Lecture 2: Neurotransmission and ANS

Question 1

Effects of botulinum toxin

Answer 1

flaccid paralysis (impairs snares of NT vesicles from fusing)

Question 2

Effects of tetanus toxin

Answer 2

spastic paralysis (impairs snare fusion too but primarily acts on INHIBITORY neurons)

Question 3

Excitatory neurotransmitters

Answer 3

Acetylcholine and glutamate

cause EPSP (excitatory post synaptic potentials) which become APs if they reach high enough threshold

Question 4

Inhibitory neurotransmitters

Answer 4

GABA and glycine

cause IPSP (inhibitory synaptic potentials) which allow Cl- to enter the cell and keep membrane potential from threshold

Question 5

Neuron-neuron and neuron-skeletal muscle post synaptic receptor type

Answer 5

ionotropic (fast)

nicotinic Ach

Question 6

Neuron-viscera post synaptic receptor type

Answer 6

metabotropic (slow)

muscarinic Ach

Question 7

What do WMDs/nerve gas do?

Answer 7

inhibit acetyl cholinesterase leading to overstimulation (convulsion, paralysis, respiratory failure)

Question 8

WMD antidotes

Answer 8

1. Diazepam (sedative prevents seizures)
2. Atropine (blocks muscarinic Ach)
3. Pralidoxime (recovers AchE function)

Question 9

ANS 2-neuron pathway

Answer 9

Preganglionic neuron (soma located in CNS)
Postganglionic neuron (located in autonomic ganglion)

Question 10

All preganglionic neurons secrete which neurotransmitter?

Answer 10

Acetylcholine (acts on post-ganglionic nicotinic receptors)

Question 11

Sympathetic ganglia are located __________ the target organ compared to parasympathetic

Answer 11

farther from

Question 12

In sympathetic branch, the preganglionic fibers are ______ than the post ganglionic fibers

Answer 12

shorter

Question 13

Location of sympathetic neurons

Answer 13

C8, thoracic, upper lumbar segments of the spinal cord

Question 14

postganglionic fibers of the sympathetic system secrete ______

Answer 14

norepinephrine

Question 15

NE activates ______ receptors

Answer 15

metabotropic adrenergic

Question 16

What is the exception to normal sympathetic preganglionic-postganglionic signaling?

Answer 16

the adrenal medulla (pregangs pass thru splanchnic nerve and synapse DIRECTLY onto medulla)

There is NO postganglionic neuron

Question 17

What does the adrenal medulla secrete?

Answer 17

epinephrine and norepinephrine

Question 18

Second exception to sympathetic signaling?

Answer 18

sweat glands (inn. by symp but activated via ACh bound to muscarinic metabotropic receptors)

Question 19

Location of parasympathetic nerves

Answer 19

Cranium (CN 3, 7, 9, 10) and sacrum

Question 20

Where are the ganglia in the parasympathetic system?

Answer 20

near the target organ

Question 21

What neurotransmitter do postganglionic fibers secrete?

Answer 21

Ach (muscarinic cholinergic receptors)

Question 22

Sympathetic nerves have ______ preganglionics and _______ postganglionics

Answer 22

short; long (Ach –> NE)

Question 23

Parasympathetic nerves have ______ preganglionics and _______ postganglionics

Answer 23

long; short (Ach –> Ach)