#2 lecture Flashcards
1
Q
Sensory receptors are specialized to
A
Specialized to respond to changes in environment, a.k.a. stimuli
2
Q
Activation of a receptor by an adequate stimulus results in
A
Results in graded potential that trigger nerve action potential along PNS fibers
3
Q
Sensory receptor neurons can be classified by
A
① stimulus
② location in body
③ structural complexity of dendrites
4
Q
Sensory receptor, neurons provide
A
Provide information regarding following classes of stimuli (general and specialized senses)
5
Q
Sensory integration
A
Processing of signals recognize consciously a.k.a. information that reaches the cortex
6
Q
Somatosensory cortex is the primary __
A
Primary side of integration of general senses from the exteroceptors, interceptors, and proprioceptors from body/ limbs
7
Q
Additional zones are responsible for?
A
Responsible for specific special senses tied into sensory organs (Visual cortex )
8
Q
Two concepts of sensory integration
A
. Sensation and perception.
9
Q
Sensation
A
Awareness of changes in the environment ( stimuli)
10
Q
Perception
A
Conscious interpretation of the stimuli and it’s consequences
11
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Integration (Sensory integration)
A
Determines how we respond and or interpret environment
12
Q
Response (Sensory integration)
A
Execute the needed action to resolve the need/decision
13
Q
Three levels of sensory integration to achieve both sensation and perception
A
① receptor level
② circuit level
③ perceptual level
14
Q
Receptor level
A
For sensation to occur stimulus must make enough graded potential to send action potential
-generator potential = graded potential (general senses)
-Receptor potential = graded potential(special senses)
15
Q
phasic receptors (receptor level)
A
Fast adapting, often giving burst of impulses at the beginning and the end of the stimuli
- photoreceptors adjust to light
- pressure receptors and touch
16
Q
Tonic receptors (Receptor level)
A
Provide a sust(ained response with little or no adaptation
- nociceptors an proprioceptorS, due to protective importance of information
17
Q
Higher level levels and receptor level can adjust from
A
(Circuit and perceptual level )
Adjust from top down
-Pain tolerance, reticular formation
18
Q
Circuit level (Sensory integration)
A
Task is to deliver impulses to appropriate region of the cerebral cortex often and relays that allow:
-Some filtering along the way and lower brain areas
-Some interaction with spinal cord reflexes
19
Q
How does circuit level work?
A
Sensory neurons send their signals along tracks to their location with the goal of getting to the cortex
-however, circuits are often arrange and realize that allow the signal to be branched to other regions along the way
-Allow more processing and interaction, including involuntary areas
20
Q
Perceptual level (Sensory integration)
A
Processing in cortex areas were info is compared and interpreted to allow motor response
-Context is taken into account
21
Q
How does perceptual level work?
A
Inner neurons in the cortex receive signals from numerous different receptor neurons and takes more into account beyond just if a stimulus was detected
-Once info is processed/interpreted signals are sent to appropriate motor response pathways
22
Q
Perception and response depends on?(Sensory integration. )
A
Depends on sending information back-and-forth between interns
23
Q
Cerebrum
A
Made of two cerebral hemispheres, which have three main regions
83% of brain mass
Made of suici and gyro that increased surface area
24
Q
Three main regions of cerebrum
A
Cerebral cortex (Gray matter)
Basal nuclei (gray matter)
White matter ( tracts connect areas)
25
. cerebrum has tracks of.? (Perception / integration areas)
White matter that connect
-Provide connection to different brain areas can talk to each other
-Association fibers
- commissural fibers
-projection fibers
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Association fibers (Cerebrum)
Connect different lobes of the brain
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commissural fibers (cerebrum)
Connect hemispheres (Corpus callosum is the major one)
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Projection fibers (Cerebrum )
Connect the cerebrum to lower areas of the brain and spinal cord
29
' commissural and projection fibers connect?
Connect opposite sides of the nervous system and play an important role in crossing over (Decussation )
30
Decussation, crossing over in our nervous system
Crossing over of tracks from one side of the nervous system to other during their neural circuit wiring
-90% of sensory/motor output crossover
-Right body controlled by left brain
-Left body controlled by right brain
31
What is between hemispheres of the brain?
