Neurons and Synapses

What is the term for the nerve cells that make up the nervous system?

neurons

Messages that nerve cells carry are in the form of…

electrical impulses

What is the small gap called of myelinated nerve fibers?

node of Ranvier

What is saltatory conduction?

signal jumps from node to node of Ranvier

Does saltatory conduction speed up or slow down electrical transmissions?

Speeds up

Identify A

Dendrite

Identify B

Nucelus

Identify C

Cell body

Identify D

Axon

Identify E

Synapse

Identify F

Schwann cell

Identify G

Node of Ranvier

Identify H

Myelin

Identify I

Axon terminal end

Identify the direction of electrical impulse (under ?)

From dendrite to axon (left to right in this example)

Identify I.

Presynaptic impulse

Identify II.

Postsynaptic impulse

What is the name for the small junction or space between two neurons?

synapse

What is the term for a chemical released into the synapse?

Neurotransmitter

How are neurotransmitters released?

By exocytosis

Why is the nerve message referred to as electrochemical? State the reason for electric and chemical

Electric: ions (Na⁺, K⁺)

Chemical: neurotransmitter across the synapse

What is the name for the neuron that releases the neurotransmitter?

Presynaptic neuron

What is the name for the neuron that receives and is affected by the neurotransmitter?

Postsynaptic neuron

Describe the release of a neurotransmitter in terms of Calcium ions and neurotransmitter molecules

Calcium ions diffuse into the pre-synaptic neuron and cause the release of the neurotransmitter molecules into the synapse

What is the effect of the presence of the neurotransmitter in the post-synaptic neuron?

It causes sodium ions to move into the post synaptic neuron, depolarizing the membrane

What is the term for the small membrane sacks that neurotransmitter are released out of?

vesicles

What type of transport is always required to move ions across a membrane?

facilitated or active transport

What is the name of the transport protein that moves ions across membranes?

gated ion channel or pump

What stops continuous synaptic transmission?

Enzymes

What is the name of synapses that use acetylcholine?

Cholinergic synapses

What enzyme breaks down acetylcholine?

Cholinesterase

Where does the choline go after it is formed?

Presynaptic neuron

Describe how neonicotinoid pesticides work on the nervous system of insects

Blocks the binding of acetylcholine which stops nerve signal and paralyzes insects

Resting potential

electrical potential of a cell that’s not conducting an electrical impulse

Action potential

reversal and restoration of electrical potential of a cell that is conducting an electrical charge

Identify A

Resting potential

Identify B

Threshold potential

identify C

Depolarized (sodium ions in)

Identify D

Repolarization (potassium ions out)

Identify E

Resting potential

Identify F

Recovery or restoration (sodium/potassium pump; active transport pump)

Identify G

Action potential

Identify H

Refractory period

What happens to sodium and potassium ions after the action potnetial?

3 sodium ions and 2 potassium ions are pumped back into original location

Describe the charges of the inside and outside a resting neuron

negative inside and positive outside

Draw and annotate the axon (represented as a tube) during resting/polarization

Draw and annotate the axon (represented as a tube) during depolarization

Draw and annotate the axon (represented as a tube) during repolarization