Chapter 7 Flashcards
Voluntary Nervous System
know your directions
Dorsal vs Ventral (Posterior vs Anterior)
Medial vs Lateral
Cranial vs Caudal (Rostral vs Caudal or Superior vs Inferior)
be able to draw the adult cross section
slide 4
no ventral mesentary
The Basic Vertebrate Cross Section (Adult Version)
understand it lmao
gray matter contains
cell bodies, not wrapped in mylin
white matter
axons are traveling, bundles of axons (cell bodies)
In CNS tract is
a bundle of axons
In the PNS usally a nerve,
not going to be a nerve, until you get a dorsal & ventral portion together, those two pieces are beginning of a nerve
ventral portion associated with
ventral root
dorsal portion associated with
dorsal root
posterior gray horn
somatic sensory nuclei
visceral sensory
lateral gray horn
visceral motor nuclei
sensory neuron
sensory through dorsal root, up towards the brain, dont have the axons coming out, PNS neurons synapse on cell bodies
motor nuclei somatic
anterior gray horn
somatic nuclei are
more superficial than visceral
motor nuclei
ventral root, signal down from brain, synapse on cell body in here, in the somatic, send out from its axon into PNS
only cells that contributing to the ventral root
motor nuclei(efferent)
dorsal root
sesnroy nuclei affarent axons
bumb in dorsal root ganglion
CNS nuclei that are recieving from the axons which are coming through the dorsal root, this is where the dorsal root axon are located, direct result of having unipolar morphology
ganglion
collection of cell bodies in the PNS
nerves in periphery
contain motor and sensory
move laterally what happens
you have a dorsal root with a ganglion, you have a ventral root, that will form a nerve (mixed spinal nerve-both motor and sesnory)
review 14:55
talks about dorsal root, axon, cell bodies
mixed spinal nerves form
a trunk, branches out
branches out
ramus, you have a dorsal and ventral root (symp. branch authonomic NS)
describe hyp. vs. exp.
epx. hold spine erect
dorsal ramus
only innervate epaxial muscles
dorsal root not the same thing as dorsal ramus
know the difference lol
ventral ramus (comes all the way down)
hypaxial muscles
neurons that exsist of the mixed spinal nerve, rami, etc. ?
presynaptic neuron, postsynaptic neuron axon potential is propigated through the axon
fiber type means?
somatic afferent
somatic efferent
visceral efferent
visceral afferent
inside of dorsal root you can
carry different fibers
can carry signals sensory information from your brain to your organs
–carry
carry sensory info. from your brain to from your organs is important because
you have to understand that you stomach is constricted or dilated, your brain has to know that, so you carry sensory information through the visceral afferent fibers these fibers can come form your organs inside your body but however there are unconcious sensations that you have to send back to your brain regarding if your vessciles are constricted or dialted, your brain has to know that if it has to cool you down or warm u up
what are the two basic divions of your body
epaxial /hypx.
from the ventral ramus you are going to return visceral sesnory info. from your vessels and other unconcious structure coming from hyp. region coming through the ventral ramus
listen to
minute 34
dorsal ramus
getting info unconcious sensory region from your expaxial region, glands that are back there, sesory info is coming through the dorsal ramus
regardless of where it comes from your organs hyp. or epaxial those fibers..
