Lumbosacral plexus Flashcards

Wilson

1
Q

Which anterior rami supply the Lumbosacral plexus?

A

Lumbar Plexus (L1-L4)

Sacral Plexus (L4-S4)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Limb buds develop from two myotomic groups.

What are they?

A

dorsal muscle mass

Ventral muscle mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Dorsal muscle mass of limb development give rise to which muscles?

A

Extensors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Ventral muscle mass give rise to which muscles?

A

Flexors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The mass of cells between the dorsal and ventral muscle mass is a precursor for?

A

Precursor for bones and tedons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Anterior division of the lumbar and sacral plexus procide innervation for?

A

Flexors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The posterior division of the lumbar and sacral plexi provide innervation for?

A

Extensors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The femoral n. receives ventral primary rami from which divisions?

A

Posterior divisions

It will supply extensor muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The obturator n. receive ventral primary rami from which divisions?

A

anterior divisions

It will supply flexor muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Common fibular n. receive ventral primary rami from which divisions?

A

Posterior divisions

It will supply extensors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Tibial n. receive ventral primary rami from which divisions?

A

anterior division

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the branches of the Lumbar plexus (L1-L4)?

A

Iliohypogastric n. (L1)

Ilioinguinal n. (L1)

genitofemoral n. (L1 and L2)

Lateral femoral cutaneous n. ( L2 and L3) - posterior division

Femoral nerve, which is mixed (L2, L3, and L4) - posterior division

Obturator n., which is mixed ( L2, L3, and L4) - anterior division

Lumbosacral trunk, to sacral plexus (L4 and L5)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the different about the lower limb rotation during fetal development compared to the upper limb

A

Lower limb rotates medially, whereas the upper limb rotate laterally

EXTENSORS - Anterior portion of lower limb

FLEXORS - posterior portion of lower limb

(THIS IS OPPOSITE COMPARED TO UPPER LIMB)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Posterior and anterior division of the lumbar plexus innervate which compartment of the thigh?

A

Posterior division - anterior compartment of thigh

Anterior division - medial compartment of thigh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Femoral n. innervates which compartment of the thigh?

A

Anterior compartment of the thigh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The obturator n. innervates which compartment of the thigh?

A

Medial compartment of the thigh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The posterior division of the sacral plexus come from which ventral primary rami?

A

L4-S2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The anterior divisions of the sacral plexus come from which ventral primary rami?

A

L4-S3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Superior gluteal n. recieves nerve branches from which ventral primary rami?

A

Posterior division of L4-S1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

The inferior gluteal n. recieves nerve fibers from which ventral primary rami?

A

Posterior division of L5-S2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The nerve to piriformis recieves nerve fibers from which ventral primary rami?

A

Posterior divison of S1 and S2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which two nerves come together to form the sciatic nerve?

A

Common fibular nerve (Posterior division L4-S2)

Tibial nerve (Anterior division L4-S3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

The nerve to obturator internus and superior gemellus recieves nerve fibers from which ventral primary rami?

A

Anterior division of L5 + S1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The nerve to quadratus femoris and inferior gemellu recieves nerve fibers from which ventral primary rami?

A

Anterior division of L4 + L5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the course of the sciatic nerve?

A

leaves the pelvis -> gluteal region via greater sciatic foramen -> emerges inferiorly to the piriformis muscle and descends in an inferolateral direction.

As the nerve moves through the gluteal region, it crosses the posterior surface of the superior gemellus, obturator internus, inferior gemellus and quadratus femoris muscles. It then enters the posterior thigh by passing deep to the long head of the biceps femoris.

Within the posterior thigh, the nerve gives rise to branches to the hamstring muscles and adductor magnus. When the sciatic nerve reaches the apex of the popliteal fossa, it terminates by bifurcating into the tibial and common fibular nerves.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Why is the piriformis an important landmark in the body?

A

The sciatic nerve emerges into the gluteal inferior to the piriformis

Damage/inflammation of the piriformis can cause Sciatica

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

The tibial division of the sciatic nerve innervates which part of the thigh?

