Autonomic Nervous System

Question 1

What does the autonoic nervous sytem control?

Answer 1

the visceral organs

Question 2

What is the goal of the autonomic nervous system?

Answer 2

Concerned with the maintenance of homeostasis

Question 3

What are the three division of the autonomic nervous system?

Answer 3

1. Sympathetic system
2. Parasympathetic system
3. Enteric System

Question 4

How ar ethe parasympathetic and sympathetic systems related?

Answer 4

Both of these systems are outputs that come out from the CNS and work together to maintain homeostasis

Question 5

T/F:The parasympathetic and sympathetic systems typically do the opposite?

Answer 5

True

Question 6

Where is the enteric system and what does it do?

Answer 6

Lines the entire digestive tract and controls the contractions of the GI tract and secretion of susbtances into the GI tract

Question 7

When is the sympathetic system activated?

Answer 7

During fight or flight situations

Question 8

When is the parasympathetic system activated?

Answer 8

When you are resting

Question 9

What does the sympathetic system cause?

Answer 9

-Increased heart rate
-Pupil dilation
Sweating

Question 10

What does the parasympathetic system cause?

Answer 10

-Increased contraction in the digestive tract
-Slows down heart rate
-Slows breathing

Question 11

Are the sympathetic and parasympathetic systems always active?

Answer 11

Yes, but one can be more active during specific situations

Question 12

What are the two neurons of the sympathetic system?

Answer 12

1. Preganglionic neuron
2. Postganglionic neuron

Question 13

Where does the preganglionic neuron of the sympathetic system originate and where deos its axon exit?

Answer 13

-Originates in the middle of the gray matter of the spinal cord
-Axon exits through the ventral root of the spinal cord and then synapses with the postganglionic neuron

Question 14

Where is the postganglionic neuron of the sympathetic system located and describe the axon?

Answer 14

-Originates just outside the spinal cord
-Long axon extend to the target

Question 15

What is a ganglion?

Answer 15

Organized cluster of neuron cell bodies in the PNS

Question 16

What is the sympathetic ganglia and where is it located?

Answer 16

Located at the postganglionic neuron

Question 17

What portions of the spinal cord are the preganglionic sympathetic neurons located?

Answer 17

Lumbar and thoracic

Question 18

WHat axons share the ventral root with the axons of the preganglionic neurons of the sympathetic system?

Answer 18

Motor neuron axons

Question 19

Describe the sympathetic ganglia

Answer 19

-Run along either side of the spinal cord
-Have connections between them which results in the sympathetic system getting activated all together

Question 20

Describe what happens when the preganglionic neuron of the sympathetic system fires an action potential?

Answer 20

1. Preganglionic neuron fires an action potential
2. This will release acetylcholine which will activate nicotinic receptors on the postganglionic neuron dendrites(excitatory)
3. Ion channels will open and Na+ will flow in and depolarize the neuron and then it will fire an action potential
4. Action potential will cause the release of norepinephrine on the target.
5. Norepinephrine will activate adrenergic receptors on the target and affects the physiology of the target cell

Question 21

What are the two types of adrenergic receptors?

Answer 21

1. Alpha-adrenergic receptors
2. Beta-adrenergic receptors

Question 22

What type of receptors are the adrenergic receptors?

Answer 22

Metabotropic since they trigger a biochemical event inside the heart that produces secondary messenger molecules

Question 23

T/F: The activation of adrenergic receptors by Norepinephrine depend on the type of cell that it targets?

Answer 23

True
In the heart it causes the heart rate to increase
In the bronchial tube it causes the smooth muscle to relax (epi pen)

Question 24

Beta-blockers?

Answer 24

Prevent nervousness by preventing the binding of norepinephrine to beta adrenergic receptors and preventing increase in heart rate

Question 25

Where are the preganglionic neurons of the parasympathetic system originating and where do their axons exit?

Answer 25

Brainstem -Their axons exit through nerves in the brainstem and they are very long and synapse onto the postganglionic neurons

Question 26

Where are the postganglionic neurons of the parasympathetic system?

Answer 26

-Near the target, has a short axon

Question 27

Are the parasympathetic ganglia lined up ?

Answer 27

No, since the postganglionic neurons are at there targets which are all over the body This means the parasympathetic system is not all activated at once instead it is activated in a more selective way

Question 28

Describe what occurs once the preganglionic neuron of the parasympathetic system fires an action potential?

