Exam 2-Synapses

Question 1

synapses

Answer 1

specialized region of contact between a neuron and its target

Question 2

electrical synapse

Answer 2

membranes nearly touch (gap junction-movement of ions)

Question 3

Otto Loewi

Answer 3

won Nobel prize in physiology of medicine; studied neurons and nervous system

Question 4

(Otto Loewi)

vagus nerve

Answer 4

cranial nerve that goes into the body

slows heart when stimulated

Question 5

(Otto Loewi)

Experiment

Answer 5

• frog’s heart in ringer’s solution (water based with ions and nutrients meant to mimic bodily environment)
• first stimulate vagus nerve on 1st heart, it will eventually affect the second heart)
• acetyl choline responsible (fragile)

Question 6

chemical synapse

Answer 6

exocytosis release chemical which binds and then reverse binds; time component; lots of advantages

Question 7

(chemical synapse)

advantages

Answer 7

• amplification of current flow
• exitatory vs.inhibitory (we can override)
• integration (can take info and make a decision)
• one-way communication
• more modifiable (plasticity)

Question 8

(Communication at chemical synapse)

neurotransmitter release

Answer 8

• vesicles: roughly the same amount of neurotrans. (get a similar response with each vesicle)
• action potential: lowers and opens Ca gated channels (Ca comes into cell and interacts with proteins to trigger exocytosis)

Question 9

(Communication at chemical synapse)

activation of postsynaptic terminal

Answer 9

depends on receptor:

• ionotropic (ligand gated, ion channel, quick response, no 2nd messenger, direct, fast IPSP and EPSP)
• metabotropic (GPCR, slower, metabolic cascade, 2nd messenger, indirect, slow PSP’s)

Question 10

(Communication at chemical synapse)

termination of signal

Answer 10

• no longer release neurotrans. (Ca channels close)
• removal of neurotrans. from synaptic cleft (diffusion, enzyme degradation, reuptake)
• loss of current (or reduction of 2nd messenger at postsynaptic target)

Question 11

neuromuscular junction

Answer 11

• folds increase surface area
• acetylcholine: when released, binds to/opens ligand-gated channels, allowing K/Na current (depol. because increase in threshold)
• acetylcholinerase (enzyme that breaks acetyl choline into choline which is taken back up into presynaptic terminal to be recycled)