Autonomic system Flashcards
The PNS branches off into what to systems?
Autonomic and Somatic system
Is the somatic system voluntary or involuntary ?
The somatic system is voluntary it relays info to and from skin and skeletal muscles.
Is the autonomic system voluntary or involuntary?
The autonomic system is involuntary it relays information to internal organs.
The autonomic system branches off into what two systems?
Sympathetic and parasympathetic systems
What does the sympathetic system control? What does the parasympathetic system control?
Sympathetic Controls organs in time of stress: Relays information to internal organs . Parasympathetic controls organs when the body is at rest.
The Autonomic Motor nervous system controls glands, cardiac and smooth muscle . What would be the other name for this system?
The other name for the autonomic motor nervous system is the visceral motor system.
The ANS regulates unconscious processes that maintain homeostasis . What are some examples of these?
blood pressure, body temperature, respiratory airflow
What are biofeedback techniques?
training that teaches some people to control hypertension, stress and migraine headaches.
What are visceral reflexes ?
Unconscious, automatic responses to stimulation of glands, cardiac or smooth muscle
Receptors for visceral reflexes detect what kind of stimuli ? What are some examples ?
Internal stimuli. EX: stretch, blood chemicals, body temperature
What are effectors ?
Glands, smooth or cardiac muscle
True or False ANS modifies effector activity ?
True, ANS doesn’t not cause the activity, it just modifies it. EX: high blood pressure activates a visceral baroreflex
Increases heart rate, BP, airflow, blood glucose levels are signs of what autonomic system?
Sympathetic system
What autonomic system assist in bodily maintenance, digestion and waste elimination ?
Parasympathetic system
Effects of Sym and Para depend upon the release of what?
Neurotransmitters
Define Autonomic Tone?
Both systems acting simultaneously on the same target organ.
Is Autonomic Tone a perfect balance between Sym and Para ? If not, what determines the unequal balance?
False , although it is possible it is mostly and unequal balance because shifts of predominance are determined by mental and physiological states .
How many neurons span the distance from CNS to effectors?
There are two neurons. • The presynaptic neuron cell body in CNS ( brain or spinal cord) and postsynaptic neuron cell body in peripheral ganglion
What kind of ganglion is defined as a string of paired autonomic ganglia lying alongside the spinal cord from the base of the skull to the coccyx (one on each side of the cord)
Sympathetic trunk ganglion
How are sympathetic chain gangion connected to spinal nerves?
By Rami
What kind of ganglion are located near the organs they serve ?
They are Autonomic ganglion called collateral ganglion
What kind of ganglion are located within the substance of the organs they serve?
Autonomic ganglion called terminal ganglion.
Where do sympathetic presynaptic neurons originate?
lateral horns of gray matter of thoracic to lumbar cord (T1-L2)
Name the three variety of pathways of preganglionic fibers in the sympathetic system
- they enter ganglia & synapse 2. They travel to higher or lower ganglia & synapse 3. They pass through chain without synapsing to reach collateral ganglia via splanchnic nerves.
Define neuronal divergence
preganglionic cells synapse with multiple post ganglionic cells . This produces a widespread effect on multiple organs.
True or False there is a simple one to one relationship between pre and post ganglionic neurons.
False
Define neuronal convergence
Each postganglionic cell may receive synapses from
multiple preganglionic cells
True or false Neuronal divergence allows sympathetic
division to have a relatively widespread effect
True , divergent starts off simple and spreads out
What is another name for the sympathetic division?
It is also called the Thoracolumbar division because they arise from the thoracic
and lumbar regions of the cord
True or false the sympathetic division has short preganglionic and long
postganglionic fibers
True
Where are the preganglionic somas in the sympathetic division ?
lateral horns and nearby regions of gray matter
How do fibers in the sympathetic division exit?
fibers exit by way of spinal nerves
T1-L2
Where do the sympathetic fibers lead to?
fibers lead to sympathetic chain of
ganglia(paravertebral ganglia)
along each side of the cord.
