(Lesson 19) Chapter 16: Sympathetic & parasympathetic Divisions Flashcards
(112 cards)
1
Q
How does the somatic nervous system operate?
A
The somatic nervous system operates under conscious control
2
Q
What type of muscles does the SNS control?
A
The skeletal muscle
3
Q
In addition to controlling skeletal muscles, what other function does the SNS serve for the body.
A
It affects long term survival
4
Q
How does the autonomic nervous system operate?
A
It operates automatically
5
Q
What does the ANS control?
A
ANS controls visceral effectors
(adipocytes, smooth/cardiac muscles, glands)
6
Q
Which systems does the ANS coordinate?
A
The ANS coordinates
1. Cardiovascular
2. Respiratory
3. DIgestive
4. Urinary
5. Reproductive
7
Q
What makes up the organization of the ANS?
A
- Integrative centers
- Visceral motor neurons
8
Q
Integrative centers
A
autonomic act. = hypothalamus
9
Q
Integrative centers
A
autonomic act. = hypothalamus
10
Q
Where are Visceral motor neurons found?
A
Found in brain & spinal cord (also known as preganglionic neurons)
11
Q
Preganglionic fibers
A
Axons of preganglionic neurons leave CNS and synapses on ganglionic neurons
12
Q
(Visceral motor neurons)
Autonomic ganglia
A
- Contains many ganglionic neurons
- Ganglionic neurons innervate viscereal effector
13
Q
Postganglionic fibers
A
Axons of ganglionic neurons
14
Q
What are the 2 divisions of the ANS?
A
- Sympathetic division
- Parasympathetic
15
Q
What’s the difference between parasympathetic and sympathetic?
A
Sympathetic increases alertness, HR, and muscular abilities (flight/fight). On the other hand parasympathetic relaxes the body during restful conditions, such as reduction of HR.
16
Q
Can the two divisions work together?
A
Yes the divisions could work independently or they could work together, with each division in charge of a specific process.
17
Q
Characteristics that make up the sympathetic division?
A
- Preganglionic fibers (thoracic and superior lumbar spinal segs.) synapse in ganglia near spinal cord.
- Preganglionic fibers are short
- Post ganglionic are long
- Prepares the body for crisis.
18
Q
What is the exception for having a long postganglionic fiber w/ the sympathetic division?
A
At adrenal medulla
19
Q
What are the 7 responses to increased sympathetic activity?
A
- Heightened mental alertness
- Increase metabolic rate
- Reduced digestive and urinary function
- Energy reserve activated
- Increased respiratory rate and respiratory passageways dilate.
- Increased HR & BP
- Sweat glands activated.
20
Q
What are the characteristics that make up the parasympathetic division?
A
- Preganglionic fibers that originate in the brain stem & sacral segments of the spinal cord
- Synapses in ganglia close to or within target organs.
- Preganglionic fibers are long & postganglionic are short.
- Parasympathetic division stimulates visceral activity
- Conserves energy and promotes sedentary activities.
21
Q
What are the 5 responses to increased parasympathetic activity?
A
- Decreased metabolic rate
- Decrease HR and BP
- Increase secretion of salivary and digestive glands
- Increase motility (movements of material in digestive tract) and blood flow in digestive tract
- Urination & defecation stimulation.
22
Q
Parasympathethic =
A
Craniosacral division
23
Q
Sympathetic=
A
Thoracolumbar division
24
Q
What is the 3rd division of the ANS?
A
The enteric nervous system
25
What are the characteristics that make up the ENS?
1. Extensive network in digestive tract walls
2. Complex visceral reflexes coordinated locally (heavily influenced)
3. Roughly 100 million neuron
4. All neurotransmitters are found within this system.
26
How many neurons are found in sensory & motor neurons?
Sensory= 10 million
Motor= 0.5 million
27
Where is the sympathetic division located?
1. The sympathetic division between segments T1 and L2 of the spinal cord
2. Ganglionic neurons in ganglia near vertebral column
3. Cell bodies of preganglionic neurons in lateral gray horns of spinal cord.
28
Where do ganglionic neurons occur?
Occur in 3 locations
1. Sympathetic chain ganglia
2. Collateral ganglia
3. Adrenal medullae
29
The sympathetic chain ganglia is located in?
