Lower Limb Anatomy (Nerves and Vessels)

Question 1

FEMORAL TRIANGLE
Boundaries:
Contents:

Answer 1

FEMORAL TRIANGLE
Boundaries:
- Superior = inguinal ligament
- Lateral = Sartorius
- Medial = Adductor longus

Contents:
- inguinal lymph nodes
- femoral sheath (medial-lateral = femoral canal, femoral vein, femoral artery)
- femoral nerve and branches (most lateral)

Question 2

Femoral A is a branch of ____.
Femoral A branches into __A__ and __B__.

A branches into ____, ____ and ____.
B branches into ____, which then branches into __C__ and __D__.

What are the 2 arteries that form the plantar arch?

Answer 2

Femoral A is a branch of EXTERNAL ILIAC A.
Femoral A branches into PROFUNDA FEMORIS A and SUPERFICIAL FEMORAL A.

A branches into LATERAL CIRCUMFLEX A, PERFORATING&MUSCULAR BRANCHES and MEDIAL CIRCUMFLEX A.
B branches into POPLITEAL A, which then branches into ANTERIOR TIBIAL A and POSTERIOR TIBIAL A.

Plantar arch is formed by
1. Dorsalis pedis A (from anterior tibial A)
2. Lateral plantar A (from posterior tibial A)

Question 3

PROFUNDA FEMORIS ARTERY branches into LATERAL CIRCUMFLEX A and MEDIAL CIRCUMFLEX A and PERFORATING & MUSCULAR BRANCHES.

____ branches supply the posterior thigh
____ branches supply the medial and anterior thigh

Answer 3

PERFORATING branches supply the posterior thigh
MUSCULAR branches supply the medial and anterior thigh

Question 4

State the point at which the femoral pulse is felt.

Answer 4

mid-inguinal point

Question 5

ADDUCTOR/SUBSARTORIAL CANAL:
- ____ A exits ____ compartment and reaches ____ knee
- Is the space between ____ ____ and ____ ____ with overlying ____ muscle
- Contents = ____ A, ____ V and ____ N and nerve to vastus medialis (______ N)

Answer 5

ADDUCTOR/SUBSARTORIAL CANAL:
- FEMORAL Aexits ANTERIOR compartment and reaches POSTERIOR knee
- Is the space between VASTUS MEDIALIS and ADDUCTOR LONGUS with overlying SARTORIUS muscle
- Contents = FEMORAL A, FEMORAL V and SAPHENOUS N (branch of femoral N) and nerve to vastus medialis (femoral N)

Question 6

BRANCHES OF COMMON ILIAC A:
- External Iliac A –> ____ A
- Internal Iliac A –> ____ A and ____ A

Answer 6

BRANCHES OF COMMON ILIAC A:
- External Iliac A –> COMMON FEMORAL A
- Internal Iliac A –> SUPERIOR GLUTEAL A and INFERIOR GLUTEAL A

Question 7

State the branches involved in CRUCIATE ANASTOMOSIS and TROCHANTERIC ANASTOMOSIS

Answer 7

CRUCIATE ANASTOMOSIS
1. lateral circumflex A
2. medial circumflex A
3. inferior gluteal A
4. 1st perforating A

TROCHANTERIC ANASTOMOSIS
1. superior gluteal A
2. inferior gluteal A
3. lateral circumflex A
4. medial circumflex A

Question 8

State the borders of the POPILTEAL FOSSA
1. Superomedial
2. Superolateral
3. Inferomedial
4. Inferolateral
5. Floor
6. Roof

Answer 8

1. Superomedial = semitendinosus + semimembranosus (closer to popliteal fossa)
2. Superolateral = biceps femoris
3. Inferomedial = medial head of gastrocnemius
4. Inferolateral = lateral head of gastrocnemius
5. Floor = popliteal surface of femur, capsule of knee joint, proximal tibia covered by popliteus
6. Roof = deep fascia

Question 9

State the origin and insertion of each muscle involved in the border of the popliteal fossa.

