Download Test 3 Notes

Stimulus – response
Name the 3 kinds of stimuli
1 .Pain, Temp. Pressure, Vibration
2. Change in internal environment
3. Change in internal environment
What detects stimuli?
Receptors/specialized nerve endings
Organization of the Nervous System
P314-338
What are the two anatomical divisions
of the nervous system?
CNS (central nervous system)
PNS (peripheral nervous system)
Name the functional divisions.
Autonomic Nervous System (ANS)
Somatic Nervous System -
Name the anatomic divisions.
CNS - brain, spinal cord and neuroglia cells
PNS- peripheral nervous system
How many cranial nerves are there? How many
spinal nerves are there?
12 pair
31 pair
What is the general name of the support cells?
Neuroglia cells
Is the autonomic functional or anatomic?
Functional
Define the ANS.
a two neuron chain from the CNS to the
neuroeffector organ
Name the two divisions of the ANS
Parasympathetic & Sympathetic
Define the Somatic Nervous System.
A one neuron chain from the CNS
to the neuroeffector organ
Functions of the Nervous System
p. 334
What are the functions of the nervous system? 7
Perceive and respond to stimuli
Coordination and control of body activities
Memory
Learning based on past experiences Deductive reasoning
Inductive reasoning
Instinctive behavior
1
Terminology of the Nervous System
Table 11.1, p. 335
A sensory neuron is a
Afferent neuron
Afferent means
Information coming in to the system
A motor neuron is a
Efferent neuron
Efferent means
Information going out of the system
A ganglion is a
A collection of neuron cell bodies
outside of the CNS
A nucleus is a
A collection of neuron cell bodies within
the CNS
Atract is a
Grouping of nerve fibers that
interconnect regions of the CNS
Neurons and Neuroglia
p. 338 Table 11.2, p. 341
Name the parts of a neuron. 3
cell body, dendrite, axon
AKA for cell body
soma
What does it contain
contains the nucleus or processing center
What does a dendrite do?
It is the receiving portion of a neuron
What does a dendrite contain?
Receptors
So you could say it is the _____ part of a
neuron.
Afferent
What does an axon do?
It is the transmitting portion of a neuron
So you could say it is the _____ part of a
neuron.
Efferent
2
Neuroglia
Name the neuroglia cells. 6
Neurolemmocytes
Oligodendrocytes
Microglia
Astrocytes
Ependymal Cells
Ganglionic Gliocytes
Myelination is the
Formation of myelin sheath
What is a myelin sheath?
A lipid layer that covers an axon or
dendrite
What is myelin made of?
myelin is a lipoproteinaceous
material composed of regularly
altematingmembranes of lipid
lamellae and protein
What neuroglia is involved in
myelination in the PNS?
Neurolemmocyte
What neuroglia is involved in
myeilnation in the CNS?
Oligodendrocyte
Myelination does what?
Provide support and aid in the
conduction of nerve impulses
Myelin is also found where?
Brain, it gives the white matter of the
brain and spinal cord (SC) and
peripheral nerves their whitish color
How does the myelination
of the PNS take place?
neurolemmocytes grow and wrap
around an axon or dendrite
What is the outer surf enclosed by
a glycoprotein sheath
The glycoprotein sheath is called
the neurolemmal sheath
Each neurolemmocyte covers approximately
1 mm of space on the axon
In between each neurolemmocyte there is a
gap
3
In between each neurolemmocyte there
is a
gap
This gap is called
a Node of Ranvier or neurofibril node
Class jfication of Neurons and Nerves
- p. 342
How are neurons classified? 3
According to direction of impulse they
would be
According to direction of impulse
travel
According to fiber diameter
According to Structure
afferent or efferent
According to fiber diameter they would
be
Type A fibers
Type B fibers
Type C fibers
Type A fibers are
Type B fibers are
Type C fibers are
Large myelinated, rapid conducting
Medium sized with less myelin
Small, less myelin, slow
According to structure they would be
Pseudounipolar
Bipolar
Multipolar
Pseudounipolar neurons are
Sensory neurons GSA, GVA
Bipolar neurons are
Special sensory neurons; SSA, SVA
Multipolar
Motor neurons; GSE, GVE
Definitions of terms
Somatic =
Visceral =
Relating to or involving the skeleton or
skeletal (voluntary) muscle
Viscera (involuntary) muscle and
autonomic innervation
4
According to specific type of tissue innervated
p.334
GSA =
General Somatic Afferent
GSA innervates
Sensory for skin, bones, joints
GSE =
GSE innervates
General Somatic Efferent
Motor to skeletal muscle
GVA =
GVA
General Visceral Afferent
Sensory, pain & stretch from viscera &
blood vessels
General Visceral Efferent
Motor to smooth rn., cardiac m. and Glands
• GVE =
GVE
• SVE =
Special Visceral Efferent
Somatic motor to SCM and trapezius
• SVA =
SVA
Special Visceral Afferent
Sensory from taste and smell
• SSA =
Special Somatic Afferent
Sensory from eye and ear
Which of the above do
spinal nerves carry? -
Spinal nerves are mixed - contain all
the “G’s”,
Do they contain any special
components?
