Exam 3 - ANS - Neurotransmitters

Question 1

Autonomic neurons are classified into two groups based on the neurotransmitter they release:

Answer 1

Cholinergic neurons, which release the neurotransmitter acetylcholine (ACh)

Adrenergic neurons, which release the neurotransmitter norepinephrine (NE), AKA noradrenalin

Question 2

which release the neurotransmitter acetylcholine (ACh)

which release the neurotransmitter norepinephrine (NE), AKA noradrenalin

Answer 2

Cholinergic neurons,

Adrenergic neurons,

Question 3

Cholinergic neurons are:

All sympathetic and parasympathetic ___

All parasympathetic ____

Sympathetic postganglionic neurons that innervate most ____

Somatic nervous system _____

Answer 3

preganglionic neurons

postganglionic neurons

sweat glands

motor neurons

Question 4

ACh is stored in synaptic vesicles, released by exocytosis, and diffuses across the synaptic cleft to bind with cholinergic receptors, causing either

Answer 4

excitation or inhibition of the postsynaptic cell

Question 5

Look at slide 4 for comparison of motor pathways

Answer 5

Nice

Question 6

most effector tissues are para or sympathetic?

Answer 6

Sympathetic

Question 7

most sweat glands are para or sympathetic?

Answer 7

Sympathetic

Question 8

Nicotonic receptors to muscarinic receptors

Answer 8

parasympathetic

Question 9

Adrenergic neurons are most sympathetic …

Answer 9

postganglionic neurons

Question 10

NE is stored in synaptic vesicles, released by exocytosis, and diffuses across the synaptic cleft to bind with adrenergic receptors where it causes either

Answer 10

excitation or inhibition of the effector cell

Question 11

look at slide 9 of ppt

Answer 11

do it!

Question 12

Different types of cholinergic receptors and different types of adrenergic receptors found in the various postsynaptic cells are largely responsible for the variety of responses elicited by…

Answer 12

binding of the neurotransmitter ligand with the receptor

Question 13

Cholinergic receptors are _____ in the postsynaptic plasma membrane

All cholinergic receptors bind ____

There are two types of cholinergic receptors:

Answer 13

integral membrane proteins

acetylcholine

two types: nicotinic and muscarinic

Question 14

named because nicotine mimics the action of ACh by binding to this type of receptor

Answer 14

Nicotinic receptors

Question 15

named because nicotine mimics the action of ACh by binding to this type of receptor

Answer 15

Nicotinic receptors

Question 16

named because a mushroom poison called muscarine binds to them and mimics the action of ACh

Answer 16

Muscarinic receptors

Question 17

Cholinergic Receptors:

Cross-reactivity between nicotinic or muscarinic?

Answer 17

Nicotine does not activate muscarinic receptors

Muscarine does not activate nicotinic receptors

Question 18

Cholinergic Receptors:

______ activates both types of cholinergic receptor

Since acetylcholine is quickly inactivated by acetylcholinesterase, the effects triggered by cholinergic neurons are ____

Answer 18

Acetylcholine

brief

Question 19

Activation of nicotinic receptors by acetylcholine causes depolarization (therefore excitation) of the postsynaptic cell:

Answer 19

Excitation of a postganglionic neuron

Excitation of a skeletal muscle fiber

Question 20

Activation of ______ by acetylcholine sometimes causes depolarization (excitation) and sometimes causes hyperpolarization (inhibition)

Answer 20

Muscarinic receptors

Question 21

Muscarinic receptors:

The effect depends on the postsynaptic cell—in some cell types it causes inhibition, and in other cell types it causes excitation:

Answer 21

Binding of ACh to muscarinic receptors of smooth muscle sphincters in the gastrointestinal tract causes them to relax

ACh causes sphincter muscles of the eye to contract

Question 22

Binding of ACh to _____ receptors of smooth muscle sphincters in the gastrointestinal tract causes them to relax

