Units 1, 2, and 3 Flashcards
The two components of the Central Nervous System?
Brain (encephalon)
Spinal Cord
how many cranial nerve pairs are in the PNS?
12 cranial pairs
How many spinal nerve pairs are in the PNS?
31 spinal nerve pairs
what and where are the Ganglia?
Groups of neuron cell bodies clustered together in the PNS
The amount of CSF produced in one day?
0.5L
Which part of the lateral ventricle lacks a choroid plexus?
Frontal cornu
How many nerve trunks carry preganglionic autonomic neurons away from the spinal cord?
6
The rhombencephalon first forms during which embryonic week?
week 5-6
Arachnoid mater is continuous with which layer at the IVF?
perineurium
Chromatolysis is a process that involves which neuron structure?
Nissl substance
List functions of astrocytes?
structural support, scar formation, glycogen storage
CSF within the subarachnoid space of the vertebral canal generally ascends into what cistern?
pontine
The pineal gland protrudes into what cistern?
ambiens
Denticulate ligaments form from what?
Pia mater
what are the openings/tubes associated with the fourth ventricle?
cerebral aqueduct, central canal, right foramen of luschka, median foramen of Magendie
which vessel is most often associated with pulsating cephalgia?
middle meningeal artery
The dura mater fuses to the coccyx via what specific extension?
Filum terminale externum
A third ventricle develops within which secondary brain vesicle?
diencephalon
which type of oligodendrocyte forms most of the myelin inside the CNS?
interfascicular oligodendrocytes
Retrograde intraneuronal movements of chemicals within a neuron are characteristics of what phenomena?
axoplasmic transport
where are neurohormones synthesized?
in the hypothalamus
how long can a process be?
a few microns to 40 inches or a few feet
what are the 4 reasons for lack of success in CNS sprouting?
blood capillary permeability changes
excessive glial cell scarring
if it reaches the old target it finds competition for reattachment.
possible allergic reactions
what are the common neurohormones?
ADH (vasopressin)
Oxytocin
Releasing Factor Neurohormones
Another name for the interventicular formina
Foramina of monro
How does chiropractic relate to the nervous system/neuroanatomy?
Adjustments alter/ influence skeletal structures which affect/influence neurological function
what are the components of the CNS?
Brain (encephalon) spinal cord (medulla spinalis)
describe the histology of CNS blood vessels?
thinner walls, internal elastic membranes are absent, considerable thinning at branches, veins are valveless (except a few spinal veins), no vaso vasorum
The myel- gives rise to?
Medulla oblongata and 4th ventricle
route of the sigmoid DVS?
begin where the transverse leaves the tentorium cerebelli and course along the mastoid process to the jugular foramen
what component of the nervous system innervates skeletal muscle?
Somatic
the brains percentage of cardiac output usage?
14-17%
how does the arachnoid mater relate to CN2?
it forms the cranial nerve sheath as the subarachnoid space and extends to the eyeball.
chromatolysis is sometimes confused with?
retispersion
the somatic nervous system has both CNS and PNS structures?
true
How many brains will follow the standard pattern of the cerebral arterial circles without anomalies?
1/2
Another name for the cerebral aqueduct?
cerebral aqueduct of Sylvius
how many neurons are involved with efferent impulses in the somatic system?
1
where do segmental arteries gains access to the spinal cord?
at the intervertebral foramen (IVF)
chief factors of blood brain perusion?
arterial blood pressure
blood viscosity
vascular resistance
intercranial pressure
acetylcholine in somatic systems is excitatory or inhibitory?
excitatory
the 4th ventricle opens into the pontine cistern in these two places?
the lateral foramina or formina of luschka
True or false
we have no conscious control over the visceral systems?
true
true or false
every tissue and cell is directly wired into the nervous system
false
true or false
both afferent and efferent fibers in the autonomic systems are subdivided into sympathetic and parasympathetic?
false
only efferent, afferent are the same
what causes cephalgia and what can help?
the meningeal arteries are sensitive to dilation
acetominophen for pain
caffeine for vasoconstriction
the parasympathetic system utilizes what specific nerves?
