Nervous System Flashcards
what is a critical point of bio research?
the machinery of the mind
“its all in the chemicals”
what is a neuron?
basic communication building block of nervous system
what do neurons do? where does each part take place?
collect, integrate, and transmit electrochemical info
dendrites collect info
cell bodies integrate info
axons and synapses transmit info
how does a nerve impulse travel?
from dendrites to the cell body to the axon, to terminal bottons
then they continues to go to next dendrites and next neuron
what contains neurotransmitters?
terminal buds
*release or don’t release (depending if activated or not)
what is the synapse?
the gap where neurotransmitters are released
more in the synapse, more affect in the body
what are the 3 different types of neurons?
sensory (afferent) neurons
motor (efferent) neurons
interneurons
what is a sensory neuron?
afferent neurons
bring info from the snesory organs to the spinal cord and brain (CNS) thus enabling us to perceive, then respond to sensory inputs like touch, pain, heat, pressure, etc
ex. carries info from sensory receptors in skin to the brain
what is a motor neuron?
efferent neuron
transmit info from the spinal cord and brain (CNS) to the periphery (outside) thus enabling our response to sensory inputs
ex. carries info from the brain to the neurons controlling leg muscles, causing response so we can walk
what is an interneuron?
vastly outnumber motor and sensory neurons (several millions of each compared to 100 billion interneurons)
facilitate within-CNS transmission of info and perform integration and organization functions
**most common neuron in brain and most important in communication for the CNS
what are neurons specialized by? what types of cells are these?
location
purkinje cells - motor control and coordination in the cerebellum
pyramidal cells- hippocampus
bipolar - more complex, used for reception and vision, two poles
what is a myelin sheath? what is it made from?
made from glial cells
provides insulation, speeds up neural transmission by causing action potentials to “jump” across the “nodes of ranvier”
electrical signals are protected and keep impulses contained - give saltatory conduction a smooth flow
what is saltatory conduction?
action potentials jumping across the rodes of ranvier
produces faster neural speed and thereby increases how quickly effects at the synapse can occur
what is a glial cell?
nurishing system - make up myelin sheath
outnumber neurons 10:1 in CNS
different varities of glial cells support different physiological functions
ex. glial cells form the blood-brain barrier, help supply nutrients to neurons, and form myelin sheaths
what is a node of ranvier?
the space between 2 myelin sheaths on an axon where depolarization and action potentials occur
*smooth transitions between myelin and nodes
what do action potentials cause?
neuronal communication
electrical signals provice communication between neurons - nerve impulse flows down the axon
changes in electrical potential lead to what? what types?
ACTION
depolarization and hyperpolarization
what is the resting membrane potential?
the electrical difference between the inside and outside of the neuron
in the resting state where are the electrical charges?
inside the neuron = slightly more negative
outside the neuron = slightly more positive
(more Na outside neuron, more K inside neuron)
what is depolarization? what is it due to?
due to excitatory signal
neurons fire when cell depolarizes
change in permeability of cell - gates open and Na+ rushes into the neuron
then inside the neurons, there is more + charge than outside the neuron
*change from negative to positive charge CAUSES action potential
what is hyperpolarization? what is it due to?
due to inhibitory signal
neuron is less likely to fire
Na+ channels less likely to allow Na+ in neuron
where does depolarization occur?
the nodes of ranvier
in depolarized region - negative is on the outside of node, positive is on the inside
what is a mirror neuron? where are they found? what can it help us study?
identified in other species too, found in frontal and parietal lobes
are activated when an organism engages in a behavior or observes another engage in that behavior - recognize another person’s goals or intentions
practiced through watching others’ activities and when you understand intentions or meaning is when it most likely happens
helps to treat autism - try to activate things in autistic people we want them to obtain
what is an agonist?
increases or facilitates neurotransmitter effects
INHANCES
ex. serotonin for depressed people
what is an antagonist?
decreased/ block neurotransmitter effects
INHIBITS
ex. dopamine for those with pyscho symptoms
what are the options of neurotransmiters to do once in the synapse?
reuptake (terminated)
bind to autoreceptor (terminated)
bind to the next neuron in the post-synaptic membrane (relased and allow the impulse to continue)
broken down by enzymes (terminated)
how does a neurotransmitter travel?
- neurotransmitters are synthesixed from chemical building blocks called precursors
- neurotransmitters are stored in vessicles
- neurotransmitter is terminated or released