Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/47

Click to flip

47 Cards in this Set

  • Front
  • Back

Neurons

Nerve cells

Two types of neuron signals

Electrical


Chemical

Electrical signal

Mostly within neurons

Chemical signal

Between neurons


(Neurotransmitters)

Central nervous system

Brain and spinal chord

Peripheral nervous system

Nerves that convey messages to and from the CNS

Information processing path

Sensor senses stimulus


Sensory neurons (sensory input) (PNS)


Integration (CNS)


Motor neurons (motor output) (PNS)


Effector reacts

Cell body

Contains nucleus and other organelles

Dendrite

Receives information

Axon

Transmits information


Usually only one

Axon hillock

Base of axon


Where action potentials are generated

Synapse

Junction between axon and other cell

What happens at the synapse

Neurotransmitters pass information from the presynaptic terminal to the postsynaptic terminal

Types of neuron shapes/sizes

Multipolar


Bipolar


Unipolar

Multipolar neurons

1 axon


2+ dendrites

Bipolar neurons

1 axons


1 dendrite

Unipolar neurons

1 axon


0 dendrites

Types of glial cells

Schwann cells


Oligodendrocytes


Astrocytes


Ependymal cells


Microglial cells

Only glial cells in peripheral nervous system

Schwann cells

Location of most glial cells

Central nervous system

Schwann cells

Make myelin

Oligodendrocytes

Make myelin

Glial cells that make myelin

Oligodendrocytes


Schwann cells

Astrocytes

Repair injury


Look like stars

Ependymal cells

Make cerebral spinal fluid

Microglial cells

Macrophages


Remove waste such as dead cells and pathogens

Resting membrane potential

The difference in electrical charge across a plasma membrane of a neuron at rest

Resting membrane potential values in a neuron

The inside is -60mV to -80mV more negative than the outside

Distribution of ions inside and outside the neuron

K+ is highest inside the cell


Na+ is highest outside the cell



Maintained by respective pumps

Ratio of Na+ and K+ pumped

3 Na+ pumped out per 2 K+ pumped in

Opposing forces that move ions in and out of the neuron reflected by resting membrane potential

Diffusion


Electrostatic pressure

Diffusion

Molecules moving from a region of high concentration to one of low concentration

Electrostatic pressure

Like charges repel and opposite charges attract

Ion channels on membrane are

Selectively permeable

Ion channels in the membrane

More K+ channels than Na+ channels


Significant output of cations


K+ outflow leads to a net negative charge inside the neuron

What happens when the negative charge builds inside the neuron

It begins to exert electrostatic pressure

What happens during electrostatic pressure

Cell pulls K+ ions back inside

Goal of diffusion and electrical forces

Equilibrium

Equilibrium potential

Eion


The membrane voltage at equilibrium for a particular ion

How to calculate equilibrium potential

Nernst equation



Eion = 62mV (log[ion]outside/[ion]inside)

How membrane potential changes during the generation of a nerve impulse

Hyperpolarization


Depolarization

Hyperpolarization

Neuron becomes more negative inside relative to the outside

When hyperpolarization occurs

When a signal is sent



Signals do not always cause hyperpolarization

Depolarization

Membrane potential moves closer to zero

When an action potential occurs

When a depolarization increases the membrane voltage to threshold



No action potential unless you have a stimulus strong enough

Threshold of action potential (value)

-55mV

All-or-none property

Either it fires at full amplitude or not at all