Lumbar Plexus & Inn of the Abdomen and Pelvis

Question 1

Lumbar Plexus

Answer 1

ventral primary rami
T12 to L4(L5) 
branches also carry sympathetic fibers
L4-L5 from the lumbar plexus becomes the 1st branch of the sacral plexus
most branches associated w/ the psoas mm

Question 2

Lumbar Plexus Components

Answer 2

Subcostal 
Iliohpogastric
Ilioinguinal 
Genitofemoral 
Lateral femoral cutaneous 
Obturator 
Femoral 
Lumbosacral trunk

Question 3

SNS

Answer 3

voluntary or subconscious control single neuron pathway
no ganglia involved in pathway
sensory input from general and special senses motor output to skeletal m
excites using acetylcholine
axons are thick and myelinated = fast conduction

Question 4

ANS

Answer 4

involuntary or unconscious control two neuron pathway
ganglia involved in pathway
sensory input from general and visceral senses motor output to cardiac, smooth m, and glands
can excite or inhibit function using acetylcholine and norepinephrine
axons are thin some are myelinated, other are not = slower conduction

Question 5

autonomic plexuses

Answer 5

collections of sympathetic postganglionic axons and parasympatheitc preganglionic axons, as well as some visceral sensory axons
sympathetic and parasympatheitc plesuses are colose to one another, but they do not interact or synapse with one another
provide a complex innervation pattern to their target organs

Question 6

cardiac plexus

Answer 6

increased sympathetic activity increases heart rate and blood pressure
increased parasympathetic activity decreases heart rate

Question 7

pulmonary plexus

Answer 7

parasympathetic pathway causes bronchoconstriction and increased secretion from mucous glands of the bronchial tree
sympathetic innervation causes bronchodilation

Question 8

esophageal plexus

Answer 8

parasympathetic axons control the swallowing reflex

Question 9

abdominal aortic plexus

Answer 9

consists of the celiac plexus, superior mesenteric plexus, and inferior mesenteric plexus = autonomic control of digestion

Question 10

hypogastric plexus

Answer 10

innervates pelvic visera = autonomic control of urinary and reproductive function

Question 11

dual innervation

Answer 11

many visceral effector (ORGANS) are innervated by postganglionic axons from both ANS divisions
actions of the divisions usually oppose each other
opposing effects are also achieved by increasing or decreasing activity in one division (one division can up regulate or down regulate the other)

Question 12

Parasympathetic Axons

Answer 12

long to Ach

short to Ach

Question 13

Sympathetic Axons

Answer 13

short to Ach

Long to Nor

Question 14

Sympathetics - Fight or Flight FXN of the ANS

Answer 14

may involve a single effector or many effectors
in mass activation, a large number of ganglionic neurons activate many effector organs
causes a heightened sense of alertness due to stimulation of the reticular activation system

Question 15

organization and anatomy of the sympathetic division

Answer 15

much more complex than the parasympathetic division both anatomically and functionally
sypathetic preganglionic neurons cell bodies are housed in the lateral horn of the T1-L2 regions of the spinal cord
preganglionic sympathetic axons travel with somatic motor neurons axons to exit the spinal cord and 1st enter the anterior roots and then the T1-L2 spinal nerves
preganglionic sympathetic axons remain with the spinal nerve fro a short distance before they branch off and leave the spinal nerve

Question 16

L and R sympathetic trunks

Answer 16

immediately anterior to the paired spinal nerves are the L and R sympathetic trunks
each is located immediately lateral to the vertebral column
a sympathetic trunk looks much like a string of beads
the string is composed of bundles of axons
the beads are the sympathetic trunk ganglia which house sympathetic ganglionic neuron cell bodies
once sypathetic trunk ganglion is approximately associated w/ each spinal n.
the cervical portion of each sympathetic trunk is partitioned into only three sympatheitc trunk ganglia, the superior, middle, and inferior cervical ganglia, as opposed to the 8 cervical spinal nerves

Question 17

white rami

Answer 17

connecting the spinal nerves to each sympathetic trunk are rami communicantes
they carry preganglionic sympathetic axons from the T1-L2 spinal nerves to the sympathetic trunk
they are associated only with the T1-L2 spinal nerves
preganglionic axons are mylinated - the white ramus has a whitish appearance
similar to enterance ramps on a highway

Question 18

grey rami

Answer 18

carry postganglionic sympathetic axons from the sympathetic trunk to the the spinal nerve
axons are unmylinated - gray rami have a grayish appearance
similar to exit ramps on a highway
connect to all spinal nerves including the cervical, sacral, and coccygeal spinal nerves
in this way sympathetic information that started out in the thoracolumbar region can be dispersed to all parts of the body

Question 19

sympathetic pathways

Answer 19

spinal n pathway
postganglionic sympathetic n pathway
the splanchinic n pathway
the adrenal medulla pathway

