Cogs17 Neurobiology of Cognition Lecture 2a

Flashcards on the structure and function of cells in the nervous system based on lecture notes.

What is the main function of ribosomes?

Site of protein production

What is the function of the mitochondria?

Produce ATP (Adenosine triphosphate) whose breakdown frees energy to power cell functions

What is the composition of the cell membrane?

Lipids (fat molecules) w/hydrophobic cilia form double layered wall

What is the main function of glial cells?

Support and buffer neurons, do NOT participate in information transfer

List three types of glial cells and their functions.

Astrocytes (nutrients, blood-brain barrier, recycle NTs, remove waste), Microglia (remove toxic materials), Oligodendrocytes/Schwann Cells (myelination)

What is the primary function of neurons?

Information transfer via processes and membrane

What is the function of dendrites?

Site of reception of incoming messages

What is the role of the Axon?

Site of release of outgoing message

What is Membrane Potential?

Difference in charge inside vs. outside cell, measured in millivolts (mV)

What is the resting potential of most neurons?

-70 mV

What is the function of the Sodium/Potassium Pump?

Actively transports 3 Na+ out and 2 K+ in to establish resting potential

What is the definition of Action Potential?

Depolarization of Neuron, Cell “Fires” AKA “Spikes” = Changes in membrane permeability of Axon, propagated via Ionic Conduction

What triggers an action potential?

NT from other Neuron, electrical stimulation, or other

What happens when depolarization reaches the terminal?

Ca++ gates there open & Ca++ enters cell, leading to Neurotransmitter (NT) release

What is the Refractory Period?

While cell is being re-polarized, it cannot fire (or resists firing)

What is the All-or-None Law in the context of action potentials?

In a given cell, an Action Potential always has the same amplitude and velocity, regardless of the intensity of the stimulus that triggered it

How does myelination affect the speed of action potential propagation?

Increases the speed of the propagation of an Action Potential

What cells form myelin in the Central Nervous System (CNS) and Peripheral Nervous System (PNS)?

Oligodendrocytes myelinate cells in Central NS (Brain and Spinal Cord), Schwann Cells in Peripheral NS

What is saltatory conduction?

Nerve impulse effectively jumps from node to node as it is propagated along the axon which increases overall speed of impulse

What is Graded Potential?

React a lot to strong stimulus, less to weak one, Unlike Action Potentials, Graded Potentials can vary in amplitude in proportion to the input stimulus