have to pass through the mixed spinal nerve then they go into the dorsal root, go past the cell body, go into the visceral afferent nucleus post.gray horn of your NS, they are going to synapse on cell bodies inside of that, signal goes up to brain so thats VISCERAL
how is somatic different from visceral in terms of interrpurting signals
you’re not recieving info from your guts but you have to be aware of whether you’re contracting hypaxial or epaxial musculature, conciously aware of those types of things,
sensory pathways
conciously aware of pressure on you whether its on hyp. or epax., somatic sensory comes in through the ventral ramus from hypx. …somatic sensory comes in from the dorsal ramus from the epax. that youre conciously aware of, goes through mixed spinal nerve, into the dorsal ramus, passes the dorsal root ganglion and synapses in the somatic afferent nucleus and then sends info to your brain
you have to understand for the upper motor neurons are referred to
are contained in the CNS and synapse onto lower motor neurons , singal that is coming from the brain uses a upper motor neuron carried down the axons inside of the spinal tracts, those axons will go into one of those nuclei tht it synapeses ona lower motor neuron
lower motor neurons
have cell bodies in the CNS (we will focus on the spinal cord) and their axons extend into PNS
last mintues on lecture 7 part one/ lecture 7 slide 13 recording
listen to recordings, slide 12
ANS
four different ways it can go
from slide 12 three imp. concepts
three main points:
1.only seeing lower motor neurons and what they do is they send their axons through the ventral root and only the ventral root where they combine in the mixed spinal nerve, givesmotor neurons access to hypx. or epax. or internal organs
- when you’re looking at the somatic vs. visceral, somatics can go directly to their target structure in the epax. or hypx.
with the visceral when it leaves to the ventral root it can not go directly through its target structure it has to use a second neuron, a post gangloic neuron to reach its target, - lower motor, only going into the PNS, not seeing the upper that are bringing signal to the lower
how sensory and motor work together
reflex arcs
what are the two types of reflex arcs?
monosynaptic, polysynaptic
monosynaptic
Stretch reflex, signal sometimes to brain, typically something you’re not aware of, not feeling it, feel muscles contracting becoming aware of it
goes directly to motor nuclei, going to contract the muscle, knee test,
polysynaptic
Withdrawal reflex (flexor reflex) Crossed extensor reflex
stretch reflex only involves
the somatic afferent and somatic efferent, not involving upper motor, doesnt need to go brain, automatically
stretch reflex Biceps
C5, C6
stretch reflex Brachioradialis
C6
stretch reflex Triceps
C7
stretch reflex Patellar
L4
stretch reflex Calcaneal Tendon
S1
reflex arc damage to the ventral root means
motor damage, can sense it but can’t contract back
reflex arc damage to the dorsal root means
sensory damage, can’t sense reflex
withdrawal reflex
polysnaptic, multiple things contract, painful stimulus gets send back from your somatic afferent you’re conciously aware, going to synapse on an interneuron because its inbetween the sensory and motor components, combines both of them
what does an interneuron do?
sends signal to brain so that you’re conciously aware of ow that hurt, at the same time to the brain, sending singals to motor neurons
two different types of signals of an interneuron
excitatory and inhibitory
what youre going to do is when you get the painful stimulus youre going to have to excite and stimulate the flexor muscles so you can pull back the limb but youre going to inhbit the extensor muscles, prevent muscles from drawing your limb back, contracting the muscles drawing muscles back
crossed extensors
also polysnaptic, painful stimulus, carried along your somatic afferent all the way back to you spinal cord again synapses on an interneuron,
detailed description of a crossed extensors
that interneuron sends the info to the brain you stepped on something painful @ the same time send signals too**both sides of the spinal cord
interesting part of a crossed extensor
if you only send the signal to contract need to send signal to other side, the other leg wont be ready to support the weight, send signals to both side
which side recieves what signal of a crossed extensor reflex arc
leg that receives pain: flexor
send signal to extensors on other side so that it will contract, support your weight
send signals to brain however the signal doesnt make you realize that the signal makes teling you what should contract, work indepdently of upper motor neuron
crossed extensor reflex, leg that is hurt:
extensors inhibited, flexors stimulated
leg that is not hurt, crossed extensor reflec
extensors stimulated, flexors inhibited
three layers that cover the nerves in CNS
known as meninges
superficial to deep meninges
1dura matter tough connective mother protects spinal cord and brain
2arachnoid matter (spider) connective tissue trubuclae
3pia matter soft, flimsy,
what else provides protection to your CNS
you have cerebral spinal fluid, cushion protect things, inbetween meninges
meninges do what
when you leave the CNS, wraps tightly around the spinal nerve as it leaves your vertebral column, forms a cuff
pia matter has?
extensions coming off, called denticulate ligaments come off of pia, extend to dura, see them inbetween those dorsal roots and ventral roots, they anchor the CNS in place, prevents spinal cord from moving aroundyour hard vertebral column
what is an overall two important concepts of nerves?
