Nervous system Part 2 Flashcards
What are the four main divisions of the brain?
the cerebrum, cerebellum, brainstem, diencephalon
What are the protective structures of the brain and why is it important to have those protections?
Meneges, cerebrospinal fluid, the skull, and blood brain barrier.
Nervous tissue is damaged by even the slightest pressure, and can not regenerate once damaged.
Ventricles
The brain has 4 ventricles
These are cavities in the brain that are filled with cerebrospinal fluid.
Two lateral ventricles, third and fourth ventricle
Where does the 4th ventricle drain?
into the central canal of the spinal cord, which also has cerebrospinal fluid.
meninges
Three layers of connective tissue membranes that cover and protect the CNS organs and enclose the cerebrospinal fluid.
Three layers of the meninges
Dura mater (outer menix)
arachnoid (middle menix)
pia mater (inner menix)
Dura mater
leathery double-layer outer menix
arachnoid menix
a loose layer seperated from the dura mater by the subdural space (middle menix)
**beneath the arachnoid menix is the subarachnoid space.
subarachnoid space
beneath the arachnid menix
contains blood vessels and is filled with cerebrospinal fluid
Pia mater
inner menix - thin connective tissue tissue tightly attached to the brain.
Cerebrospinal Fluid
a special fluid formed in the walls of ventricles from blood plasma by permeating the choroid plexus
choroid plexus
formed by a network of blood vessels and within the ventricles
CSF that is made in the walls of the ventricals by blood plasma permeates the choroid plexus
CSF circulates through the ventricles and into the mengines.
Cerebrospinal fluid
circulates through the ventricles into the meninges
cushions the brain and spinal cord by providing buoyancy allowing the brain to float
Blood brain barrier
a diffusion barrier that prevents most particles from entering the system tissue
this keeps the brain and spinal cord separate from general blood circulation
formed by glial cells- astrocytes
astrocytes
glial cell
blood brain barrier is formed by relatively impermeable brain capillaries, due to astrocytes
this barrier provides a stable chemical environment for the neurons
why is a stable chemical environment important in the brain?
to protect neurons from chemical variations that could cause uncontrollable firing of neurons
cerebrum
foremost part of brain
largest part of brain -83% of brain mass
contains 2 large masses - left and right cerebral hemispheres
median longitudinal fissure
separates the right and left cerebral hemispheres
The right cerebral hemisphere controls the left side of the body and the right cerebral hemisphere control the left side of the body
gyri
the cerebral cortex has raised ridges of tissue called gyri (like mountains)
sulci separate the gyri -these are shallow grooves (valley in between the mountain)
transverse fissure
separates the cerebrum from the cerebellum
corpus callosum
a bridge of white nerve fibers called corpus callosum that connects the cerebral hemispheres
cerebral cortex
outer portion of cerebral hemispheres that is highly convoluted and gray in color
Frontal lobe
controls higher levels of executive functions such as reasoning and decision making
controls motor function
permits control over voluntary muscle actions
parietal lobe
receives sensory information from receptors in the mouth for taste and located in the skin, such as those for touch, pressure, pain
occipital lobe
interprets visual imput
temporal lobe
has sensory areas for hearing and smelling
Primary areas of cerebral cortex
in each lobe receive or send information for one type of sensory or motor information
association areas of cerebral cortex
mainly work to integrate more than one type of sensory information for purposeful action- ex. primary motor cortex in the frontal lobe
primary motor cortex
controls voluntary motor movements for all parts of the body
primary sensory cortex
receives all direct sensory imput from the body
also called post central gyrus or somatosensory cortex
What do all four lobes have?
association areas which receives information from other lobes and integrates it to higher, more complex levels of consciousness
ex. artist abilities, learning, memory intellect
Broca’s area
located in the frontal lobe and is responsible for speech production
Wernicke’s area
located in the temporal lobe and is responsible for speech comprehension
consciousness
the cerebrum is responsible for consciousness - a state of being aware and awake to a person’s surroundings
Cerebrum
portion of the brain that governs higher thinking, intelligence, reasoning
controls activités of lower parts of the brain including the brain stem, diencephalon, limbic system and cerebellum
can override the functioning of lower parts of the brain (ex. when a person uses meditation to reduce a high heart rate.
how does the cerebrum initiate voluntary control?
by acting on sensory input via the thalamus
brainstem
the medulla oblongata, midbrain, pons are in the midbrain
medulla oblongata
lies between the spinal cord and pons and anterior to the cerebellum.
