CNS Exam 1 Flashcards
What is nervous system dominant in? (3 things)
coordination
Association
Integration
What 2 things can’t the nervous system store?
oxygen/glucose
How many cranial nerve pairs in PNS?
12
How many spinal nerve pairs in PNS?
31
What does the somatic NS innervate?
skeletal muscles (voluntary)
What does the Autonomic/Visceral NS innervate?
glands, smooth and cardiac muscles (involuntary)
What is the Parasympathetic NS?
rest and digest
What makes up the Craniosacral subdivision?
CN: 3, 7, 9, 10
SN: 2, 3, 4
What is the sympathetic NS?
fight or flight
What makes up the Thoracolumbar subdision?
T1 - L2
What do neuroblasts give rise to?
neurons
What do glioblast cells give rise to?
astrocytes and oligodendrocytes
What do glioblast cells play a role in?
structural support
Most numerous cell of the adult CNS?
astrocytes
What is the function of astrocytes?
form scar tissue during injury
2 types of astrocytes
protoplasmic and fibrous
What astrocytes are found in grey matter?
protoplasmic
What astrocytes are found in white matter?
fibrous
2 types of oligodendrocytes
perineuronal sattelites and interfascicular
Where are perineuronal satellites Oligodendrocytes found and what is there function?
found in gray matter;
nutrition storage
Where are interfascicular Oligodendrocytes found and what is there function?
found in white matter; form myelin around axons in CNS.
What cells line the central canal and ventricles of CNS?
ependymal cells
What serve as a leaky barrier between CSF and CNS parenchyma
ependymal cells
Ependymal cells secrete CSF and form the…
choroid plexus
Where are tanycytes located?
in the 3rd ventricle
What is the most common primary brain tumor?
astrocytoma
What is the most lethal primary brain tumor?
glioblastoma
What primary brain tumors restrict flow of CSF?
ependymoma
What is the function of Microglia?
phagocytic, responsible for clearing dead and damaged tissue
What does the neural crest tissue give rise to?
PNS structures
What do neuroblasts depend on to guide them as they migrate through the CNS
glial cells (astrocytes)
What neurons carry visceral or somatic sensory info?
unipolar
Where are unipolar neurons found?
in dorsal root ganglian
What neurons are associated with special sense structures?
bipolar
How many axons can a neuron have?
only 1!
What direction do sensory neurons carry info?
toward CNS
What direction do motor neurons carry info?
away from the CNS
neuron that runs between equivalent structures on opposite sides of the CNS
commissural
neuron that begins in one structure and terminates in a different structure of the CNS
projection
neuron in the spinal cord that begins and ends at the same cord level
intra segmental
neuron in the spinal cord that begins at one cord level and terminates at another cord level
inter segmental
3 types of structures that meet to form a synapse in the CNS?
axoaxonic
axodendritic
axosomatic
What do axoaxonic structures connect to?
axon
What do axodendritic structures connect to?
dendrites
What do axosomatic structures connect to?
axosomatic
Nissl bodies respond quickly and appear to dissolve but really the bodies are just dispersed and this is known as
chromatolysis
fragmentation of the golgi apparatus under injured conditions
retispersion
What is the function of microtubules?
help maintain cell shape
What direction is slow transport?
anterograde
What is the speed of slow transport directly related to?
axon length
Does slow transport need ATP?
no
What direction does fast transport occur?
anterograde or retrograde
What molecules do slow transport carry?
protein building blocks
What molecules do fast transport carry?
synaptic vessicels and lysosomes
What is fast transport related to?
not axon length but energy denpendent
anatomical and functional unit of the nervous system?
neuron
an extension of the neuron away from its cell body
neuron process
a neuron process conducting an impulse (charge) toward the cell body (can be several dendrites)
dendrite
single neuron process carrying the impulse (charge) away from the cell body toward a synaptic or neuromuscular junction
axon
a raised area of the cell body from which an axon arises; in the CNS most action potentials are initiated here
axon hillock
a dominantly long process, if present, of a neuron. Usually an axon but can be a dendrite too
nerve fiber
Where can myelin covers be found
both PNS and CNS fibers
When myelin cover is present where it only covers…
long process (fibers)
What is the minimal diameter size an axon needs to be in order to be myelinated?
greater than 2 microns
What nerve fibers have Schwann cells?
every PNS
If fibers have Schwann cells are they myelinated?
no
where one Schwann covering cell meets another
internodes
What Mesodermally derived connective tissue is high vascular and next to the neuron?
endoneurium
What Mesodermally derived connective tissue is virtually inelastic and continuous w/ the dura matter?
epineurium
What Mesodermally derived connective tissue is the most elastic and becomes continuous with the pia and arachnoid?
perineurium
What is the virtually inelastic outer coat of a nerve?
epineurium
What is the thickest and outermost of the meninges?
dura mater
What are the 2 layers of the cranial vault?
endosteal dura and meningeal dura
What is the outer highly vascular dura layer which serves as a periosteum to the cranial bones?
endosteal dura
What is the inner more fibrous layer of the dura?
meningeal dura
How many dura layers are in the vertebral canal?
only 1 (the meningeal dura)
What is the potential space?
real space
where is the epidural space created?
along the vertebral canal
What is the epidural space filed with?
areolor and adipose connective tissue
Where is the internal vertebral venous plexus?
epidural space
How is the dura attached w/in the vertebral canal?
fused from rim of foramen magnum thru filum terminale
then, from lower sacrum to first to coccygeal segment.
what are meningovertebral ligaments?
dura making attachment into ligaments or periosteum of:
the axis,
lower cervical and occasionally thoracic vertebarae
What is the double layer or meningeal dura extending into a few fissures of the brain?
dural falces
What 2 flexures are present before the 3rd and 4th weeks of development
cervical and cephalic
What is located in the great longitudinal cerebral fissure between the Rt/Lt cerebral hemisphere?
