Post on 05-Jan-2016
The Central Nervous System
The Central Nervous System
Neuron Neuron
The basic functional unit of the The basic functional unit of the CNS CNS
Exhibits excitabilityExhibits excitability Exhibits conductivity Exhibits conductivity
The microscopic gap separating The microscopic gap separating neuronsneurons
SynapseSynapse
Neurotransmitters Neurotransmitters
A chemical substance capable A chemical substance capable of transmitting an impulse of transmitting an impulse across the synaptic cleft across the synaptic cleft
Contained in small sacs called Contained in small sacs called vesicles vesicles
Variety of neurotransmitters Variety of neurotransmitters
Cause Cause acuteacute CNS reaction CNS reaction Small moleculeSmall molecule Rapidly actingRapidly acting
Which are these?Which are these?
ANSWERS:ANSWERS:
AcetylcholineAcetylcholine Dopamine, Epinephrine, Dopamine, Epinephrine,
Norepinephrine, Serotonin Norepinephrine, Serotonin Asparate, Gamma- Asparate, Gamma-
aminobutyric acid (GABA), aminobutyric acid (GABA), Glutamate, Glycine Glutamate, Glycine
Variety of neurotransmitters: Variety of neurotransmitters:
Causes prolonged CNS Causes prolonged CNS reactions reactions
Large moleculeLarge molecule Slow actingSlow acting
Which are these?Which are these?
Answers: Answers:
Adrenocorticotropic hormone Adrenocorticotropic hormone (ACTH)(ACTH)
InsulinInsulin
Factors: Factors:
Synaptic fatigueSynaptic fatigue UpregulationUpregulation DownregulationDownregulation
Dysfunction Dysfunction
Excessive stimulation:Excessive stimulation:
1. Muscle cramps1. Muscle cramps
2. Convulsions2. Convulsions
3. Psychotic symptoms3. Psychotic symptoms
4. Hallucinations4. Hallucinations
5. Tension5. Tension
And........And........
Depression results in:Depression results in:
1. Decreased levels of 1. Decreased levels of consciousness consciousness
2. Respiratory depression2. Respiratory depression
Narcotics and Analgesics Narcotics and Analgesics
Mechanism of action:Mechanism of action:
Bind to opiod receptors on cell Bind to opiod receptors on cell membranes of specific neurons membranes of specific neurons in the brain resulting in in the brain resulting in decreased paindecreased pain
Analgesics & Antipyretics Analgesics & Antipyretics
Mechanism of action:Mechanism of action:
Inactivates cyclooxegenayse Inactivates cyclooxegenayse which prevents prostaglandin which prevents prostaglandin formationformation
Sedatives & Hypnotics Sedatives & Hypnotics
BarbituratesBarbiturates BenzodiazepinesBenzodiazepines Nonbarbiturates & Nonbarbiturates &
NonbenzodiazepinesNonbenzodiazepines
Mechanism of Action Mechanism of Action
BarbituratesBarbiturates Inhibits functionInhibits function
of nerve cellsof nerve cells
BenzodiazepinesBenzodiazepines Bind with Bind with
receptors to receptors to increase the increase the effects of GABAeffects of GABA
Antianxiety Drugs Antianxiety Drugs
Benzodiazepines are the most Benzodiazepines are the most commoncommon
Mechanism of action:Mechanism of action:
Facilitate the inhibitory effects Facilitate the inhibitory effects of GABAof GABA
Antidepressant Drugs Antidepressant Drugs
Types of drugs:Types of drugs:
1. Tricyclic antidepressants1. Tricyclic antidepressants
2. SSRI2. SSRI
3. MAOI3. MAOI
Mechanism of Action Mechanism of Action
Increases the amount of Increases the amount of neurotransmitters neurotransmitters
(serotonin & epinephrine)(serotonin & epinephrine)
Antipsychotics Antipsychotics
Treats psychotic processesTreats psychotic processes Mechanism of action:Mechanism of action:
Decreases the effects of Decreases the effects of Dopamine by occupying Dopamine by occupying receptor sitesreceptor sites
Anticonvulsants Anticonvulsants
Treats seizure disordersTreats seizure disorders Mechanism of action is unclearMechanism of action is unclear
May: May:
1. Decreases neuronal 1. Decreases neuronal excitability excitability
2. Prevents spread of impulses2. Prevents spread of impulses
Alcohol Alcohol
Depresses the CNSDepresses the CNS Rapidly absorbed from the Rapidly absorbed from the
stomach and small intestinesstomach and small intestines Quickly distributed to all body Quickly distributed to all body
tissuestissues