Neurotransmission Flashcards
What contains the nudou and metaticar apparitas of the mason?
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What encases the neuron and is sometimes referred to as the somatic membrane?
The cell membrane; on the axon, it is known as the axonal membrane.
What is the role of dendrites?
Dendrites receive information from other neurons.
What is the function of the axon?
To conduct electrical activity down to the axon terminals.
What is contained in axon terminals, and why is it important?
Vesicles filled with neurotransmitter (NT); essential for transmitting signals to other neurons.
What is the difference between myelinated and unmyelinated axons?
Myelinated axons conduct signals faster due to the myelin sheath, which enables saltatory conduction.
What do axons form in the PNS and CNS?
Axons form nerves in the Peripheral Nervous System (PNS) and tracts in the Central Nervous System (CNS).
Where are ions located in relation to neurons?
Ions are located inside cellular membranes (intracellular fluid) or outside cells (extracellular fluid).
What causes the resting potential in neurons?
An uneven concentration of ions between the inside and outside of the cell creates a resting potential of -70 mV.
What ions contribute to the resting potential?
Potassium (K+), sodium (Na+), chloride (Cl-), and large protein molecules (A-).
How do ions move across the membrane, and what two forces drive this movement?
Ions move down their concentration gradient and are influenced by electrostatic pressure.
How do ions move across the membrane, and what forces drive this movement?
Ions move down their concentration gradient and are influenced by electrostatic forces, where like charges repel and opposites attract.
What helps maintain the resting potential by regulating ion distribution?
The sodium-potassium pump transports Na+ out and K+ into the cell.
What is an action potential?
A brief reversal of membrane potential from negative to positive, allowing signal conduction.
At what voltage does a neuron reach the threshold to produce an action potential?
-55 millivolts (mV).
What happens to the neuron’s charge during an action potential?
The charge briefly reverses, making the inside of the neuron positive compared to the outside.
What causes the change in charge during an action potential?
Na+ ions enter the cell followed by K+ ions leaving the cell.
What is the refractory period in a neuron?
A period after an action potential when the neuron cannot fire again until it resets.
What is saltatory conduction and what structure enables it?
Saltatory conduction is the jumping of action potentials between Nodes of Ranvier, enabled by the myelin sheath.
What is synaptic transmission?
The process where an action potential leads to neurotransmitter release from the presynaptic neuron to the postsynaptic neuron.
How is neurotransmitter released into the synaptic cleft?
Vesicles bind with the presynaptic membrane, releasing neurotransmitter into the cleft through exocytosis.
The two main types of postsynaptic receptors
ionotropic receptors and metabotropic receptors
What determines whether a postsynaptic potential is excitatory (EPSP) or inhibitory?
Whether the neurotransmitter opens sodium (Na+, excitatory) or chloride (Cl-, inhibitory) channels.
How are neurotransmitters removed from the synaptic cleft?
By reuptake into the presynaptic neuron or enzymatic degradation.
Name an excitatory neurotransmitter and an inhibitory neurotransmitter.
Glutamate (excitatory) and GABA (inhibitory).
Which disease is associated with reduced levels of acetylcholine and specific brain pathologies?
Alzheimer’s Disease.
Which neurotransmitter imbalance is related to depression?
Abnormalities in cholinergic, catecholaminergic, and serotonergic transmission.
Which disorder involves demyelination of axons, leading to delayed or blocked signals?
Multiple Sclerosis.
What causes Parkinson’s Disease on a cellular level?
Loss of dopaminergic neurons in the substantia nigra, leading to dopamine imbalance.