True or false sympathetic consists of Short, lightly myelinated preganglionic neurons?
True
True or false sympathetic division consists of Long
, unmyelinated postganglionic neurons
True
In the sympathetic division what are the ganglion closest to?
spinal cord
True or false white & gray communicating rami suspend ganglia from spinal nerve
True
How many paths can a preganglionic fiber in the sympathetic division take? what are they?
There are three different paths . The preganglionic fiber may synapse IN the ganglion, The preganglionic fiber may pass through sympathetic ganglion without synapsing and synapse in a more distant ganglion, Lastly a preganglionic neuron can ascend or descend to another ganglion .
Sympathetic nerve fibers(Post ganglionic) leave the paravertebral ganglia by what three routes?
spinal nerves,sympathetic nerves and, splanchnic nerves
How do post ganglionic fibers leave while exiting the spinal nerve?
postganglionic fibers exit by way of the gray ramus, return to the spinal nerve or its subdivision, and travel the rest of the way to the target organ
What post ganglionic route innervates most effectors in the body wall?
The spinal route innervates sweat glands, piloerector muscles,blood vessels of the skin and skeletal muscles.
Which Nerve originates from T5-T12 and passes through the chain without synapsing ?
Splanchnic Nerve
How do post ganglionic fibers leave when exiting through the sympathetic nerve route?
postganglionic fibers leave by way of sympathetic nerves that extend to the heart, lungs, esophagus, and thoracic blood vessels
What are the three major collateral ganglia?
celiac, superior mesentric , and inferior mesentric
What do the unmyelinated postganglionic axons of the ciliac ganglion innervate?
stomach, liver, gallbladder, spleen, kidney, small intestine, and the ascending and transverse colon
What does the inferior mesentric ganglion innervate?
the viscera of the distal intestines and pelvis
What does the superior mesentric ganglion innervate?
proximal intestine and abdominal organs.
Where are the adrenal glands located?
Paired glands sit on superior pole of each kidney
What part of the Adrenal gland secretes steroid hormones ?
The cortex of the Adrenal gland
The sympathetic system and adrenal glands work together and form what system?
The Sympathoadrenal system
Where do preganglionic fibers in the Parasympathetic system originate?
The pons and medulla oblongata for crnial nuclei and spinal cord segments S2-S4
What cranial nerves run along the pathwyas of parasympathetic preganglionic fibers?
CN’s III, VII, IX, & X
What is the parasympathetic function of CN(III)
Oculomotor nerve, narrows pupil and focuses lens
What is the parasympathetic function of CN(VII)
Facial nerve, regulates secretion of tears, lacrimal, and 2 salivary glands
What is the parasympathetic function of CN(IX)
Glossalpharyngeal nerve, regulates parotid salivary gland
What is the parasympathetic function of CN(X)
Vagus nerve, muscles, and glands of the viscera as far inferiorly as the proximal half of the colon
True or false In the parasympathetic nervous system pre ganglionic nerves are long
true
True or false In the parasympathetic nervous system post ganglionic nerves are short
true
What is the enteric nervous system?
The NS of the digestive track
True or false the Enteric NS has its own reflex arcs
True
What , in specific , does the enteric system do?
Regulates motility of viscera and secretion of digestive enzymes and acid in concert with the ANS
What , in specific , does the enteric system do?
Regulates motility of viscera and secretion of digestive enzymes and acid in concert with the ANS
What two plexus does the enteric NS form?
myenteric, and submucosal plexus
True or false does the enteric system arise from the brain stem or spinal cord?
False
What does the Enteric NS innervate? (same as ANS)
Smooth muscle and glands
The Myenteric and submocosal plexus Controls activity of gastrointestinal tract in three ways
Controls intestinal peristalsis, modulating blood flow through gut, and regulates the release of secretions from the gastrointestinal glands.
True or false , the gastrointestinal activities can be influenced by the parasympathetic system only.
False both the sympathetic and parasympathetic can influence the gastrointestinal activities.
What determines the effects of the autonomic nervous system?
