Exam 4 Flashcards
what are the 4 major regions of the brain
cerebrum (two hemispheres; five lobes per hemisphere)
diencephalon
brainstem
cerebellum
gyri
ridges
sulci
derpessions between ridges
fissues
deep sulci
what matter is the brain and spinal cord composed of
gray and white tissue
gray matter
made of neuron cell bodies, dendrties, and unmyelinated axons
white matter
consists of myelinated axons
cerebral cortex and the cerebral nuclei are
grey matter
cranial meninges
three connective tissue layers
separate and support soft tissue of brain
enclose and protect blood vessels supplying the brain
help contain and circulate cerebrospinal fluid
cranial meninges from deep to superficial
pia mater
arachnoid mater
dura matter
pia matter
innermost of the meninges; adheres to brain surface
thin layer of areolar connective tissue
arachnoid mater
lies external to pia mater
made of a web of collagen and elastic fibers
lies deep to dura mater
-subdural space is a potential space that can fill with blood if a vein is ruptured (subdural hematoma)
arachnoid trabeculae
extends to pia mater through subarachnoid space
subarachnoid space
contains cerebrospinal fluid
dura mater
though outer membrane
made of dense irregular connective tissue in 2 layer
-meningeal layer (deeper layer of dura)
-periosteal layer (more superficial layer of dura)
-layers are usually fused but in some areas they separate to form dural venous sinuses that drain blood from the brain
the epidural space is a potential space between dura and skull
-contains arteries and veins
what does the periosteal layer form
the periosteum on internal surface of cranial bones
ventricles
cavities within the brain that are lined with ependymal cells and contain cerebrospinal fluid
connect with each other and with spinal cord’s central canal
lateral ventricles
large cavities in cerebrum
separated by medial partition, septum pellucidum
third ventricle
narrow space in middle of diencephalon
connected to each lateral ventricle by an interventricular formen
what connects the lateral ventricle to the third ventricle
interventricular foramen
fourth ventricle
sickle-shaped space between pons and cerebellum
connected to third ventricle by cerebral aqueduct
opens to subarachnoid space medially and laterally
narrows before merging with central canal of spinal cord
cerebropsinal fluid (CSF)
clear, colorless liquid surrounding CNS
circulates in ventricles and subarachnoid space
provides buoyancy; reduces brain’s apparent weight by 95%
protects CNS by providing a liquid cushion
keeps CNS environment stable by transporting nutrients and wastes and protecting against chemical fluctuations
what forms CSF
choroid plexus
-specialized tissue in each ventricle
-layer of ependymal cells and blood capillaries
CSF formation
blood plasma is filtered through capillary and modified by ependymal cells
in addition, ependymal cell secretions and interstitial fluid from subarachnoid space help make CSF
CSF circulation
CSF is continuously formed and reabsorbed
-formation begins in choroid plexus of ventricles
-CSF flows from lateral ventricles into third ventricle
-From 3rd ventricle into fourth
-after passing through apertures, it flows in subarachnoid space and down into central canal of spinal cord
-excess CSF flows into arachnoid villi and drains into dural venous sinuses
cerebrum
two large hemispheres on superior aspect of brain
origin of all complex intellectual functions
center of
-intelligence and reasoning (thought memory judgement)
-voluntary motor control
-special sense interpretation (visual auditory)
longitudonal fissure
deep cleft separating left and right hemispheres of cerebrum
what connects the cerebrum
white matter tracts
corpus collosum
largest white matter tract providing a connection between cerebral hemispheres
cerebral hemispheres connection with the brain
left hemisphere recieves sensory signals from right side of body and sends motor signals to right side of body
what are the 5 lobes of the cerebrumm
frontal
parietal
temporal
occipital
insular
frontal lobe
anterior part of cerebrum
-posterior border is deep central sulcus
-frontal lobe has varied functions
precentral gyrus controls
voluntary movement
frontal lobe controls
motor control
concentration
verbal communicaiton
decision making
planning
personality
parietal lobe
serves general sensory functions
-evaluating shape and texture of objects
temporal lobe
located inferior to lateral sulcus
-hearing and smell
occipital lobe
functions in vision and visual memories
insula
small lobe that can be observed by pulling away temporal lobe
functions in memory and sense of taste
primary motor cortex
primary motor cortex located in precentral gyrus
also called somatic motor area
controls skeletal muscle activity on opposite side of body
-project contralaterally (opposite side) wihtin brainstem or spinal cord
hands tongue and face heavily impacted
motor speech area
located in inferolateral portion of left frontal lobe
controls movements for vocalization
frontal eye field
on superior surafce of middle frontal gyrus
regulates eye movements needed for reading and binocular vision
premotor cortex (somatic motor association area)
located anterior to primary motor cortex
coordinates learned, skilled activites
what are the motor areas of the cerebrum
primary motor cortex
motor speech area
frontal eye field
premotor cortex
what the sensory areas of cerebrum
primary somatosensory cortex
somatosensory association area
primary visual cortex
visual association area
primary auditory cortex
auditory association area
primary olfactory cortex
primary gustatory cortex
primary somatosensory cortex
located in postcentral gyrus of parietal lobes
receives somatic sensory information from
-proprioceptors, touch, pressure, pain, temperature receptors
lips fingers and genitals heavily impacted
primary somatosensory cortex
located in postcentral gyrus of parietal lobes
receives somatic sensory information from
-proprioceptors, touch, pressure, pain, temperature receptors
lips fingers and genitals heavily impacted
motor areas are found in what area of the brain
frontal lobes
somatosonsory association area
immediately posterior to postcentral gyrus (in parietal lobe)
integrates touch information allowing us to identify objects by feel
primary visual cortex
located within occipital lobe
visual association area
surrounds primary visual cortex
integrates color, form, memory to allow us to identify things we see like faces
primary auditory cortex
located within temporal lobe
auditory association area
located in temporal lobe
interprets sounds; stores and retrieves memories of sounds
primary olfactory cortex
located within temporal lobe
provides conscious awareness of smells
primary gustatory cortex
located within insula
involved in processing taste infromation
what are the function brain regions
prefrontal cortex
wernicke area
gnostic area
all integrate information from multiple association areas
prefrontal cortex
located rostral to premotor cortex (in frontal lobe)
complex thought, judgement, personality, planning, deciding
still developing in adolescence
wernicke area
typically located in left hemisphere (temporal lobe)
involved in language comprehension
gnostic area (common integrative area)
integrates information from variety of sensory association areas
sights, smells, sounds, converge and brain becomes aware of sitaution
(lunchtime)
where is white matter and white gives it that color
lies deep to grey cerebral cortex
composed of myelinated axons grouped into tracts
association tracts
connect regions of cerebral cortex within same hemisphere
arcuate fibers: short tracts connecting neighboring gyri
longitudinal fasciculi: longer tracts connecting gyri in different lobes
commissural tracts
commissures connect regions in different hemispheres
include corpus callosum, anterior and posterior commissure
projection tracts
link cerebral cortex to inferior brain regions and spinal cord
-corticospinal tracts carry signal from cerebral cortex to spinal cord
-as this projection tract passes between thalamus and cerebral nuclei it is called the internal capsule
hemisphere specialization (cerebral lateralization)
two sides of cerebrum exhibit differences in higher-order functions
categorical hemisphere is usually left hemisphere
-specialized for language abilities, functions in categorization and analysis
-contains wernicke area and motor speech area
representational hemisphere is usually right hemisphere
-concerned with visuospatial relationships, imagination, comparison of senses
two hemispheres communicate through the corpus callosum and other commussures