chapter 7 the peripheral nervous system: efferent...
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Chapter 7Chapter 7
The Peripheral Nervous The Peripheral Nervous System: Efferent DivisionSystem: Efferent Division
by Dr. Jay M. Templin
© Brooks/Cole - Thomson Learning
Nervous System
Central PeripheralNervous Nervous
System (CNS) System (PNS)
Brain, Spinal Cord Cranial/SpinalNerves
Peripheral Nervous System
Somatic AutonomicNervous Nervous System System
Consist of cranial Consist of and spinal nerves nerve fibersinnervating innervatingskeletal muscles visceral organs
•Cervical •cord
•Thoracic •cord
•Lumbar •cord
•Sacral •cord
•Vertebrae•Cervical •nerves
•Thoracic •nerves
•Lumbar •nerves
•Sacral •nerves
•Coccygeal•nerve
•Cauda•equina
There are two efferent fibers innervating the effector organ
(visceral organs)
There is only one efferent motor fiber innervating the
effector organ (skeletal muscles)
Efferent fibers release two types of neurotransmitters (see difference between sympathetic and parasympathetic systems)
Motor nerve fibers release acetylcholine which act on
nicotinic Ach receptors
Efferent fibers originate in brain stem or spinal cord
Efferent motor fibers originate in brain stem or spinal cord
Regulate autonomous body functions
Carry motor information out of the NS
Autonomic Nervous SystemSomatic Nervous System
Efferent Outputs
(Brain stem or Spinal cord) (Visceral organ)
© Brooks/Cole - Thomson Learning
Autonomic Nervous System
Origin of Sympathetic Preganglionic Fibers
in Spinal Cord
Autonomic Nervous System
Sympathetic ParasympatheticSystem System
Mediate fight or Mediate rest or flight responses digest responses
Cholinergic receptors
Adrenergic Receptors
Figure 7.3Page 241
Eye
Nasal mucosa
Sympathetic
Spinal nerves
Sympathetictrunk
Splanchinonerves
Liver
Gallbladder
PancreasAdrenal gland
Kidney
Smallintestine
ColonRectumUrinary bladder
Genitalia
Lung
Heart
Spinalnerves
Cranialnerves
Salivaryglands
Parasympathetic
Parotid gland
Trachea
Lacrimal gland
Stomach
SpleenSympathetic preganglionic fiber
Parasympathetic postganglionicfiber
Parasympathetic preganglionicfiber
Sympathetic postganglionic fiber
Autonomic ganglion is located far from the spinal cord, near the
effector organ
Autonomic ganglion is located near the spinal cord, far from effector
organPostganglionic fibers release acetylcholine
Postganglionic fibers release noradrenaline
Autonomic fibers originate from brain stemand sacral spinal segment
Autonomic fibers originate from thoracic
and lumbar spinal segment
Rest or digest responseFlight or fight response
Parasympathetic System
SympatheticSystem
Autonomic Control of PupillaryReflex
Autonomic Control of Lens: Adaptation
Fight or Flight Response
StressDanger
Increase heart beatsIncrease blood pressure (Vasoconstriction)
Increase air flow into airwaysRelease of glycogen into blood stream
Dilation of skeletal blood vesselsDilation of pupilsIncrease sweating
Down regulation of digestion and urinary activity
Peripheral Nervous System
Somatic AutonomicNervous Nervous System System
Consist of cranial Consist of and spinal nerves nerve fibersinnervating innervatingskeletal muscles visceral organs
Motor Unit: consist of all muscle fibers innervated by one motor
neuron
Neuromuscular Junction
© Brooks/Cole - Thomson Learning
Neuromuscular Junction
http://www.blackwellpublishing.com/matthews/nmj.html
http://www.toppermost.biz/Junction.html
http://www.microvet.arizona.edu/Courses/MIC420/lecture_notes/clostridia/clostridia_neurotox/movie/botulinum_movie.html
http://www.pbs.org/wnet/closetohome/animation/gaba-anim2-main.html