Spinal Nerves, Lymph and Blood supply of the Lower Limb

Question 1

Where do the nerves come out in the Cervical Spine, and how many afferent nerves leave the cervical spine?

Answer 1

• The nerves come from above the vertebra

- Goes from C1-8; 8 is above T1

Question 2

What plexus comes out of the Cervical Spine?

Answer 2

The Brachial Plexus (Upper Limb Region)

Question 3

Where do the nerves come out of the Thoracic spine, and how many leave the Thoracic spine?

Answer 3

• The nerves come from below of the vertebra

- Goes from T1-12

Question 4

Where do the nerves come out of the Lumbar Spine, and how many leave the Lumbar Spine?

Answer 4

• The nerves come from below of the vertebra

- Goes from L1-5

Question 5

Where do the nerves come out of the Sacral Spine, and how many leave the Sacral Spine?

Answer 5

• The nerves come out through the sacral formina
• Goes from S1-5
• • Their is an nerve coming from the coccyx called the Coccygeal nerve *

Question 6

The spinal cord doesn’t grow with age as fast as bony and soft tissue, in an adult where does the spinal cord end?

Answer 6

In the area of T12 and L1

Question 7

From the spinal cord ending at T12-L1 area in adults, peripheral nerves still grow beyond this point. What are the peripheral nerves called which are beyond the spinal cord?

Answer 7

Cordae Equina

Question 8

What is the main differences between afferent and efferent nerves?

Answer 8

Afferent nerves (Sensory) - these nerves are sending signals from the body, such as skin and muscles, to the brain; eg the skin sensing that is it cold
Efferent nerves (Motor) - these nerves are sending signals from the brain to the body; eg the CNS sends signals to trigger Goosebumps in the skin to warm up

Question 9

What are the physical characteristics of nerves in the vertebral foramen Name 4-6 features

Answer 9

• Spinal Cord
• Ventral Root (Anteriorly, and sends efferent messages)
• Dorsal Root (Posteriorly, and sends afferent messages)
• Mixed Spinal Nerve
• Ventral Ramus
• Dorsal Ramus

Question 10

How do the ventral and dorsal rami pass around the thoracic cavity?

Answer 10

Ventral Nerves (Efferent) - Passes all the way round the inside of the thoracic region, called the intercostal nerve, will reach around towards the sternum.
Dorsal Nerves (Afferent) - Reaches to the skin and muscle, anterior the rib, and enter to the vertebral region through the posterior.

Question 11

What is the definition of Dermatomes?

Answer 11

Patches of skin where the nerves from the spine are activated in a particular area

Question 12

What is the definition of Myotomes?

Answer 12

Segmented muscles for each spinal cord level; a single cord will NOT cover a singular muscle

Question 13

What is the definition of Sclerotomes?

Answer 13

Segmented bony region for each spinal level; not the most accurate technique but can suggest why a nerve pressed sometimes in bones

Question 14

What is the thick membrane that protects the CNS when it leaves the intervertebral foramen?

Answer 14

Dura Mater

Question 15

What are 3 common injuries which involved with the mixed spinal nerves and how they cause injury?

Answer 15

• Intervertebral joints are prone to arthritis, especially lumbar spine; the inflammation can manipulate the joint to push and pressure the nerve.
• Osteophytes can grow into a mixed spinal nerves due to arthritis
• The intervertebral discs being herniated, which is the nucleus if the disc breaks through the damaged membrane, annulus, and can press on the nerve.

Question 16

What is the function of the ANS (Autonomic Nervous System)?

Answer 16

To regulate natural body processes autonomously

Question 17

What are the functions of the two parts of the ANS?

Answer 17

Sympathetic - For emergency situations

Parasympathetic - Conserving natural bodily functions

Question 18

What is unique about the sympathetic nervous system?

Answer 18

It has its own ‘spinal cord’ which is contains preganglionic axons which are in the vicinity of the vertebral column; anterior to body of the vertebrae.
*They originate in transverse processes of the thoracic and travel down to the first 2/3 lumbar vertebras

Question 19

What 3 specific nerves come from the 1st lumbar vertebra?

Answer 19

• Iliohypogastric
• Ilio-inguinal
• Genitofemoral

Question 20

What 6 specific nerves come from the 2nd lumbar vertebra?

Answer 20

• Lateral Cutaneous of the Thigh
• Femoral
• Iliopsoas
• Accessory obturator
• Obturator
• Genitofemoral

Question 21

What 5 specific nerves come from the 3rd lumbar vertebra?

Answer 21

• Lateral Cutaneous of the Thigh
• Femoral
• Iliopsoas
• Accessory Obturator
• Obturator

Question 22

What 5 specific nerves come from the 4th lumbar vertebra?

Answer 22

• Femoral
• Iliopsoas
• Accessory Obturator
• Obturator
• Lumbosacral

Question 23

What specific nerve, primarily, come from the 5th lumbar vertebra?

Answer 23

Lumbosacral Trunk

Question 24

What 5 specific nerves come from the 1st sacral vertebra?

Answer 24

• Sciatic Nerve
• Inferior Gluteal
• Superior Gluteal
• Obturator Internus
• Gemelli

Question 25

What 8 specific nerves come from the 2nd sacral vertebra?

Answer 25

- Sciatic Nerve - Piriformis - Inferior gluteal - Visceral Branch - Obturator Internus - Gemelli - Pudenal - Posterior Femoral Cutaneous Nerve

Question 26

What 6 specific nerves come from the 3rd sacral vertebra?