1. Both sides of the vertebral column
30
The sympathetic chain ganglia controls effectors within the:
1. Body wall
2. Inside the thoracic cavity
3. In heads
4. In limbs
31
Collateral ganglia
1. are anterior to vertebral bodies
2. Contain ganglionic neurons that innervate tissues and organs in abdominopelvic cavity.
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3. Adrenal medullae
1. Very short axons
2. When stimulated releases neurotransmitters into blood stream.
3. Function as hormones to affect target cells throughout body
36
What hormones does adrenal medullae release into the blood stream?
The adrenal medullae releases the hormones epinephrine & norepinephrine into the bloodstream
37
Organization & anatomy of the sympathetic division?
1. Ventral roots of spinal segments T1-L2 contain sympathetic preganglionic fibers
2. Give rise to myelinated white ramus
3. Carry myelinated preganglionic fibers into sympathetic chain ganglion
4. May pass through sympathetic chain ganglion and synapse at collateral ganglia or in adrenal medullae.
38
What are the physical characteristics that make up neural tissue?
1. Extremely delicate
2. Extracellular environment must maintain homeostatic limits
3. If regulatory mechanisms breakdown, then this results in neurological disorders.
39
When do neurological disorders appear?
They appear why regulatory mechanisms break down.
40
What functions does the nervous system serve?
(The orchestra conductor of the body)
1. It monitors all other systems
2. Issues commands that adjust their activities (like a conductor)
41
What are the effects of anatomical changes in the NS?
1. Linked to functional changes
2. Neural processing becomes less efficient w/ age
3. Memory consolidation become more difficult
4. Secondary memories become harder to access
42
The effects of anatomical change to the NS w/ sensory systems?
1. loss in acuity of hearing, balance, vision, smell, and taste
2. Reaction time slows down
3. Weakened reflexes or being to disappear.
43
Impact of motor control on the NS with aging
1. Precision decreases
2. Takes longer to perform
44
What is incaptation and which age group does it impact?
Incapacitation means that the individual's NS can no longer function adequately to fulfill daily activities. It generally impacts the elderly or those have have suffered CNS damage.
45
Due to aging, do the elderly experience neurological changes that interfere with their abilities to perform their daily tasks?
Approximately 85% of elderly population develop changes that do NOT interfere with their abilities to perform daily tasks.
46
What is senility?
AKA senile dementia
Senility are degenerative changes that include
1. Memory loss
2. Anterograde amnesia
3. Emotional disturbances
4. Alzheimer's disease.
47
What are some potential intracellular & extracellular changes that can occur in CNS neurons?
1. Plaques
2. Tangles
3. Lipofuscin
4. Neurofibrillary tangles
48
What are lipofuscin?
Granular pigment w/ no known function
49
What are neurofibrillary tangles?
Masses of neurofibrils form dense math inside cell body & axon.
50
How do plaques fall into extracellular changes in the CNS?
They are extracellular accumulations of fribrillar proteins that surround abnormal dendrites and axons.
51
What's considered a change to the synaptic organization of the brain?
1. Number of dendritic branches, spines, and interconnections decreases
2. Synaptic connections lost
3. Rate of neurotransmitter production declines.
51
What's considered a change to the synaptic organization of the brain?
1. Number of dendritic branches, spines, and interconnections decreases
2. Synaptic connections lost
3. Rate of neurotransmitter production declines.
52
What are the possible consequences of reducing the flow of blood in the brain?
1. Arteriosclerosis
2. Cerebrovascular accident (CVA) or stroke
53
Explain what occurs during arteriosclerosis.
1. Fatty deposits in walls of blood vessels.
2. increases chance of rupture
3. decreases blood flow through arteries
54
List the common age-related anatomical changes that can occur in the nervous sys.
1. Reduction in brain size and weight
2. Reduction in number of neurons
3. Decrease in blood flow to the brain
4. Changes in synaptic organization of brain
5. Intracellular and extracellular changes in CNS neurons.
55
At what age do anatomical and physiological changes begin to occur?
The changes begin after brain has reached maturity. This is generally around the age of 30.
56
Approximately what percent of the elderly population experience changes in mental performance and CNS function?
