nervous system Flashcards
what are the parts of the CNS?
brain
spinal cord
CN I,II
parts of PNS?
peripheral nerves (e.g radial,sciatic nerves) ganglia (sensory, autonomic) other CN, III-XII
what are the 3 germ layers?
ectoderm, mesoderm, endoderm
what is the thin part of ectoderm?
skin (surface) ectoderm
what is the thick part of ectoderm above the notochord?
neural ectoderm
what is the neural groove?
when a part of the neural ectoderm inveginates to the mesenchyme.
a groove is found between 2 folds.
what is the neural tube?
when 2 folds will meet and enclose the neural groove, a neural tube will form and migrate to the mesenchyme.
what are the cell is the neural fold?
neural crest- from neural fold cells.
what is the thickening on the anterior part of the surface ectoderm, in front of the neural tube?
placod ectoderm
what will form the brain and what will form the spinal cord?
cranial part of neural tube will form the brain,
caudal part of neural tube will form the spinal cord.
(neural tube will form the CNS)
what are the 3 primary brain vesicles, found at the cranial end of the neural tube?
- forebrain (prosencephalon)
- midbrain (mesencephalon)
- hindbrain (rombencephalon)
- the caudal continuation of these 3 is the spinal cord
- this is until the 5th week, after which these primary brain vesicles transform to secondary vesicles.
what are the derivatives of the prosencephalon?
secondary brain vesicles
- telencephalon (end brain) with 2 hemispheres
- -> 2 hemispheres r+l
- -> telencephalon impar (unpaired), found between them. - diencephalon
what are the derivatives of the mesencephalon?
secondary brain vesicles
there are no derivatives, it remains mesencephalon/midbrain
what are the derivatives of the rombencephalon?
secondary brain vesicles
- metencephalon
- -> pons [ant]
- -> cerebellum [post] - myencephalon
- ->medulla oblongatab(it is between pons and spinal cord)
*caudally is the spinal cord
what is the wall of primary and secondary vesicles?
neural ectoderm, will form Glial cells and neurons.
what is the cavity of the hemispheres?
lateral ventricles.
what is the opening between telencephalon impar and the cavity of the hemispheres?
interventricular foramen (of Monroe)
what is the common cavity between the telencephalon impar and diencephalon?
the 3rd ventricle
what is the common cavity of the rombencephalon, of the the pons, medulla and cerebellum?
4th ventricle (behind pons and medulla, in front of the cerebellum)
what is the connection between 3rd and 4th ventricles?
cerebral aquaduct (sylvian cannal) it is due to proliferation of cells in the mesencephalon which makes the space narrower, tube like.
what are the 2 main sulcus we need to identify?
central sulcus
lateral sulcus
what are the parts of the inferior frontal gyrus?
pars orbitalis
pars triangularis
pars opercularis
*these are bordered by the ascending and horizontal parts.
what is between the superior frontal sulcus and inferior frontal sulcus?
the middle frontal gyrus
what is the gyrus above the corpus callosum?
cingulate gyrus, with cingulate sulcus above.
what is the continuation of the cingulate sulcus?
marginal sulcus
what is the border between the parietal and occipital lobes?
parieto-occipital fissure
what is the most important fissure of the occipital lobe?
calcarine sulcus.
what is found between the calcarine sulcus and parieto-occipital sulcus?
triangular - shaped cuneus.
in front of the cuneus- precuneus [quadrangular shaped, btw marginal sulcus and parieto-occipital sulci]
what is in front of the precuneus?
para-central lobule
which 2 lobules are between the intra-parietal sulcus?
superior parietal lobule + inferior parietal lobule
which 2 parts belong to the inferior parietal lobule?
supramarginal gyrus
angular gyrus
(two C shaped)
how can you find easily the 2 gyri of the inferior parietal lobule?
at the end of the lateral sulcus - the supramarginal gyrus can be found.
at the end of the superior temporal sulcus - the angular gyrus can be found.
[Wernicke’s area]
what is the continuation of the lingual gyrus?
para hippocampal gyrus
the fusion of the 2 vertebral arteries gives which artery?
the Basilar a.
where can we find the 3rd cranial nerve?
between:
posterior cerebral a. AND superior cerebellar a.
what are the branches of the vertebral a.?
it gives:
- posterior inferior cerebellar a.
- anterior spinal a.
- posterior spinal a.
what are the emissarian veins?
connection between intracranial veins + diploe,
and intracranial veins + extracranial veins.
which 2 veins are in the roof of the 3rd ventricle?
- internal cerebral vein
- -> vein of septum pellucidum
- ->thalamo-striate vein
- -> superior choroidal vein - great cerebral vein (of Gallen)
- ->drains to straight sinus
what is the cavity of the hemisphere?
the lateral ventricle
what are the parts of the lateral ventricle?
