BIOL G220: Ch. 15 Flashcards
Terms and concepts from Ch. 15: Brain and Cranial Nerves
four major regions of the brain
cerebrum
diencephalon
brainstem
cerebellum
brain features include (2)
gyri
sulci
directional terms of brain includes (2)
rostral (anterior)
caudal (posterior)
the human brain is divided into ___ lobes with the ___ lobe buried inside, called the _____
5; 5th; insula
cerebrum includes (3)
frontal lobe
temporal lobe
occipital lobe
brainstem includes (3)
midbrain
pons
medulla oblogata
olfactory bulbs runs into olfactory ____
tracts
pituitary gland sits in ___ of sphenoid bone
sella turcica
optic nerves cross optic chiasms and become ______ tracts
optic
pituitary gland aka
hypothesis
diencephalon includes (4)
corpus callosum
interthalamic adhesion
thalamus
hypothalamus
bundles of myelinated axons (white matter) are called _____
tracts
tracts compose the ____ and _____ of the diencephalon
corpus callosum, interthalamic adhesion
corpus callosum is the
main structure for communication between L and R brain hemisphere
interthalamic adhesion is
structure for communication between L and R thalamus
most basic part of the brain is the
brain stem (pons and medulla oblongata)
gray matter
houses motor neuron and interneuron cell bodies, dendrites, telodendria, unmyelinated axons
gray matter forms .. (2)
the cortex (upper layer), which covers the surface of most of the adult brain and discrete internal clusters called cerebral nuclei
white matter
made up of myelinated axons and is deep to the gray matter of the cortex
ganglion
cluster of neuron cell bodies within the PNS
center
group of CNS neuron cell bodies with a common function
nucleus
center in the CNS that displays discrete anatomic boundaries
nerve
axon bundle extending through the PNS
nerve plexus
network of nerves in PNS
tract
CNS axon bundle in which the axons have a similar function and share a common origin and destination
funiculus
group of tracts in a specific area of the spinal cord
pathway
centers and tracts that connect he CNS with body organs and systems
cortex
outer layer of gray matter in cerebrum and cerebellum; consists of densely packed neuron cell bodies
cerebral hemisphere
either of two symmetrical halves of the cerebrum, separated by the longitudinal fissure
supports and protects the brain (4)
bony cranium
protective connective tissue (meninges)
CSF
blood-brain barrier
cranial meninges are three CT layers that.. (4 functions)
- separate soft tissue of the brain from bones of cranium
- enclose and protect blood vessels that supply the brain
- contain and circulate cerebrospinal fluid
- form some of the brains that drain blood from the brain
layers of cranial meninges include (3)
pia mater
arachnoid mater
dura mater
from superior to inferior in skull and posterior to anterior on spinal cord, the cranial meninges are arranged..
dura mater
arachnoid mater
pia mater
the space between arachnoid mater and pia mater is called
subarachnoid space (contains CSF)
the dura mater is composed of two layers called the …
periosteal layer (superior) meningeal layer (inferior)
the potential space between the dura mater and the arachnoid mater is called
subdural space
subdural space normally has ___ space, but the layers can separate and fluid may ____
no; build
sulci
small grooves in between gyri
fissures
large grooves in the brain
septa
sit in between fissures to connect the brain; created by the meningeal layer of the dura mater
inside the septa are spaces called…
dural venous sinus
dural venous sinus helps to drain ___ out of the brain. it is also how CSF ___ the arachnoid mater from the brain
blood; leaves
providing stabilization and support, the four cranial dural septa are…
falx cerebri
tentorium cerebelli
falx cerebelli
diphragma selae
falx cerebri
projects into longitudinal fissure and separates left and right cerebral hemispheres
tentorium cerebelli
horizontal fold that separates cerebrum from cerebellum
falx cerebelli
separate left and right cerebellar hemispheres
diaphragma selae
small septum between pituitary and hypothalamus
running within the margins of dural septa, the four dural venous sinuses are…
superior sagittal sinus
inferior sagittal sinus
transverse sinuses
occipital sinus
superior sagittal sinus
runs within the superior margin of the falx cerebri
inferior sagittal sinus
runs within the inferior margin of the falx cerebri
transverse sinuses
run within the posterior border of the tentorium cerebelli
occipital sinus
runs in the posterior vertical border of the falx cerebelli
dural venous sinous is made of the ____ layer of the ____ mater
meningeal; dura
arachnoid granulation functions to allow ______ to enter ____ and drain
CSF; dura mater
confluence of sinuses
connecting point of sinuses
ventricles
cavities within the brain that contain cerebral spinal fluid
lateral ventricles
