MHS Module 6 - brain, cerebrum p1

explain the brain:

contains 97% nervous tissue

brain of males is larger than females

• no correlation between brain size and intelligence

what are the regions of the brain:

cerebrum

cerebellum

diencephalon

brainstem

what is the cerebrum:

largest part of the brain

divided into left and right cerebral hemispheres

functions of cerebrum:

conscious thoughts, intellect, memory

explain the cerebral cortex of cerebrum:

is a surface layer of grey matter

has rounded elevations of gyri that increase surface area

how is gyri separated:

shallow depressions (sulci)

or deep grooves (fissures)

where is the grey matter of cerebrum:

in cerebral cortex and basal nuclei

where is the white matter of cerebrum:

deep to cerebral cortex

around basal nuclei

explain the longitudinal cerebral fissure:

separates cerebral hemispheres

explain central sulcus:

divides anterior frontal lobe from posterior parietal lobe

motor and sensory areas

explain pre central gyrus of parietal lobe:

forms anterior border of central sulcus

explain post central gyrus of parietal lobe:

forms posterior border of central sulcus

explain the lateral sulcus:

separates frontal lobe from temporal lobe

explain the insula:

island of cortex

lies medial to lateral sulcus

explain parieto-occipital sulcus:

separates parietal lobe from occipital lobe

what are the 4 fibres apart of the white matter of the cerebrum:

association fibres

longitudinal fasciculi

commissural fibres

projection fibres

explain association fibers of the cerebrum:

has arcuate fibres:

• short fibres

• connect one gyrus to another

forms connections within one hemipshere

explain longitudinal fasiculi of cerebrum:

longer bundles

connect frontal lobe to other lobes in same hemisphere

explain commissural fibres of cerebrum:

bands of fibres connecting 2 hemispheres

corpus callosum=made up of commissural fibres

anterior commisure: formed bundle of white matter fibres

explain projection fibres of cerebrum:

link cerebral cortex to diencephalon, brainstem, cerebellum and spinal cord

pass through diencephalon

what is the internal capsule:

all ascending and descending projection fibres

explain basal nuclei:

masses of grey matter

embedded in white matter of cerebrum

directs subconscious activities

explain the structure of basal nuclei: + explain components

caudate nucleus:

• large head and slender, curving tall

lentiform nucleus:

• putamen (lateral)

• globus pallidus (medial)

claustrum:

• thin layer of grey matter close to putamen

functions of basal nuclei:

subconscious control of skeletal muscle tone

coordination of learned movement patterns e.g walking

what are functional principles of the cerebrum:

the cortex of each cerebral hemisphere receives somatosensory information from and sends motor commands to the opposite side of the body

what are the motor areas of the cerebrum:

primary motor cortex

pyramidal cells

explain primary motor cortex:

surface of pre central gyrus

explain pyramidal cells:

neurons of primary motor cortex

what are the sensory areas of the cerebrum:

primary somatosensory cortex

special sensory cortices:

• visual cortex

• auditory cortex

• olfactory cortex

• gustatory cortex

explain the primary somatosensory cortex:

surface of postcentral gyrus

explain the visual cortex

receives visual information

explain the auditory cortex

receives information about hearing

explain the olfactory cortex:

receives information about smell

explain the gustatory cortex;

recieves information from taste receptors

explain the association areas of the cerebrum:

connected to sensory and motor regions of cortex

interpret incoming data or coordinate a motor response

explain the premotor cortex

also called somatic motor association area

coordinates learned movements

explain the parts of sensory association cortex

somatosensory association cortex

visual association area

auditory association area

explain the somatosensory association cortex:

monitors activity association cortex

explain the visual association area:

interprets activity in visual cortex

explain the auditory association area

monitors auditory cortex

explain the integrative centres of the sensory association areas in cerebrum

in lobes and cortical areas of both cerebral hemispheres

receive information from association areas

direct complex motor functions

perform analytical functions

explain wernickes area in the brain:

language comprehension

primarily associated with left cerebral hemisphere

recieves information from sensory association area

coordinates access to visual and auditory memories

explain brocas area of the brain:

speech production

primarily associated with cerebral hemisphere

regulates patterns of breathing and vocalisation

explain the prefrontal cortex of frontal lobe:

coordinates information relayed from all cortical association areas

performs intellectual functions

explain hemispheric lateralisation:

functional differences between left and right cerebral cortex hemispheres

function of left cerebral hemisphere:

reading, writing, speech and language, decision making

function of right cerebral hemisphere:

analyses sensory information

recognition of faces and voice inflections