Exam2 Flashcards
neuraxis
an imaginary line drawn through the center of the length of the CNS, from the bottom of the spinal cord to the front of the forebrain
ipsilateral
located on the same side of the body
contralateral
located on the opposite side of the body
transverse sections (cross sections)
with respect to the CNS, a slice taken at right angles to the neuraxis
frontal section (coronal section)
a slice through the brain parallel to the forehead
horizontal section
A slice through the brain parallel to the ground
sagittal sections
a slice through the brain parallel to the neuraxis and perpendicular to the ground
neural tube
a hollow tube, closed at the rostral end, that forms from ectodermal tissue early in embryonic development; serves as the origin of the CNS
ventricular zone
a layer of cells that line the inside of the neural tube; contains progenitor cells that divide and give rise to cells of the CNS
progenitor cells (founder cells)
cells of the ventricular zone that divide and give rise to cells of the CNS
radial glia
special glia with fibers that grow radially outward from the ventricular zone to the surface of the cortex; provide guidance for neurons migrating outward during brain development
symmetrical division
division of a progenitor cell that gives rise to two identical progenitor cells; increases the size of the ventricular zone and hence the brain that develops from it
asymmetrical division
division of a progenitor cell that gives rise to another progenitor cell and a neuron, which migrates away from the ventricular zone toward its final resting place in the brain
apoptosis
death of a cell caused by a chemical signal that activates a genetic mechanism inside the cell
cervical vertebrae
vertebrae of the neck area; 7 vertebrae
atlas
top cervical vertebra - pivot for head
Axis
2nd cervical vertebra; includes odontoid process
odontoid process
part of axis that forms pivot point
thoracic
upper chest cavity vertebrae; 12 vertebrae
articulations
point of attachment for ribs and hip bones
lumbar
lower back vertebrae ; five vertebrae
sacral
fused vertebrae forming back of pelvic girdle; five vertebrae
coccyx
fused vertebrae forming “tail bone”; five vertebrae
transverse process
bone extensions to each side of vertebrae, anchor points
spinous process
bone extensions on dorsal aspect of vertebrae, anchor points
central foramen
opening in the bone down the core of the vertebral column
dura mater
tough, outer protective layer of meninges
arachnoid
thin middle layer of meninges, lots of vascularization
pia mater
thin inner layer of meninges, holds shape and protects brain
central gray matter
neuron somas (butterfly)
dorsal root
afferent sensory fibers entering spinal cord
ventral root
efferent motor fibers leaving cord
dorsal root ganglion
unipolar somas of cutaneous sense neurons
Bell & Magendi
developed the “Law of Roots”
central lumen
circulation of CSF
fila
finger-like branching of the roots, distribute information through cord
Rami comunicantes
send info into the sympathetic ganglion chain
spinal root
a bundle of axons surrounded by connective tissue that occurs in pairs, which fuse and form a spinal nerve
cauda equine
horse’s tail; a bundle of spinal roots located caudal to the end of the spinal cord;
dorsal horn
contains somas for sending sensory info up to brain
ventral horn
contains somas for motor neurons
gracile tract
carries ipsilateral epicritic sensory info to brain stem
cuneate tract
carries ipsilateral epicritic sensory info to brain stem
ventral spinothalamic tract
carries contralateral protopathic info to brain
lateral spinothalamic tract
carries contralateral protopathic info to brain
direct pyramidal tract
carries ipsilateral motor info from cortex (20%)
lateral pyramidal tract
- carries contralateral motor info from cortex (80%)
simple reflex arc
a simple behavior performed by spinal neurons alone
segmental reflex
a reflex involving a single vertebral level
suprasegmental reflex
a reflex involving multiple vertebral levels
cranial vascularization
supplies the brain with blood
cerebral artery
serves the outer surface of brain
carotid artery
serves the inner core of brain
arachnoid granulations
enhances transfer between CSF and blood supply
subarachnoid space
filled with CSF, floats and protects brain, waste removal; fluid filled space that protects the brain
Superior Sagital Sinus
blood pool on upper surface of cortex, waste removal
origin of the cranial nerves
see pons and general hindbrain areas
pons
white matter paths into cerebellum from cerebral cortex, areas for arousal and sleep
brachium conjunctivum
path into cerebellum (inner)
brachium pontis
path into cerebellum (outer)
decusation of the pyramids
point on hindbrain where motor fibers decussate
cerebral peduncles
white matter paths from lower brain into cerebrum
laminae quadrigenima
collective name for colliculi
superior colliculi
visual motor control center (pupils, tracking, convergence)
inferior colliculi
auditory relay center
medial geniculate nucleus
auditory relay center; a group of cell bodies within the ___________ body of the thalamus; receives fibers from the auditory system and projects fibers to the primary auditory cortex
lateral geniculate nucleus
the only subcortical synapse for “seeing”;
choroid plexus
contains ependemal cells; the highly vascular tissue that protrudes into the ventricles and produces cerebrospinal fluid
4th ventricle
reservoir of CSF; the ventricle located between the cerebellum and the dorsal pons, in the center of the metencephalon
Aqueduct of Sylvius
CSF circulation between 3rd and 4th ventricles
cerebellum
posture, balance, muscle tone, ballistic timing, well learned behaviors
tectum
dorsal part of midbrain (includes the superior and inferior colliculi)
tegmentum
ventral part of midbrain, motor nuclei here; includes the periaqueductal gray matter, reticular formation, red nucleus, and substantia nigra
deep cerebellar nuclei
Nuclei located within the cerebellar hemispheres; receive projections from the cerebellar cortex and send projections out of the cerebellum to other parts of the brain
medulla oblongata
located in myencephalon; controls vital functions such as regulation of the cardiovascular system, respiration, and skeletal muscle tonus