NO, contain no special components
Which do cranial nerves carry?
Can have G or S or a mix of the two
Connective tissue covering of a nerve
p. 344, figure 11.11
Epineurium surrounds what?
Entire nerve
Perineurium surrounds
Bundles of nerve fibers
Endoneurium surrounds
Individual nerve fiber
5
Fasciculus =
A bundle of nerve fibers
Transmission of Nerve Impulse
p. 346-348
Appendix #2
Nerve Impulse =
movement of sodium and potassium
ions along the length of a nerve fiber
This results in
The creation of a stimulus that
excites another neuron or tissue
Irritability =
Ability of dendrites and cell bodies
to respond to a stimulus
The stimulus is converted to
An electrochemical impulse
Conductivity
Transmission of an impulse along an
axon or dendrite
Resting Membrane Potential =
Before a nerve fiber can respond to
a stimulus it must be polarized.
Polarization =
exists when there is an
electrochemical gradient present
between the inside of the cell and
the outside of the cell.
What does this mean?
Positive charge on the outside
Negative charge on the inside
Which are the positive ions?
Sodium ions
Which are the negative ions?
Potassium ions
Which are on the inside of the cell?
Potassium ions
Which are on the outside?
Sodium ions
And the cell membrane is a
Semi permeable membrane
6
Depolarization =
A stimulus causes ions gates in the
cell membrane to open
When they open what happens?
a rapid influx of sodium into the cell
which causes a reversal of polarity
called depolarization
Ion gates are what cause
cell membranes to be
Semi permeable
Does depolarization just happen
at one ion gate?
NO, a wave of depolarization is
conducted down the length of the
nerve fiber
Repolarization =
Sodium/potassium pump pumps
sodium back out of the cell and potassium
into the cell to re-establish the resting
membrane potential.
All or None Response =
When a stimulus of sufficient
strength triggers an action potential
the nerve “fires”
What is the in between stage
Of a nerve firing?
The is no in between, it is either
Firing or it is at rest
Can a nerve impulse travel
in two directions?
Nerve impulses only travel in one
direction
Is there a loss of voltage as the wave travels NO
to the end of the axon or axon terminus?
Threshold =
The internal voltage at which the
cell will spontaneously depolarize
7
Synapse p. 347, figure 11.15
Define synapse =
The connecting point between the axon
terminal of the neuron and the cell
membrane of a cell
Presynaptic neuron =
Axon terminal which is sending the infb
Postsynaptic tissue =
Cell/tissue receiving the info
Axon Terminal =
Synaptic bulb, knob - distal portion of the
axon
Synaptic Vesicles =
Located in the axon terminal, contain
neurotransmitter chemicals(the info)
Synaptic Cleft =
Gap between the pre and post synaptic cells
Threshold =
the internal voltage at which the cell will
spontaneously depolarize
Synapse =
A functional connection between the axon
terminal (presynaptic neuron) and the cell
membrane of (postsynaptic cell)
8
Name three neurotransmitters =
1. Ach = Choline + Acetyl Co A
2. Acetylcholinesterase
3. Norepinephrine
IPSP =
Inhibitory Post Synaptic Potential
Are chloride ions negative or positive?
Negative
Where are chloride ions ( Cl—) found?
Inside the cell/neuron
EPSP =
Excitatory Post Synaptic Potential
Are sodium ions negative or positive?
Positive
Where are sodium ions (Na+) found?
Outside the cell/neuron
Resting Membrane Potential =
The electrical state of a non-firing neuron
This resting potential is due to?
An imbalance of charged ions between the
inside of the cell and the outside of the cell
What kind of charge is on the outside
of the membrane?
Positive
So the inside would be?
Negative
What does Na+ do in an
action potential?
Rushes through the membrane, into the cell
What does K+ do in an action potential
Rushes through the membrane, out of the
cell
After the action Potential is over
what happens to the Na+ & K+?