one in each hemisphere of cerebrum
septum pellucidum
separates the two lateral ventricles
third ventricle is found in
diencephalon
fourth ventricle is found between
pons and cerebellum
cerebral aqueduct
where csf drains from third ventricle and through to fourth ventricle
the interthalamic adhesion runs across one lobe across the ___ ventricle and into the other lobe
third
cerebral spinal fluid
clear, colorless liquid that circulates in the ventricles and subarachnoid space
cerebral spinal fluid functions (3)
buoyancy
protection
environmental stability
buoyancy (csf)
brain floats in the CSF
protection (csf)
provides liquid cushion
environmental stability (csf)
transports nutrients and removes waste from brain
choroid plexus
mass of blood cell structures inside the brain that create the CSF; made from ependymal cells
steps of production and circulation of CSF (5)
- CSF produced by the choroid plexus in the ventricles
- CSF flows form the third ventricle through the cerebral aqueduct into the fourth ventricle
- CSF in the fourth ventricle flows into the subarachnoid space and into the central canal of the spinal cord
- As the CSF flows through the subarachnoid space, it removes waste products and provide buoyancy to support the brain
- excess CSF flows into arachnoid villi, then drains into the dural venous sinuses. The greater pressure on the CSF in the subarachnoid space ensures that CSF moves into the venous sinuses without permitted venous blood to enter the subarachnoid space
blood-brain barrier
regulates what substances can enter interstitial fluid of brain
capillary endothelial cells and astrocyte ____ _____ contribute to the BBB
perivascular feet
BBB is missing or reduced in three distinct locations of CNS:
- choroid plexus (CSF production, high flow rate)
- hypothalamus (endocrine system needing circulatory access for hormone distribution)
- pineal gland (circadian rhythm)
CNS contains ___ ___ in capillaries to prevent any leakage
tight junctions
through through astrocyte provides more ______
control
cerebrum
location of conscious thought processes and origin of intellectual functions
cerebrum contains a large number of ____ that are needed for complex analytical and integrative functions
neurons
cerebrum contains.. (3)
outer cortex
inner white matter
cerebral nuclei (deep regions of gray matter)
surface of cerebrum is marked by.. (3)
sulci
gyri
fissures (deep groove)
cerebral hemispheres
two halves composing the cerebrum
the paired cerebral hemispheres are divided by a _____ _________ the extends along the midsagittal place
longitudinal fissure
the hemispheres are separate from one another, except at a few locations where bundles of axons called _____
tracts
tracts
form white matter regions that allow for communication between the two hemispheres
corpus callosum
largest tract and main tract that connects the two hemispheres
overlap and indistincts boundaries in the cerebral hemispheres permit a single region of the cortex to exhibit..
several different functions
some aspects of cortical function cannot easily be assigned to..
any single region
with few exceptions, both cerebral hemispheres receive their ______ information from and project _____ commands to the opposite sides of the body
sensory; motor
hemispheric lateralization
two hemispheres appear as anatomic mirror images, but display some functional differences
lobes of cerebrum
frontal lobe parietal lobe temporal lobe occipital lobe insula
frontal lobe contains… (4)
primary motor cortex (in precentral gyrus)
premotor cortex
frontal eye field
motor speech area (Broca)
insula contains.. (1)
primary gustatory cortex
parietal lobe contains .. (4)
primary somatosensory cortex (in postcentral gyrus)
somatosensory association area
part of wernicke area
part of gnostic area
occipital lobe contains.. (2)
primary visual cortex
visual association area
temporal lobe contains.. (5)
primary auditory cortex auditory association area primary olfactory cortex part of wernicke area part of gnostic area
frontal lobe is located ____ to the frontal bone and forms ____ part of cerebral hemisphere
deep; anterior
frontal lobe ends _____ at the central sulcus; ____ border marked by the lateral sulcus
posteriorly; inferior
precentral gyrus
mass of nervous tissue in the frontal lobe immediately anterior to central sulcus
frontal lobe in involved with …(6)
voluntary motor function concentration verbal communication decision making planning personality
parietal lobe forms the _____ part of each hemisphere and underlies the ____ bone
superoposterior; parietal
parietal lobe terminates _____ at the central sulcus, ____ at the lateral sulcus, and ____ at the parieto-occipital sulcus
anteriorly, laterally, posteriorly
postcentral gyrus
mass of nervous tissue in the parietal lobe immediately posterior to central sulcus
parietal lobe is involved with..
