Autonomic nervous system Flashcards
Think of parasympathetic and sympathetic systems in a new way
Sympathetic is energy needs to be expended (can have longer lasting effects than parasympathetics)
Parasympathetic is energy needs to be stored
What are the three main subdivisions of the autonomic nervous system?
Sympathetic
Parasympathetic
Enteric nervous system
T/F, the somatic and autonomic nervous systems are not much different.
Truth!
What is the one difference between the somatic and autonomic nervous system?
Sympathetic and parasympathetic efferents do not reach their targets directly: a two neuron chain is involved
In sympathetics and parasympathetics, how are preganglionic and postganglionic fibers myelinated?
Preganglionic- thin myelin
Postganglionic- unmyelinated
Where are the sympathetic ganglia (collection of cell bodies) located?
Where are the parasympathetic ganglia located? What does this tell you about the pre and post synaptic fibers?
Sympathetic: near CNS/vertebral column
Parasympathetic: near innervated organ
This tells us that presynaptic sympathetic fibers are short and post synaptic ones are going to be very long.
We also know that the presynaptic parasympathetic fibers are very long and the post synaptic ones are very short
What neurotransmitter is used for sympathetics and parasympathetics?
Ach is used in parasympathetics as well as the 1st synapse in the sympathetic
NE is used in the 2nd sympathetic synapse
Where does the sympathetic system travel?
Preganglionic fibers fromT1-L2/3. It also travels in the spinal nerve to the sympathetic chain, prevertebral ganglia, and the adrenal gland
Where does the parasympathetic system travel?
The preganglionic neurons are located in the brainstem and sacral cord. It travels in the cranial and sacral nerves. It outflows to the thoracic, abdominal, and pelvic viscera
Y/N does the parasympathetic system travel to the limbs?
No.
What is the nucleus for CN III- oculomotor?
Edigner-Westphal nucleus
The superior cervical ganglion is associated with which region of the body?
Head and neck
What is the purpose of the ciliary muscle?
Accommodates the lens for near vision, reading close up
What is the path of a signal that travels to the oculomotor muscles?
Starts at the midbrain- the Edinger-Westphal nucleus- goes to the ciliary ganglion- goes to the muscle
Where is the superior salivatory nucleus? (salivatory- salivate, you salivate in your mouth, which is on the face so we’re talking about the facial nerve CN VII)
It is in the tegmentum of the pons
Where do axons of the facial nerve terminate?
Pterygopalatine ganglion and the submandibular ganglion.
What is the path of the facial nerve?
Tegmentum of the pons- submandibular or pterygopalatine ganglion- submandibular/sublingual salivary glands or lacrimal/nasal glands
To which nucleus does CN IX arise from?
The inferior salivatory nucleus on the medulla
What is the path of the glossopharyngeal nerve?
Starts in the inferior salivatory nucleus on the medulla, goes to the otic ganglion, and ends in the parotid gland
From which nuclei does the vagus nerve arise from?
Dorsal motor nucleus of the vagus and the nucleus ambiguus
Dorsal motor nucleus and nucleus ambiguus serve what?
DMN- GI tract and gut
NA- the heart
What is the path of the vagus nerve (CN X)?
Arises from dorsal motor nucleus of the vagus and the nucleus ambiguus of the medulla and terminates on the wall of the target tissue
Where does sacral parasympathetic outflow occur?
On the sacral cord, S2-S4, in the lateral horn area.
How do axons leave the sacral cord and where do they go?
They leave within the ventral root and course within the splanchnic nerves. They terminate on the wall of the target tissue
Sacral parasympathetic outflow is responsible for what?
the bladder and the rectum
What is the neurotransmitter that is used in the parasympathetic nervous system?
acetylcholine
The parasympathetic fibers that go to the ciliary ganglion go to what?
the iris- the oculomotor nerves (III)
The parasympathetic fibers that go to the pterygopalatine ganglion go to what?
the lacrimal gland (VII)
The parasympathetic fibers that go to the submandibular ganglion go to what?
the submandibular gland (VII)
The parasympathetic fibers that go to the otic ganglion go to what?
the parotid gland (IX)
The parasympathetic fibers of the vagus nerve go to what?
heart, lungs, airways, stomach, liver, pancreas, and the small and large intestine
Preganglionic sympathetic fibers leave the ventral root and then do one of four things. What are those four things?
- Some fibers synapse in the nearest ganglion
- Some ascend the chain and synapse in the SCG or MCG (superior or middle cervical ganglion)
- Some descend, synapse in the lumbar/sacral ganglia
- Some traverse the chain and emerge as splanchnic nerves
The superior cervical ganglion ascends with what other structure?
The internal carotid artery
How do the postganglionic fibers reach the head?
Via the cervical ganglia and the carotid plexus
What is horner syndrome?
It is the loss of sympathetic innervation to the face.
What characterizes Horner Syndrome?
eyelid droop, small pupil, apparent sunken eye, and dry skin
What is the one difference between Horner Syndrome and Congenital Horner Syndrome?
Heterochromia- differently colored eyes
What is referred pain and how does it work?
It is pain from the viscera perceived as arising from the surface IE heart pain during myocardial infarction referred to chest and arm.
It occurs/works when the visceral structure is innervated by the same cord level as the surface structure
What does the enteric nervous system provide innervation for?
The intestinal tract and the pancreas and gall bladder
What does the enteric nervous system do?
It provides primary control of motility and secretion
