Drug Site of Action and Mechanism of Action Flashcards
neurons combine to form many structures
NOTABLE BRAIN DIVISIONS, STRUCTURES, AND THEIR FUNCTIONS (3)
- BRAINSTEM/HINDBRAIN
- MIDBRAIN
- FOREBRAIN.
Brainstem/Hindbrain portion (4)
pons ,medulla, reticular formation , cerebellum
Pons
– Contains nerve pathways relaying sensory
info to thalamus, cerebral cortex,cerebellum, refines motor commands
– Plays a role in body movement, sleep, dreaming (pons neurons fire rapidly in dreaming)
- contains the locus coeruleus (group of cell bodies), which is involved in SNS activity (gets us ready to react) –> need to respond to something!!! (bear) –> alerting higher centers in the brain
- drugs affecting sleeping affect the pons
- pons= latin for bridge –> bridge b/t brainstem and cerebellum
- psychedelics impact the pons too
Medulla
– Site of “life-maintaining” centres (breathing, HR, BP centres)
– Contains “vomiting centre”
- lowest structure in the brain
- damage can cause death
- sensitive to drugs –> depressed with drugs (respiratory) they stop breathing –> will cause permanent damage if anoxic for a while
types of neurons (3) and characteristics
sensory: transmit sensory info picked up by neurons (eyes, ears, skin, nose) transmit info to a variety of areas in the brain
motor neurons: travel from the brain to innervate muscles
Interneurons: neurons that connect other neurons
parts of a neuron
- cell body ( housekeeping of the cell)–> synthesize chemicals (NT) contains genetic info of the neuron
- axon –> projection from the cell body (length will vary from type of neuron –> MN longer)
- covered in fatty sheath (myelinated)
- the spots with no fatty sheath = nodes of ranvier
end of axon = synaptic endballs
- NT at the end of these endballs (chemicals that are released by the neuron) - dendrites: (INs have a lot of dendritic branching)
neurons communicate with one another by releasing ____
NTs
dendrites job is to ____
receive NTs from other neurons
cerebellum nickname and why
little brain –> plays a role in cognitive tasks
- analyse sensory info
- solves problems
thin white line in front of the cerebellum and behind the medulla =
RF
forebrain cortical structure (outside)
cerebral cortex
Cerebellum job
- Controls fine motor movement (threading a needle), motor
coordination, postural adjustments (tripping and staying up)
– Plays a role in number of cognitive tasks
drugs affecting it:
- alcohol (staggering)
- THC
Reticular Activating System
role:
controls:
pathways
- ascending ____ –> ___–> ___
damage
drug
– Plays a role in ANS reactions; readying one to act
– Controls wakefulness/neurological alertness
- a lot of white matter (myelination) with grey matter (cell bodies
- ascending and descending pathways of RF
- ascenging = RAS** –> from medulla recieves sensory info –> neurons synapse with bodies in RF –> continue on upwards to higher center of the brian
- damage = coma****
- drug = rhohypnol (sedation)
Raphe Nuclei
– Plays a role in sleep
MIDBRAIN areas (2)
- Inferior and Superior Colliculi
– Relay and process (at basic level) auditory and visual information respectively - superior: visual info process
inferior: auditory info process - the info travels up to thalamus –> auditory cortex (inf) and occipital cortex (sup)
drugs: alcohol affects - Ventral Tegmental Area
– Contains cell bodies involved in drug dependency
FOREBRAIN area (5)
- Thalamus
Hypothalamus
Hippocampus
Basal Ganglia
Cerebral Cortex
Thalamus
connection with ______ regulates ____ and _____ of CC
drugs (2)
– Referred to as “relay center” or “traffic officer”
– Sends sensory information to cerebellum and cerebral cortex
– Sends motor commands to muscle groups (coming from primary motor cortex (synapse in thalamus) )
- in connection with RAS, the thalamus regulates general arousal and excitability of the cerebral cortex
drugs: psychadelics, opitates
hypothalamus (below the thalamus)
connection with ____ regulates ______ (hunger, sex drive, thirst)
drugs: (3)
– In connection with pituitary gland regulates physiologically based drives
- pit releases hormones to regulate
- regulates behaviours and psychological based drives (hunger, thirst, sex drive)
Drugs: THC (munchies), opiates (decreased sex drive), cocaine/meth (increased sex drive)
Hippocampus
role (2)
drug (3) THC. Alc,,, ____
– Plays a role in learning and memory; formation of new memories
- plays a role in drug dependency behaviours (places can be trigger for drug use from this area) (places associated to drug use)
drugs: THC, barbituates, alcohol
FOREBRAIN Reinforcement/Pleasure/Reward Centers
– Include (3) and play a role in ____
- Mesolimbic Dopamine System (group of dopmaiinergic neurons to release dopamine across limbic system) –> begins in the vnetral tegmental area
- Nucleus Acumbens
- prefrontal cortex (plays a role in pleasure when highly active)
– Play a role in intense euphoric effects of some drugs
and addiction (e.g., amphetamine, cocaine, heroin)
Basal Ganglia (many structures) Plays a role in
drugs (1)
- integrating voluntary motor movements ( this is a motor area)
- Maintaining posture and muscle tone
- Learning/forming automatic S-R behaviours i.e., habits****
relies on normal levels of dopamine, less dopamine levels cause reduction in BG fucntion
drugs: antipsychotic drugs —> affecting function of BG**
Cerebral Cortex
◦ Responsible for higher mental processes
e.g., language, reasoning, decision making,
problem solving
◦ Has four divisions, referred to as lobes
Lobes of the cerebral cortex
Frontal –> motor association cortex (motor planning), primary motor cortex
◦ Parietal–> somatosensory association cortex (proprioception) , primary somatosensory cortex (representation of body (homunculus))
◦ Occiptal –> primary visual cortex, visual association cortex (recognition with the visual association cortex)
◦ Temporal –> amygdala and hippocampus