Answer 26

- Obturator Internus - Gemelli - Posterior Femoral Cutaneous Nerve - Cutaneous Nerves - Pudenal - Pelvic Splanchnic nerve (Bladder)

Question 27

What 3 specific nerves come from the 4th sacral vertebra?

Answer 27

- Pelvic Splanchnic nerve - Pudenal - Levator ani nerve

Question 28

What is the specific nerves from the 5th sacral vertebra and coccygeal?

Answer 28

Anococcygeal nerve

Question 29

What are the nervous routes of the major anterior nerves?

Answer 29

Femoral Nerve: Arises from underneath the psoas major and inguinal ligament to the anterior shaft of the femur Obturator Nerve: Arises from the Lumbar plexus posteriorly. through the obturator foramen and travels along the medial side of the femur.

Question 30

What does the femoral nerve supply?

Answer 30

All the quadriceps

Question 31

What does the obturator nerve supply?

Answer 31

All the adductors *Half of adductor magnus*

Question 32

What is the Saphenous nerve, and what does it supply?

Answer 32

It is apart of the femoral nerve and extends below the knee, down to the medial side of the ankle; it is a cutaneous nerve and doesn't supply any muscles

Question 33

What does the sciatic nerve supply?

Answer 33

All the hamstrings *and half of adductor magnus*

Question 34

Where does the sciatic nerve come from?

Answer 34

The 2nd sacral vertebra and passes underneath the piriformis through the Greater Sciatic Notch, then travels inferiorly and becomes the Common Peroneal nerve.

Question 35

What happens with Common Peroneal nerve once it reaches the knee?

Answer 35

The Common Peroneal nerve splits at the popliteal fossa

Question 36

What does the popliteal fossa split the Common Peroneal nerve into?

Answer 36

- Sural Nerve (Cutaneous) - Tibial Nerve - Deep Peroneal - Superficial Peroneal

Question 37

What does the tibial nerve supply?

Answer 37

It supplies: - Soleus - Tibialis Posterior - Flexor Hallucis Longus - Flexor Digitorum Longus

Question 38

What does the Common Peroneal supply?

Answer 38

Supports both gastrocnemius' heads

Question 39

The tibial nerve splits into two more nerves, what are they and what do they supply?

Answer 39

Medial Plantar Nerve: Supplies the Adductor Hallucis, Flexor Digitorum Brevis and Flexor Hallucis Brevis Lateral Platnar Nerve: Supplies the Adductor digiti minimi, Flexor digiti minimi, Adductor Hallucis and interossei

Question 40

What are the nervous routes of the Superficial Peroneal Nerve, and what does it supply?

Answer 40

It passes laterally, inferiorly to the dorsum of the foot; around the cuneiforms. It supplies the Peroneus Longus and Peroneus Brevis.

Question 41

What are the nervous routes of the Deep Peroneal Nerve, and what does it supply?

Answer 41

It passes anteriorly to the dorsum of the foot around the 1st and 2nd metatarsal. It supplies the Tibialis Anterior, Extensor Digitorum Longus, Extensor Hallucis Longus and Extensor Digitorum Brevis

Question 42

How does the blood supply reach the lower limb?

Answer 42

- Begins in the left ventricle where its pumped through the aorta - Travels inferiorly through the abdominal artery, more posteriorly, and splits left and right. - Also splits the artery into the internal iliac artery, that supplies the pelvic contents, and the external iliac arteries which goes to the limbs

Question 43

What happens the External Iliac Artery to supply the lower limb?

Answer 43

- It passes underneath the inguinal ligament and forms the femoral artery, it lies in the adductor canal; *Deep to the sartorius and against adductor magnus*

Question 44

As the Femoral artery, what is the route which it takes down to the foot?

Answer 44

- Passes inferiorly down the leg, moving posteriorly to the popliteal fossa; becoming the popliteal artery - Moves down the shaft of the tibia where it splits into the anterior (ATA) and posterior tibial artery (PTA) - The ATA travels inferiorly and runs down the interosseous membrane to the front of the ankle joint passing between the tendons of the Tibialis Anterior and EDB. - The PTA travels in the middle of the lower limb, passing the medial malleolus and underneath the sustentaculum tali to the plantar of the foot.

Question 45

Vein routes, what are significant about deep and superficial veins?

Answer 45

- Deep Veins --> Follow paths of arteries | - Superficial Veins --> DON'T

Question 46

What are the two main superficial veins in the lower limb?

Answer 46

- Long Saphenous | - Short Saphenous

Question 47

What is the route of the Long Saphenous vein?

Answer 47

- Originates on the venule dorsal arch of the foot - Travels in front of the medial malleolus - Superiorly and medially travels up the leg, behind the knee - Continues to travel medially upto the Deep Femoral Vein which where the venous blood is drained

Question 48

What is the route of the Short Saphenous vein?

Answer 48

- Originates on the venule dorsal arch - Travels posteriorly around the fibula malleolus - Rises superiorly to just blow the knee joint where venous blood drains into the Deep Popliteal Vein

Question 49

Where are the lymphatic channels running?

Answer 49

- The lymph capillaries intertwine with the blood capillaries in the interstitial fluid - In the lower limb, the lymphatic route mimic the two saphenous veins

Question 50

Where are the two main locations of lymph nodes in the lower limb, and what are the function of lymph nodes?

Answer 50

The function of lymph nodes are filtering systems which brake down unwanted cells in the lymphatic fluid. The main locations in the lower limb are: - Popliteal Fossa (Short Saphenous) - Inguinal Region (Long Saphenous)