general sensory functions
temporal lobe is located ___ to the lateral sulcus underlying the ___ bone
inferior; temporal
temporal lobe is involved with (2)
hearing and smell
occipital lobe is located in the ____ region of each hemisphere underlying ____ bone
posterior; occipital
occipital lobe in involved with.. (2)
processing incoming visual information and storing visual memories
insula is located ___ to the lateral sulcus
deep
insula is involved in..(2)
memory and interpretation of taste
functional areas of cerebrum (3)
motor areas
sensory areas
association areas
motor areas of cerebrum
control voluntary motor function; motor neurons
sensory areas of cerebrum
provide conscious awareness of sensation; sensing from periphery of body
association areas of cerebrum
integrate and store information ; integrate and process incoming and outgoing information
primary motor cortex (somatic motor area)
controls voluntary skeletal muscle activity
primary motor cortex is located within the ____ gyrus; axons project ___ to brainstem and spinal cord
precentral; contralaterally
primary motor cortex innervation to various body parts can be diagrammed as a ____ on the precentral gyrus
motor homunculus
motor speech area (broca area)
controls muscular movements necessary for vocalization
motor speech area is locating in most individuals within the ______ portion of the left frontal lobe
inferolateral
frontal eye field
controls and regulates eyes movements and binocular vision
frontal eye field is located on ____ surface of middle frontal gyrus, immediately anterior to _____ cortex
superior; premotor
primary somatosensory cortex
receives general somatic sensory information from touch, pressure, pain, and temperature receptors
primary somatosensory cortex is located within the ___ gyrus
postcentral
____ ______ may be traced on the surface of the primary somatosensory cortex
sensory homunculus
primary visual cortex function and location
receives and processes incoming visual information; occipital lobe
primary auditory cortex function and location
receives and processes auditory information; temporal lobe
primary gustatory cortex function and location
processes taste information; insula
primary olfactory cortex function and location
provides conscious awareness of smell; temporal lobe
motor areas include.. (3)
primary motor cortex, motor speech area (Broca’s), frontal eye field
sensory areas include … (5)
primary somatosensory cortex primary visual cortex primary auditory cortex primary gustatory cortex primary olfactory cortex
association areas include.. (6)
premotor cortex somatosensory association area auditory association area visual association area wernicke area gnostic area
premotor cortex
somatic motor association area
processes motor information and coordinates learned, skilled motor activities
premotor cortex location
frontal lobe immediately anterior to precentral gyrus
somatosensory association area
integrates and interprets sensory information
somatosensory association area location
parietal lobe immediately posterior to post central gyrus
auditory association area
interprets characteristics of sound and stores memories of sound
auditory association area location
within temporal lobe, posteroinferior to the primary auditory cortex
visual association area
processes visual information
visual association area location
occipital lobe
wernicke area
recognizes and comprehends spoken and written language
wernicke area location
located within left hemisphere where it overlabs the parietal and temporal lobes
gnostic area
common integrative area
integrates all sensory, visual, and auditory information
gnostic area locations
composed of regions of the parietal, occipital, and temporal lobes
higher-order processing centers process incoming information from..
several different association areas
higher-order processing centers ultimately direct either extremely complex ___ activity or complicated ____ functions
motor; analytical
higher-order processing centers involve functions such as speech, cognition, understanding ____ relationships, and general ____
spatial; interpretation
higher-order processing centers are housed in _____ cerebral hemispheres
both
central white matter is ___ to cortical gray matter
deep
central white matter is composed primarily of ______ axons
myelinated
most axons are bundled into tracts which can be classsified as one of three categories:
- association tracts
- commissural tracts
- projection tracts
association tracts can be classified into two types:
arcuate fibers
longitudinal fasciculi
arcuate fibers
connect neighboring gyri within a single cerebral lobe
longitudinal fasciculi
connect gyri between different cerebral lobes of the same hemisphere
commissural tracts
connect corresponding lobes of the right and left hemispheres
projection tracts
connect cerebral cortex to the diencephalon, brainstem, cerebellum, and spinal cord
cerebral nuclei
paired masses of gray matter found deep within the central white matter
specific nuclei of cerebral nuclei (4)
caudate nucleus
amygdaloid body
lentiform nucleus
claustrum
lentiform nucleus is composed of..
putamen and globus pallidus
corpus striatum is composed of..
