Lumbosacral Plexus Flashcards
Name all the nerves in the sacral trunk
Superior gluteal n. Inferior gluteal n. Nerve to periformis Common fibular n. Sciatic n (tibial branch) quadratus femoris/Inferior gemellus Obturator internus/superior gemellus Posterior femoral cutaneous n. perforating cutaneous n. pudendal n.
Lumbar plexus
VENTRAL PRIMARY RAMI!
T12-L4/L5
carry autonomics (sympathetic/parasympathetic)
L4/L5 of lumbar plexus
form to contribute the first branch of the sacral plexus
Subcostal n @
T12
iliohypogastric n @
T12/L1
Ilioinguinal n. @
L1
Lumbosarcal trunk
L4/L5
Femoral n. (posterior divisions)
L2, L3, L4
Obturator n (antieror divisions)
L2/L3/L4
most branches of lumbar plexus are associated with what muscle?
psoas m.
Lumbar plexus: name all the nerves
subcostal iliohypogastric ilioinguinal genitofemoral lateral femoral cutaneous femoral obturator lumbosacral trunk
ANS
invol. or uncon. control
two neuron pw
ganglial involved in pw
sensory input from general and visceral senses, motor output to cardiac, smooth muscle and gland
can exist or inhibit function using acetylcholine/norepinephrine
axons thin, some myelinated
SNS
voluntary or subconscious
no ganglia involved in pw
sensory input from and special sense, motor output to skeletal muscle
excites using acetylcholine
axons are thick and myelinated
Greater splanchnic n.
T5-T9
Lesser splanchnic n.
T10-T11
Least splanchnic n.
T12-L2
Lumbar splanchnic n.
L1-L2
Sacral splanchnic n.
1, 2, 3rd sacral ganglia
Pelvic splanchnic n.
S2-S4
sympathetic plexuses =
collections of postganglionic axons
from spinal cord via sym. trunk
parasympathetic plexuses =
collections of preganglionic axons
from cranial and caudal origins
sym and para sym plexi interactions
they don’t.
cardiac plexus: sym vs para sym
sym: increases heart rate/blood pressure
parasym: decreases heart rate
Hypogastric plexus
innervates pelvic viscera, which is autonomic control of urinary and reproductive function
Parasympathetic axons
preganglionic axon is myelinated and long, postganglionic is short and unmyelinated
sympathetic axons
preganglionic is short, branched, and myelinated
postganglionic is long and unmyelinated
mass action
a large number of ganglionic neurons activate many effector organs
Sympathetic division:
how preganglionic axons travel,
where their neurons are housed
neurons in the lateral horns of T1-L2
travel with somatic motor neurons to exit the spinal cord, and first enter the anterior root and then the T1-L2 spinal nerves
Left/Right Sympathetic Trunks
one sympathetic ganglion is associated with each vertebra except in the cervical region where there is a superior, middle, and inferior ganglia
