Plexuses Flashcards
Means braid, a briad or intermingling of several spinal nerves
Plexus
A network of nerves supplying the UE (arm)
Brachial Plexus
Which ventral rami form brachial plexus
C5,6,7,8,T1 spinal nerves
RTDCB
Robert Taylor Drinks Cold Beer
Rami Trunks Divisions Cords Branches
Where are the rami that form the brachial plexus located?
Neck, superior to the clavicle
Distal to the rami trunks are formed..
Upper trunk is formed by
Middle trunk is formed by
Lower trunk is formed by
C5 and C6
C7
C8 and T1
Each trunk divides into two divisions, name them
Anterior and Posterior Divisions
What does the anterior division of brachial plexus supply?
What about the posterior division?
Flexor/Anterior compartment of the arm
Extensor/posterior compartment of the arm
Distal to the divisions, 3 cords are formed. Name them
Lateral Cord
Medial Cord
Posterior Cord
This cord is from the anterior division of the upper and middle trunks
Lateral Cord
This cord is from the anterior division of the lower trunk
Medial Cord
This cord is from the posterior divisions of all 3 trunks
Posterior Cord
The cords of the brachial plexus are related to the
Axillary Artery
The medial cord lies __ to the artery
The lateral cord lies ___ to the artery
The posterior cord lies ___ to the artery
Medial
Lateral
Posterior
Which nerves does the posterior cord form?
Axillary and Radial Nerve
Which nerves does the lateral cord form?
Musculocutaneous and median
Which nerves does the medial cord form?
Ulnar and median
The most laterally placed nerve on the M of the brachial plexus
The most medially placed nerve on the M of the brachial plexus
What runs down the middle?
Musculotcutaneous nerve
Ulnar Nerve
Median nerve
What muscles does the axillary nerve supply?
Deltoid and teres minor
What muscles does the radial nerve supply?
Posterior Arm and Posterior Forearm
The musculocutaneous nerve pierces the corachobrachialis and supplies what muscles?
Anterior muscles of the arm
The median nerve supplies which muscles?
Anterior forearm muscles
Lateral and Deep muscles of the hand
What muscles does the ulnar nerve supply?
Anterior muscles of the forearm
Medial muscles of the hand
Injury to the MC nerve would cause weakening of what actions?
Forearm Flexion and Supination
A fraction of the humerus typically leads to an injury to the radial nerve. What actions would weaken?
Wrist extension (Wrist Drop)
Extension of the forearm
Injury to the median nerve would weaken what actions?
Flexion of 2nd and 3rd fingers
Injury to the ulnar nerves weakens what actions?
Loss of hand muscles except thenar group
Which plexus supplies the lower limbs?
Lumbosacral plexus
Which spinal nerves does the lumbosacral plexus comprise?
L1-5, S1-4
What part of the body does the lumbar plexus formed from L1-L5 supply?
Anterior and Medial thigh
What muscle of the body does the lumbar plexus formed from L1-3 supply?
Psoas Major, before specific nerve is formed
What muscle and part of the body does the femoral nerve L2-4 supply?
Iliacus (hip)
Anterior Thigh
What part of the body does obturator nerve L2-4 supply?
Medial Thigh
Ventral rami of L2-4 unite to form two nerves
Femoral nerve and obturator nerve
NAVEL in the femoral triangle (lateral to medial)
Nerve artery vein
obturator nerve splits into two, femoral does not
!
Formation of the sacral plexus is by the lumbosacral trunk and ventral rami, which nerves do these correspond to?
Lumbosacral trunk - L4,5
Sacral Ventral Rami S1-4
Sciatic nerve is formed by lumbosacral trunk and which sacral nerves?
S1,2,3
The longest and thickest nerve in the body is
Sciatic nerve
What does the sciatic nerve supply?
Lower limb except anterior and medial thigh
What nerves does the sciatic nerve split off to make?
Common fibular nerve
tibial nerve
The larger component of the sciatic nerve, it supplies most of the hamstring and the posterior leg;
Tibial Nerve
What muscles of the leg does the tibial nerve supply?
The posterior muscles of the leg
Muscles of the foot
What does the tibial nerve divide into?
Medial and Lateral Plantar Nerve
The smaller, lateral division of the sciatic nerve and is superficial to the lateral compartment of the leg and divides into superficial and deep branches
Common Fibular Nerve
Branch of sacral plexus that supplies the gluteus medius and minimus, and tensor facia latae
Superior Gluteal Nerve
Branch of the sacral plexus that supplies the gluteus maximus
Inferior Gluteal Nerve
Branch of the sacral plexus that supplies the muscles and skin of the perineum (rea between thighs from coccyx to pubis)
Pudendal Nerve
Branches of the sacral plexus also supply lateral rotators of the thigh, which spinal nerves?
-piriformis, quadratus femoris, inferior/superior gamellae
L5,S1, S2
An injury to the femoral nerve would cause a loss of what action?
Leg extension (strong)
Injury to the obturator nerve would cause loss of what action?
Adduction of the thigh
Injury to the tibial nerve would cause the loss of what actions?
Plantar Flexion (strong), Inversion, Extension of thigh (weak)
Injury to the superficial fibular would cause the loss of what action?
Eversion
Injury to the deep fibular nerve would cause the loss of what action?
Dorsiflexion, inversion of the foot (weak)
A rupture of the annulus fibrosus allowing the protusion of the nucleus pulposus
Pushes on the nerve root exiting from the cord
Herniated Disc
Which region is herniated discs common?
Lumbar region sciatic nerve and its components are affected
-area subjected to weight bearing activity
Do all peripheral nerves(radial/tibial) carry both motor and sensory information?
Yes
