#3 Neurodegeneration Flashcards
(27 cards)
What structures comprise the CNS?
The brain and spinal cord.
What is the role of astrocytes in the CNS?
They help control chemical balance and are more abundant than neurons.
Which cells are involved in myelination in the CNS?
Oligodendrocytes.
What does the PNS consist of?
All nerves outside the CNS, including the somatic, autonomic, and enteric nervous systems.
Which cells are responsible for myelination in the PNS?
Schwann cells.
What is the function of an axon?
Transports signals via action potentials; may be myelinated by Schwann cells.
What is the soma?
The cell body of a neuron.
What is the role of dendrites?
Receive signals from other neurons.
Can most adult neurons regenerate after injury?
No, most are post-mitotic and cannot be replaced after injury.
What are the functions of CSF?
Protects the CNS, reduces pressure on structures, provides nutrients, flushes out harmful substances, protects blood vessels, and acts as a hormone transporter.
What are the meninges?
Protective membranes under the cranium: dura mater, arachnoid mater, and pia mater.
Where is CSF located within the meninges?
Between the arachnoid mater and pia mater.
How do neurons communicate across a synapse?
Via chemical neurotransmitters or electrical signals.
What triggers neurotransmitter release at the synapse?
Influx of calcium ions leading to exocytosis of neurotransmitter vesicles.
Name some types of neurotransmitters.
Acetylcholine, biogenic amines (e.g., serotonin, dopamine), amino acids (e.g., glutamate), purines (e.g., ATP), neuropeptides (e.g., oxytocin), and unique molecules like nitric oxide.
What is the difference between excitatory and inhibitory neurotransmitters?
Excitatory neurotransmitters (e.g., glutamate) increase the likelihood of an action potential, while inhibitory neurotransmitters (e.g., GABA) decrease it.
What is excitotoxicity?
Cell damage caused by excessive levels of excitatory neurotransmitters like glutamate.
What is neurodegeneration?
The pathological atrophy or death of specific neurons.
What are some causes of neurodegeneration?
Viruses, CNS injury, lack of oxygen and glucose (e.g., stroke), protein misfolding (e.g., amyloids in Alzheimer’s), genetic factors, alcoholism.
Why are neurons particularly vulnerable to death?
They require a constant supply of oxygen and glucose, rely on mitochondrial oxidative phosphorylation, and have limited capacity for repair.
What does ‘rostral’ refer to?
The front of the brain.
What does ‘caudal’ refer to?
The lower or tail end.
What does ‘dorsal’ refer to?
The back or upper side.
What is gray matter?
Contains nerve cell bodies, dendrites, and synapses; responsible for information processing and interpretation.
