Chapter 12 - Central Nervous System Part 1
_____________ of mass of brain (cerebral cortex)
40%
______________ of humans have left-sided dominance ; usually results in right-handedness
90%
present in one hemisphere (usually the left); motor speech area that directs muscles of speech production; active in planning speech and voluntary motor activities
Broca's area
consists of brain and spinal cord
CNS
damage in areas of primary motor cortex are seen in
a stroke, paralyzes muscles controlled by those areas
also called prefrontal cortex; most complicated cortical region; involved with intellect, cognition, recalls, and personality
anterior association area
multimodal association cortex is divided into three parts
anterior association, posterior association, and limbic association
Broca's areas is
anterior to inferior premotor area
premotor cortex is
anterior to pre central gyrus
located posterior to primary auditory cortex; stores memories of sounds and permits perception of sound stimulus
auditory association cortex
site of conscious mind:
awareness, sensory perception, voluntary motor initiation, communication, memory storage, understanding
forebrain moves toward
brain stem (midbrain, pons, medulla oblongata)
by contrast, individuals with a damaged visual association area ______________________
can see, but they do not comprehend what they are looking at
basic pattern found in CNS
central cavity surrounded by grey matter, with white matter external to grey matter
is "executive suite" of brain
cerebral cortex
each hemisphere has three basic regions
cerebral cortex of grey matter superficially white matter internally basal nuclei deep within white matter
refers to hemisphere that is dominant for language
cerebral dominance
adult brains have four regions:
cerebral hemisphere diencephalon brain stem (midbrain, pons, medulla oblongata) cerebellum
contain outer layer of grey matter called the cortex
cerebral hemisphere and cerebellum
telencephalon gives rise to two
cerebral hemispheres ; which together makes the cerebrum
ventricles are filled with
cerebrospinal fluid (CSF)
_______________ also have scattered areas of grey matter nuclei amid white matter
cerebrum and cerebellum
cerebral hemispheres double back and envelope ____________ and midbrain while creasing and folding to increase surface area
diencephalon
the third ventricle lies in the
diencephalon
functional imaging (PET and MRI) of brain show specific motor and sensory functions are located in discrete cortical areas called
domains
four general considerations of cerebral cortex
each hemisphere is concerned with contralateral (opposite) side of body lateralization (specialization) of cortical function can occur in only one hemisphere conscious behavior involves entire cortex in one way or another
ventricles are lined by
ependymal cells (neuroglial cells)
diencephalon becomes the
epithalamus, thalamus, hypothalamus, and retina
anterior association area development depends on
feedback from social environment
Hemispheres communicate almost instantaneously via
fiber tracts and functional integration
third ventricle is connected to the
fourth ventricle via cerebral aqueduct
controls voluntary eye movement
frontal eye field
location of motor areas of cerebral cortex
frontal lobe ; motor areas act to control voluntary movement
damage to the primary visual cortex results in
functional blindness
brain stem as addition ______________ matter nuclei scattered within _____________ matter
grey ; white
short, nonmyelinated neurons and cell bodies
grey matter
thin superficial layer of ______________ in cerebral cortex
grey matter (composed of neuron cell bodies, dendrites, glial cells, and blood vessels, but no axons)
in insula just deep to temporal lobe; involved in perception of taste
gustatory cortex
fourth ventricle lies in
hindbrain
paired ____________________ are large, C-shaped chambers located deep in each hemisphere
lateral ventricles
division of labor between hemispheres ; hemisphere are not identical
lateralization
controls language, math, and logic
left hemisphere
part of limbic system; involved cingulate gyrus, parahippocmpal gyrus, and hippocampus; previous emotional impact that makes a scene important to us and help establish memories
limbic association area
myelencephalon become the
medulla oblongata
tumors or other sessions of the anterior association area may cause
mental and personality disorders, including loss of judgement, attentiveness, and inhibitions
cerebral cortex contains three types of functional areas
motor areas:control voluntary movement sensory areas: conscious awareness of sensation association areas: integrate diverse information
upside-down caricatures represent. contralateral motor innervation of body regions
motor homunculi
receive inputs from multiple sensory areas; send outputs to multiple areas; allows us to give meaning to information received, store in memory, tie to previous experience, and decide on actions
