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150 Cards in this Set

  • Front
  • Back
what is neurulation?
process of neural induction and formation of neural tube
what's a neural tube?
is hollow tube made from the pear-shaped region of ectoderm called neurectoderm
what are primary brain vesicles?
formed by 4th week

are dilations of neural tube at anterior end

are 3 dilations;
1. prosencephalon = forebrain
2. mesencephalon = midbrain
3. rhombencephalon = hindbrain
what are secondary brain vesicles?
appear at 5th week

are divisions of primary brain vesicles
prosencephalon or forebrain becomes
anteriorly - telencephalon: become the hemispheres
posteriorly - diencephalon: where optic cups come from

rhombencephalon becomes:
anteriorly - metencephalon: forms pons and cerebellum
posteriorly - myelencephalon: becomes medulla oblongata
what do the terms basal plate and alar plate refer to?
generally refer to developing CNS regions with
basal plate - motor and
alar plate - sensory neurons

in spinal cord
basal plate - ventral horn
alar plate - dorsal horn
what are the lateral ventricles?
two ventricles found in outpocketings of telencephalon

ventricle of diencephalon is 3rd ventricle
ventricle of rhombencephalon is 4th ventricle
what/where is the cerebral aqueduct?
is small region between the 3rd and 4th ventricles
what are the third and fourth ventricles?
third ventricle - ventricle of diencephalon

fourth ventricle - ventricle of rhombencephalon
what is the ependymal layer?
is layer of neural tube from which neuroblasts, or cells that give rise to neurons, first appear

near surface of ventricle
what's the mantle layer?
future gray matter of spinal cord

from cells of ependymal lyaer that have differentiated and migrated short distance
where's the marginal layer?
is cell-free zone with neurites - or long, thin processes from cells of mantle layer

near edge of spinal cord

will be white matter of spinal cord

becomes thick in dorsal and ventral spinal cord, thin in middle
what's the choroid plexus?
from very vascularized roof of myelencephalon

invaginates into 4th ventricle
what do the cerebral hemispheres usually do in normal people?
are centers of reasoning, memory, emotion

also are higher control of muscles - problem of paralysis with stroke
what does the diencephalon do?
is relay center connecting sensory systems with cerebral hemispheres

regulates ANS
what does the midbrain do?
is small region containing cell bodies of CN III and groups of neurons that interpret hearing/vision
what's the hindbrain?
includes cerebellum, pons, medulla oblongata
what does the cerebellum do?
is subconscious regulation of equilibrium, locomotion and posture
what does the pons do?
is bridge tween cerebral hemispheres, cerebellum and spinal cord
what does the medulla oblongata contain?
cell bodies of many of cranial nerves and other fiber tracts connecting the spinal cord with rest of the brain
what's the neurectoderm?
is pear-shaped region of ectoderm
what makes up the neural plate?
is from thickening of neurectoderm at midline

3 week embryo
what are neural folds?
are lateral margins of neural plate that elevate, move toward one another and fuse
what's the neural tube?
hollow tube of neurectoderm
what are neuropores?
are holes at either end of neural tube before they have fused
what do the cells of the neural tube become?
neurons and glia of CNS
what does the hollow center of the neural tube become?
is called the neural canal and stays hollow in adult brain as ventricles
what's the neural canal?
is the hollow center of the neural tube
why is the anterior end of the neural tube larger than the posterior end? what do these ends eventually become?
anterior is larger because tube is made from pear-shaped ectoderm

anterior end becomes brain
posterior end becomes spinal cord
what process of the development of the CNS is particularly susceptible to mutation, or environmental insult? why?
neurulation

is problem because many women don't know they're pregnant at time, and can be taking prescription or recreational drugs
what's a result of abnormal neurulation?
spinal bifida
where do the primary brain vesicles form from?
dilations at anterior end of neural tube at 4 weeks of develoment
what are the names of the three primary brain ventricles?
1. prosencephalon - forebrain
2. mesencephalon - midbrain
3. rhombencephalon - hindbrain
what are the flexures in embryonic CNS development?
4th week of development

