Autonomic Nervous System Flashcards
1
Q
How is the nervous system classified by physical location?
A
- CNS vs. PNS
2
Q
How is the nervous systems classified by function?
A
- autonomic vs. somatic
3
Q
What is the autonomic nervous system?
A
- actions not under conscious control i.e. voluntary, visceral function
4
Q
What is the somatic nervous system?
A
- conscious functions i.e. movement, respiration, posture
5
Q
How is the autonomic nervous system dividided?
A
- sympathetic vs. parasympathetic
6
Q
Where do the divisions of the autonomic nervous system originate?
A
- both in CNS
7
Q
Where do the divisions of the autonomic nervous system exit?
A
- through the brain in preganglionic efferent n. fibers
- sympathetic exits through throacic and lumbar spinal n.
- parasympathetic exits through cervical and 3rd-4th sacral
8
Q
Which way does information flow in efferent n?
A
- brain to body
- EFFerent causes an EFFect in EFFector organs
9
Q
Which way does information flow in afferent n?
A
- body to brain
- sensation
10
Q
What are preganglionic neurons?
A
- originate in CNS
- connect to ganglia in PNS
11
Q
What are ganglia?
A
- relay stations
- pass information to postganglionic neurons
12
Q
What are postganglionic neurons?
A
- nerves that terminate on effector organs
13
Q
Describe the circle of information
A
- CNS sends signal via effernt n. to target organs
- target organs do X and send signal back via afferent n. to CNS
- CNS processes info and sends a signal
14
Q
What are the NT of the ANS?
A
- acetylcholine (ACh)
- norepinephrine (NE)
15
Q
Where is ACh released from?
A
- cholinergic n. fibers
- all preganglionic efferent autonomic fibers and postganglionic efferent autonomic parasympathetic fibers
- somatic n. fibers to skeletal M.
16
Q
Where is NE released from?
A
- adrenergic n. fibers
- postganglionic efferent autonomic sympathetic fibers
17
Q
How is ACh made?
A
choline + acetylCoA with choline O-acetyltransferase –> ACh
18
Q
Where is ACh synthesized?
A
- nerve fiber mitochondria
19
Q
Where is ACh stored in the presynaptic nerve?
A
- quanta in vesicles
20
Q
How is ACh released from the presynaptic nerve?
A
- action potential causes and influx of Ca2+
- Ca2+ interacts with vesicle containing ACh
- stimulates vesicle to fuse with membrane
- dumps ACh into synaptic cleft
21
Q
What does ACh do in the synaptic cleft?
A
- binds to and activates ACh receptors (ACh-R)
22
Q
How is ACh broken down in synaptic cleft?
A
- AChesterase
23
Q
What do adrenergic n. fibers release?
A
- NE
24
Q
What is the major function of adrenergic n. fibers?
A
- make adjustments in responses to stressful situations
- i.e. fight or flight
25
What are actions of the stimulation of adrenergic n. fibers?
- increased HR & BP
- mobilize energy stores
- increase blood flow to skeletal M.
- decrease blood flow to skin and internal organs
- dilate pupils and bronchioles
26
What is the nickname for the sympathetic nervous system?
- fight or flight
27
What is the nickname for the parasympathetic nervous system?
- rest & digest
28
How is adrenergic action terminated?
- NE metabolism
- diffusion
- reuptake
29
How is NE metabolized in the termination of an adrenergic stimulation?
- by catalytic enzymes
| - i.e. monoamine oxidase (MAO)
30
What are receptors?
- proteins designed to bind endogenous molecules
31
How to receptors bind with substrates?
- highly specifically
| - special interactions
32
What are two types of autonomic receptors?
- cholinergic
| - adrenergic
33
What are two types of cholinergic receptors?
- muscarinic
| - nicotinic
34
What are three types of adrenergic receptors?
- alpha 1 & 2
- beta 1 & 2
- dopamine
35
What do muscarinic and nicotinic receptors bind?
- only ACh
36
What do alpha and beta receptors bind?
- only NE
37
What are non-cholinergic, non-adrenergic ANS tissues?
- complex
38
Which branch of the ANS is known as trophotopic?
- parasympathetic
39
Which branch of the ANS is known as ergotrophic?
- sympathetic
40
What are the effects of the parasympathetic n on the cardiovascular system?
- decreased HR
41
What are the effects of the sympathetic n on the cardiovascular system?
- manages BP
- increased HR
- increased cardiac output
- venous tone via vasodilation
- renin produced to manage fluid vol.
42
How is the CV system mediated?
- feedback loop
43
How is the ANS function controlled?
- presynaptic regulation
- postsynaptic regulation
- other integrated systems
44
How is the presynaptic terminal regulated in the ANS?
- alpha 2 receptors
| - beta receptors
45
How do alpha 2 receptors regulate the presynaptic terminal in the ANS?
- present on presynaptic n.
- bind NE
- negatively feedback to decrease NE release
46
What is an autoreceptor?
- receptor that responds to NT release from the cell it is part of
47
What is a heteroreceptor?
- receptor that responds to NT released from other neurons
48
How do beta receptors regulate the presynaptic terminal in the ANS?
- increase NE release
49
How is the postsynaptic terminal regulated in the ANS?
- up/down regulation
| - action of one receptor is affected by the action of another receptor
50
What is up and down regulation?
- the body creates more receptors or destroys excess in response to drug levels over long periods of time
51
What happens when drugs are stopped abruptly when there has been up/down regulation?
- supereffect
52
What can be the result of a receptor blocked from stimulation of NE or ACh?
- opposite effect as if it had bound to the receptor
53
What does the sympathetic system do to the eye?
- pupillary dilation (contraction of iris M)
54
What does the parasympathetic system do to the heart?
- decrease HR
| - decrease contractility
55
What does the sympathetic system do to the blood vessels?
- vasocontraction and dilation based on which receptor is stimulated
56
What does the parasympathetic system do to the bronchioloar smooth M?
- contraction i.e. bronchoconstriction
57
What does the sympathetic system do to the GI tract?
- slows activity
| - blocks passage via contracted sphincters
58
What does the parasympathetic system do to the GI tract?
- increases activity
- opens passage via relaxed sphincters
- increases secretions
59
What does the sympathetic system do to the GU smooth M?
- prevents uriniation
60
What does the parasympathetic system do to the GU smooth M?
- facilitates urination
61
What is the effect of the ANS on the metabolic functions?
- sympathetic stimulates energy production and release
