Lumbosacral Plexus and Blood to the Lower Limbs Flashcards
Lumbar plexus
L1-L4
Limb muscles develop from which two myotomic cel groups? What do those two groups develop into?
Dorsal muscle mass (extensors)
Ventral muscle mass (flexors)
Which nerve provides supplies cutaneous innervation to the lateral part of the thigh? Which fibers make up this nerve?
Lateral femoral nerve (L2-L3)
Which nerve(s) delevop from the posterior diviision of the lumbar plexus?
lateral femoral cutaneous nerve
femoral nerve
This nerve provides motor innervation to the anterior part of the thigh as well as cutaneous branches that go to the skin that covers those muscles
Femoral nerve
This nerve provides motor innervation to the anterior muscle mass and arises from the anterior dicition of the lumbar plexus
Obturator nerve
The posterior compartment of the thigh is innervated by the __________ nerve.
Sciatic
The ___________ division of the lumbar plexus innervates the anterior compartment of the thigh and the ___________ division of the lumbar plexus innervates the medial compartment of the thigh.
Posterior; anterior
The femoral nerve enters the thigh by passing deep to the _____________ ligament entering the femoral triangle.
Inguinal
The obturator nerve goes into the pelvis and travels through the obturator foramen to get to the _________ part of the thigh.
Medial
What is the lumbosacral trunk?
It is a communication/contribution tot he sacral plexus from the lumbar plexus. It makes up part of L4 and all of L5.
What nerves arise from the sacral plexus? What fibers contribute to these nerves?
Posterior
Superior gluteal (L4, L5, S1)
Inferior gluteal (L5, S1, S2)
Nerve to piriformis (S1, S2)
Common fibular (L4, L5, S1, S2)
Anterior
Tibial nerve ((L4, L5, S1, S2, S3)
Nerve to obturator (L5)
Nerve to quadratus femoris (L4)
The common fibular nerve comes off the ___________ division.
Posterior
The tibial nerve comes off the ___________ division.
Anterior
Do the two divisions of the sciatic nerve ever mix?
No they never mix, they remain separate
Where does the sciatic nerve divide into the common fibular and tibial nerves?
in the popliteal fossa
The ____________ nerve remains in the middle of the popliteal fossa and the ____________ nerve shifts laterally.
Tibial nerve; common fibular
As the common fibular nerve crosses the neck of the fibula it becomes….
Deep fibular
Superficial fibular
What compartements do the two divison of the common fibular nerve innervate?
Deep fibular nerve
- Innervates: Anterior compartment of the leg
Superficial fibular nerve
- Inenrvates: Lateral compartment of the leg
The ___________ nerve innervates the posterior compartment of the leg.
Tibial nerve
Does the tibial nerve run with the tibial artery?
Yes
After crossing behing the _________, the tibial enrve terminates as which to nerves?
Medial malleolus
Medial plantar nerve; Lateral plantar nerve
What compartment does the medial plantar nerve innervate?
The medial compartment of the foot
What compartment does the lateral plantar nerve innervate?
Lateral, interosseous and central compartments of the foot
*In the central compartment, the flexor digitorum brevis and the 1st lumbrical are innervated by the medial plantar nerves
The anterior femoral nerve terminates as which nerve? What does this nerve innervate?
The anterial femoral nerve terminates as the saphenous nerve (cutaneous). The saphenous nerve supplies the medial part of the leg, both anterior and posterior parts of medial
*Note: At this stage, the saphenous nerve is barely sensory. It is called saphenous because it runs with the saphenous vein.
What nerve does the posterior femoral nerve run with?
The sciatic nerve
The obturator nerve terminates as the cutaneous branch to the skin over the __________ part.
medial
Lession of the ________ results in decreased sensation in a single dermatome.
Dorsal root and/ or the spinal nerve
A lesion of a ____________ results in decreased sensation in a portion of a dermatome.
Ventral or dorsal primary ramus
What dermatome represents the inguinal ligament? What about the umbilicus?
L1
T10
What does it mean if sensory loss involves 2 or more dermatomes?
Sensory changes involving 2 or more dermatomes suggest lesion of a plexus or its branches
The main blood supply to the lower limb arises from the ___________ artery. What are the exceptions?
External iliac artery
Exceptions include the superior and inferior gluteal arteries which arise from the internal iliac artery
The external iliac becomes the _________ artery when it passes beneth the inguinal ligament.
