The Autonomic Nervous System Flashcards Preview

Pharmacology Test #2 > The Autonomic Nervous System > Flashcards

Flashcards in The Autonomic Nervous System Deck (64):
1

What are the 2 major components of the nervous system?

Brain

Nerves

2

How do nerves transmit info to the effector cells?

neurotransmiters

3

What are the two ways nervous system is classified?

By physical location

By function

4

How is the nervous system divided by physical location?

Central = brain and spinal cord

Peripheral = everything else

5

How is the nervous system divided by function?

Autonomic Nervous System

Somatic Nervous System

6

What does the Autonomic Nervous System do?

involves actions not under conscious control

controls visceral functions --> cardiac output, blood flow to vital organs, digestion

7

What does the Somatic Nervous System do?

Involves conscious functions

Movement, respiration, posture

8

How is the autonomic nervous system broken up?

Sympathetic = thoracolumbar

Parasympathetic = craniosacral

9

How does the autonomic nervous system exit the brain?

through preganglionic efferent nerve fibers

10

Where do the parasympathetic fibers exit the central nervous system?

exit through the cranial nerves and 3rd and 4th lumbar spinal nerves

11

Where do sympathetic fibers exit the central nervous system?

sympathetic fibers exit through thoracic and lumbar spinal nerves

12

Describe Efferent Nerves

Preganglionic neurons

Postganglionic neurons

13

Where do the preganglionic neurons originate and where do they go?

originate in the CNS and connect to ganglia in peripheral nervous system

14

What do postganglionic neurons do?

terminate on effector organs

15

What do the ganglia do?

act as relay stations to pass messages on to postganglionic nerves

16

What do afferent neurons do?

They regulate the autonomic nervous system by sensing actions and providing feedback to the CNS

bring info from effector organ to CNS

17

What are the neurotransmitters of the autonomic nervous system?

Acetylcholine

Norepinephrine

18

Which types of nerves release acetylcholine (ACh)?

cholinergic nerve fibers

ALL preganglionic efferent autonomic (sympathetic and parasympathetic) fibers

Somatic nerve fibers to skeletal muscles

19

Which types of nerves release norepinephrine?

adrenergic nerve fibers

MOST postganglionic sympathetic nerve fibers

20

What is the precursor molecule and enzyme that make ACh?

acetyl - CoA

O-acetyltransferase

21

Where is ACh synthesized in the nerve?

mitochondria

22

How is it stored in the nerve?

stored as packages of quanta in vesicles at the axon terminal

23

What stimulates the release of ACh?

Ca2+

24

What happens when ACh is released into the synaptic cleft?

binds to ACh - receptors

25

How is ACh action terminated?

Acetylcholinesterase (AChE) breaks down ACh --> choline and acetate

26

What happens if ACh isn't broken down?

continues to interact w/ receptors until it is broken down

27

Where are adrenergic nerve fibers found?

postganglionic neurons of the sympathetic nervous system

28

What do adrenergic nerve fibers do?

make adjustments in response to stressful situations

fight or flight

29

What are some of the actions of adrenergic nerve fibers?

increase HR and BP

mobilize energy stores

increase blood flow to skeletal muscles

divert blood flow from skin and internal organs

dilate pupils and bronchioles

30

Name the 3 ways norepinepherine is terminated?

metabolized by catalytic enzymes --> monoamine oxidase (MAO)

diffusion away from receptor site (then metabolized)

reuptake into terminal by norepinephrine transporter (NET) or other cells

31

What are receptors?

proteins that bind to endogenous molecules and then pass "message" to signaling proteins

32

What do agonists do?

mimic endogenous molecules that bind to receptors and produce signal

33

What do antagonists do?

they block signal

34

What are the two types of cholinergic receptors?

muscarinic receptors

nicotinic receptors

35

What are the 4 major adrenergic receptors?

alpha1 and alpha2 adrenoceptors

beta1 and beta2 adrenoceptors

36

Which system is the major target of the autonomic nervous system?

