Lumbosacral Plexus and Blood to the Lower Limbs

Question 1

Lumbar plexus

Answer 1

L1-L4

Question 2

Limb muscles develop from which two myotomic cel groups? What do those two groups develop into?

Answer 2

Dorsal muscle mass (extensors)

Ventral muscle mass (flexors)

Question 3

Which nerve provides supplies cutaneous innervation to the lateral part of the thigh? Which fibers make up this nerve?

Answer 3

Lateral femoral nerve (L2-L3)

Question 4

Which nerve(s) delevop from the posterior diviision of the lumbar plexus?

Answer 4

lateral femoral cutaneous nerve

femoral nerve

Question 5

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

Answer 5

Femoral nerve

Question 6

This nerve provides motor innervation to the anterior muscle mass and arises from the anterior dicition of the lumbar plexus

Answer 6

Obturator nerve

Question 7

The posterior compartment of the thigh is innervated by the __________ nerve.

Answer 7

Sciatic

Question 8

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.

Answer 8

Posterior; anterior

Question 9

The femoral nerve enters the thigh by passing deep to the _____________ ligament entering the femoral triangle.

Answer 9

Inguinal

Question 10

The obturator nerve goes into the pelvis and travels through the obturator foramen to get to the _________ part of the thigh.

Answer 10

Medial

Question 11

What is the lumbosacral trunk?

Answer 11

It is a communication/contribution tot he sacral plexus from the lumbar plexus. It makes up part of L4 and all of L5.

Question 12

What nerves arise from the sacral plexus? What fibers contribute to these nerves?

Answer 12

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)

Question 13

The common fibular nerve comes off the ___________ division.

Answer 13

Posterior

Question 14

The tibial nerve comes off the ___________ division.

Answer 14

Anterior

Question 15

Do the two divisions of the sciatic nerve ever mix?

Answer 15

No they never mix, they remain separate

Question 16

Where does the sciatic nerve divide into the common fibular and tibial nerves?

Answer 16

in the popliteal fossa

Question 17

The ____________ nerve remains in the middle of the popliteal fossa and the ____________ nerve shifts laterally.

Answer 17

Tibial nerve; common fibular

Question 18

As the common fibular nerve crosses the neck of the fibula it becomes….

Answer 18

Deep fibular

Superficial fibular

Question 19

What compartements do the two divison of the common fibular nerve innervate?

Answer 19

Deep fibular nerve

• Innervates: Anterior compartment of the leg

Superficial fibular nerve

• Inenrvates: Lateral compartment of the leg

Question 20

The ___________ nerve innervates the posterior compartment of the leg.

Answer 20

Tibial nerve

Question 21

Does the tibial nerve run with the tibial artery?

Answer 21

Yes

Question 22

After crossing behing the _________, the tibial enrve terminates as which to nerves?

Answer 22

Medial malleolus

Medial plantar nerve; Lateral plantar nerve

Question 23

What compartment does the medial plantar nerve innervate?

Answer 23

The medial compartment of the foot

Question 24

What compartment does the lateral plantar nerve innervate?

Answer 24

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

Question 25

The anterior femoral nerve terminates as which nerve? What does this nerve innervate?

Answer 25

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.**

Question 26

What nerve does the posterior femoral nerve run with?

Answer 26

The sciatic nerve

Question 27

The obturator nerve terminates as the cutaneous branch to the skin over the __________ part.

Answer 27

medial

Question 28

Lession of the ________ results in decreased sensation in a **single** dermatome.

Answer 28

Dorsal root and/ or the spinal nerve

Question 29

A lesion of a ____________ results in decreased sensation in a **portion** of a dermatome.

Answer 29

Ventral or dorsal primary ramus

Question 30

What dermatome represents the inguinal ligament? What about the umbilicus?

Answer 30

L1 T10

Question 31

What does it mean if sensory loss involves 2 or more dermatomes?

Answer 31

Sensory changes involving 2 or more dermatomes suggest lesion of a plexus or its branches

Question 32

The main blood supply to the lower limb arises from the ___________ artery. What are the exceptions?

Answer 32

External iliac artery **Exceptions** include the superior and inferior gluteal arteries which arise from the internal iliac artery

Question 33

The external iliac becomes the _________ artery when it passes beneth the inguinal ligament.

Answer 33

Femor

Question 34

Is the femoral artery superficial or deep?

Answer 34

Very superficial

Question 35

Does the femoral artery lie anterior or posterior to the head of the femur?

Answer 35

Anterior

Question 36

What are special chararestics of the femoral artery?

