Nerves and vessels of the lower limb Flashcards
How many sacral nerves are there?
5
How many coccygeal nerves are there?
1
Which spinal nerves supply each of the following: Neck Upper Limb Trunk Lower Limb Perineum
Neck: C1-C4 Upper Limb: C5-T1 Trunk: T2-L1 Lower Limb: L2-S3 Perineum: S2-C1
Which muscles does the superior gluteal nerve innervate?
Gluteus medius
Gluteus minimus
Tensor fasciae latae
The femoral nerve innervates all the muscles in the anterior compartment of the thigh. Which extra spinal root contributes to the innervation of iliopsoas?
L1
Which nerve roots are responsible for: Inversion Eversion Toe Extension Toe Flexion
Inversion: L4
Eversion: L5S1
Toe Extension: L5S1
Toe Flexion: S12
What nerve supplies sensory innervation to most of the posterior of the thigh?
Posterior cutaneous nerve of the thigh
Which two spinal nerve roots are responsible for sensory innervation of most of the posterior side of the lower limb?
S1 and S2
What are autonomous sensory zones?
Regions where you can be confident of the spinal root affected if there is any abnormal sensation in those regions
Which part of the lower limb does the obturator nerve supply sensory innervation to?
Inner part of the thigh
Which part of the leg does the saphenous nerve provide sensory innervation to?
Medial part of the leg
Which nerve provides sensory innervation to most of the dorsum of the foot?
Superficial peroneal nerve
Where can the common peroneal nerve be damaged easily?
At the neck of the fibula
What are the consequences of damage to the common peroneal nerve?
Foot drop
Loss of sensation to the dorsum of the foot at least
No change in reflexes or autonomic function
Describe the position of the posterior tibial artery relative to the medial malleolus.
It is posterior to the medial malleolus
Where can the dorsalis pedis pulse be felt?
Just lateral to the extensor hallucis longus tendon
Where can the posterior tibial artery pulse be felt?
Just posterior to the medial malleolus
What is cut-down and when it is performed?
It is an emergency procedure to gain access to the veins of a patient in shock
Where is the incision made in cut-down?
2 cm lateral and proximal to the medial malleolus
What is intermittent claudication?
Muscle pain induced by exercise and relieved by rest, that is caused by inadequate blood supply to the affected muscles (associated with arterial disease)
What is compartment syndrome?
Ischaemia caused by trauma-induced increased in pressure in a confined limb compartment
What is the normal pressure in muscle compartments?
25 mm Hg
What pressure is required to collapse vessels?
50-60 mm Hg
What are the causes of acute and chronic compartment syndrome?
Acute – trauma-associated
Chronic – exercise-induced
What is the treatment of acute compartment syndrome?
Emergency fasciotomy
How do varicose veins form?
Valve dysfunction in the superficial, deep and perforating veins
Saphenofemoral junction valve is the most important
NOTE: can cause lipodermatosclerosis and ulcers
Divisions of lumbosacral plexus
Either anterior or posterior
Note: Posterior divisions tend to supply anterior compartments due to how leg pronates during embryology
Supply of femoral nerve
Anterior thigh compartment
Supply of obturator nerve
Medial adductor compartment of thigh
Supply of sciatic nerve
Posterior thigh
All of leg and foot
Branches of sciatic nerve
Tibial and common peroneal
Significance of piriform muscle with regards to vessels
Anything above is superior gluteal and anything below is inferior gluteal
Where does sciatic nerve branch
Just superior to knee condyles on posterior side
Route of common peroneal nerve
Wraps laterally around fibula to anterior side just below knee
Route of tibial nerve
Descends down posterior side of tibia
Division of tibial nerve
At foot becomes medial and lateral plantar nerve
5 lower limb nerves
Femoral Obturator Sciatic Superior gluteal Inferior gluteal
Spinal nerves of femoral nerve
L234 posterior fibres
Spinal nerves of obturator nerve
L234 anterior fibres
Spinal nerves of sciatic nerve
L3 4 5 and S123
Anterior and posterior fibres
Spinal nerves of sup gluteal
L4 and 5
S1
Spinal nerves of inf gluteal
L5 S12
Supply of superior gluteal nerve
Gluteus medius and minimus
Tensor fascia lata
Supply of inferior gluteal nerve
Gluteus maximus
Supply of sciatic nerve
Posterior thigh
Leg and foot
Principles of segmental supplies
Muscles supplied by 2 adjacent segments
Any same action on joint supplied by same nerve supply
Opposing muscles 1-2 segments above or below
The more distal in the limb the more caudal the cell body in spine
Signs of prolapsed disc L5/S1
Motor loss of eversion
Sensory loss of outer foot
Loss of ankle jerk
Overall blood supply to leg
External iliac
Femoral
Popliteal
Trifurcation to anterior and posterior tibial and peroneal
Route of femoral artery
Run down anterior compartment of thigh and to the posterior of knee through hiatus of adductor Magnus
Point at which femoral becomes popliteal
After passing posteriorly through hiatus of adductor Magnus
What does anterior tibial artery become
Dorsalis pedis artery just softer crossing artery
What forms greatsaphenous vein
Dorsal venous arches of foot just anterior and superior to medial malleolus
Where does saphenous vein join femoral vein
After passing through saphenous opening
Main superficial veins of leg
Small saphenous and great saphenous
Importance of perforating veins in leg
Contain valve allowing blood flow from superficial veins
Important thing regarding venous grafts
Valves only allow flow in one direction so when done must be orietated properly
