Organization of the Nervous System Flashcards
what is the division of the Nervous system?
CNS and PNS
what makes up the CNS?
what makes up the PNS?
Spinal cord + brain
Cranial nerves + ganglia + spinal nerves
what is another word for CNS?
neuroaxis
where do we find grey matter in the brain?
what makes up the grey matter?
in the cortex (cell body, dendrites and glia)
non-myelinated axons
where do we find most of the white matter?
what makes up the white matter?
in the inner brain
myelinated axons
what does the blue line divide?
supratentorial from infratentorial
what hemisphere of the brain is usually dominant?
left hemisphere
what are these Brodmann numbers for?:
- 44, 45
- 22
- 8
- 4
- 1,2,3
- 17
- Broca
- Wernecke
- Frontal Eye field
- Primary motor gyrus
- Primary sensory gyrus
- Primary Visual field
what makes up the brainstem?
midbrain, pons, medulla
where do we find most cranial nerves and nuclei?
within brainstem structures
what is the function fo the cerebellum?
plan and execute movement and balance by comparing what the muscles do to the action that was intended to occur
Identify these areas
- Thalamus
- Pineal gland
- Superior colliculus
- Inferior colliculus
- Cerebellum
- Pons Base
- Tegmentum
- Medulla
- Hypothalamus
how do you know if there is brainstem damage?
ipsilateral cranial nerve symptoms
+
contralateral body deficit
where is the reticular formation in the brain?
what is its funciton?
what do you get if it is damaged?
the brainstem
control consciousness
coma
Name the Cranial Nerves
- CN 1
- CN 2
- CN 3
- CN 4
- CN 5
- CN 6
- CN 7
- CN 8
- CN 9
- CN 10
- CN 11
- CN12
- olfactory
- optic
- oculomotor
- trochlear
- trigeminal
- abducens
- facial
- vestibulocochlear
- glossopharyngeal
- vagus
- Accessory
- hypoglosseal
what encloses the brain?
what is its function?
the meninges
protect and isolate CNS
what are the 3 parts of the meninges?
what is the leptomeninges?
dura + arachnoid + pia
pia + arachnoid
the meninges has 2 layers that form these 2 structures?
falx cerebri
tentorium cerebelli
what does the dura do?
strong elastic covering which supports the brain, separates the two hemispheres from each other
what are these structures?
1) falx cerebri
2) tentorium cerebelli
what are the spaces that are created by penetrating arteries through the dura?
virchow spaces
what is a meningeal herniation?
what is an example of a lesion that may lead to a meningeal herniation?
space occupying lesion
epidural hematoma
what is a epidural hematoma?
what will it look like in a CT?
what can this lead to?
lesion to the side of the head, damaging the middle meningeal artery (near the pterion) and bleeding into the space between the skull and dura
In a CT lesion looks like an oval
leads to a transtentorial herniation and may also cause duret hemorrhages
what is this?
transtentorial herniation
what is this?
duret hemorrhages
what is this?
epidural hematoma
what is Meningitis?
what symptoms indicate meningitis?
what time frame is important?
bacterial or viral infection that affect the brain and leptomeninges
high fever, stiff neck, photophobia, phonophobia, headache, nausea, Confusion, disorientation, difficulty waking up
first 48 hours
identify the type of meningitis
1) caused by Neisseria meningitis and is highly contagious, there is a rash present
2) meningitis that is not contagious and has no rash
3) meningitis that follows an infection of tuberculosis and occurs frequently in immuno-compromised individuals
1) meningiococcal meningitis
2) pneumococcal meningitis
3) tuberculosis meningitis
what is this?
bacterial meningitis
what is this?
bacterial meningitis
what are the 4 key symptoms for bacterial meningitis?
nuchal rigidity, sudden high fever, and altered mental status and a rapidly spreading petechial rash
identify the type of meningitis
1) meningitis that occurs due to viral or immune related disease
2) meningitis due to a infection with enterovirus, and is very contagious in kids
3) meningitis that occurs mainly in immuno-compromised patients (HIV)
4) meningitis caused by spreading of a tumor from lung or breast
1) asceptic meningitis
2) viral meningitis
3) fungal meningitis
4) neoplastic meningitis
what are 3 tests that are done to test for meningitis?
what do you test in each?
