Chapter 5 Flashcards
Acetylcholine (ACh)
activates skeletal muscles in SNS; inhibits heart beats; may inhibit OR excite organs in the autonomic system
Epinephrine
AKA Adrenaline; mobilizes body during flight or fight
Norepinephrine
AKA Noradrenaline; accelerates heart beat in mammals
Neurotransmitter
chemical released by a neuron onto a target with an excitatory or inhibitory effect
What are neurotransmitters outside of the nervous system called?
Hormones
What disease does Dopamine play a role in?
Parkinson’s Disease
How do electron microscopes work?
Projecting a beam of electrons through a very thin slice of tissue. The varying structure of the tissue scatters the beam onto a reflective surface where it leaves an image
Synaptic Vesicles
Organelle consisting of a membrane structure that encloses a quantum or neurotransmitter
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 in voluntary movement
Dopamine
Amine neurotransmitter; plays a role in coordinating movement, attention, learning, and behaviors that are reinforcing
Synaptic Cleft
Gap that separates the presynaptic membrane from the postsynaptic membrane
Chemical Synapse
junction where messenger molecules are released from one neuron to excite the next neuron
Presynaptic Membrane
encloses molecules that transmit chemical messages; forms the axon terminal
Postsynaptic Membrane
contains receptor molecules that receive chemical messages
Microtubule
Transport structure that carries substances to the axon terminal
Mitochondrion
Organelle that provides the cell with energy
Storage Granule
Large compartment that holds synaptic vesicles
Postsynaptic Receptor
site to which a neurotransmitter molecule binds
Gap Junction
electrical synapse; where the prejunction and the postjunction cell membranes are fused. ion channels in on cell membrane connect to ion channels in the other membrane, forming a pore that allows ions to pass directly from one neuron to the next
Why do we rely mostly on chemical synapses when gap junctions send messages more quickly?
chemical synapses are flexible in controlling whether a message is passed from one neuron to the next, they can amplify or diminish a signal sent from one neuron to the next, and can alter their signals to mediate learning
Neurotransmission Steps
- Synthesis
- Release
- Receptor Action
- Inactivation
Neurotransmission Steps: 1. Synthesis
some neurotransmitters are transported from the cell nucleus to the terminal button and others are made from building blocks imported into the terminal and are packaged into vesicles there
Neurotransmission Steps: 2. Release
In response to the action potential, the transmitter is released across the membrane by exocytosis; Ca+ flows in and binds to protein calmodulin and causes two chemical reactions–1. releases vesicles bound to presynaptic membrane 2. releases vesicles bound to microfilamens in the axon terminal
Neurotransmission Steps: 3. Receptor Action
The transmitter crosses the synaptic cleft and binds to a receptor