Name: __KEY____________________________ Period: _______
Nervous packet continued…
CHAPTER 11: AUTONOMIC NERVOUS SYSTEM
I. COMPARISON OF SOMATIC AND AUTONOMIC NERVOUS SYSTEMS
OBJ: Compare the main structural and functional differences between the somatic and autonomic
parts of the nervous system.
Somatic nervous system (SNS) includes both _sensory_ and _motor_ neurons.
Somatic sensory neurons convey input form receptors for the special senses:
 _vision________________
 _hearing________________
 _taste________________
 _smell________________
 _equilibrium________________
Also receptors for somatic senses:
 _pain___________________
 _temperature___________________
 _touch___________________
 _proprioceptive sensations________________________________
These are all consciously perceived…
Sensory motor neurons synapse with _skeletal muscle_ and produce _conscious, voluntary
movements_.
Skeletal muscles also generate _breathing_ movements.
Autonomic sensory neurons are associated with sensory receptors that monitor _internal
conditions_.
 _blood CO2 levels_________________________
 _degree of stretching in walls of internal organs or blood vessels__________________
Autonomic motor neurons regulate _cardiac_ and _smooth_ muscles, and _glands_.
These cannot be consciously suppressed or altered.
Comparison of somatic and autonomic motor neurons
Somatic motor neurons extend from _CNS_ to _skeletal muscle fibers that it stimulates_.
Autonomic motor pathways consist of _two_ motor neurons.
 _preganglionic neuron____________
o Has cell body in CNS
 _postganglioninc neuron__________
o Lies entirely in PNS
Autonomic also has two main branches:
 _sympathetic division_________________________
 _parasympathetic division_____________________
Define dual innervation: _organs that receive impulses from both sympathetic and
parasympathetic neurons_ end of page 10
COMPARISON OF SOMATIC AND AUTONOMIC MOTOR NEURON PATHWAYS TO THEIR EFFECTOR
TISSUES.
II. STRUCTURE OF THE AUTONOMIC NERVOUS SYSTEM
OBJ: Identify the structural features of the autonomic nervous system.
Preganglionic neurons, ganglia, and postganglionic neurons and how they relate to the activities
of the ANS.
READ THROUGH THIS SECTION, PAGES 278-283; EXAMINE THE DIAGRAMS. TAKE NOTES IN THE
SPACES PROVIDED, QUESTIONS ON THIS WILL BE MINIMAL ON THE TEST.
A. Organization of the Sympathetic Division
Also called thoracolumbar division because of outflow of sympathetic nerve impulses comes
from thoracic and lumbar segments of spinal cord; cell bodies of preganglionic neurons in 12
thoracic and first two lumbar segments of spinal cord and extend to sympathetic ganglion where
they synapse with postganglionic neurons. Most sympathetic preganglionic neurons are short
but have many branches thus can synapse with many postganglionic neurons that in turn
synapse with autonomic effectors. Most postganglionic from superior cervical ganglion
associated with sweat glands, smooth muscles of the eye, blood vessels of the face, nasal
mucosa, and salivary glands; few associated with others from middle and inferior cervical
ganglion supply the heart. In thoracic region postganglionic axons from sympathetic trunk serve
heart, lungs, and bronchi also some sweat glands, blood vessels, and smooth muscle of hair
follicles in skin. Postganglionic neuron in abdomen follow arteries courses to abdominal and
pelvic autonomic effectors. This division also includes adrenal glands, inner part adrenal
medullae; these cells release hormones into the blood (epinephrine & norepinephrine); these
hormones intensify responses elicited by sympathetic postganglionic neurons.
