Vessels and nerves of the lower limb

Question 1

Overall, outline the organisation of spinal nerves in terms of what they supply

Answer 1

C1-4 : neck
C5-T1 : upper limb
T2-L1 : trunk
L2-S3 : lower limb
S2-C1 : perineum

Question 2

Where do nerves to the lower limb emerge from the spinal cord

Answer 2

Lumbosacral plexus

Femoral n. supplies anterior compartment of thigh.

Obturator n. supplies medial (adductor) compartment of thigh.

Sciatic n. (or its terminal branches Tibial and Common Peroneal ns.) supply the remaining compartments (i.e. post. thigh, ant. and post. leg, foot)

Question 3

Outline the nerves present in the buttock and posterior thigh

Answer 3

ABOVE piriformis:

Superior gluteal nerve

BELOW piriformis

Inferior gluteal nerve (winds back up toward gluteus maximus)

Sciatic nerve

Posterior cutaneous nerve of thigh

Question 4

Outline the nerves present in the leg and foot

Answer 4

Sciatic nerve splits into tibial nerve (medially) and common peroneal nerve (laterally)

Common peroneal winds around the fibula to the lateral and anterior portions of the leg. Gives off sural communicating branch

Tibial branch continues down the posterior leg, gives off medial sural cutaneous nerve, which connects with the sural communicating nerve to form the sural nerve (sensory to the calf)

Tibial branch then splits into the medial and lateral plantar nerve

Question 5

Which spinal cord segments make up the common peroneal nerve.

What about the superficial peroneal nerve

What about the deep peroneal nerve

Answer 5

Common= L4-S2

Superficial peroneal nerve (for the lateral muscles of the leg) L4-S1

Deep peroneal nerve (for anterior muscles of the leg) .. L5-S2

Question 6

Which muscles does the tibial nerve supply

Answer 6

The posterior leg

and its branches supply the muscles on the plantar side of the foot too

Question 7

T/F the tibial nerve supplies all the intrinsic muscles of the foot

Answer 7

F… tibial supplies all the muscles in the sole of the foot via medial and plantar nerves

but intrinsic muscle on the dorsum of the foot (extensor digitorum brevis) is supplies by the deep peroneal nerve

Question 8

Which muscles are suppied by the medial and lateral plantar nerves

Answer 8

These nerves are branches of the the tibial nerve

Medial plantar:

Abductor hallucis,
FDB, FHB, lumbrical to the second digit

Lateral plantar: all other muscles in the sole of the foot (but not any that come from the posterior leg e.g. FHL, which is supplies by tibial)

Question 9

Outline the spinal cord levels contributing to femoral nerve

Answer 9

Femoral Nerve (L234, posterior fibres)

Iliopsoas (+L1), ant. thigh

Question 10

Outline the spinal cord levels contributing to obturator nerve

Answer 10

(L234, anterior fibres)

Medial (adductor) compartment of thigh

Question 11

Outline the spinal cord levels contributing to sciatic nerve

Answer 11

(L345S123, ant. & post. fibres)

Post. thigh; leg; foot

Question 12

Outline the spinal cord levels contributing to superior gluteal nerve

Answer 12

(L45S1)

Gluteus medius and minimus, Tensor fascia lata

Question 13

Outline the spinal cord levels contributing to inferior gluteal nerve

Answer 13

(L5S12) (Gluteus maximus)

Question 14

What type of mucles do the anterior divisions and the posterior divisions of a limb plexs supply

Answer 14

Anterior divisions = flexor muscles
Posterior divisions = extensor muscles

(C5-T1 = upper limb
L2-S3 = lower limb) 

referring to SEGMENTAL MOTOR SUPPLY

Question 15

State the principles of segmental supply

Answer 15

Muscles supplied by two adjacent segments
Same action on joint = same nerve supply
Opposing muscles 1-2 segments above or below
More distal in limb = more caudal in spine