Answer 22

muscarinic

Question 23

In muscarinic receptors, ACh causes sphincter muscles of the eye to ____

Answer 23

contract

Question 24

Activation of muscarinic receptors, defecation

Answer 24

relaxation

Question 25

Activation of muscarinic receptors, miosis

Answer 25

contraction

Question 26

Activation of muscarinic receptors causes DUMBELS syndrome:

Answer 26

Defecation, Urination, Miosis, Bronchoconstriction, Emesis, Lacrimation, Salivation - This is consistent with the previous slide, which stated: - Binding of ACh to muscarinic receptors of smooth muscle sphincters in the gastrointestinal tract causes them to relax - ACh causes sphincter muscles of the eye to contract

Question 27

Review Slides 16, 17, and 18 and the associated diagrams

Answer 27

DO IT!

Question 28

Activation of nicotinic receptors by ACh causes depolarization (excitation), whereas activation of muscarinic receptors by ACh...

Answer 28

...sometimes causes depolarization (excitation) and sometimes causes hyperpolarization (inhibition)

Question 29

Adrenergic receptors are integral membrane proteins in the postsynaptic plasma membrane All adrenergic receptors bind both ____ Adrenergic receptors are activated by . . .

Answer 29

norepinephrine and epinephrine Norepinephrine released by sympathetic postganglionic neurons Epinephrine and norepinephrine released as hormones into the blood by the adrenal medulla

Question 30

There are two types of adrenergic receptors:

Answer 30

α receptors | β receptors

Question 31

Adrenergic receptor activity The receptors are further classified into subtypes based on responses they elicit and drugs that activate or block them:

Answer 31

α1 and α2 β1, β2, and β3 Activation of subscript 1 receptors (α1 and β1) is usually excitatory Activation of subscript 2 receptors (α2 and β2) is usually inhibitory β3 is found only on cells of brown adipose tissue, where activation causes thermogenesis

Question 32

Activation of subscript 2 receptors (α2 and β2) is usually

Answer 32

inhibitory

Question 33

β3 is found only on cells of

Answer 33

brown adipose tissue, where activation causes thermogenesis

Question 34

activation of β3 causes:

Answer 34

thermogenesis

Question 35

activation of β3 causes:

Answer 35

thermogenesis

Question 36

Norepinephrine activity ends when it is either Taken up by the axon that released it (reuptake) Enzymatically inactivated by . . .

Answer 36

``` Catechol-O-methyltransferase (COMT) Monoamine oxidase (MAO) ```

Question 37

Norepinephrine lingers in the synaptic cleft longer than does acetylcholine, meaning...

Answer 37

effects triggered by adrenergic neurons usually last longer than effects due to cholinergic neurons

Question 38

is a substance that binds to a receptor and triggers a response in the cell.

Answer 38

agonist

Question 39

also binds to the receptor, but it fails to activate the receptor and actually blocks the receptor from activation by agonists.

Answer 39

antagonist

Question 40

activates a receptor but does not cause as much of a physiological change as does a full agonist.

Answer 40

partial agonist

Question 41

The receptors of the human body work by being stimulated or inhibited by natural agonists and antagonists (such as hormones and neurotransmitters), or synthetic agonists and antagonists (such as drugs)

Answer 41

You're on your way to being a PA!

Question 42

___receptors are located predominantly in the heart.

Answer 42

β1

Question 43

When adrenalin (norepinephrine and epinephrine released by the adrenal medulla) binds to β1 receptors,

Answer 43

the heart rate and strength of contraction are increased.

Question 44

α1 receptors are located in blood vessels of virtually all sympathetic target organs except the heart. When adrenalin (norepinephrine and epinephrine released by the adrenal medulla) binds to α1 receptors,

Answer 44

blood vessels and visceral organ sphincters constrict (but the pupils of the eye dilate).

Question 45

Alpha blockers are adrenergic blockers that attach mainly to the α1 receptors of veins and arteries. They "block" the effects of adrenalin on α1 receptors, relaxing the muscles that constrict blood vessels, allowing blood to pass more easily.

Answer 45

Pharmacological Application— Alpha blockers

Question 46

Alpha blockers are adrenergic blockers that attach mainly to the α1 receptors of veins and arteries. They "block" the effects of adrenalin on α1 receptors, relaxing the muscles that constrict blood vessels, allowing blood to pass more easily.

Answer 46

Pharmacological Application— Alpha blockers

Question 47

Dual innervation Most body organs receive innervation from both divisions of the ANS The divisions generally work _____

Answer 47

in opposition to each other

Question 48

The balance between sympathetic and parasympathetic activity is called

Answer 48

autonomic tone

Question 49

Autonomic tone is regulated by the

Answer 49

hypothalamus.

Question 50

Usually when the activity of one division is increased....

Answer 50

the activity of the other is decreased

Question 51

The two divisions of the ANS affect body organs differently because...

Answer 51

The postganglionic neurons release different neurotransmitters Effector organs possess different adrenergic and cholinergic receptors

Question 52

Dual innervation Rather than thinking of the two ANS divisions as antagonistic, consider of them to be complementary.

Answer 52

The sympathetic division is the accelerator and the parasympathetic is the brake. Interaction between the two is required to drive the car

Question 53

Single Innervation: Some structures receive only sympathetic innervation:

Answer 53

