E3 Ch. 13 Flashcards
what is the CNS composed of
brain and spinal cord
rostral
toward nose
caudal
toward tail
which part of the neural tube does the brain arise from
rostral part
what are the 3 primary brain vesicles in 4 week old embryo
prosencephalon, mesencephalon, rhombencephalon
prosencephalon
forebrain
mesencephalon
midbrain
rhombencephalon
hindbrain
divisions of prosencephalon
telencephalon and diencephalon
divisions of rhombencephalon
metencephalon and myelencephalon
list the structures of the adult brain that develop from secondary brain vesicles
telencephalon, diencephalon, metencephalon, myelencephalon
structures in the telencephalon
cerebral hemispheres
structures in the diencephalon
thalamus, hypothalamus, and epithalamus
structures in the metencephalon
bons and cerebellum
structures in the myelencephalon
medulla oblongata
what structures are included in the brain stem
midbrain, pons, and medulla oblongata
brain classified into four regions
brain stem (midbrain, pons, and medulla), cerebellum, diencephalon, cerebral hemispheres
cortex
outer layer of gray matter, formed from neuronal cell bodies, located in cerebrum and cerebellum
what types of cells line the ventricles of the brain
ependymal cells
location of lateral ventricles
located in cerebral hemispheres
location of third ventricle
lies in diencephalon
what structure connects the third ventricle with the lateral ventricles
interventricular foramen
cerebral aqueduct
connects 3rd and 4th ventricles
location of fourth ventricle
lies in hindbrain, connects to central canal of the spinal cord
what structures are included in the brain stem
midbrain, pons, and medulla oblongata
what are some general functions of the brain stem
passageway for all fiber tracts running b/t cerebrum and spinal cord, innervation of face and head, produces automatic behaviors necessary for survival, integrates auditory and visual reflexes
which structure is the most caudal level of the brain stem
medulla oblongata
where is the choroid plexus located
lies in roof of the fourth ventricle
list the 4 external landmarks of the medulla
pyramids, decussation of the pyramids, inferior cerebellar peduncles, and olive of medulla
what is located in the core of the medulla
reticular formation
what are the visceral centers of the reticular formation found in the core of the medulla
cardiac, vasomotor, medullary respiratory, and centers for hiccuping, sneezing, swallowing, and coughing
which structure is considered the “bridge” b/t the midbrain and medulla oblongata
the pons
the pons contain the nuclei of which cranial nerves
V-trigeminal, VI- abducens, VII-facial
what does the pons contain
motor tracts (coming from cerebral cortex), and pontine nuclei
what is the pontine nuclei and its function
connects portions of cerebral cortex and cerebellum, sends axons to cerebellum though middle cerebellar peduncles
where is the midbrain located
b/t the diencephalon and pons
cerebral aqueduct
central cavity of midbrain
what is periaqueductal gray matter and what is it involved in
surrounds cerebral aqueduct, involved in fight or flight reaction and mediates response to visceral pain
what is the corpora quadrigemina and what are its divisions
larget nuclei located in midbrain, divided into superior and inferior colliculi
function of superior colliculi
nuclei that act in visual reflexes
inferior colliculi
nuclei that act in reflexive response to sound
what is embedded in the white matter of the midbrain
2 pigmented nuclei: substantia nigra and red nucleus
substantia nigra
neuronal cell bodies containing melanin, functionally linked to basal nuclei
red nucleus
lies deep to substantia nigra, largest nucleus of the reticular formation
function of cerebellum
smoothing and coordinating body movements, helps maintain equilibrium
subdivisions of cerebellar hemispheres
anterior lobe, posterior lobe, and flocculonodular lobe (tiny)
in order to coordinate body movements, the cerebellar cortex receives what 3types of information
info on equilibrium, info on current movements of limbs, neck, and trunk, and info from cerebral cortex
process in which cerebellum coordinates movement
- receives info on movement from motor cortex of cerebrum
- compares intended movement w/ body position
- sends instructions back to cerebral cortex to continuously adjust/fine-tune motor commands
what are some higher cognitive functions of the cerebellum
learning new motor skill, participates in cognition (language, problem solving, task planning)
what are cerebellar peduncles
thick tracts connecting cerebellum to brain stem
what are the different types of cerebellar peduncles
superior, middle, and inferior cerebellar peduncles
diencephalon
forms central core of forebrain, surrounded by cerebral hemispheres, border third ventricle, primarily composed of gray matter
what are the 3 paired structures that comprise the diencephalon
thalamus, hypothalamus, and epithalamus
function of thalamus
relay stations for incoming sensory message, sends axons to regions of the cerebral cortex, “gateway” to cerebral cortex
location of hypothalamus
lies b/t optic chiasm and mammillary bodies
function of hypothalamus
main visceral control center of body; controls ANS, emotional responses, regulation body temp, hunger/ thirst, behavior, sleep-wake cycles, endocrine system, formation of memory
epithalamus
