CH 12: Synapses

Question 1

Electrical synaptic transmission

Answer 1

Near instantaneous transmission through gap junctions and ion channels

Question 2

Chemical synapse

Answer 2

Neurotransmitters released and bind to continue signal

Question 3

Synaptic vesicle

Answer 3

Packaged with Neurotransmitter

Question 4

Postsynaptic receptor’s

Answer 4

Neurotransmitter receptors

Question 5

Six categories of neurotransmitters

Answer 5

1. Acetylcholine
2. Amino acids
3. Monoamines
   3a.
   3b.
4. Neuropeptides
5. Gases
6. Purines

Question 6

Neuro transmitters in the acetylcholine group

Answer 6

ACh

Question 7

Neurotransmitters in the amino acids group

Answer 7

GABA

Question 8

Neural transmitters in the monoamine’s group

Answer 8

3a. Serotonin, histamine

3b. Catecholamines:
-Epinephrine
-Norepinephrine
- Dopamine

Question 9

Neuropeptides are:

Answer 9

Chains of amino acids

Question 10

Gases that behave like neurotransmitters:

Answer 10

(Can freely pass-through axon terminal) NO, CO

Question 11

Purines that acts like neural transmitters

Answer 11

Adenosine, ATP

Question 12

Acetylcholine is stimulatory in _________, but inhibitory in ________

Answer 12

Skeletal muscle tissue
Cardiac tissue

Question 13

ACh Synaptic transmission; Excitatory pathway

Answer 13

1. Action potential reaches axon terminal; opens VG Ca^2+ channel; Ca^2+ move in causing depolarization
2. Ca^2+ Triggers exocytosis of ACh
3. Vesicles refill so long as Ca^2+ Is an axon terminal
4. ACh diffuses across synapse; binds to ligand gated ACh receptors on postsynaptic neurons
5. Causes local potential on postsynaptic neuron; Could lead to action potential if threshold reached
   

Question 14

Inhibitory pathway: GABA

Answer 14

GABA opens Cl- channels; Cl- enters and Hyperpolarizes the cell (more neg) so harder to stimulate postsynaptic neuron

Question 15

Excitatory pathway – androgenic
Ex: Norepinephrine

Answer 15

1. NE receptor is bound to G protein
2. NE binds to NE receptor; breaks off G protein
3. G protein activates adenylate cyclase enzyme which activates cAMP
4. cAMP is secondary messenger with downstream effects
5. One downstream if it can be opening up particularly can get a channels which allows ions to come in and have postsynaptic potential

Question 16

Signal amplification

Answer 16

One neural transmitter can activate tons of downstream messengers with lots of downstream effects

Question 17

End of ACh transmission signal

Answer 17

6. Degrading of neurotransmitter AChE breaks down ACh
7. Reuptake of a neurotransmitter into presynaptic neuron
8. Diffusion (Broken up pieces diffuse back into presynaptic neuron across plasma membrane)

Question 18

Neuromodulators

Answer 18

Longer-term affect over multiple neurons whereas neurotransmitter is short term effect across one synapse

Question 19

Postsynaptic potentials

Answer 19

Activation or inhibition of postsynaptic neurons as transmit across Synaptic cleft

Question 20

EPSP

Answer 20

Excitatory postsynaptic potential; any neurotransmitter that helps excite or depolarize postsynaptic neuron

Ex: ACh in skeletal muscle

Question 21

IPSP

Answer 21

Inhibitory postsynaptic potential; neural transmitter that prevents stimulation of postsynaptic neuron: hyperpolarization
Ex: GABA
ACh in cardiac tissue

Question 22

Net summation

Answer 22

Combination of IPSPs and EPSPs = Depolarized or hyperpolarized

Question 23

Temporal summation

Answer 23

Effects from one presynaptic neuron over time ( can reach threshold)

Question 24

Spatial summation

Answer 24

Effect from multiple neurons at the same time ( can reach threshold)

Question 25

Presynaptic facilitation

Answer 25

One neuron indirectly enhances the effects of another by Further enhancing presynaptic neurons ability to fire postsynaptic neuron

Question 26

Presynaptic inhibition

Answer 26

One neuron inhibits firing of another; increases amount of IPSPs so no neurotransmitter is released from second neuron