Answer 9

Superomedial = Semitendinosus (o = ischial tuberosity, i = pes anserine at medial side of tibia), Semembranosus (o = ischial tuberosity, i = medial condyle of femur)

Superolateral = Biceps femoris (o = ischial tuberosity, i = head of fibula)

Inferomedial = Gastrocnemius (medial head) (o = medial condyle of femur, i = tendocalcaneus)

Inferolateral = Gastrocnemius (lateral head) (o = lateral condyle of femur, i = tendocalcaneus)

Question 10

State the contents in popliteal fossa

Answer 10

1. lymph nodes and fat
2. neurovascular structures (superficial to deep) (NVA) - tibial nerve, popliteal vein, popliteal artery

Question 11

Pulse of DORSALIS PEDIS A on dorsum of foot is best felt between
____ and ____

Answer 11

Pulse of DORSALIS PEDIS A on dorsum of foot is best felt between
EXTENSOR HALLUCIS LONGUS TENDON (inserts at base of 1st metatarsal) and EXTENSOR DIGITORUM LONGUS TENDON (inserts at base of distal phalanges of lateral 4 toes)

Question 12

Pulse of POSTERIOR TIBIAL A is best felt between ____ and ____

Answer 12

Pulse of POSTERIOR TIBIAL A is best felt between POSTERIOR ASPECT OF MEDIAL MALLEOLUS and MEDIAL BORDER OF CALCAENAL TENDON (TENDOCALCANEUS)

Question 13

State the 3 veins involved in venous drainage of the lower limbs (general). State where they are located if relevant.

Answer 13

1. superficial veins - great and small saphenous veins (located in subcutaneous tissue)
2. deep veins (deep to deep fascia)
3. perforating veins (allows blood to flow from superficial veins to deep veins)

Question 14

State the course of the GREAT SAPHENOUS VEIN.

State what structure follows the GREAT SAPHENOUS VEIN.

Answer 14

COURSE:
1. dorsal venous arch in foot
2. ascends anteriorly to medial malleolus up the leg and posteromedial to knee joint
3. ascends up the thigh
4. saphenous opening in fascia latae
5. common femoral vein at saphenofemoral junction

Saphenous nerve follows great saphenous vein

Question 15

State the course of the SMALL (SHORT) SAPHENOUS VEIN.

State the structure that follows the SMALL (SHORT) SAPHENOUS VEIN

Answer 15

COURSE:
1. dorsal venous arch
2. small saphenous vein winds around lateral side of foot to back of leg
3. ascends up posterior leg
4. drains into popliteal fossa

Sural nerve follows course of small (short) saphenous vein

Question 16

Fill in the blanks for the deep vein.

Answer 16

Question 17

PERFORATING VEINS
- Contains ____ which allow blood to flow ____ from ____ veins to ____ veins
- Once in ____ veins, blood is propelled by muscular contractions to the ____ V
- Arterial pulsation also helps venous blood to move (deep veins are in ____ sheath together with arteries = venous ____)
- ____ action helps to pump venous blood upwards

Answer 17

PERFORATING VEINS
- Contains VALVES which allow blood to flow UNIDIRECTIONALLY from SUPERFICIAL veins to DEEP veins
- Once in DEEP veins, blood is propelled by muscular contractions to the FEMORAL V
- Arterial pulsation also helps venous blood to move (deep veins are in VASCULAR sheath together with arteries = venous COMITANTE)
- PLANTARFLEXION action helps to pump venous blood upwards

Question 18

VARICOSE VEINS
- Common in ____ parts of lower leg
- Occurs due to ____ ____ resulting in blood flowing from ____ V to ____ V instead through ____ V

Answer 18

VARICOSE VEINS
- Common in POSTEROMEDIAL parts of lower leg
- Occurs due to VALVULAR INCOMPETENCY resulting in blood flowing from DEEP V to SUPERFICIAL V instead through PERFORATING V

Question 19

DVT (Deep Vein Thrombosis) is a ____ that forms in the ____ V of the lower leg (usually between the ____ and ____)
- Clot may travel through the veins and lodge in ____ or ____ –> death
- Clots can cause ____, ____ and ____

Answer 19

DVT (Deep Vein Thrombosis) is a BLOOD CLOT that forms in the DEEP Vof the lower leg (usually between the ANKLE and UPPER CALF)
- Clot may travel through the veins and lodge in HEART or LUNGS –> death
- Clots can cause TISSUE DAMAGE, SKIN LESIONS and ULCERATION

Question 20

State the nerve roots involved in lumbar plexus and sacral plexus as well as their location.

Answer 20

LUMBAR PLEXUS - L1-L4 (in posterior abdominal wall)

SACRAL PLEXUS - L4-S4 (in pelvis)

Question 21

State the course of the femoral N, obturator N and sciatic N. State the location of each nerve in the thigh and the muscles they innervate.

