Unit 2: Neuroscience Pt. 1 Flashcards
Structures of a neuron
- Soma
- Nucleus
- Dendrites
- Axon
- Nodes of Ranvier
- Myelin Sheath
- Terminal branches/Synaptic Nob/buttons
Soma
Fleshy, cell body –> where all life processes occur
Nucleus
holds DNA
Dentrites
End parts that branch off from the soma
they recieve messages from other neurons
Axon
long part
carry signals from the soma to the end of the neuron
Nodes of Ranvier
gaps in the myelin sheath that allow signals to “jump” along the axon
Saltatory Conduction
Myelin Sheath
glial cells that serve as fatty insulation which help signals travel faster
Multiple sclerosis = loss of myelin sheath
Terminal branches
send signals to other cells
Signals go: dendrite, soma, axon, terminal branches
Action Potential
List events
- Resting potential
- Depolarization
- Repolarization
- Refractory period
Refractory period
After action potential, neuron is unresponsive to a signal for a short amount of time
Neuroplasticity
the brain’s ability to change its activity (build new neural pathways) in response to change
Questions usually regard hemispherectomies
Nerve impulse/firing
series of action potentials propogated down axon from dendrites to terminal branch
wave of action potentials
Firing threshold
minimum stimulation neededd for action potential to ensue
Neurons have an all of nothing response
Neurotransmitters
chemical messengers, released from presynaptic neurons into synapses when AP reaches terminal branches
Agonist drugs
enhance the normal response –> imitate neuro transmitters to elicit same response
some also prevent reuptake
Antagonist drugs
prevent normal cellular response and block the normal NT from binding
Acetylcholine
AMAC
A - acetylcholine
M - memory and muscle contraction
A - (low) = Alzheimer’s disease
C - Curare: antagonist –> poison and paralysis
Serotonin
Helps with mood, sleep, hunger regulation, and alertness
low = depression
SSRIs - Selective Serotonin Reuptake Inhibitor
Ecstacy - agonist (also inhibits reuptake)
Dopamine
Deals with movement, attention, and emotion
too high - schizophrenia (too much emotion)
too low - Parkinson’s disease (too little muscle control)
Cocaine = agonist
Endorphins
bind to opiate receptors to reduce pain and stress
opiods = agonists
Noradrenaline/Norepinephrine
deals with arousal/alertness
GABA (gamma-aminobutyric acid)
inihibitory NT - reduces activity in the CNS
Low = insomina
High = temors/seizures
stimulated by alcohol, inhibited by caffiene
Peripheral Nervous system
deals with movement, autonomous functions (breathing)
subsections: motor and sensory neurons
Central Nervous System
brain and your spinal cord
Motor/efferent neurons
E - exit the brain
carry messages from brain to muscles
Sensory/Afferent neurons
A - approach the brain
outside (sensory info) to the brain
Autonomic NS
part of the motor system
controls unconcious things: sympathetic and parasympathetic
Sympathetic NS
Fight or flight:
- raised heart rate
- low stomach activity
- dilate pupils
- release epinephrine
Parasympathetic NS
Opposite of sympathetic
cool down after fight or flight
Endcrine System
hormone secreting cells that translate longer processes (often coordinnate growth, stress, and internal equilibrium).
Hormone
chemical substances that travel through the blood to affect a target cell (similar to NTs)
works with the parasympathetic and symathetic nervous systems
Endocrine glands
secrete hormones into the blood (ex. pancreas)
Exocrine glands
release secretions (sweat glands, salivary glands, tear ducts, etc.)