“roof” of third ventricle, consist of tiny group of nuclei, includes pineal gland (pineal body)
pineal gland
secretes hormone melatonin, under influence of hypothalamus, aids in control of carcadian rhythm
fissures
deep grooves that separate major regions of brain
transverse fissure
separates cerebrum and cerebellum
longitudinal fissure
separates cerebral hemispheres
sulci
grooves on surface of cerebral hemispheres
gyri
twisted ridges b/t sulci
what does the parieto-occipital sulcus separate
occipital from parietal lobe
list the lobes of the cerebral cortex
frontal, parietal, occipital, temporal, and insula
what does the cerebral cortex enable us to do
home of conscious mind; aware of ourselves and sensations, initiate/control voluntary movements, communicate, remember, and understand
what are the 3 general kinds of functional areas in the cerebral cortex
sensory, association, and motor areas
multimodal association areas of cerebrum
receive and integrate input from multiple regions of cerebral cortex
motor cortex of cerebrum
plans and initiates voluntary motor functions
describe cerebral cortex info. processing
- sensory info received by primary sensory cortex
- info relayed to sensory association area
- multimodal association area receive input in parallel from sensory areas
- motor plan enacted
what are sensory areas
cortical areas involved in conscious awareness of sensation
where area sensory areas located
parietal, temporal, and occipital lobes- distinct regions of each lobe interpret each of the major senses
where are primary somatosensory cortex located
along the postcentral gyrus
somatosensory cortex involved n
conscious awareness of general somatic senses, spatial discrimination (precisely locates stimulus, certain regions more adept in distinguishing precise stimuli)
sensory homunculus
body map of the sensory cortex
somatosensory assoication cortex location
posterior to primary somatosensory cortex
what does the somatosensory association cortex do
integrates different sensory inputs (touch, pressure), draws upon stored memories of past sensory experiences (e.g. recognize keys/coins in pocket w/out looking at them)
primary visual cortex location
deep w/in calcarine sulcus (medial part of occipital lobe)
function of primary visual cortex
receives visual info that originates on retina, exhibits contralateral function
visual association area function
surrounds primary visual area, continues processing of visual info. (analyze color, form, movement)
function of primary auditory cortex
conscious awareness of sound, waves excite receptors in inner ear, impulses trasmitted to primary auditory cortex
location of primary auditory cortex
superior edge of temporal lobe
location of auditory association area
posterior to primary auditory cortex
function of auditory areas
permits evaluation of different sounds, processes auditory stimuli serially and in parallel
wernicke’s area
involved in recognizing and understanding speech
function of vestibular cortex
conscious awareness of sense of balance
location of vestibular cortex
posterior part of insula, deep to the lateral sulcus
function of gustatory cortex
conscious awareness of taste stimuli
location of gustatory cortex
“roof” of lateral sulcus
location of olfactory cortex
medial aspect of cerebrum located in piriform lobe
function of olfactory cortex
olfactory nerves transmit impulses to olfactory cortex, provides conscious awareness of smells
what is the olfactory cortex part of
rhinencephalon- “nose brain”
what is included in the rhinencephalon “nose brain”
piriform lobe, olfactory tracts, and olfactory bulbs
function of rhinencephalon
connects brain to limbic system, explains why smell triggers emotions, involved w/ consciously identifying and recalling specific smells
where are visceral sensory areas located and what types of sensory input are received
w/in lateral sulcus on insula lobe, receives pain, pressure, and hunger
what are motor areas
cortical areas controlling motor functions
list the different motor areas
premotor cortex, primary motor cortex, frontal eye field, Broca’s area
location of premotor cortex
anterior to precentral gyrus
function of premotor cortex
controls more complex movements, receives processed sensory info. (visual, auditory, general somatic sensory), controls voluntary actions dependent on sensory feedback, planning movements
function of primary motor cortex
controls motor functions
location of primary motor cortex
precentral gyrus
pyramidal cells
large neurons of primary motor cortex, axons cross over to opposite side of brain (contralateral), specific types control specific areas of body
corticospinal tracts of motor cortex
descend though brain stem and spinal cord, axons signal motor neurons to control skilled movements
somatotopy
body is represented spatially in the primary motor cortex
where does the frontal eye field located
lies anterior to premotor cortex
where is Broca’s area located
left cerebral hemisphere
function of Broca’s area
manages speech production, connected to language comprehension areas in posterior association area
what does the corresponding region to Broca’s in the right cerebral hemisphere control
emotional overtones to spoken words
what are multimodal association areas
large areas of cerebral cortex that receive sensory input from multiple sensory modalities and sensory association areas and makes associations b/t kinds of sensory info.
