CNS: The Cerebrum Flashcards
cerebrum
most rostral part of brain
accounts for 83% of brain mass
transverse fissure and longitudinal fissure
longitudinal fissure
separates cerebral hemispheres
transverse fissure
separates cerebrum and cerebellum
sulci and gyri in cerebrum
sulci: shallow grooves on the surface of cerebral hemispheres
gyri: ridges of brain tissue between sulci
deep sulci
center sulcus
lateral sulcus (fissure)
parieto-occipital sulcus
five major lobes of cerebrum
frontal lobe temporal lobe parietal lobe occipital lobe insula lobe
central sulcus
separates frontal lobe and parietal lobe
bordered by precental gyrus anteriorly and postcentral gyrus posteriorly
lateral sulcus
sometimes called a fissure
separates temporal lobe from parietal and frontal lobes
insula lobe
positioned deep within the lateral sulcus and forms part of its floor
cerebral cortex (gray matter)
primary sensory areas sensory association areas multimodal association areas premotor cortex (motor association cortex) primary motor areas
cerebrum white matter
commissure, projection fibers, association fibers
deep cerebral gray matter
basal ganglia, basal forebrain nuclei, claustrum
the cerebral cortex
2-4 mm thick
folds in cortex triple its surface areas
approximately 40% of brain mass
contains billions of neurons arranged in six layers
no fiber tracts
most sensory information is routed through the thalamus to the cerebral cortex
functional areas in cerebral cortex
primary sensory cortex sensory association areas multimodal association areas premotor cortex (motor association cortex) primary motor cortex
primary sensory cortex
receives sensory information resulting in awareness of the sensation
sensory association areas
receive information from the primary sensory cortex and interpret (give meaning to) the sensory input
multimodal association areas
receive input in parallel from multiple sensory areas and integrate/interpret the information aided by past experiences
develop a motor response
premotor cortex
motor association cortex
plans and coordinates complex movements and relays the plan to the primary motor cortex for implementation
primary motor cortex
enacts plan
cerebral cortex: primary sensory areas
primary somatosensory cortex primary visual cortex primary auditory cortex vestibular (equilibrium) cortex gustatory (taste) cortex primary olfactory (smell) cortex visceral sensory area
primary somatosensory cortex
located along the postcentral gyrus of the parietal lobe
involved with awareness of general somatic senses:
touch, pressure, vibration, pain, temperature
spatial discrimination
ability to precisely locate a stimulus
sensory receptors in periphery relay signals through spinal cord, brain stem, thalamus, and up to the primary somatosensory cortex
sensory homunculus
body map of the sensory cortex in the postcentral gyrus
vestibular cortex
processes information of the vestibular apparatus
responsible for conscious awareness of sense of balance (position of the head in space)
located in the posterior part of the insular lobe deep to the lateral sulcus
gustatory cortex
processes taste stimuli from the tongue
function involved in the conscious awareness of taste stimuli
located in insula on the “roof” of the lateral sulcus
primary olfactory cortex
processes smell
lies on the medial aspect of the cerebrum in a small region called the piriform lobe which includes the hooklike uncus
olfactory nerves from the nasal cavity transmit impulses to the olfactory cortex and provides conscious awareness of smells
piriform lobe
region of medial cerebrum which houses the primary olfactory cortex
includes the hooklike uncus
rhinencephalon
olfactory cortex is in this part of the brain
includes parts of the cerebrum that receive olfactory signals: piriform lobe, olfactory tracts, olfactory bulbs
connects to limbic system in the brain which explains why smells trigger emotions
involved with consciously identifying and recalling specific smells
parts of the cerebrum that receive olfactory signals
piriform lobe
olfactory tracts
olfactory bulbs
located in the rhinencephalon
visceral sensory areas
located deep within the lateral sulcus of the insula lobe
receives general sensory input (pain, pressure, hunger) from abdominal and thoracic organs
primary visual cortex
located deep within the calcarine sulcus on the posterior and medial part of the occipital lobe
damage to this area can cause blindness
largest of all sensory areas
receives visual information that originates from the retina
exhibits contralateral function
first of a series of areas processing visual input at the level of putting sensory stimuli from the two eyes together and noting object orientation
calcarine sulcus
houses primary visual cortex
posterior and medial part of the occipital lobe
primary auditory cortex
sound waves excite receptors in the inner ear cochlea which triggers impulse transmission to primary auditory cortex where conscious awareness of sound including loudness, rhythm, and pitch is detected
located at superior edge of temporal lobe
sensory association areas
somatosensory association cortex
visual association areas
auditory association areas
somatosensory association cortex
lies posterior to the primary somatosensory cortex
integrates different sensory inputs, eg touch and pressure from somatosensory cortex to understand sensations
draws upon stored memories of past sensory experiences, eg ability to feel and recognize keys or coins in your pocket without looking at them
visual association area
surrounds the primary visual area and covers much of the occipital lobe
continues the processing of visual information by analyzing color, form, and movement
about 30 cortical areas for visual processing have been identified
complex visual processing extends into temporal and parietal lobes
visual information proceeds anteriorly through these visual areas into two streams (dorsal and ventral streams)
visual association area: dorsal stream
“where” pathway
extends through the posterior parietal cortex to the post-central gyrus
perceives information about spatial relationships about objects
visual association area: ventral stream
“what” pathway
passes information into inferior part of the temporal lobe
responsible for recognizing words, objects, faces
auditory association area
lies just posterior and lateral to the primary auditory cortex
permits evaluation of different sounds such as a screech, thunder, or music and integrates memories of past sounds
auditory stimuli are processed serially along two pathways from the auditory association area to the multimodal association areas
auditory areas: posterolateral pathway
“where” pathway
through the parietal lobe to the lateral pre-frontal cortex evaluates location of stimulus
auditory areas: anterolateral pathway
“what” pathway
from the anterior temporal lobe to the inferior region of the frontal lobe
processes information related to sound identification
Wernicke’s area
in one hemisphere, the auditory association area overlaps with Wernicke’s area
includes superior-posterior temporal lobe and inferior-posterior parietal lobe
functional brain region involved in recognizing and understanding spoken words
function of Wernicke’s area
involved in recognizing and understanding spoken words
Wernicke’s aphasia
receptive aphasia
impaired ability to understand spoken words and sentences and comprehend speech
often associated with damage to Wernicke’s area
multimodal association areas
posterior association area
anterior association area
limbic association area