The Na+ is pumped out of the cell & the K+
is pumped back into the cell
What is the pump called?
Sodium-Potassium Pump
9
What does a Sodium-Potassium Pump
use for energy?
ATP
For every ____Na+ pumped_____
there are — K+ pumped back —.
For every 3 Na+ pumped OUT
there are 2 K+ pumped back IN.
What kind of membrane is it?
Selectively permeable membrane
It is more permeable to____
than to_____
More permeable to K+
Less permeable to Na+
What are the large negatively
charged ions called?
Anions
Where are they found?
Inside the cell/neuron
What are they made of?
chloride ions ( Cl-)
Is the plasma membrane
permeable to Cl —
NO
How many steps in an action potential?
7
Step 1.
Adequately intense stimulus
Mechanical, Electric or chemical
• Stimulus can be?
Step 2.
Membrane permeability changes and
Na+ diffuse into cell
Step 3.
As Na+ move into cell, the
transmembrane potential reaches zero
(loss of polarity = depolarization)
• This can be called
Step 4.
Na+ cause inside of cell to become
positive in relation to outside =
(reversal of polarity)
Is this happening all over the cell?
No, just at one place.
Step 5.
The reversal of polarity stimulates
the area next to it — which stimulates
the area next to it - which stimulates
the area next to it - which stimulates
the area next to it all the way to the
axon terminal
10
Step 6.
Back at the point of initial
stimulation there is a decrease in
permeability of the membrane to
Na+ & an increase to K+
• What does K+ now do?
Diffuses rapidly out of the cell
• This results in?
Outside of membrane becoming
more positive than the inside.
• This is called Repolarization
Step 7
Sodium-potassium pump
re-establishes Na+ & K to their
normal resting levels
So the neuron is now ready to be
Stimulated to the point of another
ACTION POTENTIAL i.e. Step 1.
The Spinal Cord
p. 372 - 379
Where is the spinal cord located?
In the vertebral canal (neural canal)
It extends from
The foramen magnum to L1
Conus medullaris =
Tapered end of spinal cord
Filum terminale =
Pin mater, attaches to coccyx
Cauda equina =
Collection of spinal nerve roots
Spinal segment =
A section of the cord where a pair of
spinal nerves arise
Basic Anatomy of the Spinal Cord
The meninges are composed of
Where does the dural sac end?
3 layers
1.
dura mater
2.
arachnoid
3.
pia mater
At S3
11
Denticulate ligament =
sawtooth like attachments of the pia to the
dura
How many are there?
20-22
What do they do?
Serve to suspend the spinal cord within the
dural sac.
They extend from
The foramen magnum to T12 -LI
White matter consists of
bundles of myelinated sensory and motor
neurons
Anterior median sulcus
Grove that run down the anterior of the
spinal cord
Posterior median sulcus =
Grove that run down the posterior of the
spinal cord
Funiculi =
Means cord or column of white Matter
How many are there?
6
Name them
Anterior funiculi – 2
Posterior funciculi – 2
Lateral Funiculi - 2
Tract =
A bundle of nerve fibers within the central
nerves system (CNS)
12
Ascending tracts =
Sensory
Descending tracts =
Motor
Gray matter is composed mostly of
Neuron cell bodies and interneurons
Interneuron =
Combinations or groups of neurons
between sensory and motor neurons
that govern coordinated activity.
Dorsal horn AKA
Posterior horn
Composed of?
Incoming axons of sensory neurons
And carries
GSA, GVA
Ventral horn AKA
Anterior horn
Composed of?
GSE neuron cell bodies
Lateral horn =
GVE neuron cell bodies (T1 to L2)
Gray commissure =
A bundle of nerve fibers passing
from one side to the other in the
brain or spinal cord
Central canal
Central canal of spinal cord
How many enlargements
does the spinal cord have?
2
Name them
Cervical and Lumbar
Functions of the spinal cord
Ascending - sensory
Impulse conduction Descending- motor
Reflex integration
Spinal segment =
Pair of spinal nerves
And they emerge from the
spinal cord through
IVF
How many spinal nerves are there?
31 pairs of spinal nerves
How many spinal segments are there?
31 spinal segments
13
How are spinal nerve formed?
formed by the union of the
Ventral root (motor)
and the Dorsal root (sensory)
Rootlets combine to form
Roots
What rootlets are there?
Ventral Rootlets and Dorsal Rootlets
Roots join to form
The spinal nerve at the IVF
Dorsal Root carries
GSA, GVA
Dorsal Root Ganglion are composed of?