Cranial nerves 3,7,9,10
sacral nerves 2,3,4
true or false
like the arachnoid mater the pia mater is avascular?
false, it is vascular
the Falx cerebri extends from…anteriorly to posteriorly
the crista galli, to the internal occipital protuberance
describe the anatomical classification of a unipolar neuron?
processes attach to the cell body from the same side and look as if they are one unit.
describe the anatomical classification of a bipolar neuron?
processes attach to the cell body on opposite ends and appear as 2 distinct processes.
describe the anatomical classification of a multipolar neuron?
only one axon leaves the cell body (though it may latter divide) and many dendrites.
subdural hematoma is most commonly due to?
rupture of bridging veins due to shear injury
what is neuropathology?
the study of neurological disease
describe efferent sympathetic nerves?
there are 2 not 1 as in somatic, the preganglionic neuron is relatively short and synapses with its postganglionic neuron which carries the impulse to target tissues. it is said to be adrenergic since the postganglionic neuron releases norepinephrine to cause changes. it has a pre to post ganglionic ratio of 1:17 and are thus more general in their reaction.
exceptions to sympathetic systems being adrenergic?
sweat glands, and arrector pili muscles
the brain is what percentage of adult body weight?
2-2.5% uses 20% Oxygen
effects of sympathetics?
excitatory in nature (fight or flight) therefore:
speeds heart rate
decreases peristalsis (digestion)
dilates pupil (for more light/better sight)
and dilates respiratory tree (for more oxygen to fight or flee)
symptoms of stroke
unconsciousness slow pulse flushed face slurred speech headaches and memory loss
glioblasts are also called?
nerve glue
is the arachnoid mater vascular?
No
the most stable and consistent side of the cerebral arterial circle?
the left side from the left internal carotid
is the Falx cerebelli fixed?
yes
denticulate ligaments are made of?
epipia
functions of astrocyctes?
BBB-blood brain barrier I- Influence neurotransmitters S- structural support S- storage of Oxygen and sugar S- Scar Tissue
This autonomic system is often referred to as the fight or flight?
sympathetic
the die- gives rise to?
the thalamus
pineal gland
3rd ventricle
true or false?
astrocyctes are the most numerous cell in the adult nervous system?
true
to what are the lateral ventricles connected and how?
to the 3rd ventricle by the interventricular foramina of (monro)
fingerlike projections of arachnoid mater into sinus’?
arachnoid villi
axoplasmic flow and transport as relating to chiropractic?
when pressure is placed on rootlets then flow and transport slow down and cells can die. subluxation can cause cell death.
another name for the cistern ambiens?
the cistern of the great cerebral vein, or superior cistern.
treatment for CSF obstruction?
surgical shunts
what do astrocytes give rise to and describe them?
protoplasmic astrocyctes- gray matter
fibrillar astrocytes- white matter
the nervous system plays a dominant role in _________,__________,_________ of body responses to internal and external demand.
coordination, association and intergration
pia mater means?
tender mother
what empties into the straight dura venous sinus (DVS)?
the inferior sagittal DVS and great cerebral vein
name and describe the third autonomic system?
- the enteric system is the intrinsic system of the gut.
- encompasses from esophagus to anal verge.
- utilizes peristaltic reflexes
In the CNS, is myelin associated with schwann cells?
no, it is interfascicular oligodendrocytes
what to oligodendrocyctes give rise to and describe them?
perineuronal satellites- gray matter, nutrient
interfascicular- white matter, CNS myelin
Location of the Lumbar cistern?
around the conus medullaris to the upper sacral canal (S2)
where are the shunts ususally redirected to?
right atrium of the heart cisterna magna pleural cavities peritoneum lumbar cul de sac
the sympathetic system utilizes what spinal nerves?
T1-L2
why do most substances not find easy access to the brain via the bloodstream?
the Blood Brain Barrier
these cells line the ventricles of the brain and serve as a leaky barrier?
ependymal cells
clinical aids in detecting CSF obstruction?
pneumoencephalography ventriculargraphy myelograms CAT scans MRI PET
true or false
as with the other meningeal layers, the PIA mater doesn’t dip into all the fissures and sulci of the brain and cord.
False,
it does dip into them
how many total nerves are in the PNS?
86
list the less common forms of glioma?
oligodendroglioma
oligoastrocytoma
gliosarcoma
choroid plexus tumore
is the dura, a vascular tissue?
yes but only a few capillaries, with arteries running on top of it
the parasympathetic system is also known as?
craniosacral
describe neuroblasts
little mitotic ability, depend on astrocytes to guide them as they spread through the CNS, damaged by alcohol and radiation as a fetus.
location of the pontine cistern?