CV system

37

What are the CV effects of the parasympathetic nervous system?

decrease heart rate

38

What are the CV effects of the sympathetic nervous system?

alters periperal vascular resistance to manage BP

heart rate

contraction force to manage cardiac output

venous tone

renin production to manage renal blood flow

39

What is the point of the autonomic function?

prevent system from overstimulation

maintain effector organ functions w/ in a narrow window of tolerance

40

How is autonomic function controlled?

presynaptic regulation

postsynaptic regulation

other integrated systems

41

How is autonomic function regulated presynaptically?

alpha2 receptors present on some nerve terminals

bind norepinephrine released from some nerves and decrease amount of norepinephrine from same neuron

Beta receptors will facilitate release of more norepinephrine

42

How is autonomic function regulated postsynaptically?

2 mechanisms:

up or down regulate receptors

action of one receptor is affected by action of other receptors

43

Why does the body up or down regulate receptors?

in response to high or low activation from neurotransmitters

44

What are effector organs?

multiple receptor sites throughout the body

sensitive to adrenergic or cholinergic action

45

Are the actions of norepinephrine and acetylcholine opposing or synergistic?

Opposing

46

Name the effects of the autonomic nervous system on the iris radial muscle

Sympathetic: contracts (pupilary dilation) --> alpha1 receptors

Parasympathetic: NONE

47

Name the effects of the autonomic nervous system on the iris circular muscle

Sympathetic: NONE

Parasympathetic: Contracts (controls light entry and accommodation --> M3

48

Name the effects of the autonomic nervous system on the ciliary muscle

Sympathetic: Relaxes (allows for better focus on distance) --> Beta

Parasympathetic: Contrats (allows focus of near objects) --> M3

49

Name the effects of the autonomic nervous system on the sinoatrial node

Sympathetic: accelerates (increase HR - chronotropic) --> Beta1 and Beta2

Parasympathetic: decelerates (decrease HR) --> M2

50

Name the effects of the autonomic nervous system on the ectopic pacemakers

Sympathetic: acclerates (increases HR) --> Beta1 and Beta2

Parasympathetic: NONE

51

Name the effects of the autonomic nervous system on the Contractility

Sympathetic: increases (inotropic) --> Beta1 and Beta2

Parasympathetic: decreases --> M2

52

Name the effects of the autonomic nervous system on the blood vessels

Sympathetic:

Contract (vasocontriction; increase BP) --> alpha

Relaxes (vasodilation; decrease BP) --> Beta2

Parasympathetic: NONE

53

Name the effects of the autonomic nervous system on the Bronchiolar smooth muscle

Sympathetic: relaxes (open airways-bronchiodilation) --> Beta2

Parasympathetic: contracts (restricts airways -bronchoconstriction) --> M3

54

Name the effects of the autonomic nervous system on the smooth muscle walls of the GI

Sympathetic: relax (slows activity) --> alpha2 and beta2

parasympathetic: contract (increase activity) --> M3

55

Name the effects of the autonomic nervous system on the GI sphincters

Sympathetic: contract (blocks passage) --> alpha1

Parasympathetic: relax (opens passage) --> M3

56

Name the effects of the autonomic nervous system on GI secretion

Sympathetic: NONE

Parasympathetic: increases --> M3

57

Name the effects of the autonomic nervous system on the bladder wall

Sympathetic: relaxes (prevents urinatin) --> Beta2

Parasympathetic: contracts (facilitates urination) --> M3

58

Name the effects of the autonomic nervous system on the genitourinary sphincter

Sympathetic: contracts (blocks urination) --> alpha1

Parasympathetic: relaxes (facilitates urination) --> M3

59

Name the effects of the autonomic nervous system on the uterus

Sympathetic:

Relaxes --> Beta2

Contracts --> alpha

parasympathetic: NONE

60

Name the effects of the autonomic nervous system on the penis

Sympathetic: ejaculation --> alpha

Parasympethic: erection --> M3

61

Name the effects of the autonomic nervous system on the Liver

Sympathetic:

gluconeogenesis --> Beta2, alpha

glucogenolysis --> Beta2, alpha

Parasympathetic: NONE

62

Name the effects of the autonomic nervous system on fat cells

Sympathetic: Lipolysis --> Beta3

Parasympathetic: NONE

63

Name the effects of the autonomic nervous system on the Kidney

Sympathetic: Renin release --> Beta1

Parasympathetic: NONE

64

What are the 3 drug effects on neurotransmitters?

Alter: synthesis, storage, release

Terminate Action

Alter neurotransmitter receptors