Ch. 5 Neuroanatomy and Neurophysiology Flashcards
Nervous systems primary function
transfer and exchange info
Neuron function
-basic cellular unit
-conducts impulses from one part of the body to another
cell body
“soma”
-made up of nucleus and cytoplasm w/in cell membrane
stem or axon
transmits signals away from the neurons cell body to connect w/ other neurons and cells
dendrites
collect incoming signals from other neurons and send the signal toward the neuron’s cell body
CNS composed of:
spinal cord and brain
PNS composed of:
peripheral nerves that connect the CNS to receptors, muscles, and glands
-includes cranial nerves (just outside of brainstem)
-somatic and autonomic NS
Somatic NS
conveys info from CNS to skeletal muscles, responsible for voluntary movement
Autonomic NS
regulates internal body functions to maintain homeostasis
-conveys info from CNS to smooth muscle, cardiac muscle, and glands
-involuntary movement
-sympathetic and parasympathetic NS
Sympathetic NS
excitatory division, prepares body for stress (fight/flight), stimulates or increases activity of organs
Parasympathetic NS
maintains and restores energy
-inhibits or decreases activity of organs
white matter
myelinated axons of neurons
gray matter
nerve cell bodies and dendrites
-working area of the brain- contains synapses (area of neuronal connection)
outer surface of brain function:
increase brain’s surface area- increase working area and cell communication area
Sulci
small shallow grooves
Fissures
deeper grooves extending into the brain
gyri
raised tissue areas
True or false: cerebrum is the largest part of the brain
true
left hemisphere
dominant for most people, controls most right-sided functions
hemisphere
controls most left-sided body functions
corpus callopsum
large bundle of white matter that connects the two hemispheres= an area of sensorimotor info exchange between the two hemispheres
Frontal lobe functions
largest and most developed lobe
-motor
-premotor area
-association cortex
-executive function (working memory, reasoning, planning, prioritizing, impulse control etc…)
-language (Broca’s area), expressive speech
-personality variables
Problems in frontal lobe lead to:
personality changes, emotional, and intellectual changes
Temporal lobe functions
-language (Wernicke’s area), receptive speech or language comprehension
-primary auditory area
-memory
-emotion
-integration of vision and sensory info
Problems w/ temporal lobe lead to:
visual or auditory hallucinations, aphasia, and amnesia
Occipital lobe function
-primary visual cortex
-integration area (vision w/ other sensory info)
Problems w/ occipital lobe can lead to:
visual field defects, blindness, and visual hallucinations
Parietal lobe function
-primary sensory area
-taste
-reading and writing
Problems w/ parietal lobe lead to:
sensory-perceptual disturbances and agnosia
Cerebral cortex
-controls many behaviors and contralateral side of the body
- sensory info relayed thalamus, then processed and integrated into cortex
-responsible for speech, cognition, judgment, perception, and motor function
Limbic system
regulates and modulates emotions and memory
-composed of hypothalamus, thalamus, hippocampus, and amygdala
Hypothalamus function
key role in regulatory functions
-appetite
-sensations of hunger and thirst
- water balance
-circadian rhythms
-body temp
-libido
-hormonal regulation
Thalamus function
sensory relay station (except for smell)
-modulates flow of sensory info- prevents overwhelming the cortex
-regulates emotions, memory, and related affective behaviors
Hippocampus function
regulates memory and converts short-term to long-term memory
Amygdala function
responsible for mediating mood, fear, emotion, and aggression
-also connect sensory smell info w/ emotions
Basal ganglia (corpus striatum)
complex feedback system to modulate/stabilize somatic motor activity (info from CNS to skeletal muscles)
-role in movement initiation (complex motor func w/ association connections
-learning and autonomic actions (walking, driving, etc…)
-contains extrapyramidal motor system or nerve tract)
-involuntary motor activities (muscle tone, posture, muscle movement coordination, common reflexes)
True or false: the basal ganglia contains both the caudate and the putamen
True- collectively, they can be considered the “entrance” to the basal ganglia - both work together to receive input from cerebral cortex
Problems w/ basal ganglia can lead to:
bradykinesia, hyperkinesia’s, and dystonia
Brainstem
made of cells that produce NTs
-includes midbrain, pons, medulla, cerebellum and reticular formation
Midbrain function (which NT is produced here?)