Pseudounipolar neuron cell bodies
Ventral Root are composed of?
GSE, GVE
Spinal segment
Spinal segment =
A cross sectional segment of the spinal
cord that gives rise to a pair of spinal
nerves (one spinal nerve from each side
of the cord)
Spinal segments have a relationship to?
Vertebral levels i.e. a portion of the cord
housed within the confines of a
vertebra.:
For example Cl spinal segment is in the
Neural canal of Atlas
L2 spinal segment is in the
Neural canal ofTi 1 vertebra
S4 spinal segment is in the
Neural canal ofLi vertebra
Bell-Magendie Law =
The dorsal root of a spinal nerve carries
sensory information, the ventral root
carries motor infbrmation
Does the ant. or post. root have an
enlargement?
Post.
What is the enlargement called?
Spinal gangion
14
The Spinal Nerve
p.400-401
1YF =
The Intervertebral Foramen
Rule for naming Spinal Nerves:
Cervical - according to the vertebra they exit above ie. C3 exits the spinal cord
superior to the third cervical vertebra, between C2 and C3
All others - according to the vertebra they exit below ie. T4 exits between T4 and
T5 vertebra.
Branches of a Spinal Nerve
What does a spinal nerve do
after it leaves the IVF?
Branches
These branches are called?
 Recurrent meningeal, Sinuvertebral, meningeal ramus
 Dorsal ramus
o medial branch
o lateral branch
 Rami communicantes
o Gray ramus - GVE
o White ramus - GVE, GVA
 Ventral ramus
o plexus
o intercostal nerves
Dorsal Ramus
 Medial branch
o superior to T6 sensory
o inferior to T6 motor
 Lateral branch
o superior to T6 motor
o inferior to T6 sensory
Rami communicantes
 Associated with the ANS
15
White rami connects with?
The spinal nerve to the paravertebral
ganglia
Gray rami connects with?
The paravertebral ganglia to the
spinal nerve
Ventral Ramus
Tissues innervated - supply motor, sensory and sympathetic fibers to the anterior and
lateral muscles ans skin of the neck and trunk and all the muscles and skin of the limbs,
including the superficial back muscles
• Form plexuses
• T1-T12 intercostal nerves
Roots and Rami?
Be able to d the following terms:
Spinal nerve =
The nerves emerging from the spinal cord
How many are there?
There are 31 pairs
What do each attach to?
The cord by two roots, anterior and
posterior, or ventral and dorsal
The latter is provided with
A circumscribed enlargement, the
dorsal root (spinal) ganglion
The two roots unite in the?
Intervertebral foramen (IVF)
The mixed spinal nerve almost
immediately does what?
Divides again into ventral and dorsal
primary rarni,
The former supplies?
The anteroläteral trunk and the limbs,
The latter supplies?
The true muscles and overlying skin of
the back.
Ventral root =
The motor root of a spinal nerve
Dorsal root =
The sensory root of a spinal nerve, having a
dorsal root ganglion containing the nerve
cell bodies of the fibers conveyed by the
root in its distal end
16
Ventral rami =
The motor root of a spinal nerve
Spinal nerve root =
Rami communicantes
• Dorsal rami
• Meningeal rami
The Cervical Plexus
p. 401, Table 12.3
The Cervical Plexus is composted of?
Cl— C4, mostly Ventral rami of C2,3 and 4
Are these branches sensory or motor?
Both
Sensory branches
Name the four Superficial Cutaneous
Branches
Lesser Occipital Nerve
Greater Auricular Nerve
Transverse Cervical Nerve
Supraclavicular Nerves
Lesser Occipital Nerve is derived from?
C2,3
It innervates?
Skin posterior to the auricle and lateral
portion of the occipital region
Greater Auricular Nerve is derived from?
C2,3
It has ____branches?
2 branches
Name the branches
Anterior branch - skin over parotid salivary
gland Posterior branch - skin over the
mastoid process and ear lobe
17
Transverse Cervical Nerve is
derived from?
C2,3 - skin of anterior
Neck
Supraclavicular Nerves is derived from?
C3,4
How many branches does it have?
3 branches
Name them.
Medial branch — Skin from clavicle to
the midline
Intermediate branch--skin of anterior chest
wall
Lateral branch — skin over the shoulder
Motor branches
Ansa cervicalis is derived from?
C 1,2,3
It innervates?