B. Organization of the Parasympathetic Division
Also called craniosacral division because of outflow of parasympathetic nerve impulses come
from cranial nerve nuclei and sacral segments of spinal cord; cell bodies of parasympathetic
preganglionic neurons located in nuclei of four cranial nerves (III, VII, IX, and X) in brain stem
and in three sacral segments of spinal cord (S2, S3, and S4). Preganglionic neurons emerge from
CNS as part of cranial nerve or anterior root of spinal nerve. Vagus nerve (cranial nerve X) carries
80% of parasympathetic outflow. Thorax axons of vagus nerve extend to ganglia in heart and
airways of lungs; in abdomen they extend to ganglia in liver, gallbladder, bile ducts, stomach,
pancreas, spleen, small intestine, transverse colon, and descending colon. Preganglionic axons
from sacral segments extend to ganglia in walls of ascending colon, sigmoid colon, ureters,
urinary bladder, and reproductive organs. Preganglionic and postganglionic synapse in terminal
ganglia located close to or actually with wall of the innervated organ. These have short
postganglionic neurons; parasympathetic responses are localized to a single effector.
III. FUNCTIONS OF THE AUTONOMIC NERVOUS SYSTEM; pages 283-285
OBJ: Describe the functions of the sympathetic and parasympathetic divisions of the autonomic
nervous system.
A. ANS Neurotransmitters
Check the appropriate neurotransmitters in the chart below:
Neurotransmitter
Acetylcholine
Norepinephrine
Sympathetic preganglionic neurons
all
Parasympathetic preganglionic neurons
all
Sympathetic postganglionic neurons
all
Parasympathetic postganglionic neurons
A few
Most
B. Activities of the ANS
1. Sympathetic Activities—“Fight or Flight”
List the “E” situations that could bring on stress:
_exercise________________
_excitement_____________
_emergency______________
_embarrassment______________________
List examples of “Fight or Flight” responses:
 _pupils of eyes dilate__________________________________________________
 _heart rate, force of heart contraction, and blood pressure increase___________
 _airways dilate, allowing faster movement of air into and out of lungs_________
 _blood vessels that supply nonessential organs (kidneys, GI tract constriction),
which reduces blood flow through these tissues; result is slowing of urine formation
and digestive activities, not essential during exercise________________________
 _blood vessels supply organs involved in exercise or fighting off danger (skeletal
muscles, cardiac muscles, liver, and adipose tissue) dilate, allowing greater blood
flow through these tissues_____________________________________________
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
_liver cells break down glycogen to glucose, adipose cells break down triglycerides
to fatty acids and glycerol, providing molecules that can be used by body cells for
ATP production______________________________________________________
 _Release of glucose by liver increases blood glucose level____________________
 _processes not essential for meeting stressful situation are inhibited___________
2. Parasympathetic Activities—“Rest and Digest”
What are the functions of the parasympathetic responses of the body? _supports body
functions that conserve and restore body energy during times of rest and recovery_______
What does SLUDD stand for? _salivation, lacrimation, urination, digestion, and defecation_
What type of responses are the five things listed above? _parasympathetic_
CHAPTER 12: SOMATIC SENSES AND SPECIAL SENSES
I. OVERVIEW OF SENSATIONS
OBJ: Define a sensation and describe the conditions needed for a sensation to occur.
A. Definition of a Sensation
What four conditions must be satisfied in order to be able to experience a sensation?
(1) _stimulus or change in environment, activate certain sensory neurons, i.e : form of light, heat,
pressure, mechanical energy, or chemical energy____________________________
(2) _sensory receptor must convert stimulus to electrical signal which produces one or more nerve
impulses if it is large enough____________________________________________
(3) _nerve impulses must be conducted along a neural pathway from sensory receptor to brain___
(4) _region of brain must receive and integrate nerve impulses into a sensation________________
B. Characteristics of Sensations
Explain how we have perceptions. _conscious sensation –“eyes see” ;specialized sensory neurons
integrated in cerebral cortex where they are interpreted _____________________
What is the relationship between perception and adaptation? _adaptation is a decrease in strength
of a sensation due to prolonged stimulus which may lead to perceptions fading or disappearing even
though stimulus persists_______________________________________________
C. Types of Sensory Receptors
Look over Table 12.1 on page 291, you will be using this information soon…
II. SOMATIC SENSES
OBJ: Describe the location and function of the receptors for tactile, thermal, and pain sensations.