``` Sweat glands Arrectores pilorum muscles Kidneys Adrenal glands (adrenal medullae) Spleen Blood vessels in general ``` There is no corresponding parasympathetic innervation in those structures The decrease in sympathetic tone suffices to decrease effects of sympathetic activation

Question 54

The sympathetic division dominates the parasympathetic division during physical or emotional stress:

Answer 54

The body preferentially requires functions that support vigorous physical activity and rapid production of ATP It does not need functions that favor the storage of energy

Question 55

The sympathetic division can be thought of as the E division:

Answer 55

Exercise, Excitement, Emergency, Embarrassment

Question 56

Activation of the sympathetic division and release of adrenal medulla hormones initiates a series of effects collectively called the fight or flight response:

Answer 56

Pupils dilate Heart rate, force of heart contraction, and blood pressure increase Airways dilate Blood vessels in abdominal viscera (such as kidneys and gastrointestinal tract) constrict Blood vessels in skin constrict (skin becomes pale) Blood flow to skeletal muscles increases Blood glucose level rises as liver cells perform glycogenolysis Gastrointestinal tract movements slow and digestive secretions decrease

Question 57

Effects of sympathetic stimulation last longer, and are more widespread than parasympathetic stimulation:

Answer 57

More extensive divergence of sympathetic postganglionic axons means more tissues are activated simultaneously Acetylcholine is rapidly degraded by acetylcholinesterase. Norepinephrine remains in the synaptic cleft longer Epinephrine and norepinephrine are secreted into the blood from the adrenal medulla, intensifying and prolonging responses due to NE released from sympathetic postganglionic neurons

Question 58

Parasympathetic responses are characterized by the acronym SLUDD:

Answer 58

``` Salivation Lacrimation Urination Digestion Defecation ``` The parasympathetic division enhances “rest and digest” activities

Question 59

Autonomic reflexes are responses that occur when nerve impulses.... Autonomic reflexes are central in regulating...

Answer 59

pass over an autonomic reflex arc conditions in the body

Question 60

The overall components of an autonomic reflex arc are the same as a somatic reflex arc:

Answer 60

``` Sensory receptor Sensory neuron Integrating center Motor neurons Effector ```

Question 61

The receptor in an autonomic reflex arc is the ____ end of a ____ neuron It responds to a stimulus, and produces a change that will eventually trigger nerve impulses

Answer 61

distal sensory

Question 62

Autonomic sensory receptors are generally

Answer 62

interoceptors

Question 63

Sensory neuron: The sensory neuron conducts nerve impulses from receptors to the CNS Visceral sensory neurons carry information concerning...