Anterior of Pons
where was the 1985 international congress of anatomy held?
london
how many openings are in the 4th ventricle and name them?
there are 5 openings right and left lateral foramen of luschka median foramen of magendi central canal and the cerebral aqueduct of sylvius
what are the functional classifications of neurons?
internuncial (entirely in CNS), afferent and efferent
which substances are able to cross the BBB and which cant?
lipid soluble can
water soluble cant
true or false
in the vertebral canal the dura still has two layers?
false
it has only one layer
how many peptides are neurotransmitters?
40
what are the potential types of perikaryon?
F- Fusiform P- Pyramidal R- Round o- Oval S- Stellate (star shaped)
what is white matter?
groups of myelinated axons
what are the stages of development?
zygote morula blastocyst inner and outer cell mass primitive streak mesoderm notochord induction of nervous system within ectoderm: neural plate, groove, fold-neural tube and crest cells
location of the superior cistern?
deep within the transverse cerebral fissure, superior to cerebellum posterior to pineal gland and midbrain.
leading cause of death in males and females over 25 with high blood pressure and arteriosclerosis?
stroke or CVA
hollow filaments made of protein?
neurofibrils
this is the processes of an efferent process?
telodendria
where are the neurochemicals usually stored?
in the vesicles or near the parasympathetic membranes
is there myelin in CNS structures?
yes
on structures greater than 1 micron
why have a nucleus or centrosome if there is no mitosis?
because it still acts as a command center and direct cell function
where in a neuron are mitochondria most abundant?
soma and telodendria
meningeal double layers extending into a few brain fissures are known as?
Dural Falces
name and describe the 3 common types of brain tumors
astrocytoma- most common
oligoblastoma- most deadly (6month-1year)
ependymoma- fills ventricles
describe CSF
clear, colorless, mostly water, few cells, higher concentration of NA+,Cl-, Mg++ ions than blood, but lower in Ca++, K+, glucose and protein.
function of nissl bodies?
staining
are astrocytes mitotic?
No
Name the secondary vesicles and where they stem from?
- prosecephalon divides into diencephalon and telencephalon.
- mesencephalon stays the mesencephalon
- the Rhombencephalon divides into Metencephalon and Myelencephalon
large cephalic expansions of the neural tube with accompanying expansions of the central canal are?
brain ventricles
which structural classes of neuron perform which functions?
unipolar- sensory
bipolar- special senses
multipolar- motor
internucial- connect sensory and motor
this is a process that joins similar processes?
collateral branch
describe fetal development and responsiveness?
8 weeks- embryo can respond to stimuli (pain)
10 weeks- spontaneously active, movement
12 weeks- can grasp
how much blood is perfused through the brain each minute?
800ml
is the somatic nervous system cholinergic or adrenergic? define both terms
its Cholinergic
cholinergic systems cause nerve impulsse through the release of acetylcholine.
Adrenergic systems effect impulse by the release of norepinephrine.
incoming nerves are________ and outgoing nerves are__________?
afferent, efferent
area where the pia mater extends around the arteriole?
pial coat
collection of blood in the subarachnoid space?
subarachnoid hemorrhage?
dominately long process?
nerve fiber
is the somatic nervous system autonomic or voluntary?
Voluntary
true or false
myelin is any covering on a nerve process?
false
it is only called myelin if it wraps several times other than that it is just a neurolemma
true or false?
there is myelin covering on telodendria, perikaryon, and the hillock?
false
it is only over the long processes
true or false
myelin can form on processes smaller than 1 micron?
false
as a rule myelin seldom forms on neuron fibers less than 1 micron.
effects of parasympathetics?
more relaxing in nature therefore: slows the heart rate speeds peristalsis (digestion) constricts pupils constricts respiratory tree
describe continuous capillaries?
no fenestra, no holes, tight junctions between cells, thick basement membrane
nerve grafts
rejoined ends of severed nerves, the gap between them is filled by a graft, sural nerve autografts are most common, it serves as scaffolding for revascularization and innervation, success is never complete
blood vessels going or coming from the CNS reconducted through this?
epipial layer of pia
when a golgi apparatus fragments during injury?
retispersion
most common site of strokes?
middle cerebral artery
compare the brain at birth to the adult brain?
at birth- it is 10% of body weight (300-400g) and uses 60% of oxygen.
in adult- 2-2.5% of body weight (1400g avg) and uses 20% oxygen.
where the Flax cerebelli fixed to?
the internal occipital crest
the area between nodes of ranvier?
internode
location of the superior petrosal DVS?
along the crest of the petrous parts of the temporal bones at the attached margin of the tentorium cerebelli
how much of a nerve cross section many epineurium consume?