Question 16

Outline the segmental supply to the lower limb (Hip, knee and ankle)

Answer 16

HIP
Flex L2L3

Extend L4L5

KNEE
Extend L3L4

Flex L5S1

ANKLE

Dorsiflex (ext) L4L5

Plantarflex (flex) S1S2

Inversion L4

Eversion L5S1

Question 17

Fibers from which root make up th posterior cutaneus nerve of the thigh

Answer 17

S1, S2

Question 18

T/F the area to which sensory innervation from S1 is provided medial to the area for S2

Answer 18

F…. on the posterior surface, S1 has a strip running straight down the leg laterally, and S2 medially

S1 then innervates the lateral side of the plantar surface of foot, and S2 the medial side of the plantar surface of the foot, with a bit of L5 in between the two on the plantar surface

Remember L3 runs to the knee and L4 runs to the floor

Question 19

Which spinal nerves provide sensation to the genitals

Answer 19

S2/3

Question 20

What are autonomous zones

Answer 20

These are the regions where single nerve roots supply distinct and non-overlapping areas of skin

Question 21

Where can autonomous zones be found in the lower limb

Answer 21

S1, in the lateral calf (S1)

L3 (in the upper thigh an infero-medially point ing segment) and

L4 in lower thigh and over the knee also inferomedially )

Question 22

The obturator nerve supplies sensory cutaneous innervation where

Answer 22

Medial thigh

Question 23

You just have to learn the peripheral cutaneous nerves

Answer 23

…..

Question 24

Outline the large peripheral cutaneous nerve areas

Answer 24

Anterior cutaneous branches of emoral nerve (lateral group) supplies most of the front of the thigh)

Interior clunial nerves/posterior cutanous nerve of the thigh supplies back of thigh and buttock

Saphenous nerve from femoral supplies medial anterior side of leg and wraps around to the medial posterior side too

Lateral sural cutaneous nerve (from common peroneal nerve) supplies the lateral side of the anterior and posterior leg

Question 25

Outline the cutaneous innervation to the foot

Answer 25

Note the small area (1st and 2nd toe) supplied by the dorsal digital nerve from the deep peroneal

Question 26

Outline the consequence of prolapsed intervertebral disc prolapse at L5/S1

Answer 26

Motor – loss of eversion Sensory – loss of sensation outer border of foot Reflex – loss of ankle jerk (S1) Autonomic – minimal

Question 27

Consequence of Lesion of Common Peroneal Nerve at Fibular Neck

Answer 27

Motor – foot drop (loss deep peroneal nerve function which dorsiflexes foot) Sensory – dorsum of foot at least Reflex – none Autonomic – minimal

Question 28

Give an overview of the arterial anatomy of the lower limb

Answer 28

``` Aorta Common iliac arteries External iliac / internal iliac arteries Femoral artery (Profunda femoris artery Circumflex femoral arteries) Popliteal artery “Trifurcation” Anterior tibial artery – dorsalis pedis artery Posterior tibial artery Peroneal artery ```

Question 29

The pulses of which arteries can be felt in the lower limb

Answer 29

Femoral artery pulse (femoral triangle) Politeal artery (popiteal fossa) Posterior tibial artery pulse Dorsalis pedis (a continuation of the anterior tibial artery)

Question 30

At which point does the femoral artery and vein become popliteal artery and vein

Answer 30

The femoral artery and vein pass from the anterior compartment to the posterior of the knee (the popliteal fossa) through the hiatus of adductor magnus muscle. After passing posteriorly, they are named the popliteal artery and vein.

Question 31

Where does the anterior tibial artery travel

Answer 31

Through the interosseus membrane

Question 32

Outline the arterial supply of the foot

Answer 32

Anterior tibial --> dorsalis pedis Posterior tibial artery --> medial and lateral plantar artery

Question 33

Where can the dorsalis pedis be palpated

Answer 33

Lateral to tibialis anterior tendon

Question 34

Where can the posterior tibial artery be palpated

Answer 34

Between the medial malleolus and the calcaneal tendon

Question 35

Outline the superficial veins of the lower limb

Answer 35