Omohyoid
Sternohyoid
Stemothyroid
Phrenic Nerve is derived from?
C3,4,5
It innervates?
The diaphragm
Other Cervical nerves:
Suboccipital Nerve is derived from?
Dorsal ramus of Cl
It is motor to?
The muscles of the SOT,
it is sensory to?
NO cutaneous sensory
What are the muscles of the SOT?
Obliquues Capitis Superior
Obliquues Capitis Inferior
Rectus Capitis Post. Minor
18
Greater Occipital Nerve is derived from?
Dorsal ramus of C2
It is sensory to?
The posterior scalp
It is motor to?
Splenius m.
The action of the splenius m. is?
One side contraction - Head rotates and
extendss
Two side contraction- extend head & neck
Third Occipital Nerve is derived from?
Dorsal ramus of C3
it is sensory to?
Medial branch is sensory to a small area of
the posterior scalp
The Brachial Plexus
p. 401 - 404, Table 12.4
The formation of the plexus?
C5,6,7,8,T1
Spinal Nerve Roots =
AKA ventral rami of spinal nerve, AKA
nerve root
19
The Brachial Plexus is made of?
Trunks
Divisions
Cords
Terminal branches
Roots =
Ventral rami of C5 to Ti
Trunks are formed by?
The convergence of roots
How many trunks are there?
3
Name them
Superior
Middle
Inferior
Superior is composed of?
Ventral rami of C5 and C6
Middle is composed of?
Continuation of C7
Inferior is composed of?
Ventral rami of C8 and Ti
Divisions
Divisions derived from?
• anterior - innervate fiexors
• posterior - innervate extensors
The trunks, 2 per trunk
Cords are named in association?
With the axillary a
Posterior cord is composed of?
All 3 posterior divisions
Lateral cord is composed of?
Anterior divisions of upper and middle
trunks, contains fibers for C5,6 and 7
Medial cord
Continuation of the anterior divisions of the
lower trunk, fibers from C8 and T1
20
Supraclavicular Branches of the Brachial plexus
Dorsal scapular n. is composed of?
C5
It innervates?
Rhomboid mm.
Levator scapulae m.
Long Thoracic n. is composed of?
C5,6,7
It innervates?
Serratus anterior m.
Nerve to the subclavius m. is composed of? C5,6
It innervates?
Subclavius in.
Suprascapular n.. is composed of?
C5,6
It innervates?
Supraspinatus m.. and Infraspinatus m.
Infraclavicular Branches of the Brachial Plexus
Lateral Cord is composed of?
C5,6,7
Lateral pectoral n. is composed of?
C5,6,7
It innervates?
Pectoralis major m.
Musculocutaneous a is composed of?
C5,6,7
It innervates?
Biceps brachii rn.,
Coracobrachialis m.,
Brachialis m.
lateral antebrachial cutaneous a
is sensory to?
Skin of lateral forearm
Lateral root of the median n..
is composed of?
C5,6,7
Medial Cord is composed of?
C8, Ti
Medial pectoral n.. is composed of?
C8, Ti
It innervates?
Pectoralis maj.& minor mm
Medial Brachial Cutaneous a
is composed of?
C8, Ti
21
It innervates?
Skin of medial & posterior
Arm
22
Medial Antebrachial Cutaneous n.
is composed of?
C8, Ti
It innervates?
Skin of medial & posterior aspect of forearm
Ulnar n. is composed of?
C8, Ti
It innervates?
Flexor carpi ulnaris in., flexor digitorum
profundus in., most of the muscles of the
hand, skin of the medial hand, little finger
and medial half of ring finger
Medial Root of Median n. is
composed of?
C8, Ti
It innervates?
Flexors of the carpus and digits, except
flexor carpi ulnaris In., lateral 2/3’s of the
hand and fingers, tips of thumb, index and
middle fingers and lateral aspect of the tip of
the ring finger, some muscles of the hand
(abductor pollicis brevis in.,flexor pollicis
brevis in., opponens pollicis m., and lateral
lumbrical m.
Posterior Cord is composed of?
C5,6,7,8,Ti
Upper subscapular n. is composed of?
C5,6
It innervates?
Subscapularis m.
Thoracodorsal n. is composed of?
C6,7,8
It innervates?
Latissimus dorsi m.
Lower subscapular n. is composed of?
C5,6
It innervates?
Subscapularis & Teres major.
23
Axillary n. is composed of?
C5,6
It innervates?
Deltoid & Teres minor m., sensory from
skin over deltoid m.
Radial n. is composed of?
