chap 2 key terms Flashcards
action potential
o Action potential- the electrical charge that travels down the axon of a neuron during transmission of a neural impulse, occurring as the result of the rapid depolarization of the neurons membrane and prompting the release of neurotransmitters.
agonists
o Agonists-in neural communication, a substance that binds to a neuroreceptor to produce a similar effect to that of a neurotransmitter in either exciting or inhibiting a postsynaptic neuron, e.g. benzodiazepine drugs are GABA receptor agonists that have sedative effects similar to GABA.
antagonists
o Antagonists- in neural communication, a substance that suppresses the release of a neurotransmitter or blocks the receptor sites, making the postsynaptic neuron less likely to fire.
autonomic nervous system (ANS)
o Autonomic nervous system (ANS)- the component of the peripheral NS (PNS) that intervates involuntary muscles and glands, including the organs of the circulatory, digestive, respiratory and reproductive systems; transmits information from the brain to organs and glands, and from these systems back to the brain.
axon
o Axon- the long, thin fibre of the neuron through which action potentials are transmitted.
axon terminals
o Axon terminals- the swollen tip of a presynaptic neurons axon, containing the synaptic vesicles from which neurotransmitters are released, that forms a synapse with the dendrite of the postsynaptic neuron.
brain
o Brain- the master organ of the CNS, responsible for receiving and processing information from the rest of the body and generating responses to it.
central nervous system (CNS)
o Central nervous system (CNS)- a major division of the nervous system consisting of all the nerves in the brain and spinal cord.
Consciousness
o Consciousness- an organisms awareness of internal or external events, including awareness of sensations, perceptions, emotions and thoughts.
dendrites
o Dendrites- the thread line branches that extend from the cell body (soma) of the neuron and receive signals from other neurons.
dopamine
o Dopamine- a modulatory neurotransmitter produced in the midbrain and adrenal glands that plays a major role in the coordination of movement and in the regulation of reward; dopamine imbalance is associated with many neurological disorders and with many mental health problems, including addictive behaviours.
enteric nervous system (ENS)
o Enteric nervous system (ENS)- largest component of the autonomic NS, which manages the functions of the digestive system; can function independently of the CNS and so is sometimes called the ‘second brain’; the extensive two-way neural connections between the ENS and the CNS, particularly via the vagus nerve, form the gut-brain axis.
excitatory neurotransmitter
o Excitatory neurotransmitter- neurotransmitters that increase the likelihood that a receiving neuron will dire an action potential.
GABA
o Gamma-amino butyric acid (GABA)- the primary inhibitory neurotransmitter; its overall effects are to calm or slow neural transmission and therefore the body’s response.
glutamate
o Glutamate- the primary excitatory neurotransmitter in the brain responsible for the fast transmission of neural messages and involves in cognitive functions.
inhibitory neurotransmitter
o Inhibitory neurotransmitter- any neurotransmitter that decreases the likelihood that a receiving neuron will fire an action potential.
Long term depression (LTD)
o Long-term depression (LTD)- a form of neural plasticity that results in a long-lasting reduction in the strength of a neural impulse due to persistent weak stimulation.
motor neurons
o Motor neurons- specialised efferent neurons within the CNS that carry motor commands from the brain and spinal cord to muscles, organs and glands to control voluntary and involuntary movements; upper motor neurons carry info from brain to spinal cord; lower motor neurons form connections between spinal cord and muscles, organs and glands.
Nervous system
o Nervous system- the integrated network of neurons, nerves, nerve tracts and associated organs and tissues, including the brain, that together coordinate a persons functioning, behaviours and responses adaptively as they interact with and adapt to their external environment.
neuromodulator
o Neuromodulator- any of a group of neurotransmitters that can affect a large number of neurons at the same time; they are slow acting but bring about long lasting change to affected neurons and synapses; responsible for a range of human behaviour related to sleep, pain, motivation and voluntary movements.
neurotransmitter
o Neurotransmitter- any chemical released from the axon terminal buttons of a presynaptic neuron into the synaptic cleft following an action potential that either excites or inhibits the postsynaptic neuron.
parasympathetic NS
o Parasympathetic nervous system- the branch of the autonomic NS that controls unconscious processes related to rest, repair and enjoyment, such as digestion, sleep, slowed heat rate, pupil constriction, sexual arousal; it calms the effects of the sympathetic NS.
parkinsons disease (PD)
o Parkinsons disease (PD)- a disease that causes tremors, muscular rigidity, slowness of movement and difficulty in initiating voluntary movement; believed to be caused by a lack of dopamine.
peripheral NS (PNS)
o Peripheral Nervous system (PNS)- the division of the NS that comprises all of the nerves outside the CNS, through which motor info is communicated from the CNS to muscles and organs of the body, and sensory info is communicated back to the CNS.