``` Dorsal venous arch Long saphenous vein (into femoral) Short saphenous vein (into popliteal) Perforating veins Sapheno-femoral junction Blood flow from SUPERFICIAL TO DEEP ```

Question 36

T/f great saphenous is a deep vein

Answer 36

F it is a superficial one

Question 37

Which veins drain the knee region

Answer 37

Genicular veins

Question 38

Which vein can be found at the medial malleolus

Answer 38

Long saphenous vein

Question 39

What is the clinical application of the LSV at the medial malleolus

Answer 39

Cut down can occur (veins collapsed due to shock, but you know there is a vein at the medial malleolus)....Shocked patient, ATLS 2cm lateral and proximal to medial malleolus now the interosseous administratin of fluid can occur

Question 40

What would result from arterial emboism

Answer 40

Sudden occlusion Acute ischaemia Intermittent claudication (muscle pain commonly in calf during activity, associated with arterial disease)

Question 41

What is compartment syndrome

Answer 41

The neuromuscular compartments of the limbs are enclosed in fibrous sheaths which confines them.

Question 42

Differentiate acute compartment syndrome and chronic compartment syndrome

Answer 42

Acute compartment syndrome (trauma associated) | Chronic compartment syndrome (exercise-induced)

Question 43

What compartments of the leg are affected by compartment sydrome

Answer 43

Commonly the anterior, posterior and lateral compartments of the leg

Question 44

What happens in compartment syndrme

Answer 44

Ischaemia caused by trauma-induced increased pressure in a confined limb compartment Normal pressure = 25mmHg; only need 50-60 to collapse vessels, so pulse still present

Question 45

How can acute compartment syndrome be resolved

Answer 45

Emergency fasciotomy required to prevent the death of muscles in the affected compartment.

Question 46

When can varicose veins result

Answer 46

Perforating veins connecting superficial and deep veins contain a valve that will allow flow only from superficial to deep. If such a valve is compromised, blood is pushed from deep to superficial veins leading to varicose veins.

Question 47

In which veins are valves present

Answer 47

Valves in superficial, deep and perforating veins

Question 48

Which valve in the lower limb venous system is important in varicose veins

Answer 48

Sapheno-femoral junction valve most important

Question 49

What is lipodermatosclerosis

Answer 49

Skin thickening, of a chronic inflammatory cause in varicose vein

Question 50

What can be a conequence of varicose veins

Answer 50

Venous ulcers Venous leg ulcers can develop after a minor injury, where persistently high pressure in the veins of the legs has damaged the skin.

Question 51

Deep veins follow what

Answer 51

The arterial supply

Question 52

What is a DVT

Answer 52

Deep venous thrombosis Clot in deep veins Proximal or distal

Question 53

What is post-phlebitic syndrom

Answer 53

Damage to veins of the leg during DVT valve dysfunction Reduced blood being carred out of the foot and leg Pain swelling and ulcers

Question 54

What is superficial thombophlebitis

Answer 54

an inflamed vein near the surface of the skin (usually a varicose vein) caused by a blood clot.

Question 55

Outline venous grafts

Answer 55

CABG... arterial by-pass surgery Vales only allow flow in one direction so graft must be oriented in the correct direction

Question 56

How does venous return usually occur from the calf

Answer 56

Deep vessels in the leg are sandwiched between muscle layers, during waling and running the contractions squueze the thin walled veins and push blood up the calves= the calf pump

Question 57

Outline the use of the surgical stockings

Answer 57

Immobility (e.g. a long plane journey) means less efficient venous return from the foot and leg. Sluggish deep venous return can lead to Deep Vein Thrombosis (DVT). Elastic surgical socks compress the superficial veins promoting more vigorous deep venous return.