Pathophysiology Exam #5 Flashcards
The autonomic nervous system is responsible for what parts of the body(5)?
TISSUES AND ORGRANS NOT USUALLY UNDER VOLUNTARY CONTROL: 1. Cardiac muscle 2. Electrical fibers of the heart 3. Smooth muscle of the blood vessels, ducts, urinary bladder, uterus and ect.(any other smooth muscle of the body) 4. Gland(many glands in the body) 5. Visceral muscle(GI)
Compare and contrast the differences in nerve pathways between somatic motor and autonomic.
Somatic Motor: -nerve cell body exits out of the anterior horn->rootlets/roots/common nerves to the anterior side and brings about a response to the skeletal muscle Autonomic: -Begins in the lateral horn of the gray matter(where nerve cell body is located) -axon passes through anterior horn/rootlets/anterior root/common spinal nerve and terminates on autonomic ganglion. -the first nerve terminates and synapse with second nerve at the autonomic ganglia -the second nerve exits the autonomic ganglia into a peripheral nerve and terminates on tissues/organs that receive autonomic innervation.
How many somatic motor neurons are there between the SC to the target tissue/organ?
1
How many autonomic neurons are there between the SC and the target tissue/organ?
2
What are the names of the two autonomic neurons between SC and the target tissue/organ?
-preganglionic neuron -postganglionic neuron
What are the two divisions of the autonomic nervous system?
-Sympathetic Nervous System(Thoracolumbar Division) -Parasympathetic Nervous System(Craniosacral Division)
Where does the name Thoracolumbar come from?
nerve cell bodies of the preganglionic neurons are from T1-L2
Where does the name Craniosacral come from?
-4 of the CNs have parasympathetic fibers(3,7,9,10) -the other preganglionic neurons are located in the sacral segments of the SC(S2-S4)
What 4 parasympathetic nerves are located in the CN?
-oculomotor(3) -facial(7) -glossopharyngeal(9) -vagus(10)
The Thoracolumbar pathways are sympathetic or parasympathetic?
sympathetic
In the ANS are the preganglionic axons myelinated or unmyelinated?
Myelinated
In the ANS are the postganglionic axons myelinated or unmyelinated?
Unmyelinated
What type of nerve fibers are postganglionic axons?
type C neurons(unmyelinated)
What are the sympathetic chain ganglia?
-lie on either side of the vertebral column -location where preganglionic neurons synapse and innervate postganglionic neurons
What are the collateral ganglia?
-lie anterior to the vertebral column
Trace the pathway of the sympathetic neuron from SC to target tissue/organ.
-exits the SC -> spinal nerve and very quickly enters into a sympathetic chain ganglia -at the sympathetic chain ganglia, they synapse with the postganglionic neuron -postganglionic neuron exits the sympathetic chain ganglia and passes out to the target tissue/organs via the spinal nerve/sympathetic nerve/splanchnic nerve
What is the function of the splanchnic nerve?
The splanchnic nerve is where the organs and tissues of the abdominal cavity get their autonomic innervation.
Is the craniosacral division of the ANS representative of sympathetic or parasympathetic?
parasympathetic
What is the most DOMINANT parasympathetic nerve in the body?
CN#10 vagus nerve
In the parasympathetic division, where do the preganglionic nerves terminate?
-terminate with the postganglionic neuron in the parasympathetic ganglia(terminal ganglia) -after terminating here the postganglionic neuron terminates and synapse with the target tissue/organ
Are there sympathetic chain ganglia or collateral ganglia involved with the craniosacral division of the ANS?
no just the sympathetic division
Describe the parasympathetic ganglia.
-called terminal ganglia -specific to the parasympathetic nervous system -ganglia are very close, sometimes even in the walls of the target organs being innervated
Are the parasympathetic preganglionic neurons myelinated or unmylenated?
myelinated
What type of nerve fibers make up the postganglionic nerves?
Type C
The vagus nerve innervates the _____ _____ and part of the _____ _____.