C5,6,7,8,T1
It innervates?
Extensor muscles of the arm, forearm,
carpus and digits; Brachioradialis m,.
Supinator m., and the lateral portion of the
Brachialis m., Sensory to the skin of the
posterior arm and forearm, lateral 2/3’s of
the hand and fingers over the proximal and
middle phalanges
Lesions of the Brachial Plexus
Erb-Duchenne Palsy involves what
nerve roots?
What would you visually observe?
C5,6
Excessive displacement of the head to the
opposite side and depression of the shoulder
on the same side.
Dorsal scapular n. damaged you
would see?
Dropped shoulder and scapula falls laterally
Suprascapular n. damaged you would see?
Loss of lateral rotators
Axillary n. damaged you would see?
Humerus rotates medially due to loss of
lateral rotators & unopposed pectoralis maj
Musculocutaneous n. damaged
you would see?

Paresis of muscles of the anterior arm and
forearm pronates due to loss of biceps
brachii m.
“Waiter’s tip”
24
Klumpke’s Palsy
What is the result of excessive
traction or abduction of the arm as
is seen in a fail when one grasps
an object to try and break the f or
when a mother jerks a child
by one arm called?
Kluinpke’s Palsy
Damage to T1 results in?
Inability to abduct the fingers (not the
thumb), atrophy of the small muscles of the
hand and loss of sensation along medial
aspect of arm
Damage to the Long Thoracic N.
will injure what nerves roots?
C5,6,7
What nerve innervates the serratus
anterior m.
Loss of innervation to the serratus
anterior would result in?
This is called
Damage to the Radial Nerve
This is seen in
Long Thoracic N.
posterior deviation of the vertebral border of
the scapula
“Winged Scapula”
Radical mastectomy or blows to the
posterior triangle of the neck
The redial nerve is composed of’?
C5,6,7,8,T1
Clinical signs depend on?
Where nerve is damaged
It is commonly damaged in?
Midshaft humeral fractures
It is also seen with?
Improper use of a crutch
“frogging”
 drunkard paralysis, AKA church pew paralysis
 “wrist drop”
25
Median Nerve Damage indicated by?
Numbness and pain in the lateral aspect of
the palmar surface of the hand, inability to
pronate the forearm, weakness in the thumb
and severe paresis in carpal flexion
Clinical signs depend on?
Where it is damaged
Commonly seen in?
Suicide attempts — wrist slashing
Carpal tunnel syndrome
The carpal tunnel is formed by?
The anterior surfaces of the carpal bones and
the flexor retinaculum
Carpal tunnel syndrome is caused by?
Compression of the median nerve in the
carpal tunnel
Clinically you will find?
Burning “pins and needle” sensation in the
palmar aspect of the lateral 3 &1/2 fingers
and paresis of the thenar muscles.
If there is NO loss to sensation over
the thenar eminence?
No palmar branch the involvement
Pronator teres syndrome
The median n. penetrates between?
Same clinical picture as
Carpal tunnel EXCEPT?
What is effected?
The two heads of the pronator teres m. just
below the elbow and can become entrapped
there
There is loss of sensation over the thenar
eminence because affects entire length of
median nerve
Palmar branch of median nerve affected
26
The Lumbar Plexus
p. 404 - 405, Table 12.5
The Lumbar Plexus is composed of?
The Femoral Nerve is composed of’?
The Femoral Nerve is motor to?
L1,2,3,4
L2,3,4
Iliacus m.
Pectineus in.
Sartorius in.
Quadriceps
The Femoral Nerve is sensory to?
Skin of anterior and medial thigh
Saphenous n. is a branch of?
Femoral n.
It innervates?
The skin of medial aspect of thigh and leg
and foot
The Obturator Nerve is composed of?
L2,3,4
It is motor to?
Adductor longus in.
Adductor brevis in.
Gradiis in.,
Obturator extemus in.
Adductor magnus m.
it is sensory to?
Skin of the medial thigh
The Ilioinguinal Nerve is composed of?
Li
It is motor to?
Part of the internal and external
abdominal obliques and transverse
abdominis m.
It is sensory to?
Skin of upper medial aspect of the thigh,
foot of the penis and scrotum, labia majora
and mons pubis
27
The Iliohypogastric Nerve is
composed of?
Li
It is motor to
Muscles of the Anterolateral abdominal wall
It is sensory to?
Skin of the lower abdomen and buttock
The Genitofemoral Nerve is
composed of?
L1,2
How many branches does it have?
2 branches
It is motor to?