About 85% percent of people over the age of 65.
57
Do anatomical and physiological changes occur right away?
No they do no occur right away, unless due to an accident. Generally, the changes accumulate over time.
58
Explain what occurs when the brain begins to reduce in size and weight.
1. Decrease in volume of cerebral cortex
2. Narrower gyri and wider sulci
3. Larger subarachnoid space (bc brain matter is shrinking)
59
Is it possible for the brain to lose neurons as one gets older?
Yes, it is possible.
Brain shrinkage is linked to the loss of cortical neurons. However, there's no neuronal loss in brain stem nuclei.
60
Where do plaques and tangles appear?
Appear in brain regions, such as the hippocampus that is specifically associated with memory processing.
61
How does alzheimer's disease correlate with plaques and tangles of neurons?
Alzheimer's is correlated with abnormal plaques and neurofibrillary tangle sin brain areas involved with memory, emotions, intelligence.
62
What factors contribute to alzheimer's?
Genetic factors play a major role.
63
What areas of the brain does alzheimer's impact?
The areas that focus on:
1. Memory
2. Emotions
3. Intelligence
64
What do tangles and plaques contain?
1. deposits of several peptides
2. Primarily two forms of amyloid B (Aß) protein.
65
Why are autonomic tones so important?
They maintain a background sympathetic tone that keeps muscles partially contracted.
66
How does the autonomic tone help increase flow?
1. Rate of NE release decreases
2. Sympathetic cholinergic fibers are stimulated (releasing ACh)
3. Smooth muscle cells (lining the blood vessel) relax
4. Vessels dilate & blood flow increases
67
What is blood vessel diameter regulated by which division?
It's regulated by the sympathetic division and not innervated by the parasympathetic division.
68
What occurs during autonomic tone?
1. Blood vessel dilates and blood flow increase
2. Blood vessel constricts and blood flow is reduced
3. Sympathetic postganglionic fibers release NE.
69
The postganglionic fibers are able to innervate which organs with the sympathetic nerves?
Innervates heart, lungs, and other structures in thoracic cavity.
70
When does sympathetic activation occur?
It activates the entire sympathetic division during a time of crisis.
71
During sympathetic activation how does the activity of tissues and organs change?
1. Release NE at peripheral synapses
2. Target specific effectors, smooth muscle fibers in blood vessels of skin.
3. Are activated in reflexes.
***Do not involve visceral effectors***
72
What are changes caused by the sympathetic activation
1. Increased alertness- stimulates reticular activating sys.
2. Feelings of energy and euphoria
3. Change in breathing.
4. Elevation in muscle tone
5. Mobilization of energy reserves.
73
Ganglionic neurons:
axon terminal
1. Form branching networks of telondria instead of synaptic terminals
2. As a result, telondria form sympathetic varicosities.
74
What are the 3 main types of Beta receptors?
1. Beta-1: hyper
2. Beta-2: relax
3. Beta-3: fat
75
What is reaction of Beta-1?
(hyper)
Increase metabolic rate
(increase activity of skeletal and cardiac muscle)
76
What is the reaction of Beta-2?
(relax)
Trigger relaxation of smooth muscles along respiratory tract- increases diameter of air passages
77
What is the reaction of B-3?
(fat)
Leads to lipolysis (the breakdown of tryglicerides in adipocytes) which releases nutrients into bloodstream
78
Where are the autonomic nuclei contained?
1. Contained in the mesencephalon, pons, and medulla oblongata (brain stem)
79
What cranial nerves are the autonomic nuclei associated with?
The cranial nerves are associated with cranial nerves III, VII, IX, X.
80
Where are the autonomic nuclei located?
In lateral gray horns of spinal segments S2-S4
81
Ganglionic neurons in peripheral ganglia?
Terminal ganglion
Intramural ganglion
82
Terminal ganglion?
Near target organ
83
What does it mean for the heart to receive dual innervation?
It means that two divisions have opposing effects on heart function.
84
Explain how do the two division have opposing effects on heart function?
1. The parasympathetic division releases ACh from the postganglionic fibers, which causes HR to slow down.
2. On the other hand, sympathetic division, NE released by varicosities accelerates heart rate.
85
How is there a balance between the 2 divisions?