contains vital centers for regulating heartbeat, breathing and vasoconstriction(blood pressure)
also has a reflex centers for vomiting, coughing, sneezing, hiccuping and swallowing
vasoconstriction
constriction of the blood vessels involved in regulation of blood pressure
Tracts in the medulla
the medulla has tracts that descend or ascend between the spinal cord and brain’s higher centers
The pons
contains bundles of axons traveling between the cerebellum and the rest of the CNS
The pons functions with the medulla to regulate breathing rate
has reflexes that deal with head movement in response to visual and auditory stimuli
midbrain
acts as a relay station for tracts passing between the cerebrum and spinal cord or cerebellum
what reflexes does the midbrain have?
reflex centers for higher level reflexes for involving visual, auditory, and tactile responses
superior and inferior colliculi
located in the posterior region of the midbrain - these regions control reflexes for the head and neck in response to sudden visual or auditory responses
spinal cord
extends from the brainstem to first lumbar vertebrae where it terminates at the conus medullaris
conus medullaris
where the spinal cord terminates
cauda equina
an extention of the cord beyond L1 that is a collection of nerve roots which ends at the coccyx
the spinal cord and the caudal equina are how all electrical impulses travel between the brain and the rest of the body
protection of the spinal cord
like the brain the spinal cord is protected by three things:
vertebrae, cerebrospinal fluid, and meninges - these are continuous from the brain
spinal dura mater
the spinal cord has a single layer of sheath called spinal dura mater that
it is separated from the the vertebral column by a cushioning fat- filled space called epidural space
epidural space
a fat filled space that separated the vertebral column from the spinal dura mater
filum terminale
an extension of Pia mater in the spinal cord that runs from the conus medullaris to the coccyx where it provides an anchor for the spinal cord
** the space between the middle arachnoid and inner pia is filled with CSF
spinal tap
the CSF filled subarachnoid space inferior to the end of the spinal cord at L1 is the location for a spinal tap - this a removal of CSF for testing/diagnostics
This region is chosen because there is less risk to damaging the spinal cord from the insertion of the long needle
two grooves of the spinal cord
anterior median fissure and shallower posterior median sulcus
central canal
the opening in the spinal cord that runs the entire length and is filled with CSF
white matter
is composed of myelinated and unmyelinated nerve fibers organized into regions called columns
tract
a bundle of axon in the CNS
ALL the tracts cross over to the opposite side in the spinal cord - this makes the left brain control the right side and the right side to control the left
ascending tracts
the white matter fibers of the spinal cord are mostly composed of ascending tracts
these proceed up to the brain to carrying sensory input
descending tracts
proceed down or within the cord carrying motor outputs with a few commissural tracts across the cord (these allow for communication between the right and left sides)
dorsal root
of the spinal cord carries incoming afferent/sensory neurons
dorsal root ganglion
contains the cell bodies of the afferent neurons from the dorsal root
ventral root
contains the axons of motor neurons
spinal nerve
the dorsal and ventral roots on each side of the spinal cord come together to form a spinal nerve
gray matter
of the cord is composed of a mixture of cell bodies of neurons
the grey matter is organized into regions called horns
there are two posterior dorsal horns and two anterior ventral horns
gray commissure
the small anterior horns are connected by a cross bar called the gray commissure
anterior ventral horns
contain somatic motor neurons whose axons serve as efferent pathways to skeletal muscles by way of the ventral roots of the spinal cord
SOMATIC motor neurons
posterior (dorsal) horns
serve as one of the afferent pathways from receptors by way of the dorsal roots of the spinal cord
lateral horns
of the gray matter are primarily located at the thoracic level of the spinal cord
these contain automatic sympathetic motor neurons whose axons serve as an efferent pathways to visceral organs
Where do the efferent pathways exit
the ventral roots of the spinal cord along with those of the somatic motor neurons
peripheral nervous system
lies outside the CNS
made up of nerves that are apart of the somatic or automatic system
somatic nervous system
somatic system contains nerves that control the skeletal muscles, skin, and joints
includes all the nerves the serve the muscular skeletal system and exterior sense organs, including the skin
exterior sense organs, including ones embedded in the skin, are receptors
receptors
receive environment stimuli and then initiate nerve impulses towards the CNS
Effectors
muscle fibers and glands are effectors which bring about a reaction to the stimulus in the PNS
automatic systems
contains nerves that control the smooth muscles of the internal organs and glands
viceral motor
the nerves in the automatic system are called visceral motor when they control smooth muscle or involuntary functions
Crainal nerves
Humans have 12 pairs of cranial nerves that are attached to the brain
these are either sensorry nerves (having long dendrites of sensory neurons only) or motor nerves ( having long axons of motor neurons only) or mixed (having long dendrites and long axons)
How are cranial nerves abbreviated and where are they located?
