3.2 How the nervous system works - neurotransmitters + cells Flashcards
Neurons
one of the major types of cells found in the nervous system, which are responsible for sending and receiving messages throughout the body
Cell body
the part of a neuron that contains the nucleus that houses the cell’s genetic material
Dendrites
small branches radiating from the cell body that receive messages from other cells and transmit those messages toward the rest of the cell
Axon
transports information in the form of electrochemical reactions form the cell body to the end of the neuron
Axon terminals
bulb-like extensions filled with vesicles
Neurotransmitters
the chemicals that function as messengers allowing neurons to communicate with each other
Neurogenesis
the formation of new neurons
Stem cells
a unique type of cell that does not have a predestined function
Glial cells
are specialized cells of the nervous system that are involved in mounting immune responses in the brain, removing waste, and synchronizing the activity of the billions of neurons that constitute the nervous system
Myelin
a fatty sheath that insulates axons from one another, resulting in increased speed and efficiency of neural communication
Multiple sclerosis
a disease in which the immune system does not recognize myelin and attacks it – can destroy the nervous system
Resting potential
relatively stable state during which the cell is not transmitting messages (net negative)
Ion channels
Small pores on the neurons cell membrane
Action potential
a wave of electrical activity that originates at the beginning of the axon near the cell body and rapidly travels (negative to positive)
Refractory period
brief period in which a neuron cannot fire
Synapse
an area consisting of a neuron’s axon terminals and different neuron’s dendrites; these structures are separated by a microscopic space into which neurotransmitters can be released
Presynaptic cell
is the neuron that releases its neurotransmitters into the synapse
Postsynaptic cell
is the neuron that receives neurotransmitters from the presynaptic cell
All or none principle
individual nerve cells fire at the same strength every time an action potential occurs
Synaptic celft
The minute space between the axon terminal and the dendrite
Reuptake
a process whereby neurotransmitter molecules that have been released into the synapse are reabsorbed into the axon terminals of the presynaptic
Glutamate
most common excitatory neurotransmitter in the brains of vertebrates
GABA
primary inhibitory neurotransmitter of the nervous system, meaning that it prevents neurons from generating action potentials
Acetylcholine
one of the most widespread neurotransmitters within the body, found at the junctions between nerve cells and skeletal muscles - voluntary movement
Dopamine
a monoamine neurotransmitter involved in such varied functions as mood, control of voluntary movement, and processing of rewarding experiences
Norepinephrine
a monoamine synthesized form dopamine molecules that is involved in regulating stress responses, including increasing arousal, attention, and heart rate
Epinephrine aka adrenaline
hormone and neurotransmitter created in the adrenal gland on the kidneys (energy + engagement)
Serotonin
a monoamine involved in regulating mood, sleep, aggression, and appetite
Agonists
drugs that enhance or mimic the effects of a neurotransmitter’s action
Antagonists
inhibit neurotransmitter activity by blocking receptors or preventing synthesis of a neurotransmitter
Hormones
chemicals secreted by the glands of the endocrine system
Hypothalamus
a brain structure that regulates basic biological needs and motivational systems
Pituitary gland
the master gland of the endocrine system that produces hormones and sends commands about hormone production to the other glands of the endocrine systems
Adrenal gland
a pair of endocrine glands located adjacent to the kidneys that release stress hormones, such as cortisol and epinephrine
Endorphins
hormones produced by the pituitary gland and the hypothalamus that function to reduce pain and induce feelings of pleasure
Testosterone
a hormone that serves multiple functions, including driving physical and sexual development over the long term - agression
