Chapter III- Basic Neuroanatomy Flashcards
Cerebral cortex
gray matter covering the outermost layer of the brain like the bark of a tree
Corpus Callosum
Layer of fibers that connect the two hemispheres
the very back of the cortex that processes vision
occipital region
some areas are dedicated to auditory processing or memory, involved in memory or hearing
temporal lobe
parietal region
synthesizes related information; i.e. connecting the dots, to be sent to the frontal cortex for evaluation as well as regulating the release function for the attentional system. It is also involved with body awareness and boundaries.
performs executive functions related to emotional regulation and decision making
prefrontal cortex
Heart of the Brain
Thalamus
Limbic system
processes emotional information and memory
The primary frequency generated by the limbic system is…
theta
associated with explicit memory
hippocampus
associated with implicit memory and fear conditioning
amygdala
Two pathways for theta
- first is lower frequency in nature, related to emotional processing
- second is high frequency in nature and tends to be related to memory processing
Basal Ganglia
controls motor movement and interfaces heavily with the cerebellum to execute learned sequences of motor action, such as playing a piano passage.
Brain stem
regulates basic life functions of the body such as heartbeat, breathing, and states of arousal ranging from sleep to hypervigilence.
cerebellum
attached to the stem at the back and maintains subroutines of the finer aspects of movement such as dancing, writing, or playing a musical passage.
Thalamus
the great relay station of the brain, and a key player in resource allocation with respect to information processing. All sensory information coming into the body goes through the thalamus which is divided up into regions corresponding to different areas of the brain.
neurons
provide electro-chemical activity
glial cells
provide maintenance and support for the neurons
Neuron is made up of…
the dendrites, the soma, the axon, and the synapse
soma
a simple battery that stores electrical energy by maintaining an electrical charge differential between the inside and outside of its cell wall.
the main fiber of the neuron
axon
Between the end of each axon and the dendrite of another cell that it connects to is a gap known as
the synapse
est period during which time the neuron recovers, i.e. rebuilds its charge
refractory
At the end of each axon is a button-shaped terminal generating chemicals known as
neurotransmitters
Receptor sites may increase or decrease over time in response to
the average volume of neurotransmitter activity
Heavy alcohol users may cause excessive amounts of dopamine to cross gaps and
receptor populations will reduce themselves eventually.
Dopamine
Source: Substantia Nigra: Attentional networks,
Major influence areas: Pleasure centers,
Associated disorders: Schizophrenia, ADHD, Addictions
Serotonin
Source: Raphe Nuclei
Major influence areas: Mood centers, Sleep cycles
Associated disorders: Depression, addiction
Norepinephrine
Source: Locus Coeruleus
Major influence areas: General arousal levels
Associated disorders: attentional networks
Acetylcholine
Source: Acetylcholine nuclei
Major influence areas: memory networks
Associated disorders: Memory problems
GABA
Global: General arousal levels Anxiety disorders
chronic high dopamine levels associated with
mania and schizophrenia
low serotonin levels
depression and negative schizophrenia.
emerges as a consequence of a chronically over-activated GABA system
anxiety
The cortex is comprised of cell groups referred to as
cell columns or macrocolumns
These columns are composed of
ell groups functionally related which run vertically through the 6 layers of the cortex
How many layers does the cortex have?
6
columns in the process of firing together…
cause the wave fronts that become recorded as EEG.
What makes up the wiring of the cortex?
axons (white matter) running in bundles along specific pathways.
adjacent areas of the brain
gyri
short fiber system resonates in
the high beta range of EEG
The long association fibers resonate in
resonate in regional areas in the lower beta and higher alpha range
global fibers resonate in
the delta and theta range
three basic long association fiber systems.
- cingulum
- uncinate fasciculus
- arcurate fasciculus
cingulum
connects frontal and parietal lobes with parts of the temporal lobes
uncinate fasciculus
connects the orbital lobe and other parts of the frontal lobe with the anterior temporal lobe. Parts of it also connect with the occipital lobe.
arcurate fasciculus
connects parts of the frontal lobe with the temporal lobe as well, especially Broca’s area and Wernicke’s area, which relate to processing and speaking language in the left hemisphere.
coherence maps
show the level of connectivity between brain areas
Lack of connectivity in the pathways running from the parietal lobes to the temporal lobes can result in
learning disorders
commissures
another fiber system, connects the hemispheres and are known as the corpus callosum and the anterior commissure
What are the commissures concerned with?
short-term memory functions and the transference of learned tasks between hemispheres.
Which side of the brain does verbal encoding occur on?
Left
Which side of the brain does verbal retrieval occur on?
Right
lack of connectivity or communication between the left and right side can result in
reduced emotional self-awareness
Diffusion Tensor Imaging
This method has allowed researchers to identify in great detail the entire fiber system of the brain. This allowed Hagmann to identify major hubs and nodes in the brain as well as how they are connected together
Brodmann’s Areas
brain areas frequently used by neurologists to associate function with location.
F3 and F4 (Brodmann’s)
related to short term and working memory
Fz (Brodmann’s)
related to area 8,6 and 9 and is related to attention
Projection tracts
fiber systems that bring information into the cortex from the thalamus as well as output information and are known as the corona radiata.
thalamus
divided into sections that connect to specific related areas of the brain
A 14 Hz rhythm appears as…
information flow to the motor cortex is progressively blocked
Barry Sterman
pioneered work demonstrating the gating system by which information is directed toward the motor cortex or blocked through thalamic oscillators
Sterman initially noted this blocking effect in experiments with…
cats and monkeys. Animals became very quiet and alert, especially the cats, when they produced the frequency that he termed, The Sensorimotor Rhythm or SMR. Sterman theorized that this was a consequence of the stilling of the central nervous system as it recruited resources to focus attention on an object of importance. Sterman found he could condition the animals to produce this frequency through feedback.
