Physiology 60: The Autonomic Nervous System And The Adrenal Medulla

Front 1

Where are the preganglionic sympathetic neuron bodies found?

Back 1

intermediolateral horn of T1-L2 spinal column

Front 2

Where are the postganglionic sympathetic neuron bodies found?

Back 2

in the paravertebral column

Front 3

Where do sympathetic preganglionic neurons enter the paravertebral column?

Back 3

white ramus of their spinal level

Front 4

Where do sympathetic preganglionic neurons leave the paravertebral column?

Back 4

any grey ramus

Front 5

What is the innervation to the adrenal medulla?

Back 5

preganglionic sympathetics

Front 6

Where are the postganglionic parasympathetic neuron bodies found?

Back 6

in the wall of the organ being innervated

Front 7

Which cranial nerve contains most of the parasympathetic fibers of the body?

Back 7

vagus (10)

Front 8

Why type of neurotransmitter is used by all preganglionic neurons?

Back 8

acetylcholine

Front 9

Why type of neurotransmitter is used by sympathetic postganglionic neurons?

Back 9

norepinephrine/epinephrine

Front 10

Why type of neurotransmitter is used by parasympathetic postganglionic neurons?

Back 10

acetylcholine

Front 11

What are varicosities?

Back 11

Areas on an organ where the neuron touches the organ; storage site for neurotransmitters

Front 12

Acetylcholine is made up of what 2 subunits?

Back 12

Acetyl CoA and Choline

Front 13

What enzyme is needed for acetylcholine synthesis?

Back 13

choline acetyl transferase

Front 14

Function of the enzyme acetylcholinesterase

Back 14

degrade acetylcholine into acetic acid/acetate+ choline

Front 15

When acetylcholine is degraded in the neuromuscular junction, what happens to the choline?

Back 15

reabsorbed into the neuron and re-used in acetylcholine synthesis

Front 16

Process of Epinephrine synthesis. Start with tyrosine

Back 16

tyrosine > Dopa > Dopamine > Norepinephrine > Epinephrine

Front 17

How does tyrosine become Dopa?

Back 17

hydroxylation

Front 18

How doe Dopa become Dopamine?

Back 18

decarboxylation

Front 19

How does dopamine become norepinephrine?

Back 19

hydroxylation in the vesicles

Front 20

How does norepinephrine become epinephrine?

Back 20

methylation

Front 21

Which is more prevalent epinephrine or norepinephrine?

Back 21

epinephrine

Front 22

What does monoamine oxidase do?

Back 22

degrades norepinephrine in the synaptic cleft/neuromuscular junction

Front 23

How is norepinephrine removed from the neuromuscular junction? (3 ways)

Back 23

reabsorbed into the neuron, diffuse into blood, monoamine oxidase degradation

Front 24

2 types of receptors for acetylcholine?

Back 24

muscarinic and nicotinic

Front 25

Opening of potassium channels usually leads to what type of response? Excitatory or Inhibitory

Back 25

inhibitory; lowers the resting potential further from the threshold as more potassium can leak out of the neurons

Front 26

Opening of sodium channels usually leads to what type of response? Excitatory or Inhibitory

Back 26

excitatory; raises the resting potential closer to the threshold as more sodium comes into the neurons

Front 27

Function of adenylyl cyclase

Back 27

create cAMP from AMP

Front 28

How does norepinephrine affect cAMP?

Back 28

increases adenylyl cyclase = more cAMP production

Front 29

Where are nicotinic receptors found for acetylcholine?

Back 29

junction between preganglionic and postganglionic autonomic neurons

Front 30

Where are muscarinic receptors found for acetylcholine?

Back 30

neuromuscular junction on organs innervated parasympathetically

Front 31

What has a greater effect on alpha receptors? Epinephrine or Norepinephrine

Back 31

norepinephrine

Front 32

What has a greater effect on beta adrenergic receptors? Epinephrine or Norepinephrine

Back 32

Epinephrine

Front 33

Epinephrine has more of an effect on which type of adrenergic receptor? (A or B)

Back 33

both equally almost (norepinephrine is mostly alpha)

Front 34

What is the structural difference between epinephrine and norepinephrine?

Back 34

epinephrine has an extra methyl group

Front 35

B2 receptors have what effect on blood vessels?

Back 35

cause vasodilation

Front 36

B1 receptors have what effect on heart rate/strength?

Back 36

increase both

Front 37

alpha receptors have what effect on blood vessels?

Back 37

cause vasoconstriction

Front 38

What 2 functions of the eye are controlled by the autonomics?