A

Posterior compartment of the thigh

(Hamstrings)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the exception of the hamstring muscles and their nerve innervation?

A

All muscles of the hamstring are innervated by the tibial division of the sciatic nerve except the short head of biscep, which is innervated by the common fibular division of sciatic nerve.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

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

A

In the popliteal fossa

Tibial nerve goes straight down and the common fibular nerve curves laterally at the neck of the fibula to go to the anterior compartment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

The common fibular nerver goes anteriorly at the neck of the femur and spilts into two branches. What are they?

A

Deep fibular n.

Superficial fibular n.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

The deep fibular nerve innervates where?

A

The anterior compartment of the leg (Extensors)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

The superficial fibular nerve innervates where?

A

Lateral compartment of leg

(Fibularis longus and brevis)

After innervating these muscles it becomes a cutaneous nerve for the lateral side of the leg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

The tibial nerve innervates where?

A

Posterior compartment of the leg

34
Q

What does the tibial nerve cross before it terminates in the foot?

A

Medial malleolus

35
Q

What are the two terminal branches of the tibial nerve and what do they supply?

A

Medial Plantar nerve

Supplies medial compartment of the foot

Lateral plantar nerve

(supplies lateral, interosseus, and central compartment of foot)

36
Q

What is an exception to innervation of the central compartment of the foot?

A

The flexor digitorium brevis and the 1st lumbrical are innervated by the medial plantar nerves

37
Q

Map of cutaneous innervation of the Lower limb

A
38
Q

What does the femoral nerve become after crossing the knee medially?

A

The Saphenous nerve

39
Q

Decreased sensation in a single dermatome is caused by what?

A

Lesion of the dorsal root and/or the spinal nerve

40
Q

A lesion of a ventral or dorsal primary ramus results in what?

A

Decreased sensation restricted to a portion of a dermatome

(Notice in the image that only L3 ventral dermatome is red so there is a lesion in the Ventral primary rami at L3)

41
Q

Lesions proximal to a plexus produces what?

A

Sensory Loss in a single dermatome

Example damage to root L3 which cause loss of L3 dermatome

42
Q

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

A

This suggest lesion of a plexus of its branches

Example: damage to L2, L3, and L4 dermatome = Femoral nerve cutaneous branch is lesioned

43
Q

The main blood supply of the lower limb arises from where?

A

external Iliac artery

44
Q

When does hte external iliac artery become the femoral artery?

A

When it passes beneath the inguinal ligament

45
Q

What does the abdominal aorta terminarte as?

A

The abdominal aorta terminates as the common iliac which divides into the external and internal iliacsarteries

46
Q

What are the characterisitcs of the femoral artery?

A

1) bissects inguinal ligament
2) very superficial
3) lies anterior to femoral head

47
Q

Which artery can be compressed against femoral head to control hemorrhage?

A

Femoral a.

48
Q

What are the good locations for taking pulse in the lower limb?

A
  1. Femoral artery (also a place for catherization)
  2. Popliteal artery (deep palpation)
  3. Dorsalis pedis artery (its right under the skin)
  4. Tibialis posterior (ankle)

Pulse should be taken bilaterally

49
Q

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

A

Cathater in femoral vein will enter right side of heard.

Cathater in femoral artery will enter left side of the heart

50
Q

What is the path of the femoral artery?

A
51
Q

What is the major branch of the femoral artery?

A

Deep femoral artery

(comes off the posterior portion of the femoral artery and supplies anterior muscles)

52
Q

What are the branches of the deep femoral artery?

A

Medial femoral circumflex artery

latral femoral circumflex artery

Perforating arteries (1-4)

53
Q

Which arterires are the main blood supply to the head of the femur?

A

Medial and latral femoral circumflex arteries

54
Q

What is the cruciate anastomosis?

A

It is a important collateral routes if femoral artery is occluded

Located at he level of the lesser trochanter

55
Q

Visual of cruciate anastamosis

(Transverse vs vertical limb)

A
56
Q

What is the popliteal artery?

