2.4 -- Synaptic Transmission

Question 1

What is the functional connection between a neuron terminal and the target cell?

Answer 1

Synapse

Question 2

In the CNS, the second cell in a synapse will be what? What about the PNS?

Answer 2

CNS – Another neuron
PNS – Another neuron, a muscle, or a gland

Question 3

What is the connection between a neuron and a muscle called?

Answer 3

Neuromuscular junction

Question 4

Can synapses be electrical, chemical, or both?

Answer 4

Both

Question 5

What are the two neurons called if one neuron is signaling another one?

Answer 5

Presynaptic and postsynaptic neuron

Question 6

Which type of synapse requires direct contact? Where does it occur?

Answer 6

Electrical synapse, happening in smooth and cardiac muscle, between some neurons of the brain, and between glial cells

Question 7

In an electrical synapse, a connexin protein forms what, causing cells to be joined directly together?

Answer 7

Gap junctions

Question 8

Most synapses involve the release of a chemical called a what and where does it release?

Answer 8

Neurotransmitter at the axon terminal

Question 9

The neurotransmitter can easily diffuse across the synaptic cleft as it is what?

Answer 9

Very small

Question 10

Which synapse is used when cells need to communicate but aren’t touching directly?

Answer 10

Chemical synapses

Question 11

Where are neurotransmitters enclosed?

Answer 11

Synaptic vesicles at the axon terminal

Question 12

How are neurons often named and how many of each neurotransmitter can it make/release?

Answer 12

By the neurotransmitter it releases, with only 1 type

Question 13

When channels open when the action potential reaches the end of the axon? What does this then cause?

Answer 13

Voltage-gated calcium channels, which fuse synaptic vesicles to the membrane for exocytosis of the neurotransmitter

Question 14

The neurotransmitter is often referred to as the chemical what?

Answer 14

Ligand

Question 15

Can the effect of a neurotransmitter hitting the next cell be inhibitory, excitatory, or both?

Answer 15

Both

Question 16

How are neurotransmitters released?

Answer 16

1). Reuptake by transporter on presynaptic terminal
2). A little might diffuse out of the cleft
3). Digested by enzyme on postsynaptic side

Question 17

The acetylcholine (ACh) receptor is what type of channel?

Answer 17

Na+

Question 18

ACh is what from all somatic motor neurons to skeletal muscle cells (and some CNS areas)?

Answer 18

Excitatory

Question 19

ACh is excitatory, inhibitory, or both in an autonomic motor neuron?

Answer 19

Both

Question 20

What are the two types of ACh receptors?

Answer 20

Nicotinic and muscarinic

Question 21

What ACh receptor is found on the motor end plate of skeletal muscle cells, in autonomic ganglia, and in some parts of the CNS?

Answer 21

Nicotinic

Question 22

What ACh receptor is found in the CNS and membrane of smooth and cardiac muscle and glands innervated by autonomic motor neurons?

Answer 22

Muscarinic

Question 23

Which type of ACh receptor is for Na+ channels only and which one is Na+, Ca2+, or K+ channels?

Answer 23

Nicotinic – Na+ channels
Muscarinic – Na+, Ca2+, or K+ channels

Question 24

What is the enzyme that cleaves ACh by hydrolizing it into what two things?

Answer 24

Acetylcholinesterase (AChE), which does acetate and choline

Question 25

Where is AChE located?

Answer 25

On the target cell membrane

Question 26

What are regulatory molecules derived from amino acids?

Answer 26

Monoamines

Question 27

Serotonin, histamine, catecholamines, and glutamate are examples of what?

Answer 27

Monoamines

Question 28

Dopamine, epinephrine, and norepinephrine are all types of what monoamine class?

Answer 28

Catecholamines

Question 29

How are monoamines inactivated?

Answer 29

By reuptake via transporters and repackaged or degraded by monoamine oxidase (MAO)

Question 30

In order for a very fast signal to be sent one from one cell to the next, it must be what?

Answer 30

In close proximity