caudate nucleus lentiform nucleus (putamen, globus pallidus)
diencephalon components (3)
epithalamus
thalamus
hypothalamus
epithalamus
partially forms posterior roof of diencephalon and covers third ventricle components
epithalamus includes.. (2)
pineal gland
habenular nuclei
pineal gland
secretes melatonin, a hormone that regulates circadian rhythm
habenular nuclei
relay signals from the limbic system to the midbrain; involved in visceral and emotional responses to odor
thalamus
paired oval masses of gray matter; lie on each side of third ventricle
each mass of the thamalus is composed of about a dozen ___ ______ with axons projecting to particular regions of cerebral cortex
thalamic nuclei
sensory impulses from all conscious senses except olfaction converge on the ______ and _____ in at least one of its nuclei
thalamus; synapse
the thalamus is the ____ and final relay point for sensory information that will be processed and projected to _______ cortex
principal; somatosensory
hypothalamus is that _____ region of the diencephalon
anteroinferior
infundibulum
thin, stalk-like and extends inferiorly from hypothalamus to attach to pituitary gland
functions of hypothalamus (7)
master control of the autonomic nervous system
master control of the endocrine system
regulation of body temperature
control of emotional behavior
control of food intake
control of water intake
regulation of sleep-wake (circadian) rhythms
brainstem connects…
prosencephalon and cerebellum to spinal cord
brainstem is the passageway for all tracts extending between the ___ and spinal cord
cerebrum
brainstem contains many ____ centers and _____ centers required for survival
autonomic; reflex
brainstem houses ___ of many of the cranial nerves
nuclei
three regions that form the brainstem
- midbrain
- pons
- medulla oblongata
midbrain
superior portion of the brainstem
____ _______ extends through midbrain and connects ____ and ____ ventricles
cerebral aqueduct; third and fourth
cerebral aqueduct of the midbrain and surrounded by…
periaqueductal gray matter
midbrain parts (3)
tegmentum
substantia nigra
superior and inferior colliculi
tegmentum
responsible for relaying information between cerebrum and cerebellum
tegmentum location
between substantia nigra and the periaqueductal gray matter
substantia nigra
control movement, emotional response, and the ability to experience pleasure and pain through dopamine
degenerations of the cells in the ___ ____ underlies parkinson disease
substantia nigra
superior and inferior colliculi
visual and auditory reflex centers, respectively
pons
bulging region on the anterior part of the brainstem
pons parts (2)
middle cerebellar peduncles
superior olivary complex
middle cerebellar peduncles
transverse fibers that connect pons to cerebellum;
pons contains ____ nuclei in the pontine respiratory center, which helps _____ ______
autonomic; regulate breathing
superior olivary complex
help localize sound
medulla oblongata
most inferior part of brainstem
medulla oblongata parts (2)
pyramids
inferior cerebellar peduncles
pyramids are composed of motor projection tracts called the _____ tracts
corticospinal
most of the axons in the pyramids cross to opposite side at a point called…
decussation of the pyramids
inferior cerebellar peduncles
paired and connect medulla oblongata to cerebellum
medulla oblongata autonomic nuclei group to form.. (3)
cardiac center
vasomotor center
medullary respiratory center
cardiac center
regulates heart rate and its strength of contraction
vasomotor center
controls blood pressure by regulating contraction and relaxation of smooth muscles in walls of arterioles
medullary respiratory center
regulates respiratory rate
other nuclei in medulla oblongata involved with coughing, ____, salivation, ____, gagging, and ______
sneezing; swallowing; vomited
cerebellum
second largest part of the brain
cerebellum is partitioned into three regions:
- outer gray matter layer of cortex
- internal region of white matter, called the arbor vitae
- cerebellar nuclei in deepest layer
cerebellum responsible for coordinating and fine-tuning …
skeletal muscle movements
cerebellum stores _____ of previously learned movement patterns
memories
cerebellum adjusts skeletal muscle activity to maintain ____ and posture
equilibrium
cerebellum receives ______ (sensory) information from the muscles and joints and uses this information to regulate the body’s ______
proprioceptive; position
cerebellum monitors the ____ of each body joint and its ____ ____
position; muscle tone
limbic system
its structures form a ring around diencephalon
structures of limbic system collectively process and experience _____
emotions
limbic system affects ____ formation through the integration of ____ _______ of physical sensations with emotional states
memory; past memories
olfaction and olfactory nerves do directly into the ___ ____, not the ______
limbic system; thalamus
cranial nerves
twelve pairs numbered with roman numerals by their position, beginning with the most anteriorly placed nerve