Brain and Behavior Communication in the Nervous System Flashcards
weight of adult brain
3Ibs
nuerons in adult brain
1000 - 10 000 billion
What is plasticity
When the brain heals itself
When is plasticity most occurrent
in childhood
what is a neuron
a nerve cell
ions involved in neuron
potassium and sodium (K+ , NA+)
all or none principal
the neuron either fires or not
Sensory
receive input from environment carry message to brain
interneuron
no contact with outside. carry info from one neuron to another
Motor Neurons
carry info to nervous system for behavioural response
dendrites
receive information from other neurons
soma
cell responsible for maintaining the life of cell
(Genetic material)
Axon
part of a neuron that serves as the cell’s internal transmitter device
meylin sheath
insulating material that protects the axons and helps speed
Nodes of Ranvier
space separating the segments of the myelin sheath covering the neurons and also helps increase speed.
terminal buttons
tiny swellings at the end of a neuron’s axon
they secrete chemicals when reached by an action potential
Synapse
a small gap between terminal button of one neuron and a dendrite of another.
pre-synaptic neuron
sends message
post-synaptic
receives message
neural impulse
possess electrical properties
resting potential
the tiny negative electrical charge in place between the inside and outside of the resting room
Action Potential (AP)
the electrical signal that travels down a neuron’s axon. (cell becomes less negative)
excitatory neurotransmitters
membrane of contracted neuron changes allowing more positive ions into the cell and increases the chances of an AP
inhibitory neurotransmitters
the cell membrane either pushes more positive ions out or allows negative ions to move in leading to a decreased action potential.
Neurotransmitters
Chemical messengers that relay neural messages across the synapse.
reflex
Hammer hitting the knee stimulates sensory neurons causing those cells to being creating action potentials