Answer 63

...chemical changes, stretch, and irritation of the viscera

Question 64

Sensory neuron: Cell bodies of visceral sensory neurons are located in the sensory ganglia of....

Answer 64

associated cranial nerves or in the dorsal root ganglia of the spinal cord.

Question 65

Integrating center Interneurons in the CNS relay signals from....

Answer 65

...sensory neurons to motor neurons

Question 66

The main integrating centers for most autonomic reflexes are in the hypothalamus and brain stem, but some integrating centers are....

Answer 66

in the spinal cord

Question 67

Efferent impulses from the integrating center propagate out of the CNS along...

Answer 67

... motor neurons

Question 68

Two motor neurons connect the CNS to the effector (the rule for the ANS):

Answer 68

Preganglionic neuron Conducts motor impulses from CNS to an autonomic ganglion and is Myelinated Postganglionic neuron Conducts motor impulses from ganglion to effector Unmyelinated

Question 69

Two motor neurons connect the CNS to the effector (the rule for the ANS):

Answer 69

Preganglionic neuron | Postganglionic neuron

Question 70

Conducts motor impulses from CNS to an autonomic ganglion and is Myelinated

Answer 70

Preganglionic neuron

Question 71

Conducts motor impulses from ganglion to effector | Unmyelinated

Answer 71

Postganglionic neuron

Question 72

Effectors in an autonomic reflex are:

Answer 72

Smooth muscle Cardiac muscle Glands The reflex is called an autonomic reflex

Question 73

We are not usually aware of autonomic activities because...

Answer 73

the integrating centers for autonomic responses are in the spinal cord or the lower regions of the brain

Question 74

Autonomic control by higher centers The major control and integration center of the ANS is the hypothalamus, which . . .

Answer 74

Receives sensory input Provides output to autonomic centers in the brain stem and spinal cord Is connected to both the sympathetic and parasympathetic divisions of the ANS

Question 75

Polygraph testing: The fact that most autonomic responses can not be consciously altered or suppressed to any great degree is the basis for polygraph (“lie detector”) tests, which take advantage of changes in certain body parameters when someone is under duress—the stress or anxiety associated with lying

Answer 75

Sweating Depth and rate of breathing Heart rate Blood pressure

Question 76

Information about a body parameter obtained by monitoring devices and displayed to the person being monitored provides ____, and may enable the individual to learn to exercise a degree of conscious control over the parameter monitored Biofeedback has been found to be effective for the treatment of headaches and migraines

Answer 76

biofeedback

Question 77

In Raynaud disease the digits (fingers and toes) become ischemic (lack of blood) after exposure to cold or with emotional stress The condition is due to....

Answer 77

....excessive sympathetic stimulation of smooth muscle in the arterioles of the digits

Question 78

_____ is an anticholinesterase drug. It inhibits the enzyme acetylcholinesterase, thus preventing enzymatic breakdown of ACh and allowing it to accumulate in the synapses

Answer 78

Neostigmine

Question 79

_____ is used to treat myasthenia gravis, a condition in which skeletal muscle activity is impaired for lack of ACh stimulation

Answer 79

Neostigmine

Question 80

treats myasthenia gravis and helps inhibit acetylcholinesterase

Answer 80

Neostigmine

Question 81

treats myasthenia gravis and helps inhibit acetylcholinesterase

Answer 81

Neostigmine

Question 82

______ help relieve depression because they prolong the activity of norepinephrine on the postsynaptic membrane (NE is frequently classified as a “feel good” neurotransmitter) Tricyclic antidepressants have the brand names Elavil and Sinequan

Answer 82

Tricyclic antidepressants

Question 83

_______ inactivates norepinephrine released into synapses of postganglionic sympathetic division neurons

Answer 83

Monoamine oxidase

Question 84

MAO inhibitors help relieve depression because they...

Answer 84

...prolong the activity of norepinephrine on the postsynaptic membrane (NE is frequently classified as a “feel good” neurotransmitter)