houses ventral tegmental area (VTA) and substantia nigra (areas of dopamine synthesis)
Pons function (which NT is produced here?)
houses locus ceruleus (area of norepinephrine synthesis)
Medulla function
together w/ the pons, contains autonomic control centers that regulate internal body functions
Cerebellum function
maintain equilibrium; acts as gross movement control center (control movement, balance, posture)
True or false: each hemisphere of the cerebellum has ipsolateral control
True
Problems w/ cerebellum can lead to:
ataxia
What test can detect issues w/ cerebellum?
Romberg test
Reticular formation system
primitive brain
-receives input from cortex- integration area for input from postsensory pathways
-innervates thalamus, hypothalamus, and cortex
glia
structures that form myelin sheath around axons and provide protection and support
synapse (synaptic cleft)
connection site and area of communication between neurons where neurotransmitters are released
True or False: synapse converts electrical signal (action potential) from the presynaptic neuron into a chemical signal (NT) that is transferred to the postsynaptic neuron
True
What are the two phases of an action potential?
Depolarization- initial phase (excitatory response), when Na and Ca ions flow into the cell
Repolarization- restoration phase (inhibitory response) when K+ leaves the cell or chloride enters the cell
True or False: Issues in either structure or chemistry of the synapse interrupt normal flow of impulses and stimuli
True, this contributes to symptoms seen often in psych disorders
Dopamine, Norepinephrine, Epinephrine and Serotonin are which type of NT?
Monoamines
-DA, Norepi, and Epi= catecholamines
-5HT = an indole
What is the precursor to dopamine?
tyrosine
Dopamine is removed from the synaptic cleft by _______ enzyme action
monoamine oxidase (MAO) enzymatic action
The four dopaminergic pathways are:
mesocortical, mesolimbic, nigrostriatal, tuberoinfundibular
What is the precursor to norepinephrine
tyrosine
norepinephrine is removed from the synaptic cleft and returned to storage via an_______
active reuptake process
Where is epinephrine produced?
adrenal glands
-epinephrine system also referred to as adrenergic system
Where is serotonin produced?
raphe nuclei of the brain stem
What is the precursor to serotonin?
tryptophan
serotonin is removed from the synaptic cleft and returned to storage via an_____
active reuptake process
Which NTs are amino acids?
glutamate, aspartate, y-aminobutyric acid (GABA), glycine
True or False: glutamate is the universal inhibitory NT
False, glutamate is the universal excitatory NT
glutamate is involved in the process of ________
kindling, which is implicated in seizure disorders and possibly bipolar disorders
True or False: aspartate is another excitatory NT
True, works w/ glutamate
True or False: GABA is the universal inhibitory NT
True
Which NT is the site of action for benzos, alcohol, barbiturates, and other CNS depressants?
GABA
True or False: glycine is another excitatory NT
False, glycine is an inhibitory NT that works with GABA
acetylcholine is which type of NT?