-ascending colon -transverse colon
The rest of the transverse colon, the descending colon, sigmoid colon, the bladder, the genitals, the rectum and the anus receives its parasympathetic innervation from the?
sacral division of the parasympathetic nervous system
What is the nerve that extends down both sides of the neck giving off collateral to almost all the tissues and organs of the thoracic and the abdominal cavities?
Vagus nerve
Where is the nerve cell body of the preganglionic neuron located?
-lateral horns of the gray matter -SC segments T1-S2
In the typical SNS, where does the preganglionic neuron terminate?
in a sympathetic ganglion(either side of vertebral column; sympathetic chain ganglia and anterior to the vertebral column before the collateral ganglia)
In the typical sequence of events of the SNS, what neurotransmitter if released when the preganglionic neuron terminates and innervates the postganglionic neuron?
acetylcholine
In the typical sequence of events of the SNS, the receptors on the dendrites of the postganglionic neurons that respond to acetylcholine are?
Nicotinic TYPE 2 receptors
In the typical sequence of events of the SNS, once the postganglionic neuron is innervated the impulse is transmitted along the axon and terminates at the synapse of the target tissue/organ. What neurotransmitter is released at this synapse?
norepinephrine
The receptors on the target tissues/organs that respond to NE are?
adrenergic receptors
What are two types of adrenergic receptors?
alpha and beta
In the typical sequence of events of the SNS, since NE is the neurotransmitter released at the synapse with the target organ/tissue, this is called what type of pathway?
Sympathetic Adrenergic Pathway
In a deviation for the typical sequence of events of the SNS, what neurotransmitter is released where the pre ganglion synapse with the post ganglion?
acetylcholine
In a deviation for the typical sequence of events of the SNS, what neurotransmitter is released where the post ganglion terminates on the target tissue/organ?
acetylcholine
In a deviation for the typical sequence of events of the SNS, the receptors on the dendrites of the postganglionic neurons that respond to acetylcholine are?
they are still NICOTINIC TYPE 2 receptors
In this deviation of the normal events of the SNS, what are the neurotransmitter receptors located on the target tissue/organ?
Muscarinic receptors.
The deviation of the typical sequence of events of the SNS occurs in very few target tissues/organs. Name 3.
-sweat glands(sweating is a sympathetic outcome -smooth muscle -some blood vessels; causing them to dilate(not all just some) THIS IS A SYMPATHETIC /MUSCARINIC OUTCOME
The deviation in the normal sequence of events in the SNS when ACh is released at the synapse of the post ganglia and the target tissue/organ receptor is Muscarinic is called.
Sympathetic Cholinergic Pathway—>because ACh is the neurotransmitter at the final synapse
Regarding the parasympathetic nervous system, where are the nerve cell bodies of the preganglionic neurons located?
-medulla -midbrain -sacral divisions of the SC CRANIOSACRAL DIVISION
When the preganglionic neuron of the PNS terminates at the parasympathetic ganglion, what neurotransmitter is released?
ACh
What types of receptors are located on the dendrites of the post ganglionic neurons that are innervated by the preganglionic neuron of the PNS?
NICOTINIC TYPE 2
In the PNS when the postganglionic neuron terminates on the target tissue/organ, what is the neurotransmitter released and what type of receptors does it bind to?
ACh & muscarinic receptors—>this brings about the final response
All parasympathetic pathways are parasympathetic cholinergic pathways(t/f) and why?
True; because ACh is the neurotransmitter released at the final synapse and binds to muscarinic receptors
At every ganglionic synapse, what is the neurotransmitter released from the preganglionic neuron?
ACh
At every ganglionic synapse, what are the receptors on the dendrites of the postganglionic neuron?
Nicotinic type 2 receptors
How is the SNS and the PNS involved in the baroreceptor response of the CV autonomic reflex centers?