Cerebral lateralization
32
Corpus callosum
-major bridge between cerebral hemisphere‘s for perceptual communication
Commercial fibers play in an important role in keeping the left and right info coordinated during perception
33
All motor (efferent) divisions of the peripheral nervous system have?
Reflexes and they all follow the same general reflex arc strategy
34
Reflex responses
Involuntary motor responses to stimulate that does not require thinking
-Somatic deal with skeletal muscle
, - autonomic deal with visceral organs
35
Fast acting of reflex response
Evolved her responses that require quick changes in physiology
-Reduce damage, maintain balance
36
Predictable reflex response
Responses are stereotypes to repeat a required function
37
Reflex response process
① Receptor: site of stimulus action
② sensory neuron: transmit afferent impulses to CNS
③ integration center ( monosynaptic,polysynaptic)
④ motor neuron: efferent impulse to effector muscle and organ
⑤ effector: muscle fiber or gland cell respond to impulse by contracting ol secreting
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Monosynaptic reflex
Sensing neuron synapses directly w/ motor neuron
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Polysynaptic reflex
Interneurons are involved in signal relay circuit
40
In somatic, nervous system motor neurons move through?
Plexus (below head)
41
Plexus (somatic nervous system )
Neurons from different spinal nerves are sorted and recombined so that all fiber is going to a specific target or put together in one nerve branch
42
Most somatic responses are handed by
Plexuses
43
Thoracic spinal nerves do not form?(Somatic nervous system. )
Do not form big plexus and instead branch into targets of the sympathetic nervous system system, a different motor division
44
. Efferent neuron mostly relay.?(somatic nervous system )
Mostly relay voluntary control
45
Where does the somatic nervous system carry signals from?
Carry signals from the CNS and relays info to skeletal muscles for predominantly voluntary control and for some involuntary reflexes
46
Withdrawal reflex (somatic reflexes )
Pain reflex to quickly draw limbs back from harm
47
Diaphragm/intercostals (somatic reflexes)
Muscles for contraction/relaxation and breathing are skeletal muscles that pass via cervical plexus/ phrenic nerve
48
Proprioreceptors reflexes (Somatic reflexes)
Sense stretch/strain and skeletal muscles to unconsciously control movements to prevent damage
49
Capsule (Somatic reflexes -stretch responses ).
Spindle shaped dendrites are surrounded by intrafusal fibers, enclosed in o connective tissue
50
Where are proprioceptor present?(Somatic reflexes.)
Present throughout the paramecium that wraps fascicles of skeletal muscles
51
Mechano receptors (somatic reflexes -stretch responses)
Response to stretch in the muscles and are involved in somatic reflexes
52
Muscle spindles help resist?(Somatic reflexes.)
. Help resist over stretching
53
Knee-jerk reflex is a?
Stretch response
54
Capsule (Somatic reflexes -relaxation responses)
Small bundles of sensory terminals coiling around fibers within a layer capsule
55
Proprioreceptors (Somatic reflexes relaxation responses )
Present throughout tendons, at the junction between the tendon fibers and skeletal muscles
56
Mecano receptors (somatic reflexes relaxation responses )
Respond to stretch in tendon fibers and are involved in relaxation reflexes
57
Tendon organs help to resist?(Somatic reflexes relaxation response. )
Resist over contraction
-Connections to skeletal muscles detect when a muscle attracts too much
58
How do tendon organs help to resist over contraction
Trigger a reflex that relaxes the contracted. muscle
tendon organ axon also has a branch that synapsis/triggers, reciprocal activation in order to contract and antagonistic muscle
-Does the opposite proprioceptor monitoring as the muscle spindle stretch response
59
Medulla oblongata and pons (ANS )
. Receive info for visceral receptors to monitor cardiovascular and breathing systems
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Hypothalamus (ANS )
Receive sensory info to regulate many processes
-Contain many sensory receptors which monitor concentration of body fluids, internal temperature, etc.
