largest branch of the lumbar plexus	Courses along the lateral border of the psoas major and passes underneath the fascia of the iliac crest Passes deep to the inguinal ligament to enter the thigh Lies within the femoral triangle, lateral to the femoral artery	Muscles of the anterior compartment of the thigh Iliacus Pectineus	Intermediate cutaneous nerve of thigh: skin over the anterior aspect of the thigh Medial cutaneous nerve of thigh (medial femoral cutaneous nerve): skin over the lower 2/3^rds of the medial aspect of the thigh Articular branch: knee joint Saphenous nerve: medial aspect of the knee, leg, and foot (see below)
Saphenous nerve	L2–L4	Pure sensory nerve Largest cutaneous branch of the femoral nerve Accompanied by the long saphenous vein in the leg	Passes through the adductor canal Becomes superficial by piercing the deep fascia behind the medial border of the patella Courses in the anteromedial aspect of the leg	None	Skin over the medial aspect of the knee, leg, and foot
Obturator nerve	L2–L4 (ventral branches)	Sensorimotor nerve	Courses within the psoas major muscle and then posterior to the iliac vessels Traverses the obturator canal to enter the thigh Terminates by dividing into an anterior and posterior branch	Muscles of the medial compartment of the thigh	Skin over the upper 1/3^rd of the medial aspect of the thigh Articular branch: hip and knee joints

Incidentally, I Got Laid On Friday: Iliohypogastric, Ilioinguinal, Genitofemoral, Lateral femoral cutaneous, Obturator, Femoral (nerves of the lumbar plexus)

Innervation of the lower extremity (ventral view) Lumbar plexus Innervation areas of the peripheral nerves (leg, ventral view) Contents and borders of the muscular lacuna and vascular lacuna Obturator canal and pudendal canal

Sacral plexus

Definition: a neural network formed by the last two lumbar nerves and the first four sacral nerves
Nerve roots: anterior (ventral) divisions of L4–S4
Anatomical location: lies within the pelvis, on the surface of the piriformis, posterior to the iliac vessels and the ureter
Supply: lower limbs and pelvis

Sacral plexus branches
Nerve	Nerve roots	Important characteristics	Course	Motor innervation	Sensory innervation
Superior gluteal nerve	L4–S1	Motor nerve	Exits the pelvis through the greater sciatic foramen above the piriformis Passes through the suprapiriform foramen with the superior gluteal artery and vein Divides into a superior and inferior branch	Gluteus medius muscle Gluteus minimus muscle Tensor fasciae latae muscle Articular branch: hip joint	None
Inferior gluteal nerve	L5–S2	Motor nerve	Exits the pelvis through the greater sciatic foramen below the piriformis Courses caudally with the inferior gluteal artery Courses deep to the fascia lata up to the popliteal fossa	Gluteus maximus muscle	None
Posterior cutaneous nerve of thigh (posterior femoral cutaneous nerve)	S2–S3	Sensory nerve	Courses through the infrapiriform foramen Courses caudally with the inferior gluteal artery Courses deep to the fascia lata up to the popliteal fossa	None	Inferior part of the gluteal region Posterior aspect of the scrotum (men) or labia majora (women) Posterior aspect of the thigh and upper calf
Sciatic nerve	L4–S3	Sensorimotor nerve Thickest nerve of the body	Courses through the infrapiriform foramen Courses towards the popliteal fossa, covered by the ischiocrural muscles (giving off muscular branches along its course) Divides into the tibial nerve and common fibular nerves that supply the leg and foot	Muscles of the posterior compartment of the thigh (hamstrings) Hamstring portion of the adductor magnus muscle Muscles of the posterior compartment of the leg (via the tibial nerve)	In the thigh: none In the leg: See tibial nerve and common peroneal nerve below.
Pudendal nerve	S2–S4	Mixed sensorimotor nerve	Passes through the infrapiriform foramen Courses around the ischial spine Passes through the lesser sciatic foramen Arrives at the ischioanal fossa Enters the pudendal canal and divides into its terminal branches here: the perineal, inferior rectal, and dorsal penile/clitoral nerves	External urethral sphincter External anal sphincter Levator ani muscles Bulbospongiosus muscle Ischiocavernosus muscle	Inferior rectal nerves Skin of the perianal region Lower third of the anal canal Perineal nerves Skin of the perineum Dorsal scrotum (men) or labia majora (women) Dorsal penile (men)/clitoral (women) nerve Dorsum of the penis/clitoris skin Responsible for penile reflex erection
Nerve to piriformis	S1–S2	Motor nerve	Does not exit the pelvis Terminates by piercing the piriformis and supplying it	Piriformis	None
Nerve to obturator internus	L5–S2	Motor nerve	Exits the pelvis through the greater sciatic foramen below the piriformis	Internal obturator muscle Superior gemellus muscle	None
Nerve to quadratus femoris	L4–S1	Motor nerve	Exits the pelvis through the greater sciatic foramen below the piriformis	Quadratus femoris Inferior gemellus muscle Articular branch: hip joint	None