CN followed by a number that corresponds to their location in relation to their position on the brainstem.
All CN nerves are located in the head, neck, and face EXCEPT the Vagus nerve
Vagus nerve
controls internal organs - only CN not found in the head, neck, or face
Special sensory nerves
carry information responsible for smell, sight, hearing, and balance
olfactory
CN 1 in the brain
special sensory nerve responsible for smell
originates in olfactory epithelium and terminates in the olfactory bulbs
**Only CN that is attached to the cerebellum NOT brainstem
Optic
CN II in the brain
special sensory nerve responsible for the sense of sight
originates in the retina of the eye and cross at the optic chiasm and synapse in the thalamus
neurons then connect to send information to the visual cortex of the occipital lobe
Oculomotor
CNIII in the brain
motor nerve responsible for eye movement in both somatic and visceral systems
somatic motor movement controls the superior, inferior and medial rectus (inferior oblique muscles of the eye)
visceral motor division controls the dialation of the pupil.
Dialtion of pupil
changes the amount of light in the eye
Trochlear nerve
CN IV in the brain
somatic motor nerve also responsible for eye movement
trochlear nerve innervates the superior oblique muscle
trigeminal nerve
CN V in the brain
mixed motor and sensory nerve
responsible for chewing (mastication) and sensation of the face, nose and mouth
Three branches of trigeminal nerve
ophthalmic branch
maxillary branch
mandibular branch
opthamalic brach
entirely sensory
receives info from the skin around the forehead to eyebrows and upper part of the nose
maxillary branch
sensory only
receives info from the lower eyelids, upper lips, upper gums, and even part of the pharynx
mandibular branch
mixed sensory and motor
receives information from the lower gums, lower lips, and teeth.
receives sensory information from the tongue for heat, cold and pressure. NOT taste
the motor branch here controls mastication of food
abducens
CN VI inside the brain
motor neuron responsible for eye movement and innervating the lateral rectus muscles - contracting this muscle makes the eye move outward
facial nerve
CN VII in the brain
mixed motor and sensory nerve
responsible for facial expressions
also responsible for sensation of tongue and taste on the anterior portion of the tongue
visceral motor functions of controlling tear glands and nasal mucus glands
vestubulocochlear nerve
CN VIII in the brain
special sensory nerve responsible for hearing and balance.
travels through a hole in the temporal lobe called internal acoustic meatus
vestibular branch for balance and equallibrium
cochlear branch for sense of hearing
glossopharyngeal nerve
CN IX (9) in the brain
mixed sensory and motor nerve
motor portion for swallowing muscles
sensory portion for taste on the posterior portion of the tongue
also contains visceral motor neurons that control parotid salivary glands
vagus nerve
CN X
mixed sensory and motor nerve which spreads widely in the abdomen
responsible for digestion, regulation of the heart rate, and sensation of the digestive tract
accessory nerve
CN XI
motor nerve responsible for the control of muscles involved in rotation of the head and movement of the upper shoulders
nerve that allows us to shrug our shoulders
hypoglossal nerve
CN XII
a motor nerve responsible for voluntary tongue movements
brachial plexus
nerves for the upper extremities branch off the brachial plexus from combinations of the ventral rami of nerves C5-T1
The ventral rami of C5-T1 form the roots of the brachial plexus
Roots of brachial plexus
the roots from the brachial plexus form 3 trunks - superior middle, inferior
then they divide further into anterior and posterior divisions
then those divisions divide into three CORDS- lateral, posterior, and middle
Where do the cords of the brachial plexus terminate?