what are the 3 multimodal association areas
posterior, anterior, and limbic association areas
where is the posterior association area located
at interface of visual, auditory, and somatosensory association areas
function of posterior association area
integrates sensory info into unified perception, allows awareness of spatial location of body (“body sense”), related to language comprehension and speech
describe the location and function of the dorsal stream of the posterior association area
extends to postcentral gyrus, perceives info about spatial relationships, “where” pathway” (location of objects)
describe the location and function of the ventral stream of the posterior association area
pases info into inferior part of temporal lobe, responsible for recognizing objects, words, and faces, “what” pathway (identifies objects)
describe the 2 ways auditory stimuli is processed
from auditory association areas though multimodal association areas
parietal lobe and lateral part of frontal lobe- evaluate location of sound (“where” pathway)
anterior region of temporal lobe and inferior region of frontal lobe- process sound identification (“what” pathway)
where is wernicke’s area found
left cerebral cortex in posterior association areas
function of wernicke’s area
speech comprehension, coordination of auditory and visual aspects of language, initiation of word articulation, recognition of sound sequence
function of corresponding wernicke’s area in the right hemisphere
creative interpretation of words, emotional overtones of speech
anterior association areas
large region of frontal lobe (prefrontal cortex), receives info from posterior association area, integrates info w/ past experience, initiates and plans motor movements, and has links to limbic system
what are the more complex functions of anterior association areas
thinking, perceiving, intentionally remembering, processing abstract ideas, impulse control, humor, empathy, stores info for less than 30 sec. etc.
function of anterior pole of frontal cortex
active in solving most complex problems, emotions, cognition at anterior part of frontal lobe
what are the 3 working memory areas of anterior association areas
visual working memory, auditory working memory, and executive area
where is the limbic association area located
medial side of frontal lobe
function of limbic association areas
memory, emotions, integrates sensory and motor behaviors, aids in formation of memory, and processes emotions
what does the left cerebral hemisphere control
language abilities, math, and logic
what does the right cerebral hemisphere control
visual-spatial skills, reading facial expressions, intuition, emotion, artistic and musical skills
what are the different types of tracts found in the white matter
commissures, association fibers, projection fibers
what are commissures tracts composed of
commissural fibers
function of commissure tracts
allows communication b/t cerebral hemispheres
what is the larges commissure tract
corpus callosum
function of association fiber tracts
connect different part of the same hemisphere
parts of wernike’s and Broca’s areas are connected by what type of tracts
association fibers
which way do projection fiber tracts run
vertically
where do projection fibers descend from and ascend to
descend from cerebral cortex and ascend to cortex from lower regions
describe internal capsule of projection tracts
projection fibers form a compact bundle, passes b/t the thalamus and basal nuclei
describe the corona radiata of projection tracts
superior to internal capsule, fibers run to and from cerebral cortex
what does the deep gray matter of the cerebrum consist of
basal nuclei (basal ganglia), basal forebrain nuclei, claustrum
basal nuclei (basal ganglia)
involved in motor control
basal forebrain nuclei
associated w/ memory
claustrum
nucleus of unknown function
amygdaloid body
located in cerebrum but is considered part of limbic system
what is the basal nuclei formed from
group of nuclei deep w/in the cerebral white matter, formed from caudate nucleus, putamen, and globus pallidus
basal ganglia
complex neural calculaors, cooperate w/ cerebral cortex in controlling movement, receive input from many cortical areas
substantia nigra
influences basal ganglia
function of basal nuclei
start, stop, and regulate intensity of voluntary movements, select appropriate muscles for a task and inhibit others, estimate passage of time.
what structures make up the basal forebrain nuclei
septum, diagonal band of Broca, horizontal band of broca, basal nucleus of Meynert
location of basal forebrain nuclei
anterior and dorsal to hypothalamus
function of forebrain nuclei
arousal, learning, memory, motor control
degeneration of basal forebrain nuclei is associated to what disease
alzheimer’s disease
function of cerebellum
process input from cerebral motor cortex, propriceptors, and visual and equilibrium pathway, smooth, coordinated skeletal muscle movements, balance and posture
function of thalamus portion of diencephalon
relays sensory impulses to cerebral cortex for interpretation, relays impulses b/t cerebral cortex and subcortical motor centers including basal nuclei (ganglia) and cerebellum, memory processing
function of hypothalamus portion of diencephalon
autonomic (involuntary) NS, regulates body temp, food intake, water balance, thirst, biolobical rhythms/drves, hormonal output, acts as endocrine organ producing ADH and oxytocin
function of cortical gray matter found in cerebral hemispheres
localizes/interpret sensory inputs, controls voluntary/skilled skeletal muscle activity, functions in intellectual and emotional processing
function of limbic system
includes cerebral and diencephalon structures (cingulate gyrus, hippocampal formation, amygdaloid body, hypothalamus, and anterior thalamic nuclei), mediates emotional response, forms/retrieves memories
function of medulla oblongata
relays sensory info to cerebellum though inferior olivary nuclei, contains visceral nuclei controlling HR, blood vessel diameter, respiratory rate, vomiting, coughing etc.