1. cephalic flexure = bend in neural tube at mesencephalon
2. cervical flexure = bend in neural tube between the rhombencephalon and spinal cord
3. pontine flexure
tween metencephalon and myelencephalon
what happens by 5 weeks in development of CNS?
appearance of secondary brain vesicles
what are secondary brain vesicles?
divisions of primary brain vesicles
what are the secondary brain vesicles are from what do they come from?
prosencephalon becomes
anterior telencephalon
posterior diencephalon
what does the telencephalon become?
the cerebral hemispheres
what forms from the diencephalon?
optic cups
what secondary vesicles does the rhombencepholon become?
anterior metencephalon
posterior myelencephalon
what does the metencephalon become?
pons, cerebellum
what does the myelencephalon become?
medulla oblongata
what are the secondary vesicles?
telencephalon
diencephalon
metencephalon
myelencephalon
what are the lateral ventricles?
two ventricles in outpocketings of telencephalon
what's the third ventricle?
ventricle of diencephalon
what's the fourth ventricle?
ventricle of rhombencephalon
what's the central canal?
is ventricle of spinal cord
what's the neuroepithelium and what role does it play in CNS development?
is epithelium of walls of neural tube
involved in formation of spinal cord
is pseudostratified epithelium
what are neuroblasts and where do they come from?
are cells that make neurons
come from surface of ventricle, area called ependymal layer or germinal matrix
what's the ependymal layer or germinal matrix and what does it do?
is surface of ventricle from which neuroblasts arise
where does gray matter of spinal cord come from?
from mantle zone or mantle layer, which is more differentiated layer of spinal cord with neurons showing up for the first time
what are neurites?
are long, thin processes extended from new neurons
grow toward outer edge of neuroepithelium
what makes the white matter of the spinal cord?
the marginal layer - is cell-free zone where neurites are

near edge of spinal cord
where are most of the motoneurons in spinal cord development?
ventral horn of spinal cord - with ventral gray matter
what makes up the ventral and dorsal horns of the spinal cord? where do they come from?
come from thickenings of mantle zones only in dorsal and ventral parts of spinal cord, middle is thin
where do neurons that process sensory input hang out in the embryological development of the CNS?
the dorsal horn with dorsal gray matter
what area does the basal plate correlate with? why?
the basal plate is an area where motor neurons are developing and correlates with the ventral horn
what area does the alar plate correlate with and why?
alar plate is area where sensory neurons are developing - this correlates with teh dorsal horn
are congential malformations of the spinal cord common?
yes
what does spina bifida refer to?
problem with fusion of vertebral arches
what's the central canal?
is ventricle of spinal cord
what does spina bifida occulta refer to?
problem with vertebrae fusing

occurs in 10% of population

usually goes undetected and doesn't cause problems
what's the neuroepithelium and what role does it play in CNS development?
is epithelium of walls of neural tube
involved in formation of spinal cord
is pseudostratified epithelium
what are neuroblasts and where do they come from?
are cells that make neurons
come from surface of ventricle, area called ependymal layer or germinal matrix
what's the ependymal layer or germinal matrix and what does it do?
is surface of ventricle from which neuroblasts arise
where does gray matter of spinal cord come from?
from mantle zone or mantle layer, which is more differentiated layer of spinal cord with neurons showing up for the first time
what are neurites?
are long, thin processes extended from new neurons
grow toward outer edge of neuroepithelium
what makes the white matter of the spinal cord?
the marginal layer - is cell-free zone where neurites are

near edge of spinal cord
where are most of the motoneurons in spinal cord development?
ventral horn of spinal cord - with ventral gray matter
what makes up the ventral and dorsal horns of the spinal cord? where do they come from?
come from thickenings of mantle zones only in dorsal and ventral parts of spinal cord, middle is thin
where do neurons that process sensory input hang out in the embryological development of the CNS?
the dorsal horn with dorsal gray matter
what area does the basal plate correlate with? why?
the basal plate is an area where motor neurons are developing and correlates with the ventral horn
what area does the alar plate correlate with and why?
alar plate is area where sensory neurons are developing - this correlates with teh dorsal horn
are congential malformations of the spinal cord common?
yes
what does spina bifida refer to?
problem with fusion of vertebral arches
what does spina bifida occulta refer to?
problem with vertebrae fusing

occurs in 10% of population

usually goes undetected and doesn't cause problems
what does spina bifida cystica refer to?
when there is a herniation of the meninges with or without the spinal cord

results from failure of vertebrae to fuse
what's spina bifida with meningocele
when only the meninges bulge through opening in vertebral column
what does the suffix -cele stand for?
herniation
what is spina bifida with mylomeningocele?
is when spinal cord is included in herniation with meninges in bulging through opening in vertebral column
what is rachischisis?
is failure of neural folds to fuse
is accompanied by abnormal development of vertebrae

luminal surface of neuroepithelium left exposed
what specific spina bifida conditions are associated with neurological deficits that include partial or total paralysis of abdominal muscles and lower limbs as well as sphincter paralysis?
1. spina bifida cystica with myelomeningocele AND
2. RACHISCHISIS
what divisions come from the rhombencephalon and when?
myelencephalon and
metencephalon