In 5 branches -
musculocanteous nerve
axillary nerve
median nerve
radial nerve
ulnar nerve
What are the other nerves that come off the brachial plexus at different location and supply the entire upper extremity?
long thoracic nerve, subscapular nerve, pectoral nerve, thoracdorsal nerves distribute sensory and motor information to locations in the upper extremity and shoulder
axillary nerve
supplies three muscles- deltoid (muscle of the shoulder), teres minor (muscle of rotator cuff), long head of triceps brachii (elbow extensor)
also carries sensory info from the shoulder joint
radial nerve
supplies the triceps brachii muscle as well as 12 muscles in the forearm controlling wrist and finger extension.
carries sensory info from the associated joint and overlying skin
follows the posterior surface of the humerus, wraps around anterior surface of the elbow, then follows the radial bone in the forearm
median nerve
supplies flexor muscles of the forearm and skin of the first 3 1/2 fingers
travels medially on the anterior surface of the elbow
ulnar nerve
supplies part of the flexor muscles of the forearm, wrist and hand as well as the skin in half of the pinky and ring finger
travels posteriorly behind the the medial side of the elbow then travels the ulnar side of the forearm
musculocutaneous nerve
responsible for flexor muscles of the arm including the biceps brachii and brachialis
travels along the radial side of the forearm
lumbar plexus
nerves arrive from the ventral rami of T12-L4
has an anterior and posterior division with a branch into the nerves to supply the pelvis and lower extremities
femoral nerve
the major nerve from the lumbar plexus
supplies the hip flexors and knee extensors as well as sensation to the skin from anterior thigh
lateral femoris cutaneous nerve
supplies sensory info from the skin of the anterior, lateral and posterior surfaces of the thigh
saphenous nerve
receives sensation from the medial surface of the leg
sacral plexus
nerves that arrives from the rami L4-S4
sciatic nerve arises from the sacral plexus and is THE LARGEST NERVE in the body
supplies inferior trunk and and posterior surface of the thigh
sciatic nerve
arises from the sacral plexus
largest nerve in the body
2 main branches - common fibular (peroneal nerve) of the lower leg and
Tibial nerve.
automatic nervous system
part of the PNS
made of motor neurons that control the internal organs automatically usually without the need for conscious intervention
what allows us to feel pain in our organs
sensory neurons that come from the internal organs
the cell bodies for these sensory neurons are in the dorsal root ganglion along with cell bodies from somatic sensory neurons
preganglionic axon
a motor neuron cell body located in the spinal cord or brain
The axon synapses with a second motor neuron located in the autonomic ganglion outside the spinal cord
postganglionic axon
after synapsing in an autonomic ganglion motor neuron synapses on an effector organ in the PNS
sympathetic system
also called the thoracolumnbar division
important during emergency situations associated with fight or flight situations
muscles require a steady supply of blood, glucose, and oxygen for muscle contraction
bronchi are dilated, heartbeat and breathing rate are increased
causes liver to deliver more glucose
inhibits digestion tract - needs to take a back seat
norepinephrine is the main neurotransmitter released
Sympathetic nervous system ganglia
sympathetic trunk ganglion, celiac ganglion, superiomesenteric ganglion, inferior mesenteric ganglion
sympathetic trunk ganglion
aka lateral ganglion -located on both sides of the spinal cord
contain ganglion for the sympathetic nervous system that control the effector organs in the trunk, head, and limbs
celiac ganglion
largest of the ganglia - these innervate the digestive tract
superiomesenteric ganglia
innervates the small intestine and part of the large intestine
inferior mesenteric ganglion
innervate the large intestine, kidneys, bladder, and sex organs
parasympathetic system
aka Crainsacral division
has more specific targets than the sympathetic division
“housekeeper division” because it promotes all internal responses associated with a relaxed state
This system causes the pupil of the eye to constrict and focus on nearby objects
promotes digestion through stimulation of smooth muscles in GI tract and secretion of digestive glands such as salivary glands
slows the heart rate down
acetylcholine is the main neurotransmitter used by the parasympathetic system.
Cholinergic
if a neuron release acetylcholine is called cholinergic
parasympathetic nervous system contains these ganglia
ciliary ganglion
pterygopalatine ganglion and submandibular ganglion
otic ganglion
Intramural ganglion
ciliary ganglion
associated with CN III
target the intrinsic eye muscle which change the pupil and lens
pterygopalatine and submandibular ganglion
associated with CN VII
targets organs for tear production, nasal glands, salivary glands
otic ganglion
associated with cranial nerve IX
target glands are parotid glands
intramural ganglion
associated with CN X
target glands are the visceral organs within the thoracic cavity
concussion
if the head is moving and is suddenly stopped as it hits an object brain damage can occur at the impact- as the brain recoils and hits the opposite side it can cause more widespread damage
brain contusion
a more serious impact injury that leads to significant tissue damage
usually causes unconsciousness (coma) ranging from hour to a lifetime
hemorhage
a rupture of a blood vessel that cause the blood to accumulate in the skull
intracranial pressure
amount of pressure available in the skull
intracranial pressure increases when there is a hemorhage because increased volume the blood takes up and compresses the brain tissue.