1) Kernig sign: Stiff hamstrings that lead to inability of fully extending the leg when hip is at right angle to supine patient.
2) Brudzinski sign: Passive neck or single hip flexion is accompanied by involuntary flexion of both hips.
3) Lumbar puncture: you look at the opening pressure and the color of CSF
what meningitis test is this?
kernig sign
what meningitis test is this?
brudzinski sign
when is opening pressure in lumbar puncture elevated?
when is opening pressure un lumbar puncture not elevated?
when is opening pressure un lumbar puncture not affected?
in bacterial meningitis
in viral meningitis
fungal or TB meningitis
when is lumbar puncture CSF color cloudy and turbid?
when is lumbar puncture CSF color normal?
when is lumbar puncture CSF color slightly cloudy?
bacterial meningitis
viral meningitis
in TB meningitis
what is wrong here?
meningitis: you can see discoloration of the meninges
what types of edema can be seen with meningitis?
At what time interval do each occur?
vasogenic edema: seconds to minutes
cytotoxic edema: minutes to hours
interstitial edema: hours ++
In vasogenic edema, fluid leaks from where to where?
from blood vessel into white matter
(usually due to increased permeability in the blood-brain barrier)
why does cytotoxic edema occur?
due to low blood flow
what is interstitial edema?
when does it happen?
CSF leaking into brain tissue
when white blood cells enter the brain or CSF
what is this?
abcess’s due to meningitis
what is encephalitis?
what are symptoms of this?
what is the most common cause?
inflammation of CNS tissue
sudden fever, headaches, stiff neck and back, confusion
viral
what is encephalitis lethargica?
how do patients look?
atypical form of encephalitis
they are motionless, in a coma-like state
what is the name for the cavities in the brain that produce CSF?
What is the direction that CSF follows?
does CSF recirculate?
Ventricles
Ventricles –> subarachnoid space –> venous drainage
nope
what are the 4 ventricles we can find?
1 & 2) Lateral ventricles
2) Third ventricle
3) Fourth Ventricle
identify the ventricles
how much CSF gets produced each day?
500 ml
what is the problem here?
hydrocephalus
what are the 2 reasons hydrocephalus occurs?
1) due to blockage of ventricles (obstructive or non-communicating)
2) due to overproduction of CSF or decreased re-absorption (non-obstructive or communicating)
identify the arteries of the CNS
what are the 2 main arteries that supply blood to the brain?
where are arteries and veins located in the brain?
1) Internal carotid arteries
2) vertebral arteries
in the sub-arachnoid space
what 2 arteries that get damaged will cause us to see bilateral symptoms when there is a vascular defect in the circle of willis?
what are the 2 branches of the internal carotid?
basilar artery and anterior cerebral artery
MCA and ACA
identify the arteries
what procedure can be used in order to observe the arteries?
what do you use?
arteriogram, use a dye
what are berry aneurysms?
where do we find 90% of berry aneurysms
weak spots on arterial walls that balloon out
in the circle of willis
what is a subarachnoid hemorrhage?
does blood pool?
what is the main complaint patients present with?
ruptured aneurysm that leads to bleeding in the subarachnoid space
no
“worst headache of my life”
what is a subdural hematoma?
damage to the superior cerebral veins from trauma to back or front of head
what is this?
a subdural hematoma
what are the major subdivisions of the brain?
- Telencephalon
- Diencephalon
- Mesencephalon
- Metencephalon
- Myelencephalon
what structures does the Telencephalon make up?
cerebral hemispheres
lateral ventricles
basal ganglia
what structures does the Diencephalon make up?
