Shared Flashcard Set

Details

Ch 45 - Neurons and Nervous Systems
BIOL197 @ UNLV; exam 3
52
Biology
Undergraduate 3
08/06/2011

Additional Biology Flashcards

 


 

Cards

Term
Neurons and Nervous Systems
Definition

process info and form action potentials

enables us to experience life

damage can be devastating

everything we feel, touch, smell :)

Term
Neurons
Definition
generate and transmit electrical signals (action potentials) down axons
Term
Nerve
Definition
a bunch of neurons 
Term
Afferent Neurons
Definition

carry info to NS

 

liiiiike if you touch your phone

Term
Efferent Neurons
Definition

carry info from NS to effectors

 

liiiike if you move your arm

Term
Interneurons
Definition

communicate between afferent and efferent

 

ie. touch a hot stove

hand jerks away

Term
Glia
Definition

support neurons physiologically

immunologically

anddd metabolically

Term
Ganglia
Definition
high numbers of neurons organized into clusters
Term
Brain
Definition
enlarged, centralized integrative center of ganglia
Term
Central Nervous System
Definition

brain and spinal cord

most NS cells are found here

Term
Peripheral Nervous System
Definition

neurons that extend/reside outside of the brain and spinal cord

basically everything else

Term
Synapses
Definition

junctions between neurons and their target cells

how neurons interact with other cells

 

ie. arm movement requires NS and muscular cells

 

Term
Neurons have:
Definition

cell body

dendrites

axon

axon terminals

neurotransmitters

Term
Cell Body
Definition
nucleus and organelles
Term
Dendrites
Definition
receive
Term
Axon terminals
Definition
synapse with target cell
Term
Neurotransmitters
Definition

chemical signals at synapse

facilitators - make sure stuff doesn't get lost

Term
Glia
Definition

more abundant in the brain than neurons!

-release neurotransmitters

-keep neurons aligned during development

-nourish neurons

-insulate axons

-protect neurons from particles

-maintain extracellular environment

-provide immune functions

Term
Oligodendrocytes and Schwann Cells
Definition

glia in the CNS and PNS that provide insulating membrane

-myelin!

Term
Myelin
Definition

covering that increases the rapidity of signal  transmission and gives NS white, shiny appearance

 

Term
Multiple Sclerosis
Definition

neurological disease

myelin becomes inflamed and breaks down

nerve detioration

 

Term
Astrocytes
Definition

contribute to blood-brain barrier by surrounding the tiniest vessels in the brain

alcohol and anesthetics break blood-brain barrier (fat soluble)

Term
Microglia
Definition

act as macrophages and mediators of inflammatory responses in immune function

 

killlll invadersssss rawwwwr

Term

Membrane Potential

Definition
difference in the electric charge on inside/outside of membrane
Term
K and Na
Definition

K is more prevalent inside the cell

Na is more prevalent outside of the cell

K leaks out = negative charge on inside

"Yeah, K, come on in / Na, you suck and you're not allowed in."

Term
Nernst Equation
Definition
calculates the value of K equilibrium potential using the K concentrations on each side
Term
Resting Potential
Definition
the steady state of membrane potential
Term
Action Potential
Definition

huge shift in membrane potential

caused by sudden ion channel openings and rapid closings

 

NERVE IMPULSE

Term
Voltage
Definition

electric potential difference

forced that causes charged particles to move between two points (pressure & water)

*key players: Na, K, Ca, and Cl-

 

Term
Sodium Potassium Pumps
Definition

actively expels Na from inside the cell

exchanges it for K outside of the cell

3:2 ratio

 

requires energy

kinda like proton pump

Term

Potassium Leak Channels

 

Definition

K naturally leaks out

 

Na has to be pumped out

 

Term
Gated Sodium Channels
Definition

controlled by voltage

chemical gradient

mechanical means

self explanatory - gates open and close

Term
Electrochemical Gradient
Definition
combination of electrical forces and chemical forces resulting from ion movement across the membrane
Term
Depolarization
Definition
inside of neuron is less negative (closer to positive) as compared to its resting potential
Term
Hyperpolarization
Definition
inside of neuron becomes more negative than resting potential
Term
Action Potentials
Definition

sudden, transient, large changes in membrane potential

2m/sec unmyelinated; 100m/sec myelinated

from -60mV --> +50 mV

Term

Action Potentials

Process

Definition

1. resting potential

2. depolarization due to Na ion channels opening

3. positive reinforcement

4. more to open in axon hillock

5. meets threshold

6. even more open

7. positive potential = action potential

8. Na voltage gates close

9. K voltage gates open

10. Na gates have refractory period

11. resting potential is reestablished

Term
Action Potential Travel
Definition

all-or-none, self-regenerating event

larger diameter axons = less resistance

myelinated areas can be "jumped"

(vertebrates) = much faster

 

ie. moving walkways at airports

Term
All-or-None
Definition
positive feedback of Na channels ensures increase until action potential is reached
Term
Self-Regenerating
Definition
stimulates the adjacent region to action potential and proceeds stepwise
Term
Nodes of Ranvier
Definition
spaces where myelinated areas are jumped
Term
Chemical Synapse
Definition

neurotransmitters from presynaptic cell induce a change in the postsynaptic cell

more common

Term
Electrical Synapses
Definition
action potential spreads directly from presynaptic to postsynaptic cell
Term
Neuromuscular Junctions
Definition

prime examples of chemical synapses

acetylcholine as a neurotransmitter

Term
Neurotransmitters
Definition

created in axon terminal

sometimes in cell body --> packaged by Golgi apparatus and transported

Term

Motor End Plate

Definition

modified part of the muscle cell plasma membrane

(receiver)

 

Term
Synaptic Cleft
Definition
actual empty space between the two membranes
Term
Neurotransmitter Action
Definition

depends on the receptor that it binds to

 

like hormones!

Term

Popular Neurotransmitters

(6)

Definition

acetylcholine

serotonin

endorphins

nitrous oxide

dopamine

norepinephrine

Term
Learning and Memory
Definition

example of long-term potentiation

linked to glutamate induced increased sensitivity due to activation of two different receptors after high frequency stimulation 

 

Term
Prozac
Definition

slows diffusion of serotonin

 

Term

Enzymatic Destruction

Diffusion

Definition
"turns off" or inactivates neurotransmitter activity
Supporting users have an ad free experience!