Autonomics

Question 1

Define homeostasis

Answer 1

maintenance of steady states in the body by coordinated physiological mechanisms

Question 2

What are some examples of ANS in homeostasis?

Answer 2

Blood glucose regulation
BP control
Blood flow
Temperature regulation
Smooth muscle - GI tracts, ducts, bronchi, uterus
GI motility & secretions
Endocrine glands - many glands receive ANS input
Exocrine glands (salivary & sweat gland)
Bladder
Vomit reflex
Sexual function

Question 3

What is only a sympathetic control?

Answer 3

sweat glands & blood vessels

Question 4

What is the importance of ANS to dentistry?

Answer 4

Routine procedure stress/anesthetic injections
Emergency medicine (w/ stress)
Environmental & disease induced stress
Malocclusion stress
Abnormal blood flow causing TMJ disease & pain

Question 5

Postganglionic neurotransmitters of sympathetic division. What do they stimulate?

Answer 5

Ach
- stimulates vasodilation & sweat glands
NE
- stimulates piloerector muscle & vasoconstriction

Question 6

___ nervous system activities are influenced by ANS

Answer 6

Enteric

Question 7

The efferent arm, in the ANS, has __ neurons & ___ synapses

Answer 7

2 & 2

Question 8

Describe (myelinated or not, location, type, length) the sympathetic & parasympathetic division in the preganglionic neurons

Answer 8

Sympathetic
- myelinated, B type, located in cell bodies in intermediolateral column, short length

Parasympathetic
- myelinated, B type, located in cell bodies in brain or sacral spinal cord, long length

Question 9

Length of the sympathetic & parasympathetic division in the postganglionic neurons

Answer 9

Sympathetic = long
Parasympathetic = short

Question 10

Discrete or diffuse for sympathetic & parasympathetic

Answer 10

Sympathetic = diffuse
Parasympathetic = discrete

Question 11

The afferent arm stimulates

Answer 11

preganglionic neuron

Question 12

Somatic nervous system enters the spinal cord through the ___, stimulates neurons in the ___ & activates or repressors ___. ANS enters the spinal cord through the ___ & stimulates preganglionic nerurons in the ___

Answer 12

Dorsal horn
Intermediolateral column
motor neuron activity

dorsal horn
intermediolateral column

Question 13

Afferent sensory system receptors

Answer 13

mechanoreceptors, chemoreceptors, nocioreceptors

Question 14

ANS effectors are ___. Where do they go through in the spinal cord?

Answer 14

Smooth muscle, cardiac muscle, glands
Ventral horn to postganglionic fiber

Question 15

Define varicosities

Answer 15

Where neurotransmitters are released

Question 16

Skeletal muscles motor neurons release ___, which binds to ___

Answer 16

Ach
Nicotinic

Question 17

What destroys Ach?

Answer 17

Acetylcholinesterase

Question 18

In the pregnanglionic neuron for the ANS, parasympathetic & sympathetic division release ___ & stimulates ___ receptor

Answer 18

Ach
Nicotinic

Question 19

In the postganglionic neuron for the ANS, the parasympathetic division release ___ & activates ___

Answer 19

Ach
Muscarinic

Question 20

In the postganglionic neuron for the ANS, the sympathetic division release ___ & activates ___

Answer 20

NE
adrenergic alpha or beta receptor

Question 21

___ & ___ are extracted from amanita mushroom to increase parasympathetic response

Answer 21

Muscarinic & nicotinic

Question 22

Special case when sympathetic postganglionic neruon release Ach occurs in ___

Answer 22

skeletal muscles

Question 23

Ach synthesis & enzymes involved

Answer 23

Choline + acetyl-CoA → acetylcholine → choline + acetate
Enzyme 1: choline acetyltransferase
Enzyme 2: acetylcholinesterase (breaks down Ach)

Question 24

Nicotinic receptor subunits

Answer 24

Has 2 alpha subunits, 1 beta, 1 gamma, & 1 delta subunit

Question 25

Muscarinic receptor is/is not a channel? What are the 5 types & describe each?