If pressure continues it pushes the brainstem down the magnum foramen which damages the brainstem and its vital life sustaining functions like heart rate, respiration, blood pressure will be lost with fatal consequences
A hemorage is serious because of the limited space in the skull for the brain to swell
Parkinson’s disease
a disorder of the basal ganglia
apraxia - impaired motor planning -results in rigid movements and difficulty executing a motor plan
ataxia - impaired motor coordination -resulting from an injury to the cerebellum
CVA (cerebrovascular accident)
Stroke -occurs when blood circulation to the brain is blocked
the tissue in that area dies due to lack of oxygen and nutrients to the brain
severity depends on which vessel is blocked -a larger artery will cause more damage than a smaller one
Ischemic stoke
ischemic - due to a blockage from a clot by fat deposit blocking the cerebral artery
TIA -transient ischemic stroke when small clot temporarily blocks blood flow but then dissolves -the person no longer experiences stroke symptoms
hemmorhagic stroke
occurs due to a brain bleed when a blood vessel in the brain ruptures
Storke outcomes
A servere stroke often causes death
If a person survives they can have paralysis, cognitive deficits, speech problems, emotional difficulties and pain
Some people can recover at least some portions of their lost functions through physical and occupational therapy
Undamaged neurons in surrounding areas can sprout are branches and spread into the damaged areas and take over lost functioning -this is called NEUROPLASICITY
Dementia
Alzheimer’s if a form of dementia which is a general term for all disorders with memory deficits
normally found in elderly and leads to mental decline and loss of control of bodily functions
alzheimers is from changes in the cerebral cortex
plaques form and entangle dendrites within the brain and prevent them from firing
lack of firing leads to death. as neurons die it causes more plaques and tangles in other neurons spreading the disease throughout all brain tissue
there is a shrinkage of the cerebral cortex gray matter and enlargement of ventricles
It begins with difficulty to remembering newly learned information, and then progresses to difficulty speaking, swallowing, and walking
This disease can cause mood and behavior issues and suspicion/paranoia of friends, caregivers, and family members
Amyotrophic lateral sclerosis
Lou Gherig’s disease
A rare neuromusular disease condition that involves progressive destruction of ventral horn motor neurons (motor neuron cell bodies)
as the disease progresses it causes paralysis - the person eventually loses the ability to speak, swallow, and eventually breath
paralysis (loss of motor functions)
causedby localized damage to the spinal cord and nerve roots
damage to the ventral root or anterior horn cells results in paralysis of the of asscociated muscles becuase impulses can not reach the muscle
Over time muscles atrophy due to lack of stimulation from the neurons
complete spinal cord injury
occurs if the spinal cord is completely severed at any level
total motor and sensory loss in regions below the site of damage, even if the spinal cord is intact below damaged site
quadriplegia
paralysis of all four limbs
can occur if damage to the spinal cord in the cervical region
carpal tunnel
compression of the median nerve
causes decreased sensation in the first three digits and half of the fourth
if a person has severe carpal tunnel and does not receive treatment than the muscles can atrophy and lead to decreased hand strength
claw hand
ulnar claw
if the ulnar nerve is damaged - this results in the inability to open the fourth and 5th finger
caused by flexion at the IP joints and hyperextension of the MCP joints In digits 4-5
sciatica
increased pressure on the sciatic nerve from surrounding muscles can result in pain followiing the sciatic nerve in the lower pelvis and posterior thigh
all except this sense is channeled through the thalamus
Sense of smell
what is the difference between primary and association areas
Primary areas in one area receive information for one type of sensory info. Association areas act to combine the different sensory information from the different areas for purposeful action
What part of the brain is responsible for homeostasis?
The hypothalamus maintains body temperature, blood pressure, water balance, sleep, thirst, hunger
the hypothalamus also controls the pituitary gland
how many pairs of spinal nerves are there?
31 pairs between the spinal cord and its extension cauda equina.