25-85%
what percentage of stroke or CVA is ischemic and hemorrhage?
85% ischemic, 10% hemorrhage
tufted prolongations of arachnoid mater that herniate into the dura mater, associated with the lining of DVS?
arachnoid villi
regeneration side notes?
- sprouts may have 10-40 pseudopodial extensions from the damaged fiber, all of which regress except the one that attaches.
- rate of regeneration varies but is close to axoplasmic flow 1-4mm/day.
- remyelination starts after the schwann cell and sprout reach the target site.
- neuron sprout and surrounding cell may aid each other.
another name for the confluence of the sinuses?
torcular herophili
true or false
like schwann cell myelin coverings, oligodendrocytes cover only one cell>
false
they can cover parts of 40 or more
what are the other names for the components of the CNS
encephalon
medulla spinalis
these penetrate the cranial vault and can be a path for infections to spread to DVS as a result of?
middle ear emissary veins
what 2 things determine the speed of impulse conduction velocity?
thickness of fiber and myelin thickness
has fine reticular elastic fibers that adhere to CNS structures?
inner pia intima
can a damaged neuron regenerate a lost of damaged part?
it depends on the extent of the damage
if a neuron degenerates, do the neurons that follow it also degenerate
no
name and describe the various forms of internuncial neurons?
commissural- between equivalent structures on opposite sides of the CNS
projection- begins in one structure and ends in another
intrasegmental- in the spinal cord it begins and end sat the same level
intersegmental- in the spinal cord it begins and ends in different levels
ipsilateral- stays on the opposite side
contralateral- crosses to the opposite side
discuss glioblasts
- functional connective tissue
- non conductile
- 10x more than neurons
- undergo mitosis but little after 5 years
what is the vertebral duras relationship to spinal nerves?
the dura becomes continuous with the 31 nerve pair coverings which act as 31 pairs of stabilizers similar to meningovertebral ligaments
are Cns grafts possible?
they have been attempted using fetal and embryonic tissues in scandinavia, mexico, and the USA
Loaction of the straight DVS?
at the junction of the Falx Cerebri, tentorium cerebelli, and falx cerebelli running posteriorly to the confluence
can cause over production of CSF resulting in increased cranial pressure?
tumors of the choroid plexus, papillomas
what is in the epidural space?
areolar and adipose tissue as well as a complex internal vertebral venous plexus
the major topic of the 1985 international congress of anatomy in london, england?
the role of co-transmitters
where doe sthe occipital DVS empty and in what direction?
left into the left transverse DVS
where does the fuse?
fused to the rim of the foramen magnum, and via the filum terminale to the dorsal surface of the sacrum and first coccygeal segment.
what is the relationship between schwann cells and fiber thickness?
the thicker the fiber, the longer the schwann cell?
true or false
the subarachnoid space is an empty space with a fixed distance of 1/2 inch
false
it is filled with CSF and arachnoid trabeculae and varies from 1/8 to 2 inches
describe the vertebral canal dura and how it is different from the cranial dura?
the inner meningeal layer is more collagenous, the outer periosteal layer is absent (it ends at the foramen magnum), there is an actual space called the epidural space
does the superior sagittal DVS contain CSF?
yes
used CSF enters the superior sagittal DVS via the arachnoid villi
true or false
the somatic nervous system has both efferent and afferent nerves?
true
because the nervous system is so specialized it is inadequately equipped for _________ and _________>
storing excess oxygen and sugar, and maintains little mitosis capacity
these penetrate the arachnoid and fuse to the dura in the vertebral canal?
denticulate ligaments
important peptide hormone details?
substance P- pain pathways, 11 amino acid sequence
1973- specific receptor sites for opiates in CNS are found
1975- natural Opiates (enkehalins) discovered
1977- larger peptide with longer effects (endorphins) are found
what are the 3 meninges?
dura mater, arachnoid mater, pia mater
another name for dura mater?
tough mother
describe dural innervation?
supatentorially- CN 5,8
Infratentorially- CN 10
what is myelin composed of?
phospholipid/ cholesterol and neurokeratin (protein)
describe the 3rd ventricle?
a narrow opening in the substance of the diencephalon
true or false
the arachnoid mater dips with the dura mater into fissures and sulci
true
but only where the dura does
what is another name for the inner dural layer?
meningeal dura
true or false
neurons may secrete any of the possibe types of neurotransmitters
false
only one type per neuron
how many neurochemicals are there?
