Lecture 3: The Nervous System and Nervous Tissue (Part 2)

Question 1

Neurons are highly _______

Answer 1

Irritable

Question 2

Action potential (nerve impulse) is always the ______ regardless of stimulus

Answer 2

Same

Question 3

___________ is required to separate opposite charges across a membrane

Answer 3

Energy

Question 4

Measure of potential energy generated by separated charge

Answer 4

Voltage

Question 5

Voltage measured between 2 points

Answer 5

Potential difference

Question 6

The flow of electrical charge (ions) between two points

Answer 6

Current

Question 7

Hindrance to charge flow (provided by the plasma membrane)

Answer 7

Resistance

Question 8

Substance with high electrical resistance

Answer 8

Insulator

Question 9

Substance with low electrical resistance

Answer 9

Conductor

Question 10

Ohm’s Law

Answer 10

V=IR

Voltage =Current*Resistance

Question 11

2 main types of ion channels

Answer 11

Leakage (nongated) channels and gated channels

Question 12

3 types of gated channels

Answer 12

Chemically (ligand), Voltage, and Mechanically

Question 13

Open with binding of a specific neurotransmitter

Answer 13

Chemically gated (ligand-gated) channels

Question 14

Open and close in response to changes in membrane potential

Answer 14

Voltage-gated channels

Question 15

Open and close in response to physical deformation of receptors

Answer 15

Mechanically gated channels

Question 16

When gated channels are open, Ions diffuse quickly across the membrane along their electrochemical gradients: Along __________ from higher concentration to lower concentration, and along _________ toward opposite electrical charge

Answer 16

Chemical concentration gradients; Electrical gradients

Question 17

Potential difference across the membrane of a resting cell

Answer 17

Resting membrane potential

Question 18

Resting membrane potential is approximately –70 mV in neurons (cytoplasmic side of membrane is __________ charged relative to outside)

Answer 18

Negatively

Question 19

Resting membrane potential is generated by:

• Differences in ________ of ICF and ECF, and
• Differential __________ of the plasma membrane

Answer 19

Ionic makeup; Permeability