Signal Transduction - Electrical and Synaptic Signalling

Question 1

Two Types of Nervous Systems in Vertebrates

Answer 1

1. Central Nervous System (CNS)
2. Peripheral Nervous System (PNS)

Question 2

Features of the Central Nervous System (CNS)

Answer 2

• Brain and Spinal Cord

Question 3

Features of the Peripheral Nervous System (PNS)

Answer 3

• Other sensory or motor components

Question 4

Two main types of cells in the Nervous System

Answer 4

1. Neurons
2. Glial Cells

Question 5

Function of Neurons

Answer 5

• Send and receive electrical impulses (nerve impulses)

Question 6

Three Types of Neurons

Answer 6

1. Sensory Neurons
2. Motor Neurons
3. Interneurons

Question 7

Sensory Neurons are…

Answer 7

A diverse group of cells specialized for the detection of stimuli

Question 8

Motor Neurons…

Answer 8

Transmit signals from the Central Nervous System to the muscles and glands with which they make connections (innervate)

Question 9

Interneurons…

Answer 9

Process signals and transmit information between parts of the nervous system

Question 10

What do Neurons contain that differentiate them from the average cell?

Answer 10

Branches called processes

Question 11

This branch or process can receive signals

Answer 11

Dendrites

Question 12

This branch or process can conduct signals

Answer 12

Axons

Question 13

The cytosol in a cytoplasm is called…

Answer 13

Axoplasm

Question 14

The Synapse is…

Answer 14

The junction between a nerve cell, gland, or muscle cell

Question 15

How do synapses occur at Neuron-to-Neuron junctions

Answer 15

Mostly between an axon and a dendrite, but it can occur between two dendrites.

Question 16

Fundamentals of Membrane Potential

Answer 16

Cells at rest normally have excess positive charge on the outside and negative charge on the inside of the cell membrane
The resulting electrical potential is called the Resting Membrane Potential (Vm)

Question 17

What is the Potassium Ion Gradient?

Answer 17

The uneven distribution of potassium ions inside and outside the cell

Question 18

What do potassium ions do because of the Potassium Ion gradient?

Answer 18

They tend to diffuse out of the cell toward the region of lower concentration.

Question 19

What is electroneutrality?

Answer 19

Ions in a solution are present in pairs, one negative and one positive

Question 20

What is a counterion

Answer 20

The oppositely charged ion in a solution

Question 21

What is the counterion for trapped anions in the cytosol

Answer 21

Potassium

Question 22

Outside the cell, what is the main cation and counterion

Answer 22

Na+ is the main cation, and Cl- is the counterion

Question 23

What is electrical potential

Answer 23

A solution must have an equal number of positive and negative charges overall, but they can be unevenly distributed.
Even when separated, they will tend to flow back toward each other.

Question 24

What creates a current

Answer 24

When oppositely charged ions move towards each other
Measured in Amperes

Question 25

What is membrane potential the result of?

Answer 25

An excess of negative charge on one side of the membrane and an excess of positive charge on the other.

Question 26

What is resting membrane potential? (Vm)

Answer 26

excess negative charge inside and excess of positive charge outside.

Question 27

Three kinds of ion channels that act like gates for ions

Answer 27

1. Voltage-gated ion channel
2. Ligand-gated ion channel
3. Leak channels

Question 28

What is a voltage-gated ion channel?

Answer 28

Respond to changes in the voltage across a membrane

Question 29

What is a Ligand-gated ion channel?

Answer 29

They open when a ligand binds to the channel

Question 30

What is a Leak Channel?

Answer 30

Allow resting cells to be somewhat permeable to cations