Femor
Is the femoral artery superficial or deep?
Very superficial
Does the femoral artery lie anterior or posterior to the head of the femur?
Anterior
What are special chararestics of the femoral artery?
- It is good location to take pulse and catheterization
- Can be compressed against femoral head to control hemorrhage
A catheter in the femoral artery or vein enters what side of the heart?
Femoral artery: Left
Femoral vein: Right
What is the course of the femoral artery?
- Starst at the inguinal ligament
- Crosses the femoral triangle
- Runs deep to the sartorius within the adductor canal
- Terminates at the adductor hiatus as the popliteal artery
The _______ circumflex artery comes off the femoral artery, wheres the __________ circumflex femoral artery comes of the deep femoral artery.
Medial; lateral
Main blood supply to the head of the femur
The medial and lateral femoral circumflex arteries
Which artery is commonly fracture in hip fractures?
Medial circumflex femoral artery
Why is anastomosis always found around joints?
You always find anastomosis around joints becuase when you bend a joint the blood flow can be cut off so yo need collateral routes
Cruciate anastomosis is located at the level of the _________
Lesser trochanter
What is cruciate anastomosis? What are it’s components? What is it’s clinical importance?
The cruciate anastomosis is a circulatory connection between blood vessels in the upper thigh of the the lateral and medial circumflex femoral arteries (tranverse limb) and the first perforating artery of the profunda femoris artery, and inferior gluteal artery ( vertical limb).
The cruciate anastomosis is clinically relevant because if there is a blockage between the femoral artery and external iliac artery, blood can reach the popliteal artery by means of the anastomosis.
Where is anastomosis common?
Around joints and when an artery crosses a fossa
The popliteal pulse can be used to diagnose what condition?
Arterial disese
The popliteal artery terminates at the inferior border of the ___________ by dividing into which arteries?
Popliteus
Anterior tibial artery; posterior tibial artery (larger)
The anterior interosseous artery travels along side which nerve? What does it supply?
It traves along side the deep fibial enrve. it supplies tha anterior compartment of the leg
The anterior tibial artery terminates at the ________, as what artery?
Malleoli; Dorsalis pedis artery
The dorsalis pedis artery travels between which two muscles?
Extensor hallucis longus
Externsor digitorum longus
What compartment does the posterior tibial artery supply?
The posterior compartment of the leg
What artery is a major branch of the posterior tibial artery? What does this artery supply? What muscle does this artery run in?
Fibular artery, which supplies the deep compartment of the posterior leg. It runs in the flexor hallicus longus.
The posterior tibial artery terminates as….
Lateral plantar artery
Medial plantar artery
*Both arteries run with their respective nerves
What are the four sites from which the pulse may be taken in the lower limb?
Femoral artery
Popliteal artery
Dorsalis pedis artery
Posterior tibial artery
What are 5 signs of arterial occlusion?
Pain
Pallor
Paralysis
Paresthesia
Pulselessness
Intermittent Claudication
Intermittent vascular claudication most often refers to cramping pains in the buttock or leg muscles, especially the calves. It is caused by poor circulation of the blood to the affected area, called peripheral arterial disease.
Veins of the limbs are organized into what 3 groups?
Deep veins (un with artery of the same name)
Superficial veins (don’t run with arteries)
Perforating veins
Vena comitate
Pair of veins
What is the course of the greater saphaneous vein?
- Begins anterior to the medial malleoulus
- Runs up the medial aspect of the leg
- Terminates at the femoral triangle into the femoral artery
Superficial veins are important to what?
Thermal regulation
What is the course of the lesser saphaneous vein?
- Negins posterior to the lateral malleolus
- Runs almost down the middle of the calf through the heads of the gastocnemius
- Terminates in the popliteal fossa
What allows blood to go from superficial veins to deep veins but from deep veins to superficial veins?
Perforating veins
What are the 4 mechanisms by which the body return blood from the big toe to the heart?
- Veins have valves which allow only one-way movement of blood to the heart
- The energy of the arterial pulse is transferred into the venae comitantes generating movement of blood.
- Venous calf pump.
- Perforating veins shunt blood from the superficial veins toward the deep veins where blood can be pumped back toward the heart.
Why is the center of gravity anterior to the rotational axis of the ankles whih produces a tendency to sway forward?
- Readiness for flight/ fight
- Calf pump
