Lumbosacral Plexus

Question 1

Name all the nerves in the sacral trunk

Answer 1

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.

Question 2

Lumbar plexus

Answer 2

VENTRAL PRIMARY RAMI!

T12-L4/L5

carry autonomics (sympathetic/parasympathetic)

Question 3

L4/L5 of lumbar plexus

Answer 3

form to contribute the first branch of the sacral plexus

Question 4

Subcostal n @

Answer 4

T12

Question 5

iliohypogastric n @

Answer 5

T12/L1

Question 6

Ilioinguinal n. @

Answer 6

L1

Question 7

Lumbosarcal trunk

Answer 7

L4/L5

Question 8

Femoral n. (posterior divisions)

Answer 8

L2, L3, L4

Question 9

Obturator n (antieror divisions)

Answer 9

L2/L3/L4

Question 10

most branches of lumbar plexus are associated with what muscle?

Answer 10

psoas m.

Question 11

Lumbar plexus: name all the nerves

Answer 11

subcostal
iliohypogastric
ilioinguinal
genitofemoral
lateral femoral cutaneous 
femoral 
obturator 
lumbosacral trunk

Question 12

ANS

Answer 12

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

Question 13

SNS

Answer 13

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

Question 14

Greater splanchnic n.

Answer 14

T5-T9

Question 15

Lesser splanchnic n.

Answer 15

T10-T11

Question 16

Least splanchnic n.

Answer 16

T12-L2

Question 17

Lumbar splanchnic n.

Answer 17

L1-L2

Question 18

Sacral splanchnic n.

Answer 18

1, 2, 3rd sacral ganglia

Question 19

Pelvic splanchnic n.

Answer 19

S2-S4

Question 20

sympathetic plexuses =

Answer 20

collections of postganglionic axons

from spinal cord via sym. trunk

Question 21

parasympathetic plexuses =

Answer 21

collections of preganglionic axons

from cranial and caudal origins

Question 22

sym and para sym plexi interactions

Answer 22

they don’t.

Question 23

cardiac plexus: sym vs para sym

Answer 23

sym: increases heart rate/blood pressure
parasym: decreases heart rate

Question 24

Hypogastric plexus

Answer 24

innervates pelvic viscera, which is autonomic control of urinary and reproductive function

Question 25

Parasympathetic axons

Answer 25

preganglionic axon is myelinated and long, postganglionic is short and unmyelinated

Question 26

sympathetic axons

Answer 26

preganglionic is short, branched, and myelinated

postganglionic is long and unmyelinated

Question 27

mass action

Answer 27

a large number of ganglionic neurons activate many effector organs

Question 28

Sympathetic division:

how preganglionic axons travel,
where their neurons are housed

Answer 28

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

Question 29

Left/Right Sympathetic Trunks

Answer 29

one sympathetic ganglion is associated with each vertebra except in the cervical region where there is a superior, middle, and inferior ganglia