Lower-Limb: Innervation, Vasculature, & Osteology Flashcards
What is a plexus?
Which plexus is associated with the lower limbs?
A plexus is a network of interconnecting nerves or vessels. The lumbosacral plexus innervates the skin and muscles of the lower limb.

The Femoral nerve is derived from which spinal nerves?
L2, L3, & L4

The Obturator nerve is derived from which spinal nerves?
L2, L3, & L4

The Sciatic nerve is derived from which spinal nerves?
L4, L5, S1, S2, & S3

The Superior Gluteal nerve is derived from which spinal nerves?
L4, L5, & S1

The inferior Gluteal nerve is derived from which spinal nerves?
L5, S1, & S2
The Sciatic n. travels down to the posterior compartment of the thigh and divides into what (2) nerves?
- Tibial n.
- Continues down into the posterior compartment of the leg
- Common Fibular n.
- Further divides into;
- Superficial Tibular n.: innervates the Lateral compartment
- Deep Tibular n.: innervates the anterior compartment
- Further divides into;

The anterior region of the thigh & leg is innervated by which spinal nerves?
L1 - L5
The Posterior region of the Thigh & Leg is innervated by which spinal nerves?
S1 - S2
The Coccygeal region is innervated by which spinal nerves?
S3 - S5
Identify which letter represents L1-L5 & S1-S2

A. L1
B. L2
C. S2
D. S3
E. L3
F. L4
G. L5
H. S1
The Patellar Reflex tests which spinal nerve?
L4
The Achilles Tendon reflex test which spinal nerve?
S1
Describe the reflex pathway for the patellar reflex

Which letter represent the Medial Malleolus?

M: The Medial Malleolus
Which letters represents the Articular Surfaces of the Medial and Lateral Condyles?

B: Lateral Condyle Articular Surface
C: Medial Condyle Articular Surface
Which letters represents the Lateral and Medial Condyle of the Tibia?

A: Lateral Condyle
D: Medial Condyle
Which letter identifies the head of the Fibula?

F: Head of the Fibula
Which letter represents the Lateral Malleolus?

N: Lateral Malleolus of the Fibula
Which letter identifies the Popliteal/Soleal line?

I: Popliteal/Soleal Line
The letter A identifies what group of bones?

A: Distal Phalanx I-V; Middle Phalanx I-IV
The letter B identifies which group of bones?

B: Proximal Phalanx I-V
The letter C identifies which group of bones?

C: Metatarsals I-V
The letter D identifies what bone?

D: Medial Cuneiform
The letter E identifies which bone?

E: Intermediate Cuneiform
The letter H identifies which bone?

H: The Talus
The letter L identifies which bone?

L: Cuboid
The letter I identifies which bone?

I: Calcaneus
Describe the Interosseous Membrane.
What is it’s function?

The interosseous membrane is a strong, fibrous sheet that connects and fills the gap between the Tibia & Fibula, with the exception of the proximal and distal ends. The openings allow for the passage of vessels.
Its function is to stabilize the tibiofibular junction and serve as an attachment for several leg muscles.
What type of joint is the ankle?
What movements can occur here?
A. The ankle is a Mortise & Tenon Joint
B. Dorsiflexion, Plantar flexion, Inversion, & Eversion
What are the (4) compartments of the Leg?
- Anterior
- Lateral
- Posterior
- Superficial Posterior
- Deep Posterior

Which membrane separates the Anterior and Deep compartments of the Leg?
The Interossesous Membrane separates the Anterior & Deep compartments and connects the Tibia & Fibula.

Which separates the Anterior and Lateral compartments of the Leg?
The Anterior Crural Septum separates the Anterior and Lateral compartment

What separates the Lateral and Superficial compartments of the leg?
The Posterior Crural Septum separates the Lateral & Superficial compartments

What separates the Superficial & Deep compartments of the Leg?
The Intermuscular Septum separates the Superficial & Deep compartments of the leg

Which Nerve innervates the Anterior Compartment of the leg?
Which artery supplies the Anterior Compartment of the Leg?
The Deep Fibular (peroneal) n. innervates the anterior leg
The Anterior Tibial a. supplies the Anterior leg

What nerve innervates the Lateral Compartment of the Leg?
Which artery supplies the Lateral compartment of the leg?
The Superficial Fibular (peroneal) n. innevates the Lateral Compartment
There is no specific artery within the Lateral compartment; The fibular branch of the Posterior Tibial a. supplies the compartment.

Which nerve innervates the Posterior Compartment (both Superficial & Deep)?
Which artery supplies the Posterior Compartment of the leg?
The Tibial n. innervates the Posterior Compartment of the Leg

What are the (2) major superficial veins of the lower-limb?
Small/lesser Saphenous
Greater Saphenous
Describe the pathway of the Small Saphenous Vein
Origin: Lateral side of the Dorsal Venous Arch of the foot
Ascends: Behind Lateral malleolus along lateral side of tendo calcaneus. Crosses the latter to the middle of the back of the leg, piercing the deep fascia in the lower popliteal space
Termination: Popliteal vein between the heads of the Gastrocnemius muscle
Tributaries: veins from lateral foot & leg.

Describe the pathway of the Great Saphenous Vein
Origin: Dorsal Venous Arch of the foot
Ascends: In front of the Medial Melleolus along the medial side of the leg, posterior to the medial condyles of the tibia and femur, medial side of the thigh to the saphenous opening

How do the Superficial and Deep lymphatic vessels differ?
Superficial vessels:
- lie in the superficial fascia
- Drains either;
- Great Saphenous
- Foot & Leg joining;
- Vessels associated with the Lesser Saphenous
- Into the popliteal nodes
Deep:
- Accompanies blood vessels
Where does the Popliteal node lie?
Within the Popliteal Fossa

Where is the Superficial Inguinal (horizontal group) located?
What structures does it drain?
Inferior & Parallel to the inguinal ligament
Drains;
- Penis
- Scrotum
- Labia
- Perineum
- Buttock
- abdominal wall

Describe the purpose of the lymphatic system
Lymph is the filtrate of blood after passing through capillary beds. The Lymphatic system then transports the lymph which later drains into a specific duct.
Where do the Deep Inguinal Lymph nodes lie?
What structures does it drain?
Deep to the deep fascia along the medial side of the femoral vein
Deep lymphatics of the lower extremity and from superficial nodes

Identify the Lymph Nodes of the Lower-Limb
- Popliteal
- Superficial Inguinal;
- Horizontal Group
- Vertical Group
- Deep Inguinal
Where does the Superficial Inguinal (Vertical Group) lie?
What structures does it drain?
Along the terminal part of the Great Saphenous Vein
Drains vessels associated with the Great Saphenous Vein
The Superficial Gluteal muscles are innervated primarily by what nerve?
What is the exception?
The Superior Gluteal nerve (L5, S1) innervates the Superficial Gluteal muscles;
- Gluteus Medius
- Gluteus Minimus
- Tensor Fasciae Latae
The Gluteus Maximus is innervated by the Inferior Gluteal Nerve (L5, S1,2)
What is the blood supply of the Gluteal Region?
The Superior & Inferior Gluteal Arteries.

Which artery supplies the Posterior Leg?
The Posterior Tibial Artery supplies the Posterior Leg.
What nerve innervates every muscle of the Posterior Leg?
The Tibial Nerve innervates the Posterior Leg;
- Gastrocnemius
- Soleus
- Plantaris
- Popliteus
- Flexor Hallucis Longus
- Flexor Digitorum Longus
- Tibialis Posterior