Answer 36

* It is good location to take pulse and catheterization * Can be compressed against femoral head to control hemorrhage

Question 37

A catheter in the femoral artery or vein enters what side of the heart?

Answer 37

Femoral artery: Left Femoral vein: Right

Question 38

What is the course of the femoral artery?

Answer 38

1. Starst at the inguinal ligament 2. Crosses the femoral triangle 3. Runs deep to the sartorius within the adductor canal 4. Terminates at the adductor hiatus as the popliteal artery

Question 39

The _______ circumflex artery comes off the femoral artery, wheres the __________ circumflex femoral artery comes of the deep femoral artery.

Answer 39

Medial; lateral

Question 40

Main blood supply to the head of the femur

Answer 40

The medial and lateral femoral circumflex arteries

Question 41

Which artery is commonly fracture in hip fractures?

Answer 41

Medial circumflex femoral artery

Question 42

Why is anastomosis always found around joints?

Answer 42

You always find anastomosis around joints becuase when you bend a joint the blood flow can be cut off so yo need collateral routes

Question 43

Cruciate anastomosis is located at the level of the \_\_\_\_\_\_\_\_\_

Answer 43

Lesser trochanter

Question 44

What is cruciate anastomosis? What are it's components? What is it's clinical importance?

Answer 44

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.

Question 45

Where is anastomosis common?

Answer 45

Around joints and when an artery crosses a fossa

Question 46

The popliteal pulse can be used to diagnose what condition?

Answer 46

Arterial disese

Question 47

The popliteal artery terminates at the inferior border of the ___________ by dividing into which arteries?

Answer 47

Popliteus Anterior tibial artery; posterior tibial artery (**larger)**

Question 48

The anterior interosseous artery travels along side which nerve? What does it supply?

Answer 48

It traves along side the deep fibial enrve. it supplies tha anterior compartment of the leg

Question 49

The anterior tibial artery terminates at the \_\_\_\_\_\_\_\_, as what artery?

Answer 49

Malleoli; Dorsalis pedis artery

Question 50

The dorsalis pedis artery travels between which two muscles?

Answer 50

Extensor hallucis longus Externsor digitorum longus

Question 51

What compartment does the posterior tibial artery supply?

Answer 51

The posterior compartment of the leg

Question 52

What artery is a major branch of the posterior tibial artery? What does this artery supply? What muscle does this artery run in?

Answer 52

Fibular artery, which supplies the deep compartment of the posterior leg. It runs in the **flexor hallicus longus.**

Question 53

The posterior tibial artery terminates as....

Answer 53

Lateral plantar artery Medial plantar artery \***Both arteries run with their respective nerves**

Question 54

What are the four sites from which the pulse may be taken in the lower limb?

Answer 54

Femoral artery Popliteal artery Dorsalis pedis artery Posterior tibial artery

Question 55

What are 5 signs of arterial occlusion?

Answer 55

Pain Pallor Paralysis Paresthesia Pulselessness

Question 56

Intermittent Claudication

Answer 56

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.**

Question 57

Veins of the limbs are organized into what 3 groups?

Answer 57

Deep veins (un with artery of the same name) Superficial veins (don't run with arteries) Perforating veins

Question 58

Vena comitate

Answer 58

Pair of veins

Question 59

What is the course of the greater saphaneous vein?

Answer 59

1. Begins anterior to the medial malleoulus 2. Runs up the medial aspect of the leg 3. Terminates at the femoral triangle into the femoral artery

Question 60

Superficial veins are important to what?

Answer 60

Thermal regulation

Question 61

What is the course of the lesser saphaneous vein?

Answer 61

1. Negins posterior to the lateral malleolus 2. Runs almost down the middle of the calf through the heads of the gastocnemius 3. Terminates in the popliteal fossa

Question 62

What allows blood to go from superficial veins to deep veins but from deep veins to superficial veins?

Answer 62

Perforating veins

Question 63

What are the 4 mechanisms by which the body return blood from the big toe to the heart?

Answer 63

1. Veins have **valves** which allow only one-way movement of blood to the heart 2. The **energy of the arterial pulse** is transferred into the venae comitantes generating movement of blood. 3. **Venous calf pump.** 4. **Perforating veins** shunt blood from the superficial veins toward the deep veins where blood can be pumped back toward the heart.

Question 64

Why is the center of gravity anterior to the rotational axis of the ankles whih produces a tendency to sway forward?

Answer 64

1. Readiness for flight/ fight 2. Calf pump