61
, ANS controls many targets that we are not in conscious control of adjusting
Involuntary nervous system
Smooth muscles (organs/vessels )
Cardiac muscle (heart contraction)
Glands (Endocrine system )
62
Motor signals heading out through ANS divide between
Between parasympathetic and sympathetic division
63
Sacral nerves ( parasympathetic division)
Send preganglionic neurons to pelvic regions
-They are not the rami
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Somatic is ___ step relay
1
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ANS is __ step relay
2
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Somatic System
Motor neurons that go to effectors (skeletal muscle) do it in a single step with no synapses in the PNS
68
ANS system
Motor neurons that go to effectors have two step motor neuron relay, such that there are synapses in the PNS
69
Are motor ganglia present in ANS?
Yes
70
Are there motor ganglia present in somatic system
No
71
Where are motor ganglia present in sympathetic
Close to spinal cord and far from targets
72
Where are motor ganglia present in parasympathetic
Far from spinal cord and close to targets
73
Myelination in somatic system
Entire motor neuron is usually very heavily myelinated leading to faster signals
74
Myelination in ANS
preganglion are lightly myelinated leading to slower signals
-postganglion are non myelinated leading to slower signals
75
Postganglion neurotransmitters in somatic system
Motor neurons that wire to skeletal muscle all release Acetylcholine, causing stimulation of muscles so that they contract
76
Postganglion neurotransmitters of ANS
postganglion neurons can either release acetylcholine or norepinephrine, which can have either stimulatory or inhibitory effects depending on the target
77
In postganglionic neurons, sympathetic neurons use….
Norepinephrine
78
In postganglionic neurons, parasympathetic neurons use…
Acetylcholine
79
Why do sympathetic and parasympathetic systems need to have different neurotransmitters
They have to balance or oppose each others responses
80
How do neurons generate different physiological responses
Chemical messengers and their receptors are more complex and varying in the ANS
81
Cholinergic receptors
Protein receptors that bind to ACh and there are types
82
2 types of cholinergic receptors
Nicotinic an muscarinic
83
Nicotinic
Always stimulatory
-dendrites of postganglionic cells
-skeletal muscles sarcolemma
- adrenal medulla
84
Muscarinic
Either stimulatory or inhibitory effects depending depending on the sub class of receptor in target
-all parasympathetic targets
85
Norepinephrine and related epinephrine are utilized mainly within …
Sympathetic division
- secreted by postganglionic cells
- secreted by chromaffin cells of the adrenal medulla
86
Adrengic receptors are either …
Stimulatory or inhibitory depend on type of receptor in target
- alpha receptor (a1 and a2)
- beta receptors (b1, b2, b3)
87
Varicosities
Swellings along postganglionic neuron axon terminals release chemicals
- infilitrate dif tissues to release amounts of chemical messengers
88
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Messengers are either …. (Varicosities )
Neurotransmitters: if stays in synapse region
- hormone : if instead enters bloodstream
90
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Gland
Group of cells that secretes one or more products
93
What do glands generally begin as
Epithelial tissue
94
Adrenal glands connect to..
Preganglionic neurons of sympathetic division
95
How are some connections made in the adrenal gland
Some connections are made in which there is no formal ANS ganglion, where the pre-ganglion neurons go directly to the adrenal gland
96
Adrenal synapses
Preganglion neurons synapse directly w/ secretory chromaffin cells in adrenal medulla
- chromaffin cell releases N/EN directly into bloodstream, makes hormones
97
Hypothalamus is a key link btwn
ANS and endocrine system
98
99
Nervous system
High speed, electrical signals along specialized neurons
-signals regulate or control other cells
-fast responses needed due to changing environment
-somatic, and autonomic nervous system
100
Endocrine system
Secrete hormones that coordinate slower but longer acting responses, including
-reproduction, development, growth, metabolism, behavior, and immunity
101
Endocrine glands
Ductless glands that produce hormones and lack ducks
-release hormones into surrounding fluid
-rich, vascular drainage
-branching networks
-pituitary, thyroid, parathyroid, and adrenal penal glands
102
Neuro endocrine organ
Neural and hormone function and example hypothalamus
103
Organs
Several organs also have special subdivisions of secretary, endocrine glands
-pancreas, gonads, and placenta
104
Signaling molecules
Each chemical binds a specific receptor
105
Although a signaling molecule can reach different cells throughout the body…
Only some cells will have a receptor that fits that molecule
106
How do signaling molecules work?