What is the purpose of the spinal cord and how does it accomplish this
The spinal cord and its extension are how all nerve impulses are sent between the brain and the rest of the body - it does this with 31 pairs of spinal nerves
What is gray matter composed of
multipolar neurons and supporting cells
describe the function of white matter in the brain
The white matter is composed of acsending tracts that carry sensory information to the brain and descending tracts that carry motor information down the spinal cord
what are the 5 types of human spinal nerves
8 pairs of cervical nerves
12 pairs thoracic nerves
5 pairs of lumber nerves
4 pairs of sacral,
1 pair coccxygeal nerves
Describe the structure of the spinal nerves
Each spinal nerve emerges from the spinal cord from two short roots -The dorsal root contains axons from sensory (afferent) neurons and conduct impulses towards the cord and the ventral root which contains axons from motor (efferent neurons) and conduct impulses away from the cord.
The two nerves come together before they leave the vertebral column.
what is a dermatome
a region of skin that carries sensory information through a specific pair of spinal nerves in the spinal cord and to the brain
Describe in detail what happens after the spinal nerves leaves the vertebral column
right after it exits the vertebral column, it divides into branches called dorsal ramus and ventral ramus
smaller dorsal ramus contains nerves that serve the dorsal portions of the trunk, including the skin and muscles of the back.
The larger ventral ramus contain nerves that serve the ventral part of the trunk as well as the upper and lower limbs.
Epithalmus
pineal gland takes up most of this region
pineal glad responsible for making melatonin that makes us feel sleepy
regulates sleep and wake cycles
in diencephalon
thalamus
roof of third ventricle
relay station for all sensory input except for smell
it takes in the information and decides what to do
Cerebellum
“mini brain”
inner white matter outer gray matter
coordinates body movements -relays info to the cerebral motor cortex
**maintains balance, eye movements, and MUSCLE TONE
even at rest our muscles remain somewhat contracted for support
Vermis
part of cerebellum coordinates motor actions of arms and legs
Limbic system
has both conscious and unconscious control
its shapes connect all the lobes
contains cingulate gyrus, hippocampus, amygdala, fornix, mammilary bodies
called the “feelings brain” stimulation of different areas can cause rage, pleasure sorrow pain
also weighs consequences and awards
cingulate gyrus
helps connect different lobes of the cerebrum -allows all lobes to talk to each other
hippocampus
in charge of memories-memories not stored here but instead acts like a relay center and decides where to store memories in the cerebrum and can pull memories
gathers all the information to put together a memory we are trying to recall from the different places they are stored in the cortex
amygdala
responsible for rage and anger outbursts
fornix
bundle of nerve fibers- connection to the hippocampus that help store and retrieve memories
mammilary bodies
fibers that project into the thalamus -assist with memory of smell
this is why memories are so tightly associated with smell- mammilary bodies in the limbic system
memory in the limbic system
short term- a few seconds (recall a phone number that was just read off and then forget)
long term- a few hours-to a lifetime
being able to study and memorize
basal ganglia
responsible for coordination with the cerebellum for motor planning movements and learning
Also has an INHIBITORY response to the cerebral cortex - it slows it down to make precise and controlled movements when our brain wants to go go go
It makes a motor plan and then relays it to the cerebral cortex so it can execute the motor plan
Apraxia-difficulty with motor planning and executing plan - parkinson’ disease
Basal nuclei (aka basal ganglia)
masses of gray matter than lie deep within each hemisphere of the cerebrum
part of the limbic system
it works with the cerebellum to regulate motor planning, movements and motor learning
what are the parts of the basal ganglia
the putamen, caudate nucleus, globus pallidus (medial and lateral) -know how to label these
cerebellar penduncles
serve to connect the cerebellum to other parts of the brain
anterior and posterior lobes of the cerebellum
receive information from the truck of the body and influence the motor activities of the truck, shoulders, and pectoral girdle muscles
vermis
part of the cerebellum that coordinates limb movements
ataxia
loss of voluntary muscle coordination - disorder of the cerebellum – intoxication can cause this
Anterior horns
for somatic motor neurons -so voluntary decisions to move -these leave through efferent pathway
posterior horns
posterior horns -afferent pathways in gray matter
sensory infö
somatic nervous system
controls joints, muscles, and skin
receptors
receive enviromental stimuli and send to the CNS
sympathetic nervous system
aka thoracolumbar division
contains preganglionic fibers from thoracic and lumber segments of the spinal cord
widespread targets
covers large region and has many effects