function of pons
pontine nuclei relay info from cerebrum to cerebellum, contains reticular formation nuclei
the medulla oblongata contains the nuclei of which cranial nerves
VIII-X and XII
the pons contains the nuclei of which cranial nerves
V-VII
function of midbrain
contains subcortical motor centers, and visual and auditory reflex centers
the midbrain contains the nuclei of which cranial nerves
III and IV
function of reticular formation
maintains cerebral cortical alertness (reticular activating system), filters out repetitive stimuli, helps regulate skeletal and visceral muscle activity and modulate pain
location of limbic system
medial aspect of cerebral hemispheres, w/in diencephalon
what is the limbic system composed of
septal nuclei, cingulate gyrus, and hippocampal formation, part of amygdaloid body
fornix
along w/ other tracts link limbic system together
cingulate gyrus
limbic system; allows us to shift b/t thoughts, interprets pain as unpleasant
what three columns does the reticular formation make
midline raphe nuclei, medial nuclear group, and lateral nuclear group
reticular activating system (RAS)
maintain consciousness and alertness, functions in sleep and arousal from sleep, malfunctions in people w/ narcolepsy
what structures protect the brain
skull, meninges, cerebrospinal fluid, and blood brain barrier
functions of the meninges
cover/protect CNS, enclose and protect vessels that supply CNS, contains CSF b/t pia and arachnoid maters
what two layers compose the dura mater
periosteal layer, and meningeal layer
arachnoid villi
project through dura mater, allow CSF to pass into dural blood sinuses
where is CSF formed
choroid plexuses in brain ventricle
where is the choroid plexus located
all 4 ventricles
what is the choroid plexus composed of
ependymal cells and capillaries
where does CSF arise from and how much is produced a day and how much is present at one time
arises from blood; 500 ml produced/day, only 100-160 ml present at any one time
function of blood-brain barrier
prevents most blood borne toxins from entering brain, allows passage of nutrients, oxygen, alcohol, nicotine, and anesthetics
function of spinal cord
attachment of spinal nerves, provide two-way conduction pathway, major center for reflexes
location of spinal chord
runs though vertebral canal, extends from foramen magnum to L1 or L2
SS of gray mater
somatic sensory; interneurons receiving input from sensory neurons
VS of gray mater
visceral sensory; interneurons receiving input from visceral sensory neurons
VM of gray mater
visceral motor; (autonomic) neurons
SM of gray mater
somatic motor neurons
what structures protect spinal cord
vertebrae, meninges, and CSF
function of CSF
liquid cushion for spinal cord and brain, nourishes brain and spinal cord, removes wastes, carries chemical signals b/t parts of CNS
ascending pathways of CNS
carry info to more rostral areas of CNS
descending pathways of CNS
carry info to more caudal regions of CNS
what type of signal do ascending pathways carry
general somatic sensory impulses
what are the 4 main types of ascending pathways
dorsal column, spinothalamic, posterior spinocerebellar, anterior spinocerebellar pathway
what types of signals do descending pathways carry
motor pathways
function of descending pathways
deliver motor instructions from brain to spinal cord
what are the 2 groups of descending pathways
pyramidal (corticospinal) tracts and other motor pathways
list the other motor pathways
tectospinal, vestibulospinal, rubrospinal, reticulospinal tracts
paralysis
loss of motor function
parasthesia
loss of sensation
paraplegia
injury to spinal cord b/t T1 and L2
quadriplegia
injury to spinal cord in cervical region, paralysis of all 4 limbs
cerebrovascular accident (stroke)
degenerative brain disease; blockage or interruption of blood flow to a brain region
alzheimer’s disease
prgressive degenerative disease leading to dementias
anencephaly
neural tube defect; cerebrum and cerebellum are absent
spina bifida
neural tube defect; absence of vertebral lamina
cerebral palsy
voluntary muscles are poorly controlled, results from damage to the motor cortex
