Nervous system III

Question 1

Synapses can either be ___ or ____

(think interaction points)

Answer 1

cell-cell interaction points

cell-effector interaction points

Question 2

Neuron synapses are…
Electrical synapses are…

Answer 2

Nearly all chemical (most common)
common in the heart

Question 3

arrival of AP to axon terminal does what

Answer 3

releases CA2+, Then causes vescicles to fuse with membrane and release hormones

Question 4

ionotropic

Answer 4

opens ion channels (fast)

Question 5

metabotropic

Answer 5

activates secondary messenger systems (slow)

Question 6

synapses are always ____ directional

Answer 6

Unidirectional, can be excitatory or inhibitory in post synaptic cell.

Question 7

What is summation

Answer 7

when multiple inputs to a single neuron interact

Question 8

Temporal Summation

Answer 8

multiple potentials arrive from a single input

Question 9

spatial summation

Answer 9

if multiple inputs occur simultaneously from different cells

Question 10

EPSPs and IPSPs can do what

Answer 10

cancel out each other’s effects.

Question 11

Example of Ionotropic synapse

Answer 11

AP arrives at synapse and opens voltage gated Ca2+ channels which eventually releases Acetylcholine

Question 12

Acetylcholine effects

Answer 12

permits Na+ and K+ flow

Question 13

what does ion flow result from

Answer 13

activation of a ligand gated channel

Question 14

Mechanism of graduated vs action potentials

Answer 14

graduated = ligand gates
action = voltage gated

Question 15

effects of myelin

Answer 15

reduces capacitance and membrane resistance

reduces cost of ion pumping with fewer channels

Question 16

axon size effect on AP speed

Answer 16

larger diameter is faster - less resistance

Question 17

why are AP’s one directional

Answer 17

after the AP, the voltage channels inactivate

Question 18

Why are muscles ideal for studying Ionotropic synapses

Answer 18

they only receive input from one neuron

Question 19

Why is the neuromuscular junction unique

Answer 19

every action potential delivered generates an action potential

most other cells are either stimulated or inhibited to a lesser extent

Question 20

What generally causes Ion flow

(what allows it into the cell most commonly regarding post synaptic cells)

Answer 20

activation of a ligand-gated channel

Question 21

Variation in graded potentials in neuromuscular junctions is due to…

Answer 21

size, and difference in neurotransmitter (NT) receptors.

Question 22

What happens to NT’s and vesicles after released

Answer 22

often recycled and degraded by enzymes.

vesicles are often recycled to couple exocytosis and endocytosis reactions

Question 23

Metabotropic Synapses

how long they take?

what do they act through?

Answer 23

act through secondary messenger systems

can occur over months/years

can alter transcription

Question 24

Metabotropic vs Ionotropic

Receptor molecule

Molecular action

Type of Synaptic effect

Answer 24

Receptor molecule

Metabotropic: G protein-coupled receptor
Ionotropic: ligand-gated channels

Molecular action

Metabotropic: active G protein - metabolic cascade
Ionotropic: Open ion channels

Type of Synaptic effect

Metabotropic: slow PSPs, modulatory changes, cell metabolism
Ionotropic: fast EPSP or IPSP