Nervous System Basics

Flashcards covering key terms and concepts related to the basic structure and function of the nervous system.

Neurons

Excitable cells that form communication lines in the nervous system.

Neuroglia

Supporting cells that protect and nourish neurons.

Central Nervous System (CNS)

The brain and spinal cord.

Peripheral Nervous System (PNS)

All other neurons and ganglia outside the CNS.

Dendrites

The input zone of a neuron that receives signals.

Soma (cell body)

Contains the nucleus and metabolic machinery of a neuron.

Axon hillock

The trigger zone where an action potential initiates if depolarization occurs.

Myelinated axon

The conducting zone of a neuron where myelin speeds up conduction.

Resting membrane potential

The stable voltage of a neuron when it is not firing, typically around -70mV

Na⁺/K⁺ ATPase pump

Active transporter that moves 3 Na⁺ out and 2 K⁺ in per ATP hydrolyzed, creating an ionic imbalance.

Leak channels

Ion channels that are always open allowing ions to move down their concentration gradients.

Gated channels

Ion channels that open or close in response to specific triggers.

Microglia

Neuroglial cells that phagocytize debris and become mobile during inflammation.

Astrocytes

Neuroglial cells that provide nutrients to neurons from blood.

Oligodendrocytes

Neuroglial cells that form myelin sheaths around axons in the CNS.

Axon terminals

The endpoint of an axon where neurotransmitters are released to communicate with other neurons or target cells.

Potassium (K⁺)

An essential ion for maintaining resting membrane potential, with higher concentrations inside the cell, crucial for action potential generation.

Sodium (Na⁺)

An essential ion for action potentials, higher outside the cell, crucial for depolarization.

Chloride (Cl⁻)

An important anion that helps maintain osmotic balance and inhibits action potentials in neurons.

Large intracellular proteins

Proteins that perform diverse roles within cells, including enzymes, structural support, and signaling.

Selectively permeable

The property of cell membranes that allows certain substances to pass while restricting others, crucial for maintaining internal homeostasis.

Leak channels

Ion channels that are always open, allowing ions to move down their concentration gradients.

Gated channels

Ion channels that open or close in response to specific triggers.

Voltage-gated channels

A type of gated channel that opens or closes in response to changes in membrane potential, crucial for action potentials in neurons.

Ligand-gated channels

Ion channels that open in response to the binding of a specific molecule (ligand), allowing ions to flow across the membrane.

Mechanically gated channels

Ion channels that open or close in response to mechanical stimuli, such as stretch or pressure, allowing ions to flow across the membrane.

Thermal gated channels

Ion channels that open or close in response to changes in temperature.