The types of neurotransmitters, and types of receptors on target cells.
Which subdivision of the Autonomic system has longer lasting effects because it reaches the bloodstream before being broken down?
The sympathetic NS .
What are the two classifications of neurotransmitters in the ANS?
Cholinergic and Adrenergic
ACh binds to what two classes of cholinergic receptor?
Nicotinic and Muscarinic receptors
Where can you find nicotinic receptors? And are they inhibitory or excitatory ?
Occur on all ANS postganglionic neurons in the adrenal medulla and at neuromuscular junctions( skeletal muscle) . Excitatory
Where can you find Muscarinic receptor? Are they inhibitory or excitatory?
Occurs on all glands, smooth muscle, and cardiac muscle . It can be either excitatory or inhibitory
True or false . Cholinergic receptors are found on dendrites and cell bodies of the entire ANS However can only be found in the target organs of ONLY the Parasympathetic NS
True
Is the mechanism for action in a cholinergic receptor Indirect? Or Direct?
Direct, a neurotransmitter binds and the ion gates open
Is the mechanism for action in a Muscarinic receptor Indirect? Or Direct?
Indirect, Muscarinic receptors use G proteins as their signaling mechanism, which begin an information cascade within the cell.
How do Muscarinic Receptor Effect Cariac muscle ?
Slows heart rate and strength of contraction
How doMuscarinic Receptor Effect the digestive system?
Increases digestive activity including secretions & peristalsis.
How do Muscarinic Receptor Effect the eye
Causes constriction of Iris
The NT neuropinephrine binds to what two classes of receptors?
Alpha and Beta Adrenergic receptors
What is the difference between Alpha and Beta Adrenergic receptors?
Alpha is exitatory and Beta is inhibitory
What are the sub classes to Alpha and Beta Adrenergic receptors?
There is Alpha 1 &2 and Beta 1&2 Adrenergic receptors
What do Beta receptors activate?
Cyclic AMP
What does Alpha 2 suppress?
cAMP production
What does Alpha 1 use as a second messenger?
calcium ions
What is the stimulation of Alpha receptors associated with ?
Constriction of small blood vessels in the bronchial mucosa
What is the stimulation of Beta receptors associated with ?
Relaxes bronchial smooth muscles which cause the bronchi of the lungs to dilate and cause an increase in the rate and force of heart contractions
In the sympathetic system where are the ganglia located and what are their names?
Located Paravertebral, and its name is sympathetic chain ganglia
In the Parasympathetic system where are the ganglia located and what are their names?
Located Prevertebral, and their names are Colleteral and Terminal ganglions
In the Sympathetic system Preganglionic axons are ____ while Postganglionic axons are ____.
Short, Long
In the Parasympathetic system Preganglionic axons are ____ while Postganglionic axons are ____.
Long, Short
What neurotransmitter is used in the sympathetic system, Postganglionic ?
Norepinephrne
What neurotransmitter is used in the Parasympathetic system, Postganglionic ?
ACh
What are the three special ganglia in the Sympathetic system ?
Superior, middle, & inferior cervical; celiac; superior, inferior mesenteric
What are the four special ganglia in the Parasympathetic system ?
Ciliary, Pterygopalantine, Submandibular, Edinger-Westphal Nucleus
What is Sympathetic tone ?
A baseline firing frequency, the average firing frequency
Define Vasoconstriction
Increase in firing frequency
Define Vasodilation
Decrease in firing frequency
What is the point of Vasomotor tone?
It shifts blood flow from one organ to another according to its needs. EX: sympathetic stimulation increases blood to skeletal and cardiac muscle, reduced blood to skin.
True or False Lacrimal glands are innervated by parasympathetic only !
TRUE
What can respond directly to sensory input from cardiac, vasomotor, and GI tract?
Reticular formation and brain stem
Sympathomimetics ___ sympathetic activity and___receptors or norepinephrine release
enhance , stimulate
Sympatholytics ____ sympathetic activity
____receptors or norepinephrine release
Suppress, inhibit
