Ch 3 Lec 10 Flashcards
Synapse
a functional connection between a neuron and its target(important these do not connect physically)
Myelin sheath
- is a whitish, fatty layer of insulation which is derived from the glial cells
- segmented by the nodes of Ranvier(here the myelin is very thin or absent)
Synaptic cleft/space
the small space between the axon terminal of one neuron and the dendrite of the other.
Neurotransmitters
chemicals that are secreted by the neurons that can carry messages across the synapse to excite or inhibit the firing of other neurons
What are five steps of chemical communication involves?
Synthesis(the process of combining things) Storage(in synaptic vesicles) Release Binding(to receptor sites) Deactivation
Excitatory transmittery
- When a neurotransmitter binds to a receptor site in the postsynaptic neuron and this causes the inflow of sodium or other positively charged ions
- Leads to depolarization
Inhibitory transmitters
- When a neurotransmitter binds to a receptor site on the postsynaptic neuron and this causes negatively charged ions(like chloride) to flow into the neuron.
- Leads to hyperpolarization
Deactivation
• After activating or inhibiting the neuron, a neurotransmitter molecule is deactivated. This can occur in two ways
1) other chemicals in the synaptic space can break them down
2) via reuptake (they are reabsorbed into the presynaptic axon terminal)
What are two Amino acid neurotransmitters and their properties?
•Glutamate
-The most prevalent excitatory neurotransmitter in the CNS
-Particularly important for learning and memory
•GABA
-The most prevalent inhibitory neurotransmitter in the CNS
-Particularly important role in anxiety and motor control
Monoamine neurotransmitters
•Catecholamines - synthesized from the amino acid tyrosine •Dopamine •Norepinephrine •Indolamine -synthesized from amino acid tryptophan •Serotonin
Acetylcholine(Ach)
- The best understood neurotransmitter
- Involved in memory and muscle activity
- Underproduction is associated with Alzheimer’s disease
- An excitatory neurotransmitter in synapse locations where neurons activate muscle cells
Endorphins’ s primary function and disorders
•Primary function: inhibition of the transmission of pain impulses
-They bind to the same receptors that are activated by opiates
•Endorphin disorders:
-pain insensitivity(results from its oversupply)
-pain hypersensitivity and immune issues(result from its undersupply)
Central nervous system(CNS)
The part of the nervous system that consists of the brain and the spinal cord.
Brain
Required for learning, thinking, language, emotion, motivation, perception of the world, etc
Spinal cord
- Required for reflexive movement
* Critical role in communicating information between the brain and the peripheral nervous system