segmentation and that they get dragged down caudually
dragging in detail
actual CNS matches up with their bony regions, occupies the entire the bony region (vertbral column) bones grow, CNS will not grow CNS stops growing, PNS will grow, CNS drap spinal nerve and ventral and dorsal roots down so nerves still merges inferior, very long nerve roots
Coneus mediarlarus
has connective tissue, very end of the meninges, where dura ends, Where dura ends anchors with the final filum terminale,
purpose to anchor your spinal cord so it doesnt bang into your vertbrae
cauda equina
consist of nerve root (looks like horses tail) not the actually nerve, the dorsal and ventral roots that contribute to the spinal nerves
segmentation
Even as an adult, still have association of segments and segmental nerves
- dermatomes, strips of your dermis specifically to a nerve, innovating it
- have names of nerve innervating it
- easiet on axial portion of ur body,
- you started as a weird teddy bear, rotated skin strips with it
- only particular parts of your skin because virus only on specific nerves of segmentation
there are segments have to understand that
segments can connect to each other, plexsus
plexsus**
A complex interconnection of adjacent segmental nerves.
your limbs only develop from hyp. regions
Because they develop from hypaxial region, where do they get the innovation? ventral rami!
how does a plexsus affect the body?
Reorder themselves so they have finer control better control which is going down to your appendages
Gives us finer control, will reorganize itself over the innervation to large block of musuclature so finer control of nervous system
how a plexsus works in the nervous system
-many nerves one target structure, multiple nerves, finer control so more control over a big block of musculature
-one single segement,
split up so it has control over more segments
how do we gain finer control in a plexsus
in a plexsus, a nervous, can go to one nerve with many targets, many nerves to one single target
how many segments does a limb consist of
6
limb splits into six
limb is going to be seperated out into a dorsal division and a ventral division
dorsal muscles
extend or elevate your limb
ventral muscles
flex, depress
THE LUMBO-SACRAL
PLEXUS
for limbs
lumbar and sacral nerves involved, basic idea, divide into dorsal and ventral, then divide into cranio(superior) /caudual(inferior) gives us four nervous structures that we’re dealing with
lumbo-sacral plexsus femoral is what quadrant?
cranial-dorsal
lumbo-sacral plexsus obdurator is what quadrant?
cranial-ventral
lumbo-sacral plexsus peroneal/fib is what quadrant?
caudal-dorsal
lumbo-sacral plexsus tibialis what quadrant?
caudal-ventral
combination of peroneal and tibial is the
sciatic nerve
gleuteals
associated with peroneal nerve, be able to seperate themselves
L2, L3, L4 Lumbosacral Plexus
Femoral
L3, L4Lumbosacral Plexus
Obturator
L4, L5Lumbosacral Plexus
Peroneal
L4, L5, S1
Lumbosacral Plexus
Superior gluteal
Lumbosacral Plexus S1,S2
Tibial
Femoral relates to which muscles?
Hip flexors, quadriceps
L2, L3, L4
Obturator relates to which muscles?
Adductors
L3-L4
Peroneal relates to which muscles?
Tibialis anterior
L4,L5
Superior gluteal relates to which muscles?
Gluteus medius and gluteus minimus
L4,L5,S1
Tibial relates to which muscles?
Gastrocnemius
S1, S2
breaking down the brachial plexsus
5/6 segmental roots three trunks 6 divisions three cords 5 terminal nerves
c4,c5,c6 THE BRACHIAL PLEXUS
superiortrunk
c7THE BRACHIAL PLEXUS
middle trunk
c8,t1 THE BRACHIAL PLEXUS
inferior trunk
each three trunks (superior, middle, and inferior in the brachial plexsus) divides into
its component dorsal and ventral divisions (recall dorsal and ventral mm.)
All dorsal divisions unite to give in the THE BRACHIAL PLEXUS
POSTERIOR CORD.
ventral divisions in the THE BRACHIAL PLEXUS
LATERAL & MEDIAL CORDS
POSTERIOR CORD what terminal nerves? in the THE BRACHIAL PLEXUS
AXILLARY N.
