Neuroscience Concepts Review

Flashcards for reviewing key concepts about neurons, neurotransmission, brain structure, and functions.

What are the main functions of dendrites in a neuron?

Dendrites receive signals from other neurons and transmit them toward the cell body.

What role does the cell body (soma) play in a neuron?

The cell body processes incoming signals and maintains cell function.

What is the function of the axon?

The axon transmits electrical impulses away from the cell body toward other neurons, muscles, or glands.

What is the myelin sheath?

A fatty layer that insulates the axon and speeds up the transmission of electrical impulses.

What are the Nodes of Ranvier?

Small gaps in the myelin sheath where ion exchange occurs, facilitating rapid signal transmission through saltatory conduction.

What is a synapse?

The junction between two neurons where neurotransmitters are released to pass signals to the next neuron.

What is the receptive zone of a neuron?

The area that receives incoming signals from other neurons or sensory receptors, consisting of dendrites and the cell body.

What is the integrative zone of a neuron?

The zone that determines if the incoming signals are strong enough to trigger an action potential, primarily located at the axon hillock.

What is the conductive zone of a neuron?

The part of the neuron that propagates the action potential along the axon.

What happens in the transmissive zone of a neuron?

Signals are sent to other neurons, muscles, or glands, primarily through the axon terminals and synapse.

What is the lock and key analogy in neurotransmission?

Neurotransmitters are like keys that fit into specific receptors (locks) to trigger a response in the postsynaptic neuron.

How does the sodium-potassium pump function?

It maintains the neuron's resting membrane potential by actively transporting 3 Na⁺ out and 2 K⁺ in, using ATP.

What is the role of calcium channels during an action potential?

Calcium channels open at the axon terminals during synaptic transmission, allowing Ca²⁺ influx that triggers neurotransmitter release.

What is the difference between ionotropic and metabotropic receptors?

Ionotropic receptors are ion channels that cause rapid changes in membrane potential; metabotropic receptors activate G-proteins for slower, longer-lasting effects.

Where do serotonin (5-HT), norepinephrine (NE), and dopamine (DA) originate in the brain?

Serotonin originates in the Raphe nuclei, norepinephrine in the Locus Coeruleus, and dopamine in the Substantia Nigra and Ventral Tegmental Area.

What is the difference between an agonist and an antagonist in pharmacology?

An agonist activates a receptor to produce a specific action, while an antagonist blocks or inhibits receptor activation.

How does myelin increase the speed of action potential conduction?

Myelin insulates the axon and allows the action potential to jump between Nodes of Ranvier, speeding up transmission through saltatory conduction.

What are the factors influencing action potential conduction velocity?

Myelination, axon diameter, temperature, and ion channel density at the Nodes of Ranvier.

What is meant by an all-or-none event in action potentials?

An action potential fires fully once a certain threshold is reached; no partial action potentials occur.

What structure is considered the relay station of the brain?

The thalamus is the relay station that projects sensory and motor signals to different cortex areas.

What are gyri and sulci?

Gyri are raised ridges on the brain's surface, while sulci are grooves that separate different brain regions.

What are the general functions of the four lobes of the brain?

Frontal Lobe: higher thinking and motor control; Parietal Lobe: sensory processing; Temporal Lobe: auditory processing; Occipital Lobe: visual processing.

What are the functions of astrocytes, oligodendrocytes, microglia, and ependymal cells?

Astrocytes support neurons and maintain the blood-brain barrier; oligodendrocytes produce myelin; microglia act as immune cells; ependymal cells produce cerebrospinal fluid.

What behaviors are associated with serotonin, dopamine, norepinephrine, and acetylcholine?

Serotonin: mood regulation; dopamine: reward; norepinephrine: arousal; acetylcholine: memory.

What features make up the cortex structure?

Folds (gyri and sulci) increase surface area; distinct layers process various information; specialized regions for different functions; plasticity allows adaptation.