A

The popliteal artery is a continuation of the femoral after it traverses the adductor hiatus.

57
Q

The branches that anastamose around the knee come from which artery?

A

Popliteal artery

58
Q

When the popliteal artery terminates at the inferior border of the popliteus what does it give rise to?

A

Anterior tibial artery

Posterior tibial artery

59
Q

What is the course of the anterior tibial artery?

A

Pierces and runs anteriror on the interosseous membrane

(Anterior interosseous artery)

Then it terminates at the malleoili as the dorsalis pedis artery

60
Q

The anterior tibial artery supplies what?

A

Anterior compartement of the leg

61
Q

Dorsalis pedis artery is a continuation of which artery?

A

anterior tibial artery

62
Q

The posterior tibial artery supplies what?

A

The posterior compartement of the leg

63
Q

What is a major branch of the posterior tubial artery?

A

The fibular artery

This artery supplies the deep compartments of the posterior leg and often runs in the flexor hallucis longus

64
Q

What is the course of posterior tibial artery?

A

Runs inferiorly on the posterior leg and crosses the ankle posterior to the medial malleolus, between the tendons of flexor digitorium and hallucis longi. It then terminate in the sole of the foot.

65
Q

What is the tarsal tunnel?

A

It is a flexor retinaculum that protects the tibials posterior artery. It is bordered by the Flexor hallucis, tibialis anterior, and flexor digitorium longus (Tom, Dick, and Harry)

66
Q

Lateral plantar artery and medial plantar artery are terminal branches of which artery?

A

Posterior tibial artery

67
Q

What do the plantar arterires run between?

A

between the 1st two muscle layers of the foot

68
Q

A weak pulse on one side is an indication of what?

A

It is a sign of Peripheral arterial Disease (PAD) or obstruction

This can be caused by atherosclerosis

69
Q

What Excerxise-Induced Claudicaiton?

A

Build up of fatty substance in the wall of an artery that can lead to tissue ischemia distal to a vascular lesion.

This is intermitent

Can cause: Muscle weakness, pain (or tingling), and/or crampin may result, especially after exercise

70
Q

What is the organization of veins in the lower limb?

A

They are organized into three groups

Deep veins

Superficial veins

Perforating veins

71
Q

This type of vein runs with artries supplying the compartments. They share their names with arterirs.

A

Deep veins

72
Q

This type of vein runs beneath the skin without acoompanying artrires. They are important for thermal regulation.

A

Superficial veins

73
Q

What are the two major superficial veins of the lower limb?

A

Great Saphenous ( drains into femoral v.) - begins at the dorsum of the foot as an arch

Lesser Saphenous ( drains into popliteal v.) - originate posterior to lateral malleolus

74
Q

The greater saphenous veins runs with what?

A

The greater saphenous nerve

75
Q

The lesser saphenous vein runs with what?

A

Sural n.

76
Q

What is the purpose of perforating veins?

A

They connect superficial veins to deep veins (not the other way around)

They contain valves

77
Q

What give rise to the perforating veins?

A

The vena comitantes, these are veins that surround arteries. When the arterires expand it pushes the blood in the vein up towards the heart. The valves prevent back flow

78
Q

What are the mechanism to direct blood from the foot to the heart?

A

Mechanism 1: Veins have values which allow only one-way movement of blood towards the heart

Mechanism 2: The energy of the arterial pulse is transferred into the venae comitantes generating movement of blood.

Mechanism 3: Deep veins, such as the fibular vein, run with or in muscles. Contraction and relaxation of muscles squeezes the vein and pumps blood towards the heart (this occurs in venous calf pump)

Mechanism 4: Perforating veins shunt blood from the superficial veins towards the deep veins where blood can be pump back towards the heart.

79
Q

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

A
  1. Readiness for flight/fight
  2. Calf-pump
80
Q

What are varicose veins?

A

Diseased or damaged valves in the perforating veins allow blood to pool in the superficial veins

i.e. where there is no pumping