SIPPS: Superior gluteal nerve, Inferior gluteal nerve, Posterior cutaneous nerve of thigh, Pudendal nerve, Sciatic nerve (nerves of the sacral plexus)

Sacral plexus Pudendal nerve Anatomy of the pelvis

Branches of the sciatic nerve

The sciatic nerve terminates at the apex of the popliteal fossa by dividing into the tibial nerve and the common peroneal nerve.
A cutaneous branch from both the tibial and common peroneal nerve unites to form the sural nerve.

Sciatic nerve branches
Nerve	Nerve roots	Important characteristics	Motor innervation	Sensory innervation
Tibial nerve	L4–S3 (ventral divisions)	Sensorimotor nerve A terminal branch of the sciatic nerve Arises at the apex of the popliteal fossa	Posterior compartment of the leg	Medial calcaneal branch: skin over the heel Medial plantar nerve: medial half of the sole (excluding the heel) and the plantar aspect of the medial 3.5 toes Lateral plantar nerve: lateral half of the sole (excluding the heel) and the plantar aspect of the lateral 1.5 toes
Common peroneal nerve (common fibular nerve)	L4–S2 (dorsal divisions)	Sensorimotor nerve	A terminal branch of the sciatic nerve Arises at the apex of the popliteal fossa Deep peroneal nerve (L4–L5) A terminal branch of the common peroneal nerve Arises at the neck of the fibula Supplies the anterior compartment of the leg Superficial peroneal nerve (L4–L5) A terminal branch of the common peroneal nerve Arises at the neck of the fibula Supplies the lateral compartment of the leg	Lateral sural cutaneous nerve (lateral cutaneous nerve of calf): skin over the lateral aspect of the leg Sural communicating nerve: joins the tibial part of the sural nerve Deep peroneal nerve: 1^st web space of the foot (i.e., the sandal gap) Superficial peroneal nerve: distal part of the anterior aspect of the leg and the dorsum of the foot (except the 1^st web space)
Sural nerve	L4–S4	Sensory nerve Formed by the union of sural (cutaneous) branches from the tibial and common peroneal nerves Accompanied by the short saphenous vein	None	Skin over the posterolateral aspect of the distal 1/3^rd of the leg and the lateral border of the foot

TIPPED: tibial nerve injury versus peroneal nerve injury
TIP: Tibial nerve Inverts and Plantarflexes the foot; injury leads to an inability to walk on the TIPtoes
PED: Peroneal nerve Everts and Dorsiflexes the foot; injury leads to foot drop

Innervation of the lower extremity (dorsal view) Sensory innervation of the foot

Clinical significance

References

Standring S. Gray's Anatomy: The Anatomical Basis of Clinical Practice. Elsevier Health Sciences ; 2016
Benglis DM, Vanni S, Levi AD. An anatomical study of the lumbosacral plexus as related to the minimally invasive transpsoas approach to the lumbar spine. Journal of Neurosurgery: Spine. 2009; 10 (2): p.139-144.doi: 10.3171/2008.10.spi08479 . | Open in Read by QxMD
Lateral Femoral Cutaneous Nerve. https://radiopaedia.org/articles/lateral-femoral-cutaneous-nerve. Updated: January 1, 2018. Accessed: November 18, 2018.
Posterior Femoral Cutaneous Nerve. https://radiopaedia.org/articles/posterior-femoral-cutaneous-nerve. Updated: January 1, 2018. Accessed: November 18, 2018.
Anterior Tibial Artery. https://radiopaedia.org/articles/anterior-tibial-artery. Updated: January 1, 2018. Accessed: November 25, 2018.
Posterior Tibial Artery. https://radiopaedia.org/articles/posterior-tibial-artery. Updated: January 1, 2018. Accessed: November 25, 2018.
Arterial Supply to the Foot. https://radiopaedia.org/articles/arterial-supply-to-the-foot. Updated: January 1, 2018. Accessed: November 25, 2018.

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Neurovasculature of the lower limbs

Summary

Overview

Arteries

Overview [1]

Veins

Overview [1]

Veins of the lower limbs

Major veins of the lower limbs

Veins of the leg

Veins of the foot

Nerves

Overview

Lumbar plexus

Sacral plexus

Branches of the sciatic nerve

Clinical significance

References

3 free articles remaining

Overview ^[1]

Overview ^[1]