Nervous System

Question 1

The major determinant of the resting potential of all cells is?

Answer 1

K+ gradient between the blood and interstitial fluid.

Question 2

If the Na+ chemical gradient between the ICF and ECF diminishes to zero, what is the most likely predicted effect on the resting membrane potential of a cell?

Answer 2

The resting membrane potential of a cell will eventually reach the equilibrium potential of K+.

Question 3

The two fundamental controls systems in animals are?

Answer 3

Hormones: slow long lasting specificity based target cells with correct receptors.
Nervous system: Fast very short duration, specificity based on delivering message precisely to the target cell only.

Question 4

CNS (central nervous system)

Answer 4

Brain and spinal cord

Question 5

PNS (peripheral nervous system)

Answer 5

Sensory neurons and Motor neurons

Question 6

PNS pathways

Answer 6

Sensory pathways -brain
Motor pathways-spinal cord

Question 7

Neurons are?

Answer 7

The functional unit of the nervous system.

Question 8

Excitable cell

Answer 8

It is able to respond to and produce an electrical signal (impulse/action potential)

Question 9

The CNS contains 3 types of neurons

Answer 9

sensory neuron
interneuron
motor neuron

Question 10

Where are the most interneurons?

Answer 10

In the CNS- multiple stages of interneurons

Question 11

The anatomy of the nervous system

Answer 11

Sensory cell >
Sensory Neuron>
Interneuron>
Motor Neuron>
Effector.

Question 12

Where is the PNS

Answer 12

Outside of the CNS

Question 13

What does the PNS consist of?

Answer 13

-Neurons
-Nerves (clusters of axons)
-Ganglia (clusters of nerve cell bodies)

Question 14

Nerve cross section:

Answer 14

both sensory and motor axons; different diameters.

Question 15

What is the resting membrane potential of the cell?

Question 16

How is the resting potential generated and maintained?

Question 17

Kevorkian

Answer 17

Built a device he called the “suicide machine”.

Question 18

What are the body fluid compartments?

Answer 18

Plasma +
ECF- Interstitial fluid 1/3
—-Cell Membrane—-
ICF-Intracellular fluid 2/3

Question 19

When an atom of an element gains or loses one or more electrons, it is called?

Answer 19

An ion of that element.

Question 20

Electric Principles are

Answer 20

Voltage
Ions
Current

Question 21

Voltage?

Answer 21

Is the potential
Measure of the driving force for moving electrical charges. Always measured as a difference between two areas.

Question 22

Ions?

Answer 22

Are molecules or atoms carrying electric charge ( they have missing or extra electrons, as in K+,Na+,CA+2, or CL-.

Question 23

Current?

Answer 23

Is the amount of electric charge moving.

Question 24

What electric charges repel?

Answer 24

Like charges repel each other

Question 25

What electric charges attract?

Answer 25

Unlike + and - charges attract

Question 26

Na

Answer 26

Sodium

Question 27

K

Answer 27

Potasssium

Question 28

Cl

Answer 28

Chlorine

Question 29

Ca

Answer 29

Calcium

Question 30

Neurons have?

Answer 30

Semipermeable membranes (some things cross easily, others do not)

Question 31

Membranes have?

Answer 31

active transport systems for ions and ion gates or pores

Question 32

Gates and Pores

Answer 32

membrane proteins that open and close to change permeability to a particular ion

Question 33

Gates and Pores respond to?

Answer 33

voltage, stretch, temperature or to ligands (chemicals) that bind to them.

Question 34

Ligands?

Answer 34

Chemicals

Question 35

How is resting membrane potential maintained?

Question 36

What charge does a resting neuron have?

Answer 36

A slight excess of negative charge inside

Question 37

Resting potential is usually?

Answer 37

-70 millivolts Mv

Question 38

Permeability of ions is regulated by?

Answer 38

ion channels

Question 39

Concentration gradients

Answer 39

import of ions

Question 40

Leak channels are

Answer 40

Always open and ion specific

Question 41

When a cell is permeable to an ion, two forces will act to drive the ion across the membrane?

Answer 41

Concentration gradient force + Electrical gradient force

Question 42

order of the forces that will drive an ion across a membrane

Answer 42

concentration gradient>electrical gradient= electrochemical force

Question 43

When does the net movement of K+ (Potassium) cease?

Answer 43

When the equilibrium potential of the ion is reached.

Question 44

*Note

Answer 44

Concentration gradient force is exactly opposed by electrical gradient (membrane potential) force.

Question 45

(E ion)

Answer 45

Equilibrium Potential

Question 46

The membrane potential necessary to balance a given concentration gradient for a single diffusible ion

Answer 46

Equilibrium Potential of an ion CG+EG

Question 47

What equation is used to calculate equilibrium potential of an ion?

Answer 47

Nernst equation

Question 48

Equation

Answer 48

[Na+]out=145mV [Na+] in=15mV z=+1 @37 degrees Celsius

Question 49

RMP of real cell depends on?

Answer 49

Concentration (XOut/Xin) of each ion and permeability of each ion

Question 50

What equation can be used to predict the RMP of a cell that is permeable to more than one ion?

Answer 50

Goldman-Hodgkin-Katz GHK equation

Question 51

RMP

Answer 51

resting membrane potential

Question 52

What counteracts the leak channels and maintains the RMP?

Question 53

When two or more graded potentials active at the trigger zone, what could potentially happen?

Question 54

Evaluate the validity of this statement: " The extracellular and intracellular fluid compartments have a stable solute composition that is in equilibrium."

Question 55

The Nernst equation predicts

Answer 55

The membrane potential resulting from permeability to a single ion.

Question 56

What does the Goldman-HodgkinKatz (GHK) equation consider that the Nernst equation does NOT?

Answer 56

Permeability of ions