Has a target cell that has receptors that combined specifically to its 3-D shape
107
How can distinct response pathways be activated under different conditions?
Signaling molecules
108
Hormones
Secreted, chemical, messengers and endocrine system
109
Steroid hormones
Derived from cholesterol
-Cholesterol as a precursor molecule
-steroid hormones come from gonads or the adrenal glands
-generally lipid soluble
110
Amino acid hormones
Range in sizes, but all includes some form of modified amino acids or peptides
-generally water soluble
-most hormones are this type
111
Small amino acid hormones
Simple amino acid derivatives also nitric oxide
112
Medium amino acid hormones
Short chains of amino acids, an example peptides
113
Large amino acid hormones
Complete/complex translated proteins
114
Are hormones produced in one body region
Yes, and they have effects in other regions
115
Are hormone/signaling molecules, chemical messengers
Yes, they are secreted into bloodstream or into interstitial fluid to communicate signals to organ systems
116
Do hormones/signaling molecules reach all parts of the body
Yes, but only target sells respond due to specificity of receptors
117
Where are hormones distributed in endocrine?
Circulatory system
118
Where do hormones reach in endocrine system?
Reach target cells by entering a circulatory system like the bloodstream or lymphatic system
119
Where are hormone/signaling molecules produced in endocrine system
Produced by ductless glands
120
Longer acting with broad effects of hormones/signaling molecules
Circulate in body for a while
-Mediate long-term responses
-growth and development, chronic responses to environment and immune response as well
121
Paracrine(hormones/signalng molecules)
Local regulators that act on neighbor cells
122
Where are paracrine signaling molecules produced
Not produced by special dedicated glance, but are secreted from cells and tissues and organs response to local stimuli
123
Why are paracrine called local regulators?
They moved by diffusion to induce very rapid responses within tissues
124
How does paracrine communication between neighbors help
Help organs respond as a unit
And example prostaglandins with rapidly trigger local immune response responses
125
Autocrime (hormones/signaling molecules)
Secreting cells are themselves to target
126
How are autocrine’s signaling molecules produce?
Produced by a cell and then our self detected by receptors on the cells own membrane
127
Are autocrine hormones usually in positive feedback
Often and positive feedback to help amplify responses
-need a circuit breaker to interrupt the runway response
128
Can some signals be both paracrine and autocrine
Yes, to boost signal
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Where are neurotransmitters secreted?
Secreted directly by neurons
131
What are neurotransmitters(hormones/signaling molecules)
Signaling molecules secreted by membrane regions were neurons interact, called synapses
132
What does a stimulated neuron release?
Release note transmitters into the space between cells
an example synapse
133
Does neurotransmitter diffuse short distance
Diffuse short distances to target sell rapidly triggering another electric impulse
134
Neurohormones
Neuronal hormones that enter blood
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What do neurohormones release?
Special brain or ANS neurons release chemical messengers that become hormones because they enter/travel in the bloodstream
137
Where are neurohormones used?
Used in neural endocrine, signaling in the hypothalamus/pituitary gland to signal and control large responses
-water balance hypothalamus
-temperature hypothalamus
-sexual development pituitary
138
Is Norepinephrine released in a general gland?
Yes
139
Pheromones
Chemical secreted outside the body
140
Where are pheromones secreted from?
Secreted from glands that act outside of the body
141
Where are pheromones produced?
Produced by one individual in order to change the behavior and physiology of other individuals
-species recognition
-social interaction and reproduction
-navigation and territory marketing
142
Do hormones vary in their solubility
Yes
143
Water soluble(hormones )
They do not pass easily through membranes so receptors are on outer cell membrane
-amino acid based hormones(usually)
144
Lipid soluble(hormones)
Past easily through cell membranes so receptors are often inside the target cell
-steroids(usually)
145
Three key events in hormone signaling
Release migration and response
146
1. Release.(hormone signaling.)
Cell/gland receives a stimulus and releases signal
147
2. Migration.(hormone signaling.)
Message is carried via bloodstream in this example
148
3. Response(hormone signaling.)
Target sells them respond to the hormone
149
Signal transaction pathway
Chain of events that leads to intracellular response
- cytoplasmic responses, enzyme, activation, and gene expression changes
150
What do water soluble hormones often need
Secondary messengers for the signal to cross membranes
151
Where will lipid soluble hormones often enter?
