Biology Journal 3/11/2014

What do “excitatory” and “inhibitory” mean? Which of these drugs are excitatory, and which are inhibitory?

Drug Excitatory or Inhibitory effects on nervous system?

Cocaine

Alcohol (ethanol)

Nicotine

Amphetamines (such as “meth”)

THC (tetrahydrocannabinol)

Benzodiazepines (such as valium, xanax, diazepam, and other

antidepressants)

Biology Journal 3/11/2014Excitatory = increase neurotransmitters and thus signalsInhibitory = decrease neurotransmitters and thus signals

Drug Excitatory or Inhibitory effects on nervous system?

Cocaine Excitatory

Alcohol (ethanol) Inhibitory

Nicotine Excitatory

Amphetamines (such as “meth”) Excitatory

THC (tetrahydrocannabinol) Inhibitory

Benzodiazepines (such as valium, xanax, diazepam, and other

antidepressants)Excitatory

What organs make up the central nervous system?

What organs make up the peripheral nervous system?

1. What kind of neuron is A?

2. What kind of neuron is B?

3. What kind of neuron is C?

AB

C

A is a motor neuron because it attaches to a muscle.B is a sensory neuron because it has sensory receptors for dendrites.C is a relay neuron because it connects neurons to other neurons. A

BC

Label this diagram

5

8

6

3

27

1

4

Label this diagram

Neurotransmitters

Receptor (for neurotransmitters)

Vesicle

Dendrite

Synapse

Transport protein

(for reuptake of neurotransmitters)

Axon terminal

Mitochondrion

What are the effects of cocaine on the synapse?Cocaine blocks dopamine transporter proteins (also known as re-uptake proteins), thus dopamine stays in the synapse, overstimulating the dopamine receptors in the receiving neuron.

What are the effects of THC on the synapse?THC reduces the release of dopamine-inhibitors. Thus, lots of dopamine is freely released, causing overstimulation of dopamine receptors.(remember, THC “inhibits the inhibitor of dopamine,” “blocks the blocker,” “shuts down the shutdowner,” etc.)

What could be some reasons that drugs like cocaine and methamphetamine are so addictive?

These drugs influence dopamine and other neurotransmitters that are involved in feelings of pleasure, calm, and the reward mechanism of the brain.

1. What is the charge inside of an axon when it is polarized?

2. What is the charge inside of an axon when it is depolarized?

3. What is the charge inside of an axon when it is repolarized?

Polarized: (-) inside axon, (+) outside axon. This is the starting, or “resting” potential.Depolarized: (+) inside axon, (-) outside axon. This occurs when the Na+1 diffuses into the axon.Repolarized: (-) inside axon, (+) outside axon. This happens when the K+1 diffuses out of the axon.

Label this neuron cell1

4 6

2

8

53

7

Label this neuron cellDendrites

Myelin sheath Schwann cell

Cell body (soma)

Axon terminals

AxonNucleus

Node of Ranvier

When does the inside of an axon have a negative charge? (write all correct letters)

A C D F G

A. When it is polarizedB. When it is depolarizedC. When it is repolarizedD. Resting potential

E. After sodium diffuses inF. After potassium diffuses outG. After the Na/K pump has reset the ions following an action potential

Which parts of an action potential involve passive transport?

A B D

A. When Na enters the neuronB. When K leaves the neuronC. When the Na/K pump is moving ions

D. DepolarizationF. The reuptake of neurotransmitters by transport proteinsG. The exocytosis of neuro-transmitters into the synapse

What step on the graph…A. is the resting potential?B. does Na diffuse into the neuron?C. is repolarization?D. does the Na/K pump re-position the ions?E. is the inside of the axon positive?

01452 and/or 3

What does the myelin sheath do for a neuron?

The myelin sheath speeds up and protects the electrical signal (action potential)

6.5 Nerves6.5.1 State that the nervous system consists of the central nervous system (CNS) and peripheral nerves,

and is composed of cells called neurons that can carry rapid electrical impulses.

6.5.2 Draw and label a diagram of the structure of a motor neuron. Dendrites and cell body with nucleus Axon and myelin sheath nodes of Ranvier motor end plates

6.5.3 State that nerve impulses are conducted from receptors to the CNS by sensory neurons, within the CNS by relay neurons, and from the CNS to effectors by motor neurons.

6.5.4 Define resting potential and action potential (depolarization and repolarization).

6.5.5 Explain how a nerve impulse passes along a non-myelinated neuron. Include the movement of Na+ and K+ ions to create a resting potential and an action potential.

6.5.6 Explain the principles of synaptic transmission. the release, diffusion and binding of the neurotransmitter initiation of an action potential in the post-synaptic membrane subsequent removal of the neurotransmitter

6.5.1 State that the nervous system consists of the central nervous system (CNS) and peripheral nerves, and is composed of cells called neurons that can carry rapid electrical impulses.