Neuro

What kinds of cells reside in the nervous system?

Neurons

What is the Neuron Doctrine?

It states that the brain is made up of discrete cells that have specialized functions.

What does the Reticular theory propose?

It posits that there are no discrete cells, suggesting a continuous neural net.

What staining technique supported the Neuron Doctrine?

Golgi staining.

What is Golgi Staining?

A technique that stains a small percentage of neurons, highlighting entire neurons.

Who is Cajal, and why is he important?

He was a skilled artist and histologist who used Golgi staining to study the brain.

What role do dendrites play in neuronal communication?

They receive signals from other neurons.

What is the function of the nucleus in a neuron?

It contains DNA and regulates cellular activities.

What is the function of the rough endoplasmic reticulum (RER)?

It is the site of protein synthesis and contains ribosomes.

What is the main role of ribosomes in a neuron?

They translate mRNA into strings of amino acids (proteins).

What are myelin sheaths and what is their function?

Cells that cover and insulate axons, increasing the speed of signal transmission.

What functions do astrocytes serve in the nervous system?

They regulate the chemical environment and remove neurotransmitters from the synaptic cleft.

What ions are crucial for neuronal function?

Sodium (Na⁺), Potassium (K⁺), Chloride (Cl⁻), Calcium (Ca²⁺).

What is the resting membrane potential?

The voltage difference across a cell’s membrane when it is not actively sending signals.

What does depolarization mean for a neuron?

The membrane potential becomes more positive.

What is an action potential?

A rapid all-or-nothing electrical signal that neurons use to communicate.

What is the sodium-potassium pump and why is it important?

It maintains high Na⁺ outside and high K⁺ inside the cell, crucial for resetting ion distributions after an action potential.

What is the absolute refractory period?

A period during which a neuron cannot fire another action potential.

How does saltatory conduction occur?

Action potentials jump from node to node along myelinated axons, speeding up conduction.

What happens at the Nodes of Ranvier?

Action potentials regenerate at these locations.

What is the Nernst equation used for?

To calculate the equilibrium potential for a specific ion.

What is the function of Kinesin in neuronal transport?

It carries materials enclosed in vesicles along microtubules.

What is membrane potential?

The electrical difference between the inside and outside of a neuron.

What does it mean for a cell to be polarized?

The inside of the neuron is more negative than the outside.

What does a voltage-gated ion channel do?

It opens in response to voltage changes across the membrane.