Answer 21

FEMORAL NERVE (dorsal rami of L2-L4)
- Formed at posterior aspect of psoas major
- Innervation = Supplies extensor (anterior) compartment of thigh (quadriceps) + pectineus + iliacus

OBTURATOR NERVE (ventral rami of L2-L4)
- Formed medial to psoas muscle and reaches adductor compartment of thigh
- Innervation = supplies adductor (medial) compartment of thigh

SCIATIC NERVE (L4-S3)
- Formed on piriformis and exits through greater sciatic foramen before splitting into common fibular N and tibial N at popliteal fossa
- Innervation = supplies leg (superficial fibular - lateral compartment of leg, deep fibular - anteiror compartment of leg, tibial - posterior compartment of leg)

Question 22

SCIATICA
- Paralysis of ____ and weak ____ of knee because ____ innervated by femoral N is still working
- All muscles below ____ are paralysed
- Foot ____ occurs due to ____
- Most common cause =

Answer 22

SCIATICA
- Paralysis of HAMSTRINGS and weak FLEXION of knee because SARTORIUS innervated by femoral N is still working
- All muscles below KNEE are paralysed
- Foot DROP occurs due to GRAVITY
- Most common cause = BULGING DISC/HERNIATED DISC

Question 23

COMMON FIBULAR NERVE INJURY
- Commonly due to =
- Paralysis of ____ and ____ of foot due to injury to ____ N –> foot ____
- Paralysis of ____ —> foot ____
- Loss of sensation on ____ leg and ____ of foot
- Foot drop + Foot inversion =

What happens during a tibial injury?

Answer 23

COMMON FIBULAR NERVE INJURY
- Commonly due to = FIBULA FRACTURE
- Paralysis of DORSIFLEXORS and EXTENSORS of foot due to injury to DEEP FIBULAR N –> foot DROP
- Paralysis of EVERTORS —> foot INVERSION
- Loss of sensation on LATERAL leg and DORSUM of foot
- Foot drop + Foot inversion = EQUINOVARUS

TIBIAL INJURY:
- Calcaneovalgus = Foot dorsiflexion + Foot eversion

Question 24

Recap:
Tibial N innervates ____, ____, ____, ____, ____, ____, ____
Tibial N branches into ____ and ____

Answer 24

Tibial N innervates GASTROCNEMIUS, SOLEUS, PLANTARIS, POPLITEUS, FLEXOR DIGITORUM LONGUS, FLEXOR HALLUCIS LONGUS, TIBIALIS POSTERIOR
Tibial N branches into MEDIAL PLANTAR N and LATERAL PLANTAR N

Question 25

Femoral N branches into posterior division and anterior division.

The posterior division branches into an important branch =

Answer 25

Femoral N branches into posterior division and anterior division.

The posterior division branches into an important branch = SAPHENOUS N

Question 26

State the nerve and nerve roots involved in the 2 reflexes:
1. Calcaneal tendon reflex
2. Knee jerk

Answer 26

1. Calcaneal tendon reflex - tap tendocalcaneus to plantarflex - S1-S2 tibial N
2. Knee jerk - tap ligamentum patallae to extend - L2-L4 femoral N

Question 27

GAIT CYCLE
- ____% stance phase, ____% swing phase
- Stance phase = heel ____ (____) to push off (____)
- Swing phase = toe off to knee strike

Answer 27

GAIT CYCLE
- 60% stance phase, 40% swing phase
- Stance phase = heel strike (DORSIFLEXION) to push off (PLANTARFLEXION)
- Swing phase = toe off to heel strike

Question 28

State the nerve roots for

Sciatic nerve:
Common fibular nerve:
Deep fibular nerve:
Superficial fibular nerve:
Tibial nerve:

Answer 28

Sciatic nerve: L4-S3
Common fibular nerve: L4-S2
Deep fibular nerve: L4-S1
Superficial fibular nerve: L5-S1
Tibial nerve: S1-S2

Question 29

State the sensory supply of
1. lateral cutaneous nerve
2. common fibular nerve
3. sural nerve
4. saphenous nerve
5. tibial nerve

Answer 29

LATERAL CUTANEOUS NERVE
- lateral side of leg down to midpoint

COMMON FIBULAR NERVE
- lateral aspect of leg from midpoint to foot
- dorsum of foot (exclude area in between great toe and 2nd phalanges)

SURAL NERVE
- area between great toe and second phalanges

SAPHENOUS NERVE
- medial aspect of leg up to knee

TIBIAL NERVE
- heel