Answer 28

1. Preganglionic neuron fires an action potential 2. Releases acetylcholine which binds to nicotinic receptors on the postganglionic neuron 3. That neuron then fires an action potential which will also release acetylcholine 4. Acetylcholine will then activate muscarinic acetylcholine receptors (found on visceral organs)

Question 29

What type of receptors are muscarinic receptors?

Answer 29

Metabotropic, activate the production of secondary messenger molecules

Question 30

What is the vagus nerve?

Answer 30

Cranial nerve, axon of preganglionic parasympathetic output goes through the nerve

Question 31

How are cardiac contractions affect by the activation of the sympathetic system?

Answer 31

-Contractions get larger and faster

Question 32

How are the cardiac contractions affected by the activation of the parasympathetic system?

Answer 32

-Contractions slow down and are less forceful

Question 33

Can the enteric system function without inputs from the rest of the nervous system?

Answer 33

Yes

Question 34

Who does the enteric system recieve inputs from ?

Answer 34

Parasympathetic and sympathetic systems

Question 35

How do the parasympathetic and sympatheitc systems regulate the enteric system during stress?

Answer 35

Sympathetic system will be active and enteric system will slow down digestion (can digest food later when the stressor is gone)

Question 36

What does the enteric system do?

Answer 36

Controls the contraction of the smooth muscle in thr GI tract

Question 37

How does the enteric system respond to norepinephrine?

Answer 37

Since norepinephrine is comparable to the sympatheitc system it will cause the enteric system to contract smooth muscle less

Question 38

How does the enteric system respond to acetylcholine?

Answer 38

Since acetylcholine is comparable to the parasympathetic system this will cause the enteric system to contract smooth muscle more

Question 39

What are the two layers of neurons in the intestine?

Answer 39

1. Myenteric plexus 2. Submucous plexus

Question 40

What does the submucous plexus of neurons control?

Answer 40

Regulates the secretion of various digestive enzymes and substances into the inside of the intestine

Question 41

What does the myenteric plexus of neurons do?

Answer 41

Innervates the smooth muscle and regulates the contractions

Question 42

What are the two layers of smooth muscle in the small intestine?

Answer 42

1. Circular smooth muscle(contraction of intestine inward) 2. Longitudinal smooth muscle(contraction of smooth muscle longitudinally)

Question 43

Why does the autonomic system need sensory inputs?

Answer 43

Need to know whats going on outside of the body in order to maintain homeostasis inside the body

Question 44

How does sensory information from the visceral organs reach the CNS?

Answer 44

1. Through the vagus nerve 2.By inputs to the spinal cord

Question 45

What is the role of the brainstem in sensory input and the autonomic nervous system?

Answer 45

1. The brainstem integrates visceral sensory inputs and autonomic outputs and project to higher brain centers involved in homeostasis

Question 46

Master controller of homeostasis?

Answer 46

Hypothalamus

Question 47

What is a nucleus?

Answer 47

Organized cluster of neurons in the CNS

Question 48

What is the role of the hypothalamus?

Answer 48

Monitors what is going inside the body and controls homeostasis through three different output pathways

Question 49

What three pathways does the hypothalamus use to maintain homeostasis?

Answer 49

1. Autonomic nervous system 2. Endocrine system 3. Behavioural system

Question 50

what are the five basic needs that the hypothalamus regulates?

Answer 50

1. Blood pressure and electrolyte balance 2. Body temperature 3. Energy metabolism 4. reproduction 5. Emergency response to stress

Question 51

T/F: The hypothalamus regulates the brainstem which is regulating outputs?

Answer 51

True

Question 52

How does the hypothalamus work when you are cold?

Answer 52

The hypothalamus has a set point of 37 if your body is 35 then the hypothalamus will send outputs to bring body temp. back up. Will communicate with the enodcrine system to release thyroxine. Will communicate with the cerebral cortex to make you feel uncomfortable and motivated to put on a sweater. Will communicate with the autonomic nervous system by making you shiver

Question 53

What happens to the hypothalamus when you have a fever?

Answer 53

1. Set point is increase by immune system to 40 2. Now you get chills because your body temp. is 37 3. When you break the fever the set point goes back to 3 4. Now you have sweats because body temp is still 40

Question 54

What does the amygdala do ?

Answer 54

Involved in the connections between feelings and physiological states and their relation to learning

Question 55

Amygdala and cerabral cortex interact with the hypothalamus and autonomic nervous system which relates the visceral responses to concious feelings and connects emotions to memories

Answer 55

Yes