Often directly enter the nucleus to act as transcription factors that induced changes in gene expression
-there is not an official second messenger
152
With so much hormone being released, why don’t all tissues respond
Not all cells expressed the same receptors nor do all cell types respond in the same way
153
Hormone responses summary
Although hormone circulate broadly not all cells respond the same way
-different receptors can detect the same hormone
-same receptor can activate distinct signal, transduction pathway among different cell types
-multiple responses can be generated via the use of a signal hormone
154
It is not always about switching between the emergency and nonemergency situations…
Often it is also about maintaining balance between systems to keep internal condition stable
155
Homeostasis
I regulation that keeps an internal condition
156
Does endocrine system play an essential role in homeostasis?
Yes, or maintaining a study day regardless of external environment
157
What is a primary control center for homeostasis?
Hypothalamus it links with pituitary gland to control homeostasis of numerous physiological states
-body temperature blood pH glucose
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Negative feedback oops
Systems help return a variable to within a normal physiological range or a steady state setpoint when the internal conditions are upset
-signal is inverted to turn the system around
162
Most control systems used to maintain homeostasis operate using
Negative feedback
163
Hormone pathway, employing negative feedback
Blood glucose homeostasis
164
Insulin and glucagon
Antagonistic hormones that maintain glucose homeostasis
165
Pancreas has clusters of…(homeostasis)
Adult crying cells called islets of langerhans
-alpha cells produced glucagon
-Beta cells produced insulin
166
Type one diabetes
Auto immune disorder
167
Type two diabetes
Chronic adaptation
168
How do hormones travel for negative feedback loop
Released from endocrine cell travel through bloodstream and interact the receptor of a target cell to cause a response
-then a negative feedback loop inhibits a response by reducing the initial stimulus
169
Positive feedback loops
External stimulus triggers, a physiological response that reinforces and amplifies that same response so the system keeps increasing its output away from the set point
-unstable if not controlled
170
External signal
Usually must break the lip or else positive feedback loops can become pathological
171
Hormone cascade pathways
Hormone can stimulate release of other hormones
172
How can one hormone stimulate the release of other hormones?(hormone cascade pathways.)
But the last hormone in the stepwise cascade activating non-endocrine tissue to make the physiological response
173
Tropic hormones(hormone cascade pathways)
Act indirectly by stimulating other endocrine glands
174
Non-tropic hormones(hormone Cascade pathways)
Act directly by stimulating response in non-endocrine target
175
Is oxytocin and ADH non-tropic or tropic
Non-tropic
176
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Why is the pituitary gland often called the master endocrine gland
Because it’s both part and directly tied to the hypothalamus
179
Does parathyroid gland release non-tropic hormones
Functions with moral stimulus to release non-tropic parathyroid hormone
180
How is growth Limited?
Negative feedback loops
181
How does negative feedback loops control growth hormones
Ensure that growth is regulated properly while still allowing use of GH in the daily metabolism
182
What does high levels of GH stimulate?
Stimulate the release of somatostatin GHIH from many digestive tissues in the pancreas, delta cells
- important monitoring point due to the insulin glucagon system
183
Somatostatin GHIH inhibits…
The release/the production of growth hormone release hormone from the hypothalamus
184
Improper level levels of GH can result in…
Abnormalities with broad
185
Hypersecretion
Growth plates are overly stimulated, resulting in forms of gigantism
- during childhood excessively tall
-during adulthood, disproportionate limbs
-often due to tumor on anterior pituitary
186
Hyposecretion
An adult it is usually not symptomatic, however
-During childhood lead to dwarfism
-slows, long bone growth other effects
187
Metabolism, short-term growth hormone
Directly, target broad tissues, and sells to grace, blood glucose and increase metabolism
-influence, blood sugar levels
-stimulate, fat and glycogen breakdown
-stimulate amino acid uptake
- assist with thermal regulation
188
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What does GH follow to make sure we have blood sugar homeostasis?