cholinergic
acetylcholine is synthesized by _____
basal nucleus of Meynert
precursors to acetylcholine are ____
acetylcoenzyme A and choline
NTs that are neuropeptides include
Non-opioid type: substance P, somatostatin
Opioid type: endorphins, enkephalins, dynorphins
Function of neuropeptides
modulate pain; decreased amount of neuropeptides thought to cause substance abuse
True or false: enzymatic destruction occurs either in the cytosol or in the synapse
True
increase in acetylcholine implicated in
parkinsonian symptoms
decrease in acetylcholine implicated in
-Alzheimer’s disease
-impaired memory
increase in dopamine implicated in
-schizophrenia
-psychosis
decrease in dopamine implicated in
-substance abuse
-anhedonia
-Parkinson’s disease
increase in norepinephrine implicated in
anxiety
decrease in norepinephrine implicated in
depression
decrease in serotonin implicated in
-depression
-anxiety
-OCD
-schizophrenia
decrease in GABA implicated in
anxiety disorders
increase in glutamate implicated in
-bipolar affective disorder
-psychosis (from ischemic neurotoxicity or excessive pruning)
decrease in glutamate implicated in
-memory and learning difficulty
-negative symptoms of schizophrenia
decrease in opioid neuropeptides implicated in
substance abuse
True or False: reuptake pumps can remove the NT from acting in the synapse
True, the NT will be reloaded into the presynaptic neuron and recycled
dopamine general functions (5)
-thinking
-decision making
-reward-seeking behavior
-fine muscle action
-integrated cognition
norepinephrine general functions (6)
-alertness
-focused attention
-orientation
-primes fight or flight
-learning
-memory
serotonin general functions (7)
-regulate sleep
-pain perception
-mood states
-temperature
-regulate aggression
-libido
-precursor for melatonin
acetylcholine general functions (7)
-attention
-memory
-thirst
-mood regulation
-REM sleep
-sexual behavior
-muscle tone
GABA general functions (4)
Reduces:
-arousal
-aggression
-anxiety
-excitation
glutamate general functions (2)
-memory
-sustained autonomic functions
peptides, opioid type, main functions (4)
-modulate emotions
-reward-center function
-consolidation of memory
-modulates reactions to stress
strucutral imaging function
provides evidence of size and shape of anatomical structures
exp: CT, MRI
computed tomography (CT) provides ______
3-dimensional view of brain structures
-differentiates based on density
advantages of CT (2)
widely available, relatively inexpensive
disadvantages of CT
-lack of sensitivity
-can’t differentiate white and gray matter
-can’t view structures close to bone tissue
-underestimate brain atrophy
-can’t image sagittal and coronal views
-suggestive, but no specific testing for psych disorders
Magnetic resonance imaging (MRI) provides _____
series of 2-dimensional images that represent the brain
advantages MRI
-can view brain structures close to skull
-can separate white and gray matter
-readily available
-resolution of brain tissue superior to CT scanning
disadvantages MRI
-expensive
-contraindications
-hard for claustrophobic pts
contraindications to MRI
-pacemakers
-metallic implants
-ventilators
functional imaging measures____
function of brain areas and bases resulting assessment on blood flow
-may use radioactive pharmaceuticals to cross blood-brain barrier
-mainly used for research
-exp: EEG, MEG, SPECT, PET
EEG and evolved potentials testing:
-least expensive
-convey info on electrical functioning of CNS
Magnetoencephalopgraphy (MEG):
-similar to EEG but detects different electrical activities
-often complementary w/ EEG
Single photon emission computed tomography (SPECT):
-provides info on cerebral blood flow
-limited availability
-expensive (less expensive than PET)
Positron emission tomography (PET)
-provides images of the brain when positron-emitting radionuclei interact w/ an electron
-expensive, requires extensive resources and support team
Tests that combine functional and structural imaging (4)
-Functional MRI (fMRI)
-3-dimensional, event-related functional MRI (3fEMRI)
-Fluorine magnetic spectroscopy
-Dopamine D2 receptor binding
How many chromosomes do humans have?
Normally 46 total (23 pairs)
What are the 4 nucleotide bases that make up DNA?
-adenine (A)
-thymine (T)
-cytosine (C)
-guanine (G)
True or False: genes direct the production of proteins
True
Pt that is a fast metabolizer of CYP4502D6 is an example of what?
a. chromosome b. genes c. phenotype d. DNA
c. phenotype
(observable characteristic of a specific trait, connected to the genetic contributions to that trait)
What does mRNA code for?
an amino acid
single nucleotide polymorphisms (SNP) detect:
single base changes in DNA sequence
True or False: variable expression of a gene for a disorder occurs at the cellular level
True
Testing for which allele is required by FDA in people of Asian descent prior to prescribing carbamazepine? (d/t risk of SJS and TEN)
HLA-B*1502 allele, an inherited variant of HLA-B gene