Answer 25

Is not - M4 & M5 are only in CNS - M1 & M3 are associated w/ smooth muscle - M2: Galpha i or o → adenylyl cyclase inhibition (decrease cAMP), opening K+ channels

Question 26

NE pathway & enzymes involved

Answer 26

L-tyrosine → L-DOPA → Dopamine → L-Norepinephrine Enzyme 1: tyrosine hydroxylase Enzyme 2: aromatic L-amino acid decarboxylase Enzyme 3: dopamine beta-hydroxylase

Question 27

epinephrine pathway & enzymes involved

Answer 27

L-tyrosine → L-DOPA → Dopamine → L-Norepinephrine → L-epinephrine (adrenalin) Enzyme 1: tyrosine hydroxylase Enzyme 2: aromatic L-amino acid decarboxylase Enzyme 3: dopamine beta-hydroxylase Enzyme 4: phenylethanolamine N-methyl transferase

Question 28

End product inhibition by ___ & ___ blocks tyrosine hydroxylase during the formation of NE

Answer 28

DA & NE

Question 29

Describe MAO & COMT

Answer 29

MAO - degrades NE in presynaptic neuron - Found in mitochondria COMT - degrades NE in postsynaptic neuron - found in liver & blood

Question 30

Chain events of NE

Answer 30

1. Action potential arrives 2. Depolarization opens voltage gated Ca2+ channels 3. Ca2+ entry causes exocytosis of synaptic vesicles & release of NE 4. NE binds adrenergic receptor on target cells 5. Receptor activation ceases when NE diffuses away or is metabolized by COMT 6. NE transported back into axon 7. NE goes back into vesicles or gets metabolized by MAO

Question 31

For each of the following, is NE or Epi preferred. Alpha1, alpha2, beta1, beta2

Answer 31

Alpha1: (NE> Epi) Alpha2: (NE> Epi) Beta1: (Epi> NE) Beta2: (Epi>>> NE)

Question 32

Define receptor affinity

Answer 32

concentration a compound elicits a response from a receptor - High affinity receptors only need a small amount of substance to activate receptors - Low affinity needs more

Question 33

Norepinephrine can activate what in alpha & beta

Answer 33

Alpha1: smooth muscle & vasoconstriction Alpha2: smooth muscle & relaxation Beta1: heart muscle contraction & increases heart rate

Question 34

Epinephrine (adrenaline) can activate what in alpha & beta

Answer 34

Alpha1: smooth muscle & vasoconstriction IP3 production Alpha2: veinoconstriction Beta1: heart muscle contraction & increase rate cAMP production Beta2: skeletal muscle blood vessels dilation & smooth muscle relaxation cAMP production Mainly activates beta2

Question 35

Examples of effects of the sympathetic nervous system

Answer 35

Increase heart & lung action (caused by increase of blood flow) Inhibition of stomach & intestinal action Constriction of blood vessels in many parts of body (like skin & GI) Liberation of nutrients for muscular action Dilation of blood vessels Inhibition of lacrimal gland & salivation Dilation of pupil (increases sight of vision) Increased anxiety/awareness Relaxation of bladder Inhibition of erection

Question 36

Is NE acting as a neurotransmitter & hormone?

Answer 36

Yes - If circulating, it’s a hormone - If released in nerve directly to target tissue, it’s a neurotransmitter

Question 37

In the following reaction, is there a faster or slower EPSP response? Preganglionic neuron releases Ach → binds to muscarinic receptor → activates postganglionic neuron

Answer 37

Slower

Question 38

In the following reaction, is there a faster or slower EPSP response? Preganglionic neuron releases Ach → binds to nicotinic receptor → activates postganglionic neuron

Answer 38

Faster

Question 39

In the following reaction, is there a EPSP or IPSP response? Preganglionic neuron releases Ach → binds to muscarinic receptor in SIF cell → releases dopamine

Answer 39

IPSP

Question 40

___ may produce long lasting EPSP or IPSPs

Answer 40

Sensory afferents

Question 41

Influences on ANS come from:

Answer 41

Spinal cord & brain stem Hypothalamus ANS influenced by neocortex & other higher brain centers Integration at every level to insure proper responses

Question 42

Does the ANS have dual innervation?

Answer 42

Yes

Question 43

Increase or decrease for the following examples in parasympathetic & sympathetic division: heart rate, stomach, pylorus, salivary flow, BV

Answer 43

- Heart rate: sympathetic increases & parasympathetic decreases - Stomach: sympathetic decreases, parasympathetic increases - Pylorus: sympathetic increases, parasympathetic decreases (induces relaxation) - Salivary flow: both increase - Blood vessels: only sympathetic

Question 44

Catabolic or anabolic for the parasympathetic & sympathetic division

Answer 44

anabolic for parasympathetic catabolic for sympathetic

Question 45

What are the 4 types of stresses

Answer 45

Fright (sympathetic) Fear and anxiety (both) Acute fear Chronic stress

Question 46

What increases norepinephrine production?

Answer 46

Ephedrine, amphetamine, pseudoephedrine

Question 47

What blocks norepinephrine production?

Answer 47

Resperine & methyldopa