Fewell lecture Notes - Neurons & CNS

Question 1

Neuron Input Zone

Answer 1

Cell Body, Dendrites

Question 2

Summation Zone

Answer 2

Axon Hillock

Question 3

Conduction zone

Answer 3

Axon

Question 4

Output zone

Answer 4

Synaptic Knobs, Presynaptic Terminals

Question 5

Bernstein’s Potassium Hypothesis

Answer 5

excitable cells are surrounded by a membrane selectively permeable to K+ ions at rest and that during excitation the membrane permeability to other ions increases. But this was wrong because more than K+ is permeable (also Na+ & Ca2+) … etc

Question 6

Nernst Equation

Answer 6

Defines the EQUILIBRIUM potentialThe electrical potential that exactly balances a chemical concentration gradient for a particular ion.If one knows the IC & EC concentration of an ion, the EP can be calculated using the Nernst Eq.

EmV=-58/z(log(concIN/concOUT))
z-> ion charge

Question 7

Hodgkin & Huxley

Answer 7

Used common Atlantic squid to discover action potentials (big axon)

Question 8

Sir Michael Foster

Answer 8

Introduced the term “synapse”

Question 9

Camillo Golgi

Answer 9

Reticular Theory -Golgi viewed the nervous system as a continuous network of interconnected cells, with nerve cells firing along in all directions (electrical synapse)

Question 10

Santiago Ramon y Cajal

Answer 10

proposed that the brain is composed of billions of individual neurons receiving information at one end and transmitting it in one direction along to the next cell (chemical synapse)

Question 11

Otto Loewi’s Experiment

Answer 11

Unsure whether signaling across synapse was bioelectrical or chemical. Proved that it was chemical with a frog heart and acetylcholine

Question 12

Neuron Doctrine (Cajal)

Answer 12

Nervous system is comprised of individual cells (contiguous)Communication –one way (forward)

Question 13

Myasthenia Gravis

Answer 13

Antibodies (immune proteins) block, alter or destroy some of the receptors for ACh

Autoimmune neuromuscular disease that causes weakness in skeletal muscles (e.g., diaphragm)

Question 14

Reticular Theory (Golgi)

Answer 14

Neurons are all interconnected (continuous)Communication –multidirectional (forward, backward, lateral) Direct Electrical Connection

Question 15

Foramen Magnum

Answer 15

On the bottom of your skull, there is a distinctive hole. The technical name for the opening is the foramen magnum –the “great hole” that the spinal cord and other critical soft tissues run through.

Question 16

Claude Bernard

Answer 16

Made the observation that
cells of the body survived
in a healthy condition only
when the temperature,
pressure and chemical
composition of their fluid
environment remained
stable
"milieu interieur" - in which the cells of the organism live
"milieu exterieur" - that phsycailly surroudns the whole organism

Question 17

Walter B. Cannon

Answer 17

coined the term
homeostasis to describe the
maintenance of nearly constant
conditions in the internal
environment
Essentially all organs and tissues
in the body perform functions to
help maintain these relatively
stable conditions
Also coined term “fight or flight”

Question 18

Homeostatic Redundancy

Answer 18

The more vital a physiological variable is, the
more systems that the body mobilizes to
regulate it
If one system should fail, others are there to
help maintain homeostasis

Question 19

Programmed Rheostasis

Answer 19

changes occur at certain phases

of the life cycle

Question 20

Reactive Rheostasis

Answer 20

changes that occur in response to a stimulus

that may or may not be encountered

Question 21

Mrosovsky

Answer 21

coined the term rheostasis