Question 20

splanchinic nerves

Answer 20

composed of preganglionic sympathetic axons
run anteriorly from the sympathetic trunk to most of the viscera
should not be confused w/ the pelvic splanchnic n associated with the parasympathetic divisions
terminate in prevertebral ganglia
called prevertebral because they are immediately anterior to the vertebral column on the anterolateral wall of the abdominal aorta
prevertebral ganglia typically cluster around the major abdominal a and are named for these arteries
sympathetic post ganglionic axons extend away from the ganglionic neurons cell bodies in these ganglia and innervate many of the abdominal organs

Question 21

Larger splanchinc nerves

Answer 21

greater thoracic splanchnic n
lesser thoracic splanchnic n
least thoracic splanchnic n 
lumbar splanchnic n 
sacral splanchnic n

Question 22

prevertebral ganglia

Answer 22

differ from the sympathetic trunk ganglia
are single structures rather than paired
are anterior to the vertebral column on the anterior surface of the aorta
located only in the abdominopelvic cavity
prevertebral ganglia include the celiac, superior mesenteric, and inferior mesenteric ganglia

Question 23

Parasympathetic division - rest and digest

Answer 23

parasympathetic division is most active during times when the body must process nutrients and conserve energy
lack of extensive divergence in preganglionic axons prevents the mass activation seen in the sympathetic division
effects of the parasympatheitc nervous system tend to be discrete and localized
parasympathetic activity can affect one group of organs w/o necessarily having to turn on all other organs

Question 24

The parasympathetic division

Answer 24

also termed craniosacral division
primarily concerned with conserving energy and replenishing nutrient stores
in most active when the boy is at rest or digesting a meal
participates along with the sympathetic division in maintaining homeostasis

Question 25

cranial nerves

Answer 25

associated with the parasympathetic division are: the oculomotor nerve (CN III) facial nerve (CNVII), glossopharyngeal nerve (CN IX), vaugus nerve (CN X)

Question 26

Vagus nerve

Answer 26

parasympathetic stimulation for the thoracic and most abdominal organs 
multiple terminal and inramural ganglia 
heart rate decrease 
decrease respiration 
constrict excites mucous production 
promotes swallowing and peristalsis 
promotes digestion

Question 27

caudal contribution of parasympathetic

Answer 27

apart from the cranial nerve components the rest of the parasypatheic innervations in the body comes from the sacral region of the spinal cord
preganglionic parasympathetic axons from neuron cell bodies in the lateral horn contributes to the formation of the superior and inferior hypogstac plexus
preganglionic axons travel to the organs and synapse with ganglia close to or in the walls of the organs

Question 28

Parasympathetic via pelvic splanchnic n

Answer 28

distal portions of large intestine 
rectum 
most reproductive organs 
urinary blader 
distal ureters
erection

Question 29

segmental innervation of abdominal visera

Answer 29

approximate spinal cord segments and spinal sensory ganglia involved in sympathetic and visceral afferent pain innervation of abdominal viscera are shown

Question 30

gallbladder visceral pain

Answer 30

T6 right

Question 31

cecum and appendix visceral pain

Answer 31

T10-T12 right

Question 32

stomach visceral pain

Answer 32

T5-T9 left

Question 33

subcostal n

Answer 33

T 12
motor to - recutus bodominis, pyramidalis, transversus abdominis, internal oblique, external oblique
sensory - skin of the anterior and lateral body wall and to the upper gluteal area

Question 34

iliohypogastic n

Answer 34

L1
transversus abdominis, internal oblique, external oblique
skin of suprapubic region
skin of upper gluteal region

Question 35

ilioinguinal n

Answer 35

L1
motor - transversus abdominins and internal oblique
sensory - root of penis and anterior scrotum in males, skin of the mons pubis and labia majora in females, skin of the medial and upper thigh in males where it constitutes the afferent limb of the cremasteric reflex

Question 36

genitofemoral n

Answer 36

L1 and L2
genital - motor to cremaster sensory to anterior scrotum or upper part of the labia majora
femoral - innervate the skin of the thigh

Question 37

lateral femoral cutaneous n

Answer 37

L2 and L3

sensory fibers to the skin of the anterolateral and posterolateral thigh

Question 38

femoral n

Answer 38

L2,L3, and L4
motor branches to iliacus, anterior thigh m
sensory branches to anterior and medial thigh and medail leg
afferent and efferent limbs of the knee jerk reflex

Question 39

obturator n

Answer 39

L2, L3, L4
motor fibers to the medial thigh m
sensory fibers to hip joint, skin of medial thigh

Question 40

accessory obturator n

Answer 40

L3 and L4

pectineus m

Question 41

lumbosacral trunk

Answer 41

L4 and L5

joins sacral plexus