Chapter 14 - ANS

Question 1

function of the autonomic nervous system

Answer 1

To control visceral functions and fine tune organs at the subconscious level to maintain homeostasis.
It can swing to the sympathetic or the parasympathetic depending on the body’s needs.

Question 2

Is the ANS primarily sensory or motor in function?

Answer 2

motor

Question 3

anatomical organization of the somatic nervous system (sns) vs the autonomic nervous system

Answer 3

Instead of one neuron from spinal cord (or brainstem) to effector, there are 2 – a preganglionic neuron from the spinal cord (or brainstem) to the autonomic ganglia and a ganglionic neuron from the ganglia to the effector.

Question 4

What structure is the major controller of the autonomic nervous system?

Answer 4

Hypothalamus

Question 5

What controls the somatic nervous system?

Answer 5

Cerebral Cortex

Question 6

What higher brain structures can have input on the master controller of the ans?

Answer 6

Cerebral cortex,
thalamus,
limbic system

Question 7

Where are the pre- & ganglionic (postganglionic) cell bodies?

Answer 7

Preganglionic neuron cell bodies are in the lateral gray horn of the spinal cord (or in cn nuclei in brainstem) and ganglionic neuron cell bodies are in the autonomic ganglia

Question 8

Where are the ganglia located (relative to the spinal cord & target organ)?

Answer 8

Sympathetic: sympathetic chain (very close to spinal cord and far from target), collateral ganglia (near spinal cord but closer to target) & adrenal medulla (far from spinal cord and can be far from target organ – releases its hormone into blood to reach target).

Parasympathetic: autonomic ganglia on or near the target organ

Question 9

What is the relative length of the preganglionic neuron to the ganglionic (postganglionic) neuron (which is long & which is short)?

Answer 9

Sympathetic: short pre and long post.
Parasympathetic: long pre and short post. exception sympathetic ns, adrenal medullae have long pre and short post to directly reach a distant target (adrenal gland)

Question 10

From what region of the cns does the motor information leave the cns?

Answer 10

Sympathetic: T1-L2. Parasympathetic: CN 3, 7, 9, & 10, and sacral segments S2-S4

Question 11

What are the physiological responses to stimulation by each division of the ans?

Answer 11

to be continued in next 9 cards……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

Question 12

Mental state

Answer 12

sympathetic heightened alertness

Question 13

Metabolic rate

Answer 13

sympathetic=increased, parasympathetic=decreased

Question 14

Pupil

Answer 14

sympathetic=dilated, parasympathetic=constricted

Question 15

Heart

Answer 15

sympathetic=increased hr & contractility, parasympathetic=decreased hr & contractility

Question 16

Lungs

Answer 16

sympathetic= dilation of respiratory passages, parasympathetic= constriction of respiratory passages

Question 17

Salivary glands

Answer 17

sympathetic=decreased saliva production (increased mucus component of saliva instead of liquid component, producing dry mouth),
parasympathetic=increased saliva production

Question 18

Sweat glands

Answer 18

sympathetic=increased sweat production

Question 19

Adrenal medullae

Answer 19

sympathetic=increased production of norpeinephrine/epinephrine for a whole body sympathetic response

Question 20

General digestive system

Answer 20

sympathetic=all digestive organ activity reduced,

parasympathetic=all digestive organ activity increased

Question 21

When is each division active?

Answer 21

Sympathetic = “fight or flight,” active when scared, exercising, or stressed. 
Parasympathetic = “rest and digest,” active when at rest and/or relatively relaxed, also post meal during resting conditions.

Question 22

What neurotransmitters are released by the preganglionic neurons?

Answer 22

Parasympathetic and sympathetic release acetylcholine (ach)

Question 23

What neurotransmitters are released by the ganglionic neurons?

Answer 23

Parasympathetic releases acetylcholine (ach) and the sympathetic releases norepinephrine

Question 24

Are the effects of the response short or long lived (relatively)? Why?

