AI.2 CNS Pharmacology Flashcards
(34 cards)
What are the primary cell types in the central nervous system (CNS)?
Neurons and neuroglia
Neurons are responsible for processing and transmitting information, while neuroglia provide support and protection.
What is a synapse?
The region or locus of communication between neurons.
What role do neurotransmitters play in the CNS?
They transmit nerve impulses across junctions, such as synapses.
Define receptor in the context of cellular biology.
A molecule on the surface or within a cell that recognizes and binds with specific molecules, producing some effect in the cell.
What are neuroglia?
Non-neuronal support cells that perform essential functions in the CNS.
List the types of glial cells.
- Astrocytes
- Oligodendrocytes
- Microglia
What is the function of astrocytes?
Provide metabolic nutrients to neurons, maintain extracellular ion concentrations, and regulate neurotransmission.
What is the role of oligodendrocytes?
Wrap around axons of projection neurons to form the myelin sheath, insulating the axons and increasing signal propagation speed.
What happens in multiple sclerosis regarding oligodendrocytes?
Damage to oligodendrocytes occurs.
What are microglia?
Specialized macrophages derived from bone marrow that act as the major immune defense system in the brain.
What is the blood-brain barrier (BBB)?
A protective separation of circulating blood from the extracellular fluid of the CNS that limits the penetration of substances.
How do drugs enter the CNS?
They must be highly hydrophobic or engage specific transport mechanisms.
What is the significance of the second-generation antihistamines regarding the BBB?
They are significantly more polar than older antihistamines, limiting their crossing of the BBB.
What type of channels are found in neuronal membranes?
Voltage-gated and ligand-gated channels.
What is a voltage-gated ion channel?
A channel that responds to changes in the membrane potential of the cell.
Give an example of a voltage-gated ion channel.
Sodium (Na) channel.
What is the function of ligand-gated ion channels?
They open in response to the binding of neurotransmitters.
What is the function of metabotropic receptors?
Engage a G protein upon binding, leading to the production of second messengers.
What are second messengers?
Molecules that relay signals received at receptors to target molecules in the cytosol and/or nucleus.
List the three major classes of second messengers.
- Cyclic nucleotides (e.g., cAMP and cGMP)
- Phosphoinositides (e.g., IP3 and DAG)
- Calcium ions (Ca2+)
What is the action potential?
A rapid change in membrane potential when a nerve cell membrane is stimulated.
Define depolarization.
The loss of a state of polarity; the inside of the cell becomes positive.
What occurs during repolarization?
Na channels close and K channels open, returning the inside of the cell to a negative charge.