Back 38

pupillary opening and lens focus

Front 39

Sympathetics do what to the pupils?

Back 39

dilate pupils

Front 40

How do parasympathetics cause pupil constriction?

Back 40

activate the ciliary muscle

Front 41

Sweat glands are innervated by sympathetic nerves. What neurotransmitter do they use?

Back 41

ACETYLCHOLINE; this in an exception, most sympathetics use epinephrine/norepinephrine

Front 42

Which has a greater effect on heart rate? Epinephrine or Norepinephrine?

Back 42

Epinephrine has a greater B-selectivity

Front 43

Which causes more vasoconstriction? Epinephrine or Norepinephrine?

Back 43

Norepinephrine; greater selectivity to alpha receptors

Front 44

Where do Epinephrine/Norepinephrine come from?

Back 44

Adrenal Medulla and post ganglionic sympathetic neurons

Front 45

If neurons are able to release Epinephrine/Norepinephrine to the organs they innervate, why do we need an adrenal medulla?

Back 45

not all organs that need Epinephrine/Norepinephrine have direct sympathetic innervation. Also Epinephrine/Norepinephrine have many effects on many different types of cells/organs

Front 46

What is sympathetic tone?

Back 46

basal rate of sympathetic discharge

Front 47

A dose of Epinephrine/Norepinephrine has what effect on blood flow?

Back 47

decreases blood flow (increases pressure)

Front 48

Removal of sympathetics in a blood vessel has what effect on blood flow?

Back 48

increase blood flow (but decrease pressure) due to excess vasodilation as parasympathetics take over

Front 49

A small dose of adrenalin is given and blood flow decreases. After removal of sympathetics in this blood vessel, the same small dose of adrenalin will have what effect on the blood flow?

Back 49

decreases even more; the vessel is now even more sensitive to the adrenalin

Front 50

What is denervation sensitivity?

Back 50

after removal of sympathetic/parasympathetic innervation to an organ, it will become more sensitive to sympathetic/parasympathetic stimulation in the future

Front 51

Why does denervation sensitivity occur?

Back 51

up-regulation of receptors after constant sympathetic/parasympathetic stimulus is removed

Front 52

What is the baroreceptor reflex?

Back 52

increased stretch in the walls of a blood vessel are detected; more stretch = high BP = brain signals for less sympathetics > lower BP

Front 53

Erection is mainly parasympathetic or sympathetic?

Back 53

parasympathetic

Front 54

Ejaculation is mainly parasympathetic or sympathetic?

Back 54

sympathetic

Front 55

What is mass discharge?

Back 55

rapid release of a lot of catecholamines in response to a stimulus (fight/flight response)

Front 56

Blood pressure, heart rate and respiratory rate are all regulated in what part of the brain?

Back 56

brain stem

Front 57

Regulation of the brain stem from higher areas comes mainly from where?

Back 57

hypothalamus

Front 58

What does albuterol do?

Back 58

sympathetomimetic drug that activates B2 receptors

Front 59

Phenylephrine works to activate which adrenergic receptors?

Back 59

alpha

Front 60

Isoproterenol works to activate which adrenergic receptors?

Back 60

beta

Front 61

How does tyramine lead to increased sympathetic tone?

Back 61

tyramine causes increased epinephrine/norepinephrine release from neurons

Front 62

How does reserpine block sympathetics?

Back 62

blocks synthesis and storage of norepinephrine in nerve endings

Front 63

How does guanethidine block sympathetics?

Back 63

inhibits norepinephrine from entering synaptic vesicles

Front 64

How does phenoxybenzamine block sympathetics?

Back 64

blocks alpha receptors

Front 65

How does propanolol block sympathetics?

Back 65

blocks beta receptors

Front 66

How does hexamethonium block sympathetics?

Back 66

inhibiting all autonomic nerves impulses

Front 67

What are pilocarpine and methacholine?

Back 67

parasympathetomimetic drugs (pilocarpine acts on muscarinic, methacholine works on both)

Front 68

What is atropine?

Back 68

parasympathetic blocker; anti-muscarinic only

Front 69

What does Neostigmine do?

Back 69

blocks acetylcholinesterase activity = less degradation of acetylcholine = more parasympathetic activity

Front 70

Nicotine has what effect on the autonomic system?

Back 70

activates sympathetic and parasympathetic postganglionic neurons

Front 71

How does tetraethyl ammonium ion help lower BP?

Back 71

blocks all autonomic ganglion (sympathetic and parasympathetic); major side effects