Thalamus
hypothalamus
3rd ventricle
what structures does the Mesencephalon make up?
the midbrain
what structure does the metencephalon make up?
pons
cerebellum
what structure does the myelencephalon make up?
medulla
4th ventricle
how do you call the telencephalon and diencephalon together?
how do you call the metencephalon and myelencephalon together?
prosencephalon
rhombencephalon
Identify the major subdivisions of the brain
If you get hit in the frontal face and damage the anterior cranial fossa, what bone will you also fracture?
what symptoms do you see?
the cribriform plate of the ethmoid bone
anosmia, CSF leakage (rhinorrea), epistaxis
if a bullet hits someone in the head, and he/she is still alive…what type of imaging do you not do?
what type of injury will you see in this case?
MRI
intracranial bleeding
what is the classification of neurons due to the amount of processes they have?
how do you identify each?
what do each do?
Unipolar: 1 axon + 0 dendrites
Bipolar: 1 axon + 1 dendrite
Pseudopolar: 1 process
• sensory system uses this type (any sensation)
Multipolar: many dendrites + many axons
• found in the CNS
where do we find bipolar neurons?
where do we find pseudopolar neurons?
where do we find unipolar neurons?
in Cranial Nerves
in all 1st order neurons of spinal cord
during development
how do we classify neurons by axonal length?
1) golgi type 1: long axons
2) golgi type 2: short axons
Golgi types are also called interneurons
how do we classify neurons by function?
1) motor
2) sensory
3) interneurons
what happens if you damage motor neurons?
what happens if you damage sensory neurons?
paralysis
can’t feel or have propioception
indentify the condition that is related to this inclusion body:
- lipofuscin
- neuromelanin
- lewy bodies
- hirano bodies
- pick bodies
- negri bodies
- cowdry type A bodies
- lafora bodies
- old age
- parkinsons (see a loss of it)
- parkinsons or lewy body disease
- alzheimers
- picks disease or frontotemporal disease
- rabies
- herpes encephalitis
- myoclonic epilepsy
what is this inclusion body?
what disease is it related to?
lewy body
parkinsons
what is this inclusion body?
what disease or condition is it related to?
lafora body
myoclinic seizure
what is this condition?
picks disease
what condition or disease is this?
pick’s disease
how are pick bodies described?
ball shaped
how do we classify axonal transport?
how fast is each?
what molecule moves material forward? backward?
what material gets transported forward?
what material gets transported backward?
- fast axonal transport = 200-400 mm/day
- slow axonal transport = 1-5 mm/day
- fast retrograde transport = 100-200 mm/day
forward = kinesin –> vesicles and proteins
retrograde/backward = dynein –> recycled membrane and lysosomes
what nerves are capable of regenerating?
why?
PNS nerves
due to the arrangement of the Schawnn cells
what is chromatolysis?
when there is neuronal damage and the nucleus moves away from the region of the axon hillock while the nissl body moves to the periphery
what is this?
chromatolysis
what is this?
when does it happen?
neuronophagia
when there is damage to the neuron and it cant be fixed so microglia cover the affected neuron
what are the glial cells?
astrocytes, ependymal, oligodendrocytes, microglia
what do glial cells do?
- provide structure and support for neurons
- produce CSF
- help in forming the Blood-brain barrier
- form scars and help healing
- myelinate neurons
what are the 2 types of supporting tissues?
which tissue does the PNS contain?
which tissue does the CNS have?
fibrous and glial
fibrous tissue
glial tissue except for the meninges which is fibrous
there are 2 types of pain systems, what are they?
what are type 4 or C nerve fibers? is it myelinated?
alpha motor axons innervate what?
wht do gamma motor axon do?
fast and slow
they are slow pain and temperature
not myelinated, it is the only 1 like this
innervate the extrafusal muscle fibers
innervate the intrafusal muscle fibers
a epidural hematoma can lead to what clinical signs?
1) can lead to transtentorial herniation
2) duret hemmorrhage
3) lucid period of minutes
4) fractured pterion
5) oval shape in CT
6) bleed in between dura and arachnoid
what can a transtentorial herniation lead to?
loss of consciousness
duret hemorrhage
compression of CN 3 (ptosis & myadriasis)
damage to a brodmann area on one side will have symptoms on which side?
What will you see if you have damage to left Brodmann area 4?
on the opposite side
you will see paralysis of the right side as well as a babinski sign
what do i have to do to get broca’s aphasia?
damage to 44, 45 on the left side