Falx Cerebri
Where the meningeal dura dips between the cerebellar hemispheres in the posterior cerebellar notch
falx cerebelli
paired structure with a right and left extension
tentorium cerebelli
The opening left in the middle between Lt. and Rt. tentorial wings is called the…
tentorial hiatus
The tentoria are actually located in the ___ ___ fissure
transverse cerebral
Meningeal dura that forms a “roof” over the sella turcica
diaphragma sellae
The dura and cephalgia (headache) are associated with what?
dura vascular tissue
Is the arachnoid mater vascular?
non-vascular
Does the arachnoid matter dip into fissures or sulci?
no
Is the dura mater a real or potential space?
potential space
Is the subdural space a real or potential space?
real space
Is the arachnoid trabeculae a real or potential space?
real space
Is the subarachnoid space a real or potential space?
real space
What does the arachnoid villi allow int the blood stream?
CSF
What is the largest cranial cistern?
cerebellomedullary cistern
The pontine cistern is the anterior aspect of what?
the pons
What are the pair of openings that enter the Pontine Cistern laterally through the 4th ventricle?
lateral foramina of Luschka
What is the largest cistern of the body?
lumbar cistern
What do arachnoid villi become when calcified?
pacchionian bodies
What do the arachnoid villi facilitate?
csf transportation
What is the function of the arachnoid villi?
allows used CSF to be removed from the subarachnoid space
Does the pia dip into all fissures and sulci of the brain and cord
yes
The denticulate ligaments in the vertebral canal are formed by…
pia
the filum terminale internum is formed primarily by…
outer pial layer
What is the space found between the pia and the blood vessel.
perivascular space
collection of blood between the skull and the periosteal dura
epidural hematoma
collection of blood between meningeal dura and arachnoid
subdural hematoma
What is the symptom of a non-traumatic subarachnoid hemorrhage?
worst headache of my life
Approximately ___ ml of blood is perfused through the brain each minute?
800 ml
80% of stroke cases patients have already reported signs of….
TIA’s
What brain arteries are the most commonly reported sites for strokes?
middle cerebral artery
What arteries supply the majority of blood to the brain?
internal carotid arteries
the most common brain anomalies involve what artery?
anterior communicating artery
What is the most stable side of the cerebral arterial circle ?
left internal carotid artery
What does the anterior cerebral blood vessel distribution supply?
frontal & longitudinal fissure and parietal & frontal lobe
What does the middle cerebral blood vessel distribution supply?
lateral aspect of all 4 lobes
What does the posterior cerebral blood vessel pattern supply?
occipital and medial temporal lobes
What small artery sends nearly 200 branches into the ventral aspect of the cord?
Anteromedial Longitudinal Artery Trunk (AMLAT)
How do the PLLAT and AMLAT enter the various vertebral levels?
via the IVF
What vessels supply the most blood to the cord?
AMLAT and PLLAT
What are the few areas of the cord that are particularly vulnerable due to minimal anastosomoses between vessels?
posterior surface of T1-3 and anterior surface near T4 and L1.
Veins lack valves with the exception of which one?
vasa vasorum
Are extremely dense capillary beds found in either gray or white matter?
gray matter
How much blood is normally present in the brain?
75 ml
What is the most common capillary type?
continuous capillary
Name 1 of 6 specialized areas of the CNS are not in continuous / in tact with BBB?
pineal body, infundibular stalk, choroid plexus, supraoptic crest, area postrema, and subfornical organ
Name a substance that can cross the BBB.
caffeine, alcohol, cocaine, nicotene, vitamin B6&12, & L-Dopa
Name a substance that does not cross the BBB.
dopamine and botox
Do venules and veins of the CNS follow the same course the arteries and arterioles follow?
no
Most cerebral veins penetrate the ____ and ___ to drain into the dural venous sinuses.
arachnoid mater and meningeal dura
many dural venous sinues reveive blood from the scalp via ___ and surrounding bone via ____.
emissary veins
diploic veins
Vault drainage of dural venous sinus blood is in the Rt. or Lt. _____ veins at the jugular foramina.
internal jugular
What is the path of blood flow through the dural venous sinus?
[DOWN AND TO THE RIGHT] Superior Sagital D.V.S. Confluence of Sinuses Transverse D.V.S. Sigmoid DVS
Most blood in this sinus flows into the right transverse dural venous sinus after passing through the ….
confluens sinuum
Most used CSF in the subarachnoid space enters the DVS through penetrating…
arachnoid villi
The inferior sagital dvs runs along the posterior 2/3 of the….
falx cerebri
Middle ear veins penetrate into the vault and drain into the ____ sinus.
superior petrosal sinuses
How does the 3rd ventricle connect to the 4th ventricle?
via cerebral aquaduct
What are the 5 openings of the 4th ventricle?
cerebral aquaduct central canal median foramen right lateral foramen left lateral foramen
name a function of the CSF?
shock absorber and buoyancy
At any one moment an individual will have how much CSF in their body?
80-150 ml