Identify the receptors for proprioception and describe their functions.
A. Tactile Sensations (Mechanoreceptors)
Which sensations are tactile? _touch, pressure, vibration, itch, and tickle_________________
What are they detected by? _itch and tickle = free nerve endings; all others encapsulated nerve
endings_
1. Touch
Two types of rapidly adapting touch receptors:
 _Corpuscles of touch (Meissner corpulses)___
 _Hair root plexuses______________________
Two types of slowly adapting touch receptors:
 _Type I cutaneous mechanoreceptors (Merkel disks)_______
 _ Type II cutaneous mechanoreceptors (Ruffini corpulses)__
2. Pressure and Vibration
How is pressure different from touch? _pressure is a sustained sensation felt over a larger
area than touch______________________________
Pressure receptors: _Type I mechanoreceptors and lamellated (pacinian) corpulses_
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What types of receptors detect lower frequency vibrations? _corpulses of touch_
Higher frequency vibrations? _lamellated corpulses_
3. Itch and tickle
How are itch sensations stimulated? _stimulation of free nerve endings by certain chemicals
like bradykinin, often a result of local inflammatory response_______________
What type of receptors sense itch and tickle? _free nerve endings___________
Can you tickle yourself? _NO_ Why or why not? _impulses are conducted to and from
cerebellum when you are moving your fingers and touching yourself does not occur when
someone else tickles you______________
Label the following sensory receptors in the skin and subcutaneous layer pictured below:
a. Meissner corpuscles (Corpuscles of touch)
e. Hair Root Plexuses
b. Pacinian corpuscles (Lamellated corpuscles)
f. Free Nerve Endings
c. Ruffini corpuscles (Type II cutaneous mechanoreceptors)
d. Merkel Disks (Type I cutaneous mechanoreceptors)
B. Thermal Sensations (Thermoreceptors)
What type of receptors are thermoreceptors? _free nerve endings______________
What are the two distinct types of thermal sensations? _coldness and warmth____
Temperatures between 10 and 40C (50-105F) activate _cold receptors_; located in the
_epidermis_.
Temperatures between 32 and 48C (90- 118F) activate _warm receptors_; located in the
_dermis_.
Below 10C and above 48C stimulate what type of receptors? _nociceptors_
These receptors produce what type of sensations? _painful sensations_
C. Painful Sensations (Nociceptors)
What type of receptors are nociceptors? _free nerve endings______
Where are nociceptors found? _almost every tissue of body except brain_________
List five different stimuli that can cause pain
 _excessive stimulus of sensory receptors; ex: bright light in your eyes_____________
 _excessive stretching of structure__________________________________________
 _prolonged muscle contractions; ex: hold weight for a long time_________________
 _inadequate blood flow to organ__________________________________________
 _certain chemical substances_____________________________________________
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III.
IV.
V.
VI.
Describe what is meant by referred pain. _pain felt in skin above or located near but not in
organ_
Describe what is meant by fast pain. _within 0.1 seconds of stimulus; acute, sharp, or prickling
pain; localized not in deep tissue_
Describe what is meant by slow pain. _begins a second or more after stimulus is applied; chronic
burning, aching, throbbing; skin deep tissue and internal organs_
Extra CREDIT OPPORTUNITY Up to 10 points
Compare and contrast how different medications like analgesics, anesthetics,
anesthesia, and opiates treat pain.
Typed 1-2 pages with at least two MLA cited references. Due by: _1/2 or 1/3 when I
see you again_
D. Proprioceptive Sensations (Proprioceptors)
Inform you consciously and unconsciously of _degree to which your muscles are contracted, the
amount of tension present in your tendons, the positions of your joints, and the orientation of
your head_
Receptors for these sensations are called: _proprioreceptors_ and they are located in _skeletal
muscles, tendons, in and around synovial joints, and in inner ear_.