RADIAL N.
LATERAL & MEDIAL CORDS what terminal nerves? in the THE BRACHIAL PLEXUS
MUSCULOCUTANEOUS N.
MEDIAN N.
ULNAR N.
C5, C6Brachial Plexus
-Axillary,nerve
Deltoid, Long head of triceps brachii
-Musculocutaneous,nerve
Biceps brachii, Brachioradialis
C7, C8Brachial Plexus
Radial
Other triceps heads, extensors
C8, T1Brachial Plexus
Median
Most wrist flexors, radial side digital flexors
C8, T1Brachial Plexus
Ulnar
Ulnar side wrist and digital flexors
understand branchial plexsus
slide 34
upper motor neurons vs. lower motor
Locations are different and key to knowing the difference
-upper CNS
show different signs
causes may very in upper and lower neurons
Causes may vary
Trauma nerve or nerve in CNS
Disease
Possible Signs
of upper motor and lower motor neurons
Paresis=weakness
Plegia=paralized
types of plegia
Quadriplegiaall four, paraplegia, hemiplegia, monoplegia-onelimb
Lower Motor Neuron Lesions characteristics
Atrophy Hypotonia Hyporeflexia Tends to affect small groups of muscles provide nutrition to muscle
hypotonia
loss of reflex, lower motor nueonrs(goes to muscle cell to contract) if you damage the neuron, cannot provide that baseline signal for contraction, flacid
hypoflexia
can still sense, lost of reflex, weak or absent, don’t show the reflex, uses lower motor neurons, wont carry signal to muscle, could be weak or absent reflex
Tends to affect small groups of muscles, lower motor lesion
not CNS, so specific muscles.. lower motor neurons, they go to specific muscles- only going to affect very small groups of muscles
maybe cannot flex, but can extend just fine because its so specific
if you had damage to peroneal nerve, (shin)
Trauma to knee or fibula Nerve root L4, L5, S1 lesion Foot Drop, toe drag called=Steppage gait, equine gait, slapping gait localized nerve damage
Damage to superior gluteal nerve (like baby walking)
Trauma to buttocks (stabbing, intramuscular injection)
Hip Drop
called waddling gait
Saturday night palsy, crutch palsy
(lower motor)
Damage to radial nerve
Wrist Drop, inability to extend arm
Upper Motor Neuron Lesions
Atrophy is rare Hypertonia -Spasticity, clonus Hyperreflexia Tends to affect large groups of muscles
Muscles working against gravity are stronger
-Pointing toes, upper limb flexors, lower limb extensors
upper motor
not just carrying signald when you want, constantly sending to lower motor neurons, baseline inhibition, no longer sending a contraction signal
hypertonia
contraction signal is not being reduced by upper neuron, muscles are rigid and tight
-get spasticity(stretch quickly,not inhibiting signal,reflex stretching is strong, stretches several times), clonus(stretches and locks in place contracting strongly, shows how strong the lower motor neurons are causing the muscle to contract when you dont inhbit them with an upper motor neuron
hypperreflexia
reflexes are stronger,
upper motor neuron lesions affects
affect large groups of muscles
as well as many lower muscle neurons
Muscles working against gravity are stronger becomes stronger than those not contracting gravity in upper motor neuron , what are examples???
Pointing toes, upper limb flexors, lower limb extensors, become much much stronger.
Lower limb-harder for you to walk, leg muscles are more tense, difficult to walk
Circumduction gait (hemiparesis) half of body
Leg extensors are hypertonic, difficult to flex knee and raise toes
May be due to stroke,
or even lesion in cervical spinal cord if arms are involved, what is the effect?
Swinging leg out
Scissors gait (paraparesis) bottom half down (cerebral palsy)
Leg extensors are hypertonic, difficult to flex knees and raise toes
May be due to trauma in thoracic region or cerebral palsy
-affecting upper motor neurons, they can still demonstrate reflexes, lose a large scale of musculature