5th week of development
where is the rhombencephalon located?
most caudal primary brain vesicle
where is the myelencephalon?
is contiguous with the spinal cord
what does the myelencephalon resemble?
open book
where are the basal plates located in the myelencephalon?

what do the basal plates contain?
ventral surface near midline

basal plates contain motor neurons
where are the alar plates of the myelencephalon?
dorsal
what are in the alar plates of the myelencephalon?
snesory interneurons
where do primary sensory neurons come from and where are they located?
primary sensory neurons are derived from neural crest cells

are located outside CNS in ganglia
what do the neurons of the basal plate of the myelencephalon eventually form?
CN XII

motor parts of CN X and CN IX
what holes in the skull are formed near the myelencephalon?
jugular foramen
hypoglossal canal
what does the choroid plexus form and where does it come from?
is made from roof of myelencephalon
becomes 4th ventricle
what does the choroid plexus make?
CSF - cerebrospinal fluid
where is the choroid plexus and how many of them are there?
are as many as there are ventricles, because there is one in every ventricle
what's the path of CSF flow?
from ventricles through openings in roof of myelencephalon
goes into subarachnoid space
is absorbed into venous blood through arachnoid villi
where are the basal plates in the metencephalon and what do they contain?
like the basal plates in the myelencephalon, the basal plates in the metencephalon are located ventrally and contain motor neurons
where are the alar plates of the metencephalon and what do they contain?
alar plates are located dorsaly and contain sensory interneurons
what do the motor neurons of basal plates of metencephalon form?
MOTOR parts of CN VII, VI, V3
where is the motor nucleus of CN IV located?
near border of metencephalon and myelencephalon
what's the cerebellar plate?
when does it form?
is projection of alar plates of metencephalon

forms around week 8
what brain region is one of the last to mature?
cerebellum
continues to develop new neurons and grow even after birth
again, where are and what are found in the basal plates of the mesencephalon?
ventrally
motor nuclei has motor neurons of CN III
where are alar plates of mesencephalon?
alar plates are always dorsally
what does the alar plate of the mesencephalon become?
superior (anterior) and
inferior (posterior) colliculi
what are the superior and inferior colliculi?
superior - serves visual system
inferior - serves auditory system
what cranial nerve is also associated with the mesencephalon?
CN IV
what's the shape of the ventricle of the mesencephalon? what's another name for it?
is long and narrow; called cerebral aqueduct
what happens if the cerebral aqueduct becomes obstructed during development?
CSF from choroid plexus in laterl ventricles of cerebral hemispheres can't go to fourth ventricle where it normally leaves

CSF accumulates in lateral ventricles forming hydrocephalus
how do we treat hydrocephalus?
place oe end of shunt into ventricle where CSF accumulates
other end of shunt into peritoneal cavity
what are the origins of the trochlear nerve CN IV?
cell bodies are in basal plates of metencephalon near mesencephalon
what's the path of the CN IV in development?
all other motor nerves exit ventrally, but trochlear nerve travel dorsally in mesencephalon
cross roof
exit dorsaly on opposite side from basal plate of origin
what does the development of CN IV have to do with visual deficits?
if problem is with movement of left eye, lesion could be in left superior oblique
left cranial nerve IV or
RIGHT side of midbrain

