Introduction to the Autonomic Nervous System: Organization of the Parasympathetic Division Flashcards
Visceral Motor innveration targets which kind of tissues?
smooth muscle and cardiac muscle, and glands
How many neurons comprise the autonomic motors system
two neurons connect the CNS to the target tissue
What are some visceral structures in the body wall
glands, arrector pili muscles, smooth muscle in the skin and vessel walls.
What are the three types of visceral Motor Innervation
Sympathetic
Parasympathetic
Enteric (gut) this is a division of the parasympathetic
Arteries to some internal organs receive only ______ Innervation
sympathetic
Nearly all of the visceral structures in the body wall receive _______ innervation only.
Sympathetic
Exceptions include: external genitalia which receives both.
Sympathetic Innervation
“Fight or Flight” (responsive)
This can be understood as the times when the body expends energy
Functions of the Sympathetic Nervous System
• Dilates pupil • Stimulates secretion of sweat glands • Increases heart rate • Increases strength of ventricular contractions • Dilates coronary vessels • Dilates bronchial passages • Increases blood flow to skeletal muscles • Decreases blood flow to digestive organs and decreases secretion by digestive glands. • Stimulates secretion of adrenaline
Parasympathetic Innervation
“rest and digest”
considering what occurs during intake
and conservation of energy
Functions of the Parasympathetic Nervous System
• Contracts pupil • Stimulates lacrimal gland secretion • Stimulates salivary gland secretion • Decreases heart rate • Decreases strength of ventricular contractions • Constricts bronchial passages • Decreases blood flow to skeletal muscles • Increases blood flow to digestive organs and increases secretion by digestive glands • Stimulates motility and secretion of gastrointestinal tract • Relaxes GI sphincters • Contracts urinary bladder
Where are the Parasympathetic Preganglionic Cell Bodies Located?
Parasympathetic = Craniosacral outflow (either brain or S2- S4 levels of the spinal cord)
For this portion we focus on the Vagus Nerve or CNS X
Where are the Sympathetic Preganglionic Cell Bodies Located?
Sympathetic = Thoracolumbar outflow (T1
L2 levels of the spinal cord)
These 14 levels of the spinal cord impact 31 dermatomes
What are some differences in the structure of both Sympathetic and Parasympathetic synaspses?
Sympathetic: the pre-ganglionic and post-ganglionic neurons are roughly the same length. With the Ganglion located somewhere in between the CNS and the target tissue.
Parasympathetic: The preg-ganglionic neuron extends from the CNS to the target tissue. Inside the target tissue the neuron will synapse with the post-ganglionic synapse
What nerve supplies parasympathetic innervation to the thoracic viscera and the organs of the upper abdomen?
The Vagus Nerve
The vagus nerves provide which type of innervation to the organs of the thorax and the upper abdomen.
parasympathetic