Genital branch —cremaster m.
It is sensory to?
Femoral branch — skin of middle anterior
surface of thigh, scrotum - in male and labia
majora in female
Lateral Cutaneous Femoral n. is
composed of?
L2,3
It is sensory to?
Skin over the lateral and anterior thigh
Lumbosacral trunk is composed of?
Inferior portion of L4,5
The Sacral Plexus, L4,5,Sl,2,3,4
p. 405 - 409, Table 12.6
The Sacral Plexus is composed of?
L4,5,S1,2,3,4
The Superior Gluteal Nerve is
composed of?
L4,5,Sl
It is motor to?
gluteus minimus and medius mm. And
tensor f latae
it is sensory to?
no cutaneous sensory branch
28
The Inferior Gluteal Nerve is composed
of?
L5,S1,2
It is motor to?
Gluteus maximus iii.
It is sensory to?
No cutaneous sensory branch
The Sciatic Nerve
The Sciatic Nerve is composed of?
L4,5,S1,2,3
The Sciatic Nerve is actually?
2 nerves in one neural sheath.
It splits into its?
Two respective divisions just proximal
to the knee.
As the sciatic nerve, it descends?
Through the posterior thigh
It sends branches to the?
Hamstrings and adductor magnus m.
The Tibial Nerve
The Tibial Nerve is composed of?
L4,5,S 1,2,3
It is motor to how many muscles?
11
Name them.
Semitendinosus
Semimembranosus mm.
Long head of biceps femoris m.
Adductor magnus m.
Gastrocnemius m
Soleus m.
Plantarism.
Popliteus m.
Tibialis posterior m.
Flexor digitorum longus m.
Flexor hallucis longus m.
Medial and lateral plantar nn innervate?
Muscles of the foot and sensory to the
skin over the plantar surface of the foot
Cutaneous sensory
Skin of the posterior leg
29
The Common Peroneal Nerve
The Common Peroneal Nerve is
composed of?
L4,5,S 1,2
It is motor to?
Short head of biceps femoris
The nerve then comes from the
Posterior side and crosses laterally over the head
of the fibula
Where it then divides?
Into 2 branches:
Name the branchs.
Superficial peroneal n.
Deep peroneal n.
The superficial peroneal is motor to?
Peroneus longus
Peroneus brevis
The superficial peroneal is sensory to?
Skin over the distal 1!3 of the anterior aspect of
the leg and dorsum of the foot
The deep peroneal n. is motor to?
Tibialis anterior m
Extensor hallucis longus m
Extensor digitorum m
Peroneus tertius m.
The deep peroneal is sensory to?
A small area of skin on the dorsum of the foot
between the first and second toes
The Pudendal Nerve
The Pudendal Nerve is composed of?
S2,3,4
It is motor muscles to the?
perineum,
levator ani u
external anal sphnicter m.,
external urethral sphnicter in.
Is it sensory to?
Skin of the penis and scrotum in male; clitoris,
labia majora and minora and vagina in female
30
Coccygeal Plexus
The Coccygeal Plexus is composed of?
S(4), 5, Cy 1
Does it have branchs?
Yes
Name them.
Branch to the coccygeus m.
Branch to the skin over the coccyx
Veterbral levels for Intercostal Nerves?
T2-T12
Dermatomes
—
—
—
—
greater occipital nerve - C2
C3,4
upper and lower extremities
T4 - nipple
Reflex Arc and Refl
Give the components of a simple reflex arch:
Receptor
Sensory neuron
Association neuron
Motor neuron
Effector organ
Give anexample of a Ipsilateral Reflexic Arc.
Knee jerk
So if a reflex is absent, where is the problem?
Reflexes are graded as to:
Normal
Hyperreflexia
Hyporeflexia
The End of the Nervous System
Have a real nice day
Review questions:
1) To detect stimuli, what must a cell posses?
2) What are the components of the PNS?
Receptors/specialized nerve endings
Sensory nerves
Motor nerves
Mixed nerves
31
3) What direction does information travel
in a spinal nerve?
Both ways
4) C1assif neurons according to the
number of processes they have and
tell me what kind of information each one carries.
Pseudounipolar neurons are
sensory neurons GSA, GVA
Bipolar neurons are special
sensory neurons; SSA SVA
Multipolar are motor
neurons; GSE, GVE
5) Give me the location of the neuron cell body
that carries, GSA info., GSE info., GVE info.,
SSAinfo., SVAinfo.,etc.