midbrain/ mesencephalon
the central of the three major divisions of the brain; contains the tectum and tegmentum and surrounds the aqueduct of sylvius
reticular formation
a large network of neural tissue located in the central region of the brain stem, from the medulla to the diencephalon; plays a role in sleep and arousal, attention, muscle tonus, movement, and various vital reflexes
periaqueductal gray matter
the region of the midbrain surrounding the aqueduct of sylvius; contains the neural circuits involved in species-typical behaviors, such as fighting and mating
red nucleus
a large nucleus of the midbrain that receives inputs from the cerebellum and motor cortex and sends axons to motor neurons in the spinal cord
substantia nigra
a darkly stained region of the tegmentum that contains neurons that communicate with the caudate nucleus and putamen in the basal ganglia; important in parkinson’s disease
thalamus
sensory relay, motor areas, pain transmission;
massa intermedia
connects two lobes of thalamus (L/R communication); a bridge of tissue that crosses through the middle of the third ventricle
hypothalamus
multiple areas controlling feeding, fleeing, fighting and mating
pituitary gland
master gland of the endocrine system
infundibular stalk
connects hypothalamus to pituitary
median emminence
point where stalk joins to pituitary
mammillary bodies
a protrusion of the bottom of the brain at the posterior end of the hypothalamus, containing some hypothalamic nuclei; part of the limbic system; memory, emotion
corpus collosum
L/R cortical communication; a large bundle of axons that interconnects corresponding regions of the association cortex on each side of the brain
anterior commisure
L/R subcortical communication
posterior commisure
L/R subcortical communication
fornix
L/R limbic communication
pineal gland
meletonin secretion, seasonal coloration, seasonal mating
optic chiasm
an X shaped connection between the optic nerves, located below the base of the brain, just anterior to the pituitary gland
anterior pituitary gland
an endocrine gland whose secretions are controlled by the hypothalamic hormones
posterior pituitary gland
an endocrine gland that contains hormone-secreting terminal buttons of axons whose cell bodies lie within the hypothalamus
basal ganglia
collection of nuclei for smoothing, starting and stopping movement; a group of subcortical nuclei in the telencephalon, the caudate nucleus, the globus pallidus, and the putamen; important parts of the motor system
caudate nucleus
input area
lenticular nucleus
collective name for globus pallidus and putamen
globus pallidus
output area
putamen
input area for motor control area
internal capsule
white matter paths for pyramidal fibers through brain
frontal lobe
motor control, motor planning, emotional expression, strategy planning, “I”, working memory, “executive function”
parietal lobe
primary somatosensory area, spatial perception, body memories, motor plans
temporal lobe
primary auditory cortex, auditory memories (sup.), visual recognition (inf.)
occipital lobe
primary and secondary visual cortex, visual memories and recognition
central fissure (central sulcus)
separates frontal from parietal lobe
precentral gyrus
primary motor cortex
postcentral gyrus
primary somatosensory cortex
primary visual cortex
the region of the posterior occipital lobe whose primary input is from the visual system; along the upper and lower banks of the calcarine fissure
primary auditory cortex
the region of the superior temporal lobe whose primary input is from the auditory system; located along the lateral fissure
primary somatosensory cortex
the region of the anterior parietal lobe whose primary input is from the somatosensory system
calcarine fissure
a fissure located in the occipital lobe on the medial surface of the brain; most of the primary visual cortex is located along its upper and lower banks
lateral fissure
the fissure that separates the temporal lobe from the overlying frontal and parietal lobes
primary motor cortex
the region of the posterior frontal lobe that contains neurons that control movements of skeletal muscles
sensory association areas
those regions of the cerebral cortex that receive information from the regions of primary sensory cortex; parietal lobe other than the primary somatosensory cortex
motor association cortex
The region of the frontal lobe rostral to the primary motor cortex; controls the primary motor cortex
prefrontal cortex
the region of the frontal lobe rostral to the motor association cortex; involved in formulating plans and strategies
neocortex
the phylogenetically newest cortex, including the primary sensor cortex, primary motor cortex, and association cortex;
cisterna superior
reservoir of CSF
cisterna cerebello-meduliaris
reservoir of CSF
third ventricle
circulation and collection of CSF; located in the center of the diencephalon
lateral ventricles
circulation and collection of CSF; left and right; found in the center of the telencephalon/two hemispheres
limbic system
a group of brain regions including the anterior thalamic nuclei, amygdala, hippocampus, limbic cortex, and parts of the hypothalamus, as well as their interconnecting fiber bundles
limbic cortex
phylogenetically old cortex, located at the medial edge of the cerebral hemispheres; part of the limbic system
cingulate gyrus
a strip of limbic cortex lying along the lateral walls of the groove separating the cerebral hemispheres, just above the corpus callosum;
hippocampus
a forebrain structure of the temporal lobe, constituting an important part of the limbic system; learning and memory
amygdala
a structure in the interior of the rostral temporal lobe, containing a set of nuclei; part of the limbic system; emotions (fear) and emotional memories
spinal nerves
combination of dorsal and ventral roots; a peripheral nerve attached to the spinal cord
sympathetic ganglion chain
one of a pair of groups of sympathetic ganglia that lie ventrolateral to the vertebral column
Posterior lateral nuclei
area of thalamus
anterior nuclei
area of thalamus
laminar nuclei
area of thalamus
posterior nuclei
area of thalamus
medial nuclei
area of thalamus
pulvinar
area of thalamus