Answer 24

Sympathetic – relatively long because adrenal medulla gets stimulated releasing norepinephrine into the blood which travels to target cells of the body. The “hormonal” response takes awhile to be cleared from the blood.
Parasympathetic – short response because it is strictly neural and when stimulus is gone, response is gone.

Question 25

What is the body’s response to sympathetic activation?

Answer 25

Heightened mental alertness, increased metabolic rate, decreased digestive & urinary functions, energy reserves mobilized, dilated respiratory passageways, increased heartrate, contractility, and blood pressure, and increased sweat production, dilation of pupil

Question 26

How are structures of the head and lower lumbar/sacral regions reached if no sympathetic fibers emerge from the brainstem or sacral region of the spinal cord?

Answer 26

Preganglionic axons ascends up sympathetic chain to synapse with ganglionic neuron cell body in cervical ganglia to reach head structures or preganglionic axons descend down sympathetic chain to synapse with ganglionic neuron cell body in sacral ganglia to reach structures in the lumbar/sacral region

Question 27

What is the role of the sympathetic chain?

Answer 27

To provide a pathway to autonomic targets, including above T1 and below L2, and to serve an one of the 3 possible synapse sites for ganglionic sympathetic neurons

Question 28

How are abdominopelvic structures reached?

Answer 28

By way of the collateral ganglia, or lower pelvic are reached by lower sympathetic chain

Question 29

What is the role of the collateral ganglia?

Answer 29

To serve as synapse sites for ganglionic sympathetic neurons serving abdominal organs.

Question 30

Can neurotransmitter arrive in the blood?

Answer 30

YES

Question 31

Describe how neurotransmitter arrives in the blood: (know the trigger, the organ and the neurotransmitter)

Answer 31

Sympathetic activation of the adrenal medulla causes the release of norepinephrine into the blood.

Question 32

What is the length of this response to neurotransmitter in the blood?

Answer 32

Relatively long lived because neurotransmitter (acting as a hormone) is in the blood and it takes awhile to clear it from the blood.

Question 33

What is the body’s response to parasympathetic innervation to organs?

Answer 33

Constriction of pupils, secretion of digestive glands, secretions of hormones activating digestive processes, increased digestive tract smooth muscle activity, increased activity of waste removal: defecation and urination, constriction of respiratory passageways, reduction of heart rate

Question 34

Which cranial nerves contain preganglionic neurons?

Answer 34

CN 3, 7, 9 and 10

Question 35

i. What structures are targeted by these visceral motor neurons?

Answer 35

Pupil, salivary glands, and tear glands

Question 36

Which cranial nerve contains most of the parasympathetic fibers of the body?

Answer 36

Vagus Nerve (10)

Question 37

What is so goddamn important about the Vagus Nerve?

Answer 37

Controls 90% of parasympathetic outflow! Innervates most thoracic and abdominal organs!!!!!!!!!

Question 38

What major organs does the vagus nerve serve?

Answer 38

Heart, lungs, stomach, liver, gall bladder, intestines, pancreas, etc.

Question 39

What is the effect of the vagus nerve on the digestive organs and heart?

Answer 39

Stimulates digestive organs and inhibits heart activity

Question 40

What is meant by dual innervation by the autonomic nervous system?

Answer 40

Both parasympathetic and sympathetic often serve the same organs but have opposite functions. They can work together, but most often, one system governs.

Question 41

What is the enteric nervous system?

Answer 41

Division of ans that serves the digestive system

Question 42

What are visceral reflexes?

Answer 42

Similar to somatic reflexes except internal organs are “automatically” responding to internal conditions

Question 43

How are visceral long reflexes different from somatic reflexes?

Answer 43

Anatomically, they are structurally similar except there are 2 motor neurons from cns to effector instead of only one

Question 44

How are visceral short reflexes different from visceral long reflexes?

Answer 44

Visceral short reflexes do not go to cns and cause reflexive activity “locally” on or near organ