Circadian clock
190
How fast is during menopause are likely due to…
Low estrogen levels, causing rapid stress response
191
What triggers, hot flashes
As levels drop below lifetime setpoint ovaries cannot easily bring levels back up
-trigger, sympathetic division stress response in the hypothalamus
-mobilize high activity mechanisms
-include dialatatingcapillaries of skin
192
Is sympathetic, short-term or long-term
Short term
193
Is pituitary short term or long-term?
Long-term a CTH
194
Is short term non-tropic or tropic
Non-tropic
195
Is long-term tropic or non-tropic
Usually tropic pathways with multiple hormone Caid steps
196
Chronic activation, long-term adrenal gland
Hypothalamus communicates via
-Portal system to interior pituitary
-releases ACTH hormones
-stimulates adrenal cortex
-releases cortisol
197
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What is a Reflex Response? What are two types?
A Reflex Response is an automatic reaction to a stimulus. The two types are Somatic and Visceral.
199
What are the different types of Somatic Reflex Responses?
The types of Somatic Reflex Responses are Intrinsic and Learned.
200
What are the 5-steps of a general Reflex Arc?
1. Stimulus 2. Receptor 3. Afferent pathway 4. Integration center 5. Efferent pathway 6. Effector.
201
Typically, what does the Somatic Division of the PNS control?
The Somatic Division of the PNS typically controls Voluntary Movement.
202
Does the Somatic Division control some involuntary functions?
Yes.
203
List some important Involuntary Reflexes controlled by the Somatic Division.
Important Involuntary Reflexes include the Knee-jerk reflex and withdrawal reflex.
204
What are Proprioceptors, and where are they located? What do they monitor?
Proprioceptors are sensory receptors located in muscles, tendons, and joints that monitor body position and movement.
205
How does The Stretch Reflex work, using Muscle Spindles? Why is it important?
The Stretch Reflex works by detecting muscle stretch through Muscle Spindles, which helps maintain posture and balance.
206
How does The Tendon Reflex work, using the Golgi Tendon Organ? Why is it important?
The Tendon Reflex works by detecting tension in muscles through the Golgi Tendon Organ, preventing muscle damage.
207
Why are 'involuntary' reflexes like the Muscle Spindle Reflex not part of the ANS?
Because they wire to Skeletal Muscle, and therefore are part of the Somatic Division.
208
What responses does the Autonomic Nervous System (ANS) control?
The ANS controls Involuntary responses.
209
What are the differences in Targets between the Somatic Nervous System and the ANS?
The Somatic Nervous System targets Skeletal Muscles, while the ANS targets Smooth Muscles, Cardiac Muscles, and Glands.
210
What are the two divisions of the Autonomic Nervous System?
The two divisions are the Sympathetic Division and the Parasympathetic Division.
211
What are some key differences between the Somatic Nervous System and ANS?
Key differences include control (voluntary vs. involuntary), targets (skeletal vs. smooth/cardiac), and pathways.
212
Where do cell-bodies of motor-neurons in the Parasympathetic Division come from?
They come from the brainstem and sacral spinal cord.
213
Where do ganglia of motor-neurons in the Parasympathetic Division typically reside?
They typically reside near or in the target organs.
214
How long are preganglionic and postganglionic neurons in the Parasympathetic Division?
Preganglionic neurons are long, and postganglionic neurons are short.
215
Approximately how much of the Parasympathetic Division does CNX supply?
CNX supplies approximately 75% of the Parasympathetic Division.
216
Where do cell-bodies of motor-neurons in the Sympathetic Division come from?
They come from the thoracic and lumbar regions of the spinal cord.
217
Where do ganglia of motor-neurons in the Sympathetic Division typically reside?
They typically reside close to the spinal cord in the sympathetic trunk.
218
How long are preganglionic and postganglionic neurons in the Sympathetic Division?
Preganglionic neurons are short, and postganglionic neurons are long.
219
Which ANS Division has cell bodies in the lateral gray horn of the Spinal Cord?
The Sympathetic Division.
220
What are Sympathetic Trunk/Chain Ganglia? Where are they located?
Sympathetic Trunk/Chain Ganglia are clusters of nerve cell bodies located alongside the vertebral column.
