Chapter 3

Question 1

EXPLAIN

What is an Electrical Neurotransmission?

Answer 1

The nerve impulse is transmitted via channel proteins

think of little bridges between the neurons

Question 2

EXPLAIN

What is a Chemical Neurotransmission

Answer 2

The nerve impulse is transmitted via neurotransmitters

Question 3

DEFINE

Electrical Potential

Answer 3

The local difference between the electrical charge across the membrane

Question 4

DEFINE

Depolarization

Answer 4

Decrease on the electrical potential

Opposite of hyperpolarization

Question 5

DEFINE

Hyperpolarization

Answer 5

Increase in electrical potential

Opposite of Depolarization

Question 6

DEFINE

Resting Potential

Answer 6

The electrical potential when a neuron is not firing (-70mV)

Question 7

DEFINE

What is an Na/K Pump?

Answer 7

A neuronal membrane mechanism that maintains the resting potential

Question 8

DEFINE

What is an Ion Channel?

Answer 8

The pores in a neuronal membrane that allows the passage of ions

Question 9

LIST

What are the 3 types of Ion Channels?

Answer 9

• Ligand Gated
• Voltage Gated
• Mechanically Gated

Question 10

EXPLAIN

How does a Ligand-gated ion channel work?

Answer 10

They open when a chemical ligand such as a neurotransmitter binds to the protein

Question 11

EXPLAIN

How does a voltage-gated ion channel work?

Answer 11

They open and close in response to changes in the membrane potential

Question 12

EXPLAIN

How does a Mechanically-gated ion channel work?

Answer 12

open in response to physical deformation of the receptor

Question 13

DEFINE

Postsynaptic Potentials

Answer 13

Changes in membrane potential in dendrites in response to neurotransmitters

Question 14

EXPLAIN

What is the difference between an electrical gradient and a chemical/concentration gradient?

Answer 14

A chemical/gradient is the difference in the amount of a substance across a space, causing it to move from high to low concentration. An electrical gradient is the difference in charge across a membrane, causing ions to move toward opposite charges.

THINK Chemical: Diffusion Electrical: Magnets

Question 15

DEFINE

Action Potential

Answer 15

The rapid depolarization of an axon

Question 16

EXPLAIN

What happens during action potential?

Answer 16

• Voltage gated Na channels open
• Na rapidly enters cell
• Cell reverses polarity
• Na channel closes, and K exits

Question 17

DEFINE

What is the refractoy period?

Answer 17

The time in which the resting potential is being restored

Question 18

EXPLAIN

Why is the refractory period needed?

Answer 18

After action potential, there is:
* too much Na in cell
* too much K outside the cell

Question 19

DEFINE

What is the All-or-None Law?

Answer 19

The magnitude of an Action Potential is independent of the magnitude of the potential change elicted

ie. It either fires fully or it doesnt at all

Question 20

EXPLAIN

What is the firing rate dependant on?

Answer 20

Dependant on the amount of stimulation by other neurons

Question 21

EXPLAIN

What is the function of Enzymes in neurotransmitter synthesis?

Answer 21

Makes neurotransmitters from precursor molecules

Question 22

EXPLAIN

What is the function of Synapatic Vesicles?

Answer 22

Store and protect neurotransmitters after synthesis

Packaged by vesicular transporters

Question 23

DEFINE

Receptors

Answer 23

Specialized proteins that are embedded in neuronal membranes to which neurotransmitters bind and activate

Question 24

LIST

What are the 2 types of Presynaptic Receptors?

Answer 24

1. Autoreceptors
2. Heteroreceptor

Question 25

# DEFINE Autoreceptor

Answer 25

Activiated by neurotransmitters released from the **same** axon terminal

Question 26

# DEFINE Heteroreceptor

Answer 26

Activiation by neurotransmitters **different** from those released by the axon terminal

Question 27

# DEFINE Ionotropic

Answer 27

A receptor that is coupled to an ion channel * NT binds to the receptor to open the ion channel * Wears off when the NT is no longer bound

Question 28

# DEFINE Metabotropic

Answer 28

A receptor that is far away from where its effects are seen * NT binds to receptor and the G protein is activated, causing intracellular signalling * Takes time for effects to wear off, even after NT is no longer bound

Question 29

# DEFINE Which receptor has these traits: * Attached to ion channel * Opens the ion channel * Effect ends when neurotransmitter unbinds * Changes the local potential

Answer 29

Iontropic Receptor

Question 30

# DEFINE Which receptor has these traits: * Seperate from its ion channel and enzymes * Uses G proteins to activate ion channel, effector enzymes and second messengers * Effect persists after unbinding * Can affect local potential, enzyme regulation, gene activiation and protein synthesis

Answer 30

Metabotropic Receptor

Question 31

# DEFINE What are the 3 subunits of G proteins?

Answer 31

α, β, γ

Question 32

# DEFINE Glutamate

Answer 32

The most abundant excitatory neurotransmitter

Question 33

# EXPLAIN When is glutamate inhibitory?

Answer 33

In mGlu group II and III which is only expressed in utero

Question 34

# DEFINE GABA (y-aminobutyric Acid)

Answer 34

Most abundant inhibitory neurotransmitter

Question 35

# DEFINE Rate-Limiting Step

Answer 35

The slowest conversion rate in the synthesis process, limiting how much of the drug can be made without artifical bypassing

Question 36

# EXPLAIN What drug can be used to bypass the rate-limiting step in the production of dopamine?

Answer 36

Levodopa

Question 37

# DEFINE Mesolimbic Pathway

Answer 37

The pathway from the midbrain (VTA) to the limbic areas | such as the nucleus accumbens, Amygdala and hippocampus

Question 38

# DEFINE Mesocortical

Answer 38

Pathway from the midbrain (VTA) to the neocortex, including the pre-frontal cortex

Question 39

# DEFINE Nigrostriatal Pathway

Answer 39

From substantia nigra to the basal ganglia

Question 40

# DEFINE Tuberoinfundibular Pathway

Answer 40

From the hypothalamus to the posterior pituitary

Question 41

# EXPLAIN What does locus coeruleus do?

Answer 41

* Projects information to cerebral cortex, amygdala, and hippocampus * Important for arousal and attention * Helps with memory * released by sympathetic nervous system

Question 42

# EXPLAIN What does the Raphe Nuclei pathway do?

Answer 42

* projects to spinal cord to regulate pain * Regulates mood * Plays a role in food intake

Question 43

# EXPLAIN What type of pathway is the nucleus basalis magnocellurlaris?

Answer 43

a Cholinergic pathway | affected greatly by alzheimers

Question 44

# LIST What 3 hrmones are released via the pituitary and pineal glands from the hypothalamus?

Answer 44

1. Oxytocin 2. Vaspressin 3. Melatonin