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Neurons, Neurotransmission, and the Nervous System
Exam #1
20
Physiology
02/20/2011

Additional Physiology Flashcards

 


 

Cards

Term
Organization of the nervous system
Definition

 

tree.gif

 

Term
Neurons
Definition

generate and propagate electrical signals

- are excitable

neuron.jpg

Term
Oligodendrocyte
Definition

Form myelin sheaths that act as insulation around nerves

- CNS

Neuroanatomy Book_img_10.jpg

Term
Schwann Cells
Definition

Form myelin sheath

- PNS

050902073203.jpg

Term
Astrocyte
Definition

blood brain barrier

(doesn't allow immune cells in either)

Astrocyte_WEB.jpg

Term
Microglia
Definition
immune cells in nervous system
Term
Ependymal cells
Definition

borders and Cerebro-Spinal-Fluid

ependymal2.gif

Term
Excitable Cells
Definition

propogate an electrical signal in response to a stimulus

- neurons and muscle cells

File-Neuron.jpg

Term
Dendrite
Definition
receive signals
Term
Axon
Definition
send signals
Term
Axon hillock
Definition
trigger zone
Term
Nodes of ranvier
Definition
non-myelinated regions
Term
Categories of neurons
Definition

*pseudounipolar

*bipolar

*multipolar

 

neuron_type.gif

 

Term
Ion movement across membranes creates electrical signals
Definition

Changes in ion permeability change the membrane potential

rcpt_sys_Nak_reup.png

Term
Electrical signals in neurons
Definition

graded potential

action potential

Term
Graded potential
Definition

can vary in magnitude

- in order for a cell to fire an action potential, need at least 55 mV

Term
Action potential (AP)
Definition
all or nothing when it comes to action
Term
Trigger zone
Definition

where action potential begins

unipolar.gif

Term
Voltage gated ion channel
Definition

biol_03_img0251.jpg

Term
What happens if the stimulus is less than 55 mV (does not reach threshold)?
Definition
Nothing.  It needs to reach threshold in order to continue trasmission