Chapter 15- Visceral Nervous System Flashcards
Autonomic Nervous System Functions
Innervation of smooth muscle, cardiac muscle, and glands
Regulate visceral functions like heart rate, blood pressure, digestion, and urination
Preganglionic Neurons
Cell body in lateral gray horn
Myelinated
Synapse with ganglia
Release acetylcholine
Postganglionic neurons
Cell body in external ganglia
Not myelenated
Synapse with effector
Release varied neurotransmitters
Sympathetic Nervous System Function
Responsible for fight, flight, or fright response
Increase heart rate and respiration
Decrease digestion and urination
Dilate eyes
Sympathetic Nervous System Structures
Originate from thoracic and lumbar vertebrae
Ganglia located next to spinal cord
Long postganglionic fibers
Postganglionic neurotransmitter is norepinephrine
Highly branched
Parasympathetic Nervous System Function
Homeostatic “Rest and Digest” Response
Decrease heart rate and respiration
Increase digestion and urination
Constrict eyes
Parasympathetic Nervous System Structures
Originate from cranial and sacral regions
Cranial nerves 3, 7, 9, and 10
Mostly vagus nerve
Ganglia in wall of effector
Short postganglionic fibers that release acetylcholine
Sympathetic Trunk Ganglia
Ganglia running alongside the vertebral column
Linked to ventral rami by rami communicantes
White rami communicantes
Myelinated axons
Preganglionic neurons
Gray rami communicantes
Unmyelinated axons
Postganglionic neurons
Prevertebral ganglia
Unpaired ganglia in abdomen and pelvis anterior to vertebral column
Ex- Celiac, mesenteric, inferior hypogastric
Cause longer preganglionic neuron
Splanchnic Nerve
Connects sympathetic trunk and prevertebral ganglia
Preganglionic and postganglionic neurons
Adrenal Medulla
Main organ of sympathetic nervous system
Releases norepinephrine and adrenaline
Directly stimulated by preganglionic fibers
Adrenal Medullary Pathway
All 1 Neuron:
-Ventral Rami
-Sympathetic Trunk
-Splanchnic Nerve
-Adrenal Medulla
Control of the Autonomic Nervous System
Reticular formation
Hypothalamus
Amygdala