30 well established but as many as 100
blood in the superior sagittal DVS runs in what direction into what structure?
it runs right, into the right transverse DVS
describe the openings of the 4th ventricle?
right and left lateral foramen of luschka- connects the 4th ventricle to the pontine cistern
median foramen of magendi- opens into the cisterna magna
central canal- opens into the central canal
cerebral aqueduct of sylvius- this connects the superior 3rd ventricle to the 4th
the space created around the arteriole by the pial coat?
perivascular space or virchow-robin space
examples of lipid and water soluble substances?
lipid-lipids, caffeine, cocaine, alcohol, nicotine, vitamin B6 and B12, L-dopa
water- Botulism, Dopamine
what is the significance of the node of ranvier and the xposure of the nerve fiber?
it is the point that a collateral branch will form if there is one.
what supplies the majority of blood to the brain?
internal carotid arteries
describe the various axon junctions?
axoaxonic- the axon synapses on the axon
axodendritic- the axon synapses on the dendrite
axosomatic- the axon synapses on the cell body
which areas or the spinal cord are particularly vulnerable to arterial problems and why?
due to minimal anastomoses, posterior surface of T1-T3 and anterior surface of T4 and L1
true or false
in the cranial vault the dura has a single layer?
false
it has 2
sites for CSF obstruction?
interventricular foramen
median lateral foramen
cerebral aqueduct
subarachnoid space near tentorium hiatus
true or false
afferent nerves in all types of systems, somatic, sympathetic, and parasympathetic, utilize only 1 cell?
true
where do nerves originate in somatic systems?
the spinal cord
describe the location of the tentorium cerebelli?
under the occipital lobes like a tent over the cerebellum
where does the tentorium cerebelli attach?
to the lateral occipital bone and the superior crest of the petrous portion of the temporal bone. the forward portion is along the posterior clinoids of the sphenoid
location of the interpeduncular cistern?
between cerebral peduncles, anterior part of the midbrain
true or false
generally the thicker the neuron fiber the thicker the myelin?
true
true or false
like other hematomas subarachnoid hemorrhages are caused only by trauma
false
they can be traumatic from cerebral contusions or nontraumatic (spontaneous) associated with a ruptured aneurysm or AV malformation.
what does the diaphragma sellae form?
the roof of the sella tursica (pituitary fossa)
an extension away from the body?
process
the purpose of the Falces?
they compartmentalize the cranial vault, act as baffles, and support the weight of the brain protect it from blows to the head
explain the terms supratentorial and infratentorial?
supra- above the tentorium
infra-below the tentorium
how much CSF is made in the choroid plexus?
70-80% of total CSF production
true or false
though different from blood CSF is similar to brain interstitial fluid?
true
a collection of blood between meningeal dura and arachnoid?`
subdural hematoma
other sites for CSF production besides the choroid plexus?
brain capillaries and enters ventricles by ependymal cells
these are processes of afferent processes?
dendrite spine
where is the Falx cerebelli located?
where the Dura dips between the cerebellar hemispheres in the posterior cerebellar notch
how are the simple squamous cells of the arachnoid mater unusual?
they can become motile and phagocytic
discuss arachnoid meningiomas?
it gives rise to many though the quickly attach to the dura mater and appear to be dural tumors
the arachnoid mater and pia mater make up the?
leptomeninges
if a neuron is damaged will it divide?
no
another name for arachnoid villi?
pacchionian bodies (when calcified) or villi
what are stalk or pillar like formations of white matter?
peduncles
true or false
the subdural space is a real space and not a potential space?
false
it is a potential space
what is neurophysiology?
the study of neurological function
how many parts do the lateral ventricles have?
5 anterior /frontal horn ventricular body collateral trigone (atrium) inferior/ temporal horn posterior/ occipital horn
areas where the subarachnoid space is particularly deep?
subarachnoid cisternae
name the components of the subarachnoid cisternae?
cisterna magna cisterna ambiens pontine cistern interpeduncular cistern lumbad cistern
the superior sagittal DVS receives blood from?
scalp
bones
cerebrum
causes of CSF obstruction?
tumors
congenitally small or absent openings/aqueducts
the Met- gives rise to?
cerebellum
pons
4th ventricle
the thickest meninge
dura mater