1. Autonomic tone is present
2. Releases small amounts of both neurotransmitters continuously.
86
How does crisis accelerate heart rate?
1. Stimulation of sympathetic innervation
2. Inhibition of parasympathetic innervation
87
What do autonomic neurons do?
1.Maintain resting level of spontaneous activity
2. Background level of activation determines autonomic tone
88
What are the two adrenergic membrane receptors that are involved with sympathetic stimulation and the release of NE and E?
1. Alpha receptors (NE more potent)
2. Beta receptors
89
What are the adrenergic receptors responsible for?
Activating enzymes on the inside of cell membrane via G-proteins.
90
ACh sympathetic terminals
1. Innervate sweat glands of skin and blood vessels of skeletal muscles and brain.
2. Stimulate sweat glands secretion and dilate blood vessels to skeletal muscles and brain.
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ACh sympathetic terminals
1. Innervate sweat glands of skin and blood vessels of skeletal muscles and brain.
2. Stimulate sweat glands secretion and dilate blood vessels to skeletal muscles and brain.
91
Nitroxideric synapse
1. Release nitric oxide as neurotransmitter
2. Neurons innervate smooth muscle in walls of blood vessels in skeletal muscles and the brain
3. Produce vasodilation and increased blood flow.
92
How does the dilation of blood vessels occur?
By skeletal muscle and the brain by ACh, NO on cholinergic, and nitroxidergic receptors.
93
How does the constriction of blood vessels occur.
To digestive and urinary system by NE, E on alpha 1 receptors.
94
How is the parasympathetic activated?
1. Centers on relaxation, food processing, and energy absorption.
2. Localized effects, last a few seconds at most.
95
What are the major effects of parasympathetic division?
1. Stimulation and coordination of defecation.
2. Contraction of the urinary bladder during urination
3. Constriction of the respiratory's passageways
4. Reduction in heart rate and in the force of contraction.
96
What do neuromuscular and neuroglandular junctions release?
They release ACh as a neurotransmitter
97
How are neuromuscular and neuroglandular junctions released?
Via small, narrow synaptic cleft.
98
How long are the effect of the stimulation of neuromuscular and neuroglandular junctions?
Are short lived (few secs) and are inactivated by acetylcholinesterase.
99
How are the neuroglandular junction inactivated?
They are inactivated by acetylcholinesterase.
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101
Sympathetic division vs. parasympathetic division?
Sympathetic= widespread impact
Parasym. = innervates only specific visceral structures. (cranial nerves or lie within abdominopelvic cavity.
102
What is autonomic tone caused by?
Caused by resting level of spontaneous activity.
103
Why is autonomic tone an important aspect of ANS function?
1. If nerve is inactive under normal conditions, can only increase activity.
2. If nerve maintains background lvl of activity, can increase or decrease activity.
104
What are some dangerous environmental toxins?
1. Muscarine
2. Nicotine
105
Why is muscarine a dangerous environmental toxin?
1. Toxin produced from poisonous mushroom
2. Binds to muscarinic receptors
2. Targets parasympathetic neuromuscular or neuroglandular junction
3. Salivation, nausea, bradycardia.
106
What are the major effects of parasympathetic division?
1. Secretion of hormones
2. Change in blood flow and glandular activity
3. Increase in smooth muscle activity.
107
What is the difference between Alpha-1 & Alpha-2
Alpha-1 =
- most common and releases intracellular calcium ions and has excitatory effect on cell.
Alpha-2 =
- Lowers cAMP lvls in cytoplasm and has ihibitory effects on cell
helps coordinate parasym. and symp.
108
What do Beta receptors do?
1. Affect membrane in many organs (stimulates, skeletal, muscles, lungs, heart, and liver.
2. Triggers metabolic changes in target cell
3. Stimulation increases intracellular cAMP lvls.
108
What do Beta receptors do?
1. Affect membrane in many organs (stimulates, skeletal, muscles, lungs, heart, and liver.
2. Triggers metabolic changes in target cell
3. Stimulation increases intracellular cAMP lvls.
109
Binding of NE/E causes opposite affect on cAMP incomparison to what receptor?
a2