multimodal association areas
embryologically, the brain and spinal cord begin as a
neural tube
openings for fourth ventricle
paired lateral apertures in side walls median aperture in roof
______________ occurs in opposite side of body from damage
paralysis
sensory areas occur in
parietal, insular, temporal, and occipital lobes
remainder of rhinencephalon in humans becomes
part of limbic system
melecephalon becomes the
pons and cerebellum
different problems arise for individuals with sessions in the part of the _____________ that provides awareness of self in space; individual may refuse to wash or dress the side of body opposite to lesion
posterior association area
large region in temporal, parietal, and occipital lobes; plays role in recognizing patterns and faces and localizing us in space; involved in understanding written and spoken language (Wemicke's area)
posterior association area
____________ becomes spinal cord
posterior end
primary motor cortex is in
pre central gyrus
helps plan movements; staging area for skilled motor activities; controls learned, repetitious, or patterned motor skills; coordinated simultaneous or sequential actions; controls voluntary actions that depend on sensory feedback
premotor cortex
located in pre central gyrus of frontal lobe
primary (somatic) motor cortex
superior margin of temporal lobes; interprets information from inner ear as pitch, loudness, and location
primary auditory cortex
medial aspect of temporal lobes (in piniform lobes); part of primitive rhinencephalon, along with olfactory bulbs and tracts; involved in conscious awareness of odors
primary olfactory cortex
located in postcentral gyro of parietal lobe; receives general sensory information from skin and proprioceptors of skeletal muscles, joints, and tendons
primary somatosensory cortex
eight main areas of sensory are
primary somatosensory cortex, somatosensory association cortex, visual areas, vestibular cortex, olfactory cortex, gustatory cortex, and visceral sensory areas
neural tube's anterior end expands, and constrictions form three
primary vesicles
_______________ located on extreme posterior tip of occipital lobe; most buried in calcimine sulcus; receives visual information from retina
primary visual (striate) cortex
primary vesicles
prosencephalon (forebrain) mesencephalon (midbrain) rhombencephalon (hindbrain)
formed from long axons that project down spinal cord
pyramidal (corticospinal) tracts
large neurons that allow conscious control of precise, skilled, skeletal muscle movement
pyramidal cells
visual-spatial skills, intuition, emotion, and artistic and musical skills
right hemisphere
primary vesicles give rise to five
secondary brain vesicles
____________________ makes us who we are
sensations, thoughts, and emotions become conscious
areas of cortex concerned with conscious awareness of sensation
sensory areas
the pair is separated by membranous ___________________
septum pellucidum
posterior to primary somatosensory cortex; integrates sensory input from somatosensory cortex for understanding of object; determines size, texture, and relationship of parts of objects being felt
somatosensory association cortex
upside-down caricatures represent contralateral sensory input from regions
somatosensory hommunculus
all muscles of body can be mapped to areas on primary motor cortex
somatotopy
primary somatosensory cortex is capable of _______________: identification of body region being stimulated
spatial discrimination
three opening connect fourth ventricle to ______________ that surrounds brain
subarachnoid space
the brain grows faster than __________________, so it must fold to occupy available space
surrounding membranous skull
forebrain becomes: midbrain: hindbrain:
telencephalon and diencephalon remains undivided metencephalon and myelencephalon
mesencephalon remains
the midbrain
each lateral ventricle is connected to the _______________
third ventricle via interventricular foramen
central cavity of the neural tube becomes the
ventricles
fluid filled chambers that are continuous to one another and to central canal of spinal cord
ventricles
posterior part of insula and adjacent parietal cortex; responsible for conscious awareness of balance
vestibular cortex
posterior to gustatory cortex; conscious of perception of visceral sensations, such as upset stomach, to full bladder
visceral sensory area
surrounds primary visual cortex; uses past visual experiences to interpret visual stimuli (ability to recognize faces); complex processing involves entire posterior half of cerebral hemisphere
visual association cortex
myelinated and nonmyelinated axons
white matter
frontal eye field is
within and anterior to premotor cortex; superior to Broca's areas
anterior association area contains
working memory needed for abstract ideas, judgement, reasoning, persistence, and planning