Cellular Properties and Communication within the Nervous System

A collection of vocabulary flashcards covering key terms and definitions related to cellular properties and communication within the nervous system.

Neuron

A nerve cell, which is the basic component of the nervous system.

Ranges from 4 to 100 microns

Size of the neuron cell

Cell body

Contains the nucleus

Dendrites

Extensions from the cell body of a neuron that receive information from other cells.

Axon

An extension from the cell body of a neuron that sends information, typically one per neuron.

Axon terminal

The axon leads to what

Attaches to another neuron, attaches to muscle, or attaches to a gland

Axon terminal continues onto what

Multipolar Neuron

The most common type of neuron in vertebrates, characterized by multiple extensions.

Multipolar neuron

Carries motor info to skeletal muscle

Bipolar neuron

Has more sensory then motor neurons

• Most common in eye and nose

Bipolar Neuron

A type of neuron most common in the eye and nose, with two extensions.

Pseudounipolar

Sensory neuron

• Contains no dendrites

• Has two axons

Motor Neurons

Neurons that send signals from the CNS to skeletal muscles.

Sensory Neurons

Afferent neurons that send information to the CNS.

Unipolar

Sensory neurons are what

Alpha and gamma motor neurons

Two types of motor neurons

Predominately in spinal cord

• Axons synapse on skeletal muscles

Where are alpha motor neurons found

Muscle contraction

Alpha motor neuron is responsible for

In intramural fibers of skeletal muscles

Gamma motor neurons are found where

Modulating muscle spindle activity

Gamma motor neuron is responsible for

Interneurons

Specialized neurons that connect sensory and motor neurons within the brain or spinal cord.

Axons from the brain and motor neurons

Axons from sensory nerves and the spinal nerves going up to the brain

Connections of interneurons

Interneurons

Process only local info

Ependymal Cell

Glial cells that line the ventricles and central canal of the spinal cord.

Ependymal cells

Assist in circulation of CSF

Schwann Cells

Glial cells that myelinate nerve fibers in the PNS.

Assist in regenerating damaged cells by making a tunnel for cover

What do Schwann cells do

Oligodendrocytes

Glial cells that myelinate nerve fibers in the CNS.

Astrocytes

Remove excess sneurontransmitters, transporting nutrients

Form the blood brain barrier

What do astrocytes do

Satellite cells

Cover soma in PNS

Microglia

Clean neural environment

During injury where they surround damaged area and clean up dead and damaged cells

When do microglia activate

Anterograde, retrograde

Types of axoplasmic transport

Anterograde

vesicle carries neurotransmitters to axon terminal

Retrograde

Once neurotransmitter has been disposed it carries empty vesicle back to the cell body

resting, local, and action potential

Types of electrical transport

Resting potential

When neurons are as -70 Mv

Local potential

neurons firing at low rate

0 only travel about 1 or 2 mm

Action potential

1. occurs when cell is at -55 Mv

2. sodium channels open, sodium goes in potassium goes out

3. Once it reaches +55Mv the action potential will occur

4. Travels the length of the entire axon

Action Potential

A rapid rise and fall in membrane potential that transmits signals along a neuron.

Ion channels

Chemical transports are done through what

Ligand, voltage, and mechanical gated

Chemical transport types

Ligand-gated

Neurotransmitters bind to ion channel protein which causes it to open

Voltage-gated

Opens once there is change on each side of the cell membrane in regards to electrical potential

Mechanically-gated

Opens to a physical stimulus

• Touch, vibration, or temperature

Synapse

The junction between a neuron and a postsynaptic cell where communication occurs.

Neuron to neuron

• Automatic firing from brainstem

electrical synapse

Chemical synapse

Presynaptic to postsynaptic terminal

• done via a neurotransmitter

Excitatory Synapse

Increases the chances of an action potential occurring in the postsynaptic cell.

Inhibitory Synapse

Decreases the chances of an action potential occurring in the postsynaptic cell.

Neurotransmitter

Chemical substances that transmit signals across synapses.

Agonist

A substance that facilitates neurotransmitter action.

Antagonist

A substance that inhibits neurotransmitter action.

Myasthenia Gravis

An autoimmune disorder that destroys ACH receptors

• causes firing of skeletal muscle

Seizures

Overactivity of Glutamate receptors

Parkinson's Disease

A neurodegenerative disorder affecting movement, caused by the loss of dopamine-producing neurons.

Multiple sclerosis

De-myelination of the Shwanna cells

• Slows down communication of the axonal transport

Gillian-barre syndrome

Occurs in the PNS after an infection

• Attacks nerve cells which causes less firing/no firing

Alzheimer’s disease

ACH breakdown in the brain