topic 18 Flashcards
general term for nerves making the plexus lumbalis, and how many?
nn. lumbales: 7 lumbar vertebrae = 7 lumbar nerves
what are the function of the dorsal root
dont participate in the plexus,
Medial branch: Innervate muscles of the back
Lateral branch: Innervate the skin over the “rump” region
what are the ventral branches of the lumbar plexus
1 - Cranial iliohypogastric nerve 2 - Caudal iliohypogastric nerve 3 - Ilioinguinal nerve 4 - Genitofemoral nerve 5 - Lateral cutaneous femoral nerve 6 - Femoral nerve 7 - Obturator nerve
1-3 we can say these arent really part of the proper lumbar plexus, as they do not intermingle with the others. we can instead call them nerves of the abdominal wall
how do you locate the lumbar muscles
ventral - M. psoas minor: Shiny/tendinous
middle - M. iliopsoas: Lateral to psoas minor
dorsal - M. quadratus lumborum: extends laterally, nothing to do with the limb, Covered ventrally by m. psoas major
how do you find the first four nerves of the lumbar plexus
Cut along linea alba and costae ultimae(stop before vertebral column) and reflect. Pull liver and kidney down, wipe with Mr. Magic
First find the two vessels that mark two of the nerves:
(1) a. abdominalis cranialis – n. iliohypogastricus cranialis
(4) a./v. circumflexa ilium profunda – N. femoris cutaneus lateralis (L3-4)
(2) N. iliohypogastricus caudalis – caudal to the cranial one, parallell
(3) Caudal to n. iliohypo. caud. is the n. ilioinguinalis
how do you find femoral and obturator nerve, and what is their origin
L3-6: N. femoris - Cut through the psoas major muscle(biggest nerve of lumbar plexus)
L4-S1: N. obturatorius - Lying on the adductor muscle supf/med
how do you find genitofemoralis, and what is the origin
L3+4: n. genitofemoralis is small, runs through inguinal canal
found by root of plexus cranial to femoral nerve (and caudal to fem cut lat (on wall)
(Th13)
n. costoabdominalis