Within the spinal cord
6) Give me examples of tissues innervated by
neurons carrying GSA, GVA, GSE, GVE,
SSA, SVA info
GSA = Skin, bones, muscles,
joints.GVA =
Visceral organs &
blood vessels
GSE = Skeletal muscle
GVE = Carduac muscle,
Glands, Smooth muscle w/in
visceral organs
SSA = Eyes & ear
7) Is most of the potassium of the body
found in or outside of the cell?
Inside
8) Define resting membrane potential
Resting Membrane Potential =
The electrical state of a non-firing
neuron
This resting potential is due to?
An imbalance of charged ions
between the inside of the cell and
the outside of the cell
9) What is a quantum?
A certain definite amount.
10) What does EPSP and IPSP mean?
Excitatory Post Synaptic Potential
Inhibitory Post Synaptic Potential
11) Define threshold.
The internal voltage at which the cell
will spontaneously depolarize
12) Name the layers of the meninges
in order from superficial to deep
Dura mater
Arachnoid
Pin mater
32
13) What are denticulate ligaments?
Sawtooth like attachments of the pia to the dura
14) What makes up the white matter
sensory and of the spinal cord?
bundles of myelinated motor neurons
15) What kind of neuron is associated
with the DRG?
Sensory
16) What kind of information is
carried in the dorsal root of a spinal nerve?
Information coming into the
CNS
17) What are the “4” branches of a spinal nerve
and what does each one innervate?
Meningeal branch —
Innervates
Meninges,
Vertebrae,
Vertebral ligaments.
Post. Ramus Innervates
Muscles
Joints
Skin of back along spinal column
Anterior Ramus
Innervates
Muscle & skin on lateral &
anterior side of trunk
Combinations of ant. rami
innervate the limbs
Rami Communicantes
Innervates
Two branches, white & gray,
go to sympathetic trunk
ganglion


Gray is composed of
White is composed of
umnyelinated fibers
myelinated fibers
18) What forms the spinal nerve?
Post & ant. spinal roots
19) What branch of the spinal nerve
forms the plexuses?
Ant. raini combine & then
split as networks of nerve
fibers, these are referred to as
“Plexuses” Exception T2 — T12
33
20) What is the association of the sensory branches of the cervical plexus to the SCM?
21) Know the named nerves in the cervical region derived from dorsal rami, Ic. suboccipital
nerve.
22) Know the spinal nerves, which contribute
to the formation of the branchesof the cervical plexus.
Cl — C4 and part of C5
23) Know the spinal nerve roots
that form the brachial plexus.
C5 — Ti
24) Discuss the formation of the
basic skeleton of the brachial plexus.
Roots — Trunks —
Ant, divisions - Post. divisions
25) Flexor muscles are innervated by _____ divisions of the BP.
26) Tell me the spinal nerve roots that contribute to the formation of the cords of the BP.
27) List the branches off of the cords of the BP.
28) How are the cords associated with the axillary artery?
29) To prevent abduction of the humerus, what nerve roots would I have to cut?
30) To stop flexion of the elbow, what nerves would I have to cut?
31) Tell me the basic motor innervation of the muscles of the upper limb.
32) What nerve roots contribute to the formation ofi thoracodorsal nerve, suprascapular nerve,
lower subscapular nerve, dorsal scapular nerve, long thoracic nerve, ulnar nerve, axillary nerve,
median nerve, etc.
33) How do you differentiate carpal tu8nnel syndrome from pronator teres syndrome?
34) Tell me the motor innervation of the muscles of the lower limb.
35) What muscles flex the knee and what nerve(s) innervate them?
36) What spinal nerves contribute to the formation of the branches of the lumbar plexus?
37) What muscles are innervated bythe femoral nerve, tibia! nerve, deep peroneal nerve,
superficial peroneal nerve, superior gluteal nerve, inferior gluteal nerve, obturator nerve, etc.
34
38) What is a dermatome?
39) Give the components of a typical reflex arch.
40) Which primary vesicle gives rise to the midbrain?
41) What are the components of the diencephalon?
42) Name the dural fold that separates the cerebrum from the cerebellum.
43) Where in the CNS do you find CSF?
44) Which cranial nerves carry taste information?
45) Which cranial nerves carry GSA information from the face and structures of the face?
46) To stop extension of the knee, what nerve would I have to cut?
47) To stop extension of the hip joint, what nerves would I have to cut?
48) What muscles medially rotate the humerus?
49) What muscles retract the scapula?
50) What muscles laterally rotate the hip?
35
36