They adapt slowly and only slightly
What is kinesthesia? _perception of body movements, allows you to walk, type, or dress
without using your eyes_
SPECIAL SENSES
Allow us to detect things in our environment…
OLFACTION: SENSE OF SMELL (Chemoreceptors)
OBJ: Describe the receptors for olfaction.
CHARACTERISTICS OF RECEPTORS:
 _first-order neuron of olfactory pathway______________________
 _tips are protected by olfactory hairs_________________________
 _stimulated by odorants; inhaled chemicals___________________
 _cells live about a month and then replaced___________________
GUSTATION: SENSE OF TASTE (Chemoreceptors)
OBJ: Describe the receptors for gustation.
CHARACTERISTICS OF RECEPTORS:
 _chemicals known as tastants stimulate them__________________
 _ electrical signal stimulate release of neurotransmitter molecules that bind to gustatory
receptors on dendrites of taste buds’ first-order neurons_
 _respond to any one of five primary tastes: sweet, sour, bitter, salty, or umami (savory,
glutamate detection)_
Let’s try something, everyone get a piece of gum. Unwrap the gum, hold your nostrils closed,
place the piece of gum in your mouth and chew, and then let go of your nostrils).
VISION (Photoreceptors)
OBJ: Describe the receptors for vision.
Identify the structures of photoreception and how they work. _retina is the beginning of visual
pathway; three layers: photoreceptor layer, bipolar cell layer, and ganglion cell layer. Two types of
cells in photoreceptor layer: rods (allow us to see shades of gray in dim light,like moonlight) and
cones (stimulated by brighter light- highly acute, color vision). Stimulation of photoreceptors have
photopigment which absorbs light and then undergo change in structure to adjust to amount of light
available; in rods photopigment is rhodopsin)___
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VII. HEARING AND EQUILIBRIUM (Mechanoreceptors)
OBJ: Describe the receptors for hearing and equilibrium.
The ear has three principle regions: the outer ear, the middle ear, and the inner ear.
Physiology of Hearing
Describe events 1-8 pictured below involved in simulations of hair cells by sound waves.
(1) _auricle directs sound waves into external auditory canal_________________________
(2) _sound waves strike eardrum; produce vibrations, eardrum vibrates in response______
(3) _central area of eardrum connects to malleus that also starts to vibrate, vibration moves from
malleus to incus to stapes_______________________________________
(4) _stapes moves back and forth, pushes the oval window in and out____________________
(5) _movement of oval window sets up fluid pressure waves in perilymph of cochlea. Inward
movement of oval window pushes perilymph of scala vestibuli__________
(6) _pressure waves move from scala vestibuli to scala tympani and eventually membrane covering
the round window causing it to bulge into the middle ear______________
(7) _pressure waves deform walls of scala vestbuli and tympani pushing vestibular membrane back
and forth, creating pressure waves in endolymph inside cochlear duct____
(8) _pressure in endolymph cause basilar membrane to vibrate, which moves hair cells of the spiral
organ against tectorial membrane. Bending of hairs stimulates hair cells to release
neurotransmitter molecules at synapses with sensory neurons that are part of vestibulocochlear
nerve, sensory neurons generate nerve impulses along nerve and sound is received and
interpreted_
Physiology of Equilibrium
Describe static equilibrium and its function. _maintenance of the position of the body relative to the
force of gravity; maintains posture and balance by providing sensory information on the position of the
head_________________________________________________________________________
Describe dynamic equilibrium and its function. _maintenance of body position in response to sudden
movements such as rotation, acceleration, and decleration; reestablish balance to disturbed equilibrium
by regulating sensitivity of hair cells in the ear_________________________
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