CN IV can be damaged by stretching midbrain (from buildup of CSF)
what structures come from the diencephalon?
1. retina
2. optic stalk
3. pineal body - helps regulate behavioral rhythms
4. infundibulum - fuses with stomodeum to make pituitary gland
5. thalamus, hypothalamus
6. choroid plexus of third ventricle comes from roof of diencephalon
what cranial nerve is also associated with the mesencephalon?
CN IV
what are the primary regions of the alar plates of the diencephalon?
thalamus and hypothalamus
what does the hypothalamus do?
regulates sleep, emotions and body temperature
what's the shape of the ventricle of the mesencephalon? what's another name for it?
is long and narrow; called cerebral aqueduct
where do the cerebral hemispheres come from?
lateral outpocketings of telencephalon
what happens if the cerebral aqueduct becomes obstructed during development?
CSF from choroid plexus in laterl ventricles of cerebral hemispheres can't go to fourth ventricle where it normally leaves

CSF accumulates in lateral ventricles forming hydrocephalus
a newborn is diagnosed with hydrocephalus resulting from an obstruction of cerebral aqueduct during development. where is the cerebral aqueduct of an embryo?
A. inside telencephalon
B. inside diencephalon
C. inside mesencephalon
D. inside the metencephalon
E. inside the myelencephalon
how do we treat hydrocephalus?
place oe end of shunt into ventricle where CSF accumulates
other end of shunt into peritoneal cavity
a newborn has asymmetric eye movements. examination reveals right oculomotor nerve palsy and left trochlear nerve palsy. a lesion associated with what part of the developing brain is consistent with this observation?
A. right mesencephalon
B. left mesencephalon
C. right telencephalon
D. right myelencephalon
E. left myelencephalon
what are the origins of the trochlear nerve CN IV?
cell bodies are in basal plates of metencephalon near mesencephalon
what does a cross section of the spinal cord look like?
labia major
what's the path of the CN IV in development?
all other motor nerves exit ventrally, but trochlear nerve travel dorsally in mesencephalon
cross roof
exit dorsaly on opposite side from basal plate of origin
what are cells around the middle of the cross section of the spinal cord called?
ependymal layer
what does the development of CN IV have to do with visual deficits?
if problem is with movement of left eye, lesion could be in left superior oblique
left cranial nerve IV or
RIGHT side of midbrain

CN IV can be damaged by stretching midbrain (from buildup of CSF)
what structures come from the diencephalon?
1. retina
2. optic stalk
3. pineal body - helps regulate behavioral rhythms
4. infundibulum - fuses with stomodeum to make pituitary gland
5. thalamus, hypothalamus
6. choroid plexus of third ventricle comes from roof of diencephalon
what are the primary regions of the alar plates of the diencephalon?
thalamus and hypothalamus
what does the hypothalamus do?
regulates sleep, emotions and body temperature
where do the cerebral hemispheres come from?
lateral outpocketings of telencephalon
a newborn is diagnosed with hydrocephalus resulting from an obstruction of cerebral aqueduct during development. where is the cerebral aqueduct of an embryo?
A. inside telencephalon
B. inside diencephalon
C. inside mesencephalon
D. inside the metencephalon
E. inside the myelencephalon
a newborn has asymmetric eye movements. examination reveals right oculomotor nerve palsy and left trochlear nerve palsy. a lesion associated with what part of the developing brain is consistent with this observation?
A. right mesencephalon
B. left mesencephalon
C. right telencephalon
D. right myelencephalon
E. left myelencephalon
what does a cross section of the spinal cord look like?
labia major
what are cells around the middle of the cross section of the spinal cord called?
ependymal layer
what is the mantle layer in the cross section of the spinal cord?
dorsal and ventral horns
where is the marginal layer of the cross section of the spinal cord?
everywhere else outside mantle layer
what's the reflex arc with the cross section of the spinal cord?
1. starts with basal plate - motor neurons
2. goes to spinal nerves - mix of afferent and efferent nerves
3. ends with sensory ganglia leading to alar plate
what's the cross section look like of the myelencephalon?
smile
what's the top of the cross section of the myelencephalon?
the 4th ventricle
which side of myelencephalon is roof?
top of smile
what comes out of the basal plates of the myelencephalon?
hypoglossal - motor
where does the third ventricle come from?
prosencephalon
what do the optic cups become?
retina
what is the optic stalk?
is root of optic cup
from prosencephalon
becomes optic nerve
where's the cerebral aqueduct?
center of mesencephalon
where's the 4th ventricle?
center of myelencephalon
what does the cross section of the metencephalon look like?
smile curled upwards, almost touching at dorsal side
what is at the center, back of the metencephalon?
4th ventricle
what is at the ventral side of the metencephalon?
what becomes pons