- anterior horn [f]
- central part\body [p]
- posterior horn [o]
- inferior horn [t]
what are the walls of the anterior horn?
ant: genu of corpus callosum
floor: rostrum of corpus callosum
roof: junction of body+genu of C.C
medial: septum pellucidum
lateral: head of caudate nucleus
what are the walls of the central part?
ant: NO anterior wall {because anterior horn}
floor: seemingly thalamus, but lamina affixa
roof: body of corpus callosum
medial: septum pellucidum, part of fornix, choroid tella of central part
lateral wall: body of caudate nucleus.
walls of posterior horn?
ant: NO anterior wall
roof: radiation of splenium of C.C + optic radiation
floor: collateral trigone
postero-medial: calcar avis, from calcarine sulcus
lateral: tapetum [radiation of fibers of c.c]
walls of inferior horn?
roof: white matter of temporal lobe [tale of caudate nucleus, stria terminalis,optic tract, lateral geniculate body]
floor: collateral eminene +hippocampus
medial: choroid tella
lateral: tapetum
anterior: amygdaloid body
what is the outer layer of the brain and what does it contain?
grey matter\cortex, contains cell bodies of neurons + glial cells + basal ganglia
what is the inner layer of the brain and what does it contain?
white matter \ medulla, longest parts of neurons, vessles, cell nuclei.
what is the boundary between parietal lobe and occipital lobe?
line between the upper part of parieto-occipital fissure and pre-occipital notch
what are the 2 layer of the dura matter in the brain?
outer, periosteal layer [gives periosteum to cranium]
inner, meningeal layer
what are the meningeal arteries?
- anterior meningeal a.
- > from ICA - middle meningeal a.
- > from maxillary a. -> from ECA - posterior meningeal a.
- >from ascending pharyngeal ->ECA
what are the septa?
duplications of the dura matter:
- falx cerebri
- falx cerebelli
- tentorium cerebelli
- diaphragma sellae [opening for stalk of hypophysis]
- trigeminal cavity [meckel’s]
what kind of space is the epidural space in the brain?
not a true space, potential epidural bleeding. [lens shaped]
between the periosteal layer and the sutures of skull
what kind of space is the subdural space in the brain?
not a true space. potential venous hemorrhage.
[bridging veins]
what is a cistern?
dilated portion of subarachnoid space,
a cavity where CSF flows
what are the functions of the CSF?
shock absorber
removes waste products of neurons and glial cells
makes brain & spinal cord lighter.
what is the dura matter spinalis?
its the dura mater of spinal cord, consists of
outer layer = endorachis
inner layer = dural sac
the epidural space in the spinal cord is..
a true space !
filled with fatty C.T + internal vertebral venous plexus.
the subarachnoid space of the spinal cord is..
a true space!
contains the CSF.
the 4th ventricle is considered as a cavity of..?
the hindbrain
what is the connection between the 3rd and 4th ventricles?
cerebral aquaduct - filled with CSF
in the brain stem, what are the 2 structures that each part has? and which part has an extra structure?
the midbrain, pons, and medulla each have a BASE + TEGMENTUM.
the midbrain also has a Tectum.
what is the cerebral peduncule?
it is in the midbrain, consists of the base + tegmentum.
2 cerebral peduncules form interpeduncular fossa.
where does the production of CSF takes place?
in the roof of 3rd ventricle
in the central part of lateral ventricle
at the inferior horn of lateral ventricle
in the 4th ventricle
what is the choroid glomus?
enlargement of choroid plexus.
choroid plexus of central part+inferior horn meet, and protrudes to posterior horn.
what is the choroid tella?
lamina choroidea epithelialis + vascular pia matter
what are the 3 gyri of the frontal lobe?
superior frontal gyrus
middle frontal gyrus
inferior frontal gyrus
what are the 3 gyri of the temporal lobe?
superior temporal gyrus
middle temporal gyrus
inferior temporal gyrus
what are the 3 parts comprising the inferior frontal gyrus?
pars orbitalis
pars triangularis
pars opercularis
what are the 2 parts of the inferior temporal lobule?
- supramarginal gyrus [cont. with lateral sulcus]
2. angular gyrus [cont. with sup. temporal sulcus]
what is the name of the cistern which is connection between median pontine cistern, and cistern of optic chiasm?
interpeduncular cistern
arteries of the willi’s circle?
anterior + posterior cerebral a.
posterior communicating a.
anterior communicating a.
internal carotid a.
main gyri of inferior parietal lobule?
angular gyrus
supramarginal gyrus
what is the gyri below the calcarine sulcus?
lingual gyrus
between which 2 layers is the epidural space of the vertebral column?
endorachis + dural sac
what are the veins forming the internal cerebral vein?
- vein of septum pellucidum
- thalamo-striate vein
- superior choroidal vein
what is the border between para-hippocampal gyrus and medial occipito-temporal gyrus?
collateral sulcus
how many cervical cranial nerves do we have?
8
what are the denticulate ligaments?
pia matter, pierces the arachnoid and attached to dural sac, anchors the spinal cord in the vertebral canal
contents of the epidural space in vertebral canal?
fatty connective tissue
internal vertebral venous plexus
superior orbital fissure is the skull exit of which cranial nerves?
- occulomotor
- trochlear
- ophtalmic of trigeminal
- abduscent
where is the dural exit of the olfactory nerve?
cribriform plate
what is the name of the fissure between the 2 hemispheres?
longitudinal cerebral fissure
what is the name of the dural septum in the transverse cerebral fissure?
tentorium cerebelli.
what is the connection between the inferior sagittal sinus and confluence sinus?
straight sinus.
what is the lateral wall of 3rd ventricle?
thalamus+hypothalamus