Chapter 5 Flashcards
Acetylcholine
First neurotransmitter discovered in the peripheral and central nervous system.
Activates skeletal muscles in the somatic nervous system and may either excite or inhibit internal organs in the autonomic system.
Epinephrine (/adrenaline)
Chemical messenger that acts as a hormone to mobilize the body for fight or flight during times of stress and as a neurotransmitter in the central nervous system.
Norepinephrine
Neurotransmitter found in the brain and in the sympathetic division of the autonomic nervous system.
Accelerates hear rate in mammals.
Neurotransmitter
Chemical released by a neuron into a target with an excitatory or inhibitory effect.
Parkinson’s Disease
Disorder of the motor system correlated with a loss of dopamine in the brain and characterized by tremors, muscular rigidity, and reduction of voluntary movement.
Dopamine
Amine neurotransmitter that plays a role in coordinating movement in attention and learning in behaviours that are reinforcing.
Synaptic Vesicle
Organelle consisting of a membrane structure that encloses a quantum of neurotransmitter.
Synaptic Cleft
Gap that separates the presynaptic membrane from the postsynaptic membrane.
Chemical Synapse
Junction at which messenger molecules are released when stimulated by an action potential.
Presynaptic Membrane
Membrane on the transmitter-output side of a synapse
Postsynaptic Membrane
Membrane on the transmitter-input side of a synapse.
Storage Granule
Membranous compartment that holds several vesicles containing a neurotransmitter
Gap Junction
Fused prejunction and postjunction cell membrane in which connected ion channels form a pore that allows ions to pass directly from one neuron to the next
What are the four steps of neurotransmission?
Synthesis
Release
Receptor Activation
Inactivation
Transporter
Protein molecule that pumps substance across a membrane
What locations are neurotransmitters often found?
Granules, microfilaments in terminal, and presynaptic membrane
Transmitter-Activated Receptors
Protein that has a binding site for a specific neurotransmitter and is embedded in the membrane of a cell
Autoreceptor
“Self receptor” in a neural membrane that responds to the transmitter released by the neuron.
What are the four ways in which neurotransmitter deactivation is achieved?
Diffusion, degradation, reuptake, glial uptake
What is the difference between type 1 and type 2 synapses?
Type 1: excitatory, located on shaft or spine of dendrite, round dense and large synapses
Type 2: inhibitory, located on the cell body, flat less dense and smaller
Small Molecule Transmitter
Quick acting neurotransmitter synthesized in the axon terminal from products derived from the diet.
What are the four criteria for identifying neurotransmitters?
- Chemical must be synthesized by or present in neuron
- When the neuron is active the chemical must be released and produce a response in some target
- Same response must be obtained when the chemical is experimentally placed on the target
- A mechanism must exist for removing the chemical from it;s site of activation after its work is done.
Histamine
Neurotransmitter that controls arousal and waking
What are the three classes of neurotransmitters?
Small molecule transmitters
Peptide transmitters
Transmitter gasses
