Spinal Nerves, Lymph and Blood supply of the Lower Limb Flashcards
Where do the nerves come out in the Cervical Spine, and how many afferent nerves leave the cervical spine?
- The nerves come from above the vertebra
- Goes from C1-8; 8 is above T1
What plexus comes out of the Cervical Spine?
The Brachial Plexus (Upper Limb Region)
Where do the nerves come out of the Thoracic spine, and how many leave the Thoracic spine?
- The nerves come from below of the vertebra
- Goes from T1-12
Where do the nerves come out of the Lumbar Spine, and how many leave the Lumbar Spine?
- The nerves come from below of the vertebra
- Goes from L1-5
Where do the nerves come out of the Sacral Spine, and how many leave the Sacral Spine?
- The nerves come out through the sacral formina
- Goes from S1-5
- Their is an nerve coming from the coccyx called the Coccygeal nerve *
The spinal cord doesn’t grow with age as fast as bony and soft tissue, in an adult where does the spinal cord end?
In the area of T12 and L1
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?
Cordae Equina
What is the main differences between afferent and efferent nerves?
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
What are the physical characteristics of nerves in the vertebral foramen Name 4-6 features
- Spinal Cord
- Ventral Root (Anteriorly, and sends efferent messages)
- Dorsal Root (Posteriorly, and sends afferent messages)
- Mixed Spinal Nerve
- Ventral Ramus
- Dorsal Ramus
How do the ventral and dorsal rami pass around the thoracic cavity?
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.
What is the definition of Dermatomes?
Patches of skin where the nerves from the spine are activated in a particular area
What is the definition of Myotomes?
Segmented muscles for each spinal cord level; a single cord will NOT cover a singular muscle
What is the definition of Sclerotomes?
Segmented bony region for each spinal level; not the most accurate technique but can suggest why a nerve pressed sometimes in bones
What is the thick membrane that protects the CNS when it leaves the intervertebral foramen?
Dura Mater
What are 3 common injuries which involved with the mixed spinal nerves and how they cause injury?
- 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.
What is the function of the ANS (Autonomic Nervous System)?
To regulate natural body processes autonomously
What are the functions of the two parts of the ANS?
Sympathetic - For emergency situations
Parasympathetic - Conserving natural bodily functions
What is unique about the sympathetic nervous system?
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
What 3 specific nerves come from the 1st lumbar vertebra?
- Iliohypogastric
- Ilio-inguinal
- Genitofemoral
What 6 specific nerves come from the 2nd lumbar vertebra?
- Lateral Cutaneous of the Thigh
- Femoral
- Iliopsoas
- Accessory obturator
- Obturator
- Genitofemoral
What 5 specific nerves come from the 3rd lumbar vertebra?
- Lateral Cutaneous of the Thigh
- Femoral
- Iliopsoas
- Accessory Obturator
- Obturator
What 5 specific nerves come from the 4th lumbar vertebra?
- Femoral
- Iliopsoas
- Accessory Obturator
- Obturator
- Lumbosacral
What specific nerve, primarily, come from the 5th lumbar vertebra?
Lumbosacral Trunk
What 5 specific nerves come from the 1st sacral vertebra?
- Sciatic Nerve
- Inferior Gluteal
- Superior Gluteal
- Obturator Internus
- Gemelli
What 8 specific nerves come from the 2nd sacral vertebra?
- Sciatic Nerve
- Piriformis
- Inferior gluteal
- Visceral Branch
- Obturator Internus
- Gemelli
- Pudenal
- Posterior Femoral Cutaneous Nerve
What 6 specific nerves come from the 3rd sacral vertebra?
- Obturator Internus
- Gemelli
- Posterior Femoral Cutaneous Nerve
- Cutaneous Nerves
- Pudenal
- Pelvic Splanchnic nerve (Bladder)
What 3 specific nerves come from the 4th sacral vertebra?
- Pelvic Splanchnic nerve
- Pudenal
- Levator ani nerve
What is the specific nerves from the 5th sacral vertebra and coccygeal?
Anococcygeal nerve
What are the nervous routes of the major anterior nerves?
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.
What does the femoral nerve supply?
All the quadriceps
What does the obturator nerve supply?
All the adductors Half of adductor magnus
What is the Saphenous nerve, and what does it supply?
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
What does the sciatic nerve supply?
All the hamstrings and half of adductor magnus
Where does the sciatic nerve come from?
The 2nd sacral vertebra and passes underneath the piriformis through the Greater Sciatic Notch, then travels inferiorly and becomes the Common Peroneal nerve.
What happens with Common Peroneal nerve once it reaches the knee?
The Common Peroneal nerve splits at the popliteal fossa
What does the popliteal fossa split the Common Peroneal nerve into?
- Sural Nerve (Cutaneous)
- Tibial Nerve
- Deep Peroneal
- Superficial Peroneal
What does the tibial nerve supply?
It supplies:
- Soleus
- Tibialis Posterior
- Flexor Hallucis Longus
- Flexor Digitorum Longus
What does the Common Peroneal supply?
Supports both gastrocnemius’ heads
The tibial nerve splits into two more nerves, what are they and what do they supply?
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
What are the nervous routes of the Superficial Peroneal Nerve, and what does it supply?
It passes laterally, inferiorly to the dorsum of the foot; around the cuneiforms.
It supplies the Peroneus Longus and Peroneus Brevis.
What are the nervous routes of the Deep Peroneal Nerve, and what does it supply?
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
How does the blood supply reach the lower limb?
- 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
What happens the External Iliac Artery to supply the lower limb?
- 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
As the Femoral artery, what is the route which it takes down to the foot?
- 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.
Vein routes, what are significant about deep and superficial veins?
- Deep Veins –> Follow paths of arteries
- Superficial Veins –> DON’T
What are the two main superficial veins in the lower limb?
- Long Saphenous
- Short Saphenous
What is the route of the Long Saphenous vein?
- 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
What is the route of the Short Saphenous vein?
- 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
Where are the lymphatic channels running?
- The lymph capillaries intertwine with the blood capillaries in the interstitial fluid
- In the lower limb, the lymphatic route mimic the two saphenous veins
Where are the two main locations of lymph nodes in the lower limb, and what are the function of lymph nodes?
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)
