Module 2.5 The Autonomic Nervous System Flashcards
What are the two divisions of the autonomic nervous system and how do they function relative to each other?
the sympathetic and parasympathetic systems. These two divisions cause essentially opposite effects on the same visceral organ; if one stimulates, the other inhibits.
Explain in detail how the sympathetic nervous system functions during an emergency.
During an emergency, the sympathetic system accelerates the heartbeat, dilates the bronchi, and increases the breathing rate supplying needed oxygen and causes the liver to deliver more glucose and inhibits the digestive tract.
What type of internal responses are promoted by the parasympathetic nervous system?
The parasympathetic system promotes all the internal responses we associate with a relaxed state.
Describe the effects caused by the parasympathetic and sympathetic nervous systems on heart blood vessels, the lungs and the digestive tract.
The parasympathetic nervous system has no effect on heart blood vessels, it constricts bronchioles of the lungs, increases peristalsis and relaxes the sphincters of the digestive tract. The sympathetic nervous system dilates heart blood vessels, dilates bronchioles of the lungs and decreases the activity of and constricts the sphincters of the digestive tract.
What is a preganglionic axon?
A motor neuron cell body located in the spinal cord or brain. The axon synapses with a second motor neuron located in an autonomic ganglion outside the spinal cord.
Why is the sympathetic system also called the thoracolumbar division?
this division contains preganglionic fibers from the thoracic and upper lumbar segments of the spinal cord, in the lateral gray horns.
Name four types of ganglia found in the sympathetic division.
1 Sympathetic trunk ganglia or lateral ganglia #2 Celiac ganglion #3 Superiomesenteric ganglion #4 Inferior mesenteric ganglion
Name five types of ganglia found in the parasympathetic division.
1 Ciliary ganglion #2 Pterygopalatine ganglion #3 Submandibular ganglion #4 Otic ganglion #5 Intramural ganglia
What is the major neurotransmitter in the parasympathetic system?
Acetylcholine
What is a postganglionic axon?
After synapsing in an autonomic ganglion, the axon of the ganglionic motor neuron synapses on an effector organ in the peripheral nervous system.
What is the primary neurotransmitter of the sympathetic nervous system used at the target organs?
norepinephrine (NE)
What is a neuron called if it releases norepinephrine?
adrenergic
What does the sympathetic trunk (lateral) ganglia control?
Located on both sides of the spinal cord, these contain the ganglia for the sympathetic nervous system that controls the effector organs in the trunk, head and limbs.
What is the celiac ganglion and what does it control?
Largest of the ganglia, these ganglia innervate the digestive tract.
What does the superiomesenteric ganglion control?
Innervates the small intestine and parts of the large intestine.
What does the inferior mesenteric ganglion control?
Innervates the large intestine, kidneys, bladder and sex organs.
What does the ciliary ganglion control? With what CN is it associated?
Associated with cranial nerve III, this targets the intrinsic eye muscles which change the pupil and lens.
What do the pterygopalatine ganglion and submandibular ganglion control? With what CN are they associated?
Associated with CN VII, the target organs are for tear production, nasal glands and salivary glands.
What does the otic ganglion control? With what cranial nerve is it associated?
Associated with CN IX, the target glands are the parotid glands.
What does the intramural ganglion control? What CN is it associated with?
Associated with CN X, the target glands are the visceral organs within the thoracic cavity.
What is another name for the parasympathetic division and why?
Craniosacral division because the preganglionic fibers originate in the brainstem and sacral division of the spinal cord.
Which division of the autonomic nervous system is widespread?
The sympathetic division.
