Neuroanatomy and chemistry Flashcards
CNS
brain + spinal cord
PNS
cranial + spinal neves
PNS..
somatic (voluntary) vs autonomic (involuntary)
ANS
sympathetic (fight or flight) vs parasympathetic (rest & digest)
Neurons 2 types of comm
Chemical communicators (neurotransmitters) Electrical (action potential)
Neuroglial cells
All cells that aren't neurons Support and nourish neutrons clean and increase communication speed memory 50% of the brain
Neurons receive info on
dendrites
Neurons have a single
axon
Where is action potential
axon hillock
we begin with many more neutrons than necessary but those not stimulated
die. not all will die= relearning is easier
food of neurons
glucose
Types of neuroglia
Astrocytes: consolidate synapses and memories
Microglia: CNS macrophage
Oligodendrytes: cns myelin, wrap around neutrons to increase comm speed
Ependymal cells: protect brain from cranium
Action potential goes from a region to a region
polarised (+) to a non polarises (-).
One way travel
electrical impulse turns into a
chemical impulse
Neurotransmission steps:
Synthesis in the neutron
Vesicular storage
Release
Reabsorption/ enzymatic degradation
True or false: there are different forms of synapse connections
true
Excitatory postsynaptic potential
change in the membrane voltage of a postsynaptic cell following the influx of positively charged ions into the cell= generates an action potential. Reaches threshold = depolarizes
inhibitory postsynaptic potential
makes a postsynaptic neutron less likely to produce an action potential
True or false: brain is functionally divided
false
Plasticity
some functions may be moved to another region in the event of damage
Reticular activating system
Consciousness: wakefulness, motor responses
Vital reflexes: HR, RR
Brainstem nuclei (medulla & pons) + afferent and efferent axons
Pons
ventilation control + motor information relay
Medulla
Autonomic functions
Motor and sensory crossover
Cerebellum
balance + posture + motor coordination
Prefrontal area
goal oriented behaviour, inhibition, short term memory
broca area
speech formation
wernicke
speech interpretation
Postcentral and precentral gyrus
pyramidal pathways
premotor brodmann area 6
extrapyramidal efferent pathways
size of gyrus =
how sensitive/ how much control you have
Limbic system
primitive brain hippocampus pineal gland corpus callous hypothalamus amygdaloid body
corpus callosum
connecte both hemispheres
pineal gland
melatonin, sleep regulation
hippocampus
memory consolidation
amygdaloid body
link between emotions and physiological response
hypothalamus
homeostasis regulation through neural and endocrine systems
Blood brain barrier protects from
toxins, drugs, immune cells, viruses bacteria
BBB permeable to
lipid soluble molecules, o2, co2, glucose
CNS components of ANS
hypothalamus
RAS
Interomediolateral Spinal Cord
Somatic nervous system
somatic motor (voluntary) conducts impulses from the CNS to skeletal muscles
ANS
visceral motor (involuntary) conducts impulses from the CNS to cardiac, smooth muscles and glands
Efferent
CNS to effectors, motor nerve fibers
Afferent
receptors to CNS, somatic and viceral sensory nerve fibers
Parasympathetic cholinergic receptor functions
decrease HR, vasodilate, increase gland secretion and propulsion
Sympathetic adrenergic receptor functions
vasoconstriction, increase HR + contractility, bronchodilation
Somatic nervous system transmitter and receptor
Acetylcholine
Nicotinic receptor
Parasympathetic transmitter and receptor
Acetylcholine
Muscarinic receptor
sympathetic transmitter and receptor
Acetylcholine
NE, epinephrine, a nd b adrenergic receptors
MRI
Imaging technique using strong magnetic fields instead of X-Rays
Essentially map the anatomy of the desired organ
Allows to determine specific features of mental illnesses
fMRI
Cerebral blood flow follows neuronal activation
So measuring cerebral blood flow variations = measuring neuronal activation variations!!
Useful to study brain activity changes for different diseases
Schizo, physiopatho
Negative sx: mesocortical pathway, DA reduced
+: mesolimbic pathway, DA increased
schizo MRI
enlarged ventricules, reduced hippocampus
schizo PET
loss of cortical tissue
schizo fMRI
decreased activity in temporal lobes
Antipsychotic mechanism of use
D2 antagonism
Antipsychotic adverse effect
blockade of histamine, ne and act receptors
Depression pathophysiology
widespread decrease of serotonin (5-HT) binding
Monoamine hypothesis depression
decrease serotonin, NE, DA
HPA axis depression
chronic activation
Anxiety pathophysiolgy
hyperactive amygdala = attentional biais to threats
hiyperactive cingulate cortex = anticipatory anxiety
impaired inhibitory neuromodulation (decreased GABA)
impaired monoamine neurotransmission (decreased 5-HT, NE)
Heightened sensitivity to ph alterations (panic)
Downregulation
Ex: opioids, bind to receptors on cells, body wants to counter, decreases number of receptors
pharmacodynamic tolerance
number of receptors
metabolic tolerance
changes in protein that metabolism, person develop more enzymes to get rid of it
tolerance
given dose produces smaller effect
cross tolerance
tolerance to one drug produces tolerance to similar drugs
physical dependence
withdrawal
psychological dependence
craving
cross dependence
ability of a drug to support dependence to another
SUD neurobiology
dopamine release reinforces behaviour= repeated use leads to down-regulation in DA synthesis and receptors
dopamine pathway
prefrontal cortex
nucleus accumbens
ventral tegmental area
binge roh
dorsal striatum
ventral tegmental area
cerebellum
withdrawal
basolateral and central amygdalda
Anticipation
prefrontal cortex, hippocampus
exercise
endorphins, exogenous opioids, decrease cortisol, increase satisfaction
stimulant
blocks reuptake of dopamine
