Neuroscience Chapter 5 Quiz

Neuron Structure and Function

• Neurons are the basic structural and functional units of the nervous system, responsible for receiving, processing, and transmitting electrical signals.
• Glial cells support neurons and include astrocytes, oligodendrocytes, Schwann cells, microglia, and ependymal cells.
• Neuron labeling includes identifying the soma, dendrites, axon, axon hillock, and synapse.
• Neurites are processes extending from the soma, including dendrites and axons. Axon collaterals are branches of an axon, while recurrent collaterals synapse on the neuron itself.
• Cytoskeleton components, including microtubules, neurofilaments, and actin microfilaments, provide structure, transport, stability, and motility to the neuron.
• Axoplasmic transport includes anterograde (soma to axon terminal) and retrograde (terminal to soma) transport.
• Protein synthesis occurs primarily in the soma with limited synthesis in axons and dendrites.
• Neuron types include sensory, motor, and interneurons.
• Dendritic arbor regulation modifies synaptic input strength.

Glial Cells and Nervous System Organization

• Glial cell types include astrocytes, oligodendrocytes, microglia, ependymal cells in the CNS, and Schwann cells, satellite cells in the PNS.
• Glial cells provide support, maintain the blood-brain barrier, myelinate axons, participate in immune responses, and produce cerebrospinal fluid.

Nervous System Organization

• Nervous system organization separates the CNS (brain and spinal cord) from the PNS (nerves and ganglia).

Membrane Properties and Electrical Signaling

• Neuron membrane structure is composed of a phospholipid bilayer and ion channels.
• Ion transport includes passive ion channels and active pumps like the Na+/K+ ATPase.
• Resting membrane potential is influenced by ion gradients and selective membrane permeability.
• The Nernst and Goldman equations define equilibrium and membrane potential, respectively.
• Action potentials are characterized by an all-or-none response, refractory periods, and phases including resting membrane potential, threshold, depolarization, repolarization, and hyperpolarization.
• Action potential speed increases through myelination and larger axon diameter.
• Voltage-gated Na+ and K+ channels control action potential generation and propagation.

Synaptic Transmission and Neurotransmitters

• Synapses are classified as electrical and chemical.
• Chemical synapses involve neurotransmitter release.
• Neurotransmitter release steps include action potential triggering Ca2+ influx, facilitating vesicle fusion, and neurotransmitter release.
• Synaptic vesicle fusion relies on proteins like synaptotagmin and SNARE complexes.
• Postsynaptic receptors are ionotropic (fast, ligand-gated) or metabotropic (slow, G-protein coupled).
• Neurotransmitters are classified by their structure, function, and receptor interaction. Criteria for neurotransmitters include being synthesized in neurons, being released upon stimulation, and producing a response to stimulation.
• Specific neurotransmitter synthesis steps and rate-limiting steps are also described (e.g., for acetylcholine, catecholamines, serotonin, and amino acid neurotransmitters).
• Different neurotransmitters are categorized as excitatory (e.g., glutamate, acetylcholine) or inhibitory (e.g., GABA, glycine).