Nervous System Flashcards
Where does neurogenesis occur
Hippocampus and caudate nucleus
Number neurons die per day
10,000
Neurons lost by age 80
2%
Neuron components
dendrites, cell body (soma), axon
Mitochondria actions
metabolic activities
Ribosomes action
synthesize new protein
Golgi complex action
prepare neurotransmitters and other substances for secretion
Myelin sheath composition and function
fatty substance made up of glial cells acts as insulator, speeds up conduction of nerve impulses
Glial cells
hold neurons together, provide neurons with nutrients, remove cellular debris
How message is transmitted within neuron
conduction
Action potential
At rest, inside of cell is negative charged, sodium channels open letting in positively charged sodium causing depolarization
Repolarization
sodium channels close and potassium channels open allowing positively charged potassium ions to leave the cell
Within neuron transmission of info versus neuron-to-neuron
Electrical, chemical
Synaptic transmission
action potential reaches axon terminal, release of neurotransmitter into synaptic cleft
Acetylcholine operates on what type of receptors
muscarinic and nicotonic
ACh in peripheral
causes muscles to contract
Myasthenia Gravis involves what NT
ACh
What NT involves REM sleep, regulation of sleep-wake cycle, and learning and memory
ACh
Nicotine effect on memory and alertness mimics what NT
ACh at nicotinic receptor sites
Degeneration of what NT in entorhinal cortex associated with Alzheimer’s
ACh
Cholinesterase inhibitors related to what NT, what are names
ACh, tacrine (Cognex), donepezil (Aricept), galantamine (Reminyl) and rivastigmine (Exelon)
Catecholamines
Dopamine, epinepherine, norepinepherine
Parkinsons associated with what NT in what brain structure
degeneration of dopamine receptors in substantia nigra
Tourette’s associated with what NT and in what brain structure
oversensitive or excessive dopamine in caudate nucleus
What NT and how are action of stimulant drugs, opiates, alcohol, nicotine reinforced
elevated levels of dopamine in the mesolimbic system (midbrain and limbic system)
Catecholamine hypothesis
some forms of depression due to lower than normal levels of norepinephrine
Role of norepinepherine in what
mood, attention, dreaming, learning and certain autonomic functions
Serotonin implicated in what
mood, hunger, temperature regulation, sexual activity, arousal, sleep, aggression, migraine headache
Elevated levels of serotonin linked to what
Schizophrenia, autism, Anorexia, Nervosa
Low levels of serotonin linked to
aggression, depression, suicide, bulimia nervosa, PTSD, OCD
what NTs related to social phobia
dopamine and serotonin
what type of NT is Gamma-aminobutyric Acid (GABA)
inhibitory
GABA involved in
eating, seizure, motor control, vision, sleep
anxiety associated with what NT
low levels of GABA
Benzos and other CNS depressants reduce anxiety by doing what to what NT
enhancing effects of GABA
Huntingon’s associated with what action and NT
degeneration of cells that secrete GABA in basal ganglia
What type of NT is glutamate
excitatory
Glutamate involved in what
learning, memory, long-term potentiation
What is long-term potentiation
formation of long term memories
What is excitotoxicity
Excessive glutamate receptor activity
what problems are associated with excitotoxicity of glutamate
seizures, stroke-like brain damage, huntington’s, Alzheimer’s, other neurodegenerative disorders
What type of NT are endorphins (endogenous morphines)
inhibitory neuromodulators
what do endorphins do
lower sensitivity of postsynaptic neurons to neurotransmitters
How are endorphins related to pain sensation
analgesic properties - prevent release of substance P
What are endorphins associated with
pain, pleasurable experiences, emotions, memory and learning, sexual behavior