-there are baroreceptors in the internal carotids and the aortic arch that respond to changes in blood pressure determined by the volume of blood ejected from the LV. -when pressure increases in these areas, baroreceptors are activated which transmits sensations towards the medulla. -when the glossopharyngeal(CN#9) and vagus(CN#10) approach the medulla, they join together to form the tracts solitarius. -this tract terminates in the nucleus solitarius in the medulla and sends impulses to the medullary CV center
What is the name of the tract where CN# 9 and 10 combine as they approach the medulla?
tractus solitarius
What is the name of the location where the tracts solitarius terminates in the medulla?
nucleus solitarius
What specific adrenergic receptor is either excited or not excited based on BP and what is the outcome?
central Alpha-2 receptors -if BP is high alpha-2 is excited—>sympathetic outflow is decreased and parasympathetic outflow is increased -if BP is low, alpha-2 is depressed—>causing sympathetic outflow to increase and parasympathetic outflow is decreased. This response either increases or decreases: HR, CO, SV and can cause veins and arteries to either dilate or constrict.
The CF medullary response by the SNS/PNS is only useful for SHORT-TERM regulation of BP(t/f)?
true-if BP increases and stays increased over hours-to-days, then the baroreceptors will reset themselves to that new BP and therefore are no longer useful in regulating BP
What is the location of the vagus nerve and what is the function in regards to the autonomic regulation of BP?
CN 10(vagus)-nerve cell body is in the medulla, efferent parasympathetic pathway thru the vagus, directly to the SA node. It is the vagal parasymp stim that slows the HR and plays a very major role in maintaining HR, CO, SV and BP
The autonomic nervous system is also regulated by higher brain centers such as the(3)….?
-cerebral hemispheres -various parts of the limbic system -various parts of the hypothalamus ALL CAN HAVE SOMETHING TO DO WITH THE REGULATION OF SYMPATHETIC/PARASYMPATHETIC AUTONOMIC OUTFLOW
How are the higher brain centers involved with autonomic regulation as related to the limbic system?
-if a person has changes in their emotional status(fear, joy, anger,etc) can often cause responses within their CV, resp system and other parts of the body under ANS control -these emotions in higher brain centers are transmitted first to the hypothalamus and then autonomic regulatory centers in the hypothalamus regulate para/symp outflow from lower brain centers to target organ/tissues when your happy your happy all over; when your sad your sad all over PROBABLY THE REASON FOR THOSE TOTAL BODY RESPONSES TO EMOTIONS IS EXPLAINED BY THIS INTERACTION
True or False: Most organs/tissues have both sympathetic and parasympathetic innervation?
TRUE -usually in a certain organ/tissue, either symp/para predominates at a certain time -just because one or the other is predominate at a given time does not mean the other one is completely absent -there is always interplay between symp/para—>although one maybe predominant dosnet mean the other one is having zero effect at that time
In the sympathetic(thoracolumbar) system, where are the nerve cell bodies/preganglionic neurons located?
lateral horns of the gray matter in the SC segments T1-L2
How many chain ganglia are there and where are they located? Which ANS are they active in?
-There are two, each located on each side of the vertebral column -Sympathetic
How many collateral ganglia are there and where are they located? Which ANS are they active in?
-4 collateral ganglia -anterior to the vertebral column -Sympathetic
What are the names of the four collateral ganglia?
-Celiac ganglion -Superior mesenteric ganglion -Inferior mesenteric ganglion -Hypogastric ganglion
In the sympathetic division of the ANS, where do the pre ganglion nerve fibers T1-T4 terminate and synapse?
-they terminate in the chain ganglion
In the sympathetic division of the ANS, when the pre ganglion nerve fibers T1-T4 terminate and synapse, what type of nerve cell fibers are innervated? ?
preganglionic nerve fibers synapse with the postganglionic neurons; type-C unmyelinated
In the sympathetic division of the ANS once the postganglionic fibers(from T1-T4) have been innervated, what happens to the impulse?
-they exit the symp chain ganglia and enter either the spinal nerves or sympathetic nerves terminating on their target tissue/organ
In the sympathetic division of the ANS once the postganglionic fibers have been innervated(T1-T4), what six tissues/organs are innervated?
-Eye: SNS regulates the diameter of then pupil and tear production -Nasal mucosa: changes the nature of of the secretions of the nose -Salivary glands(sublingual/submandibular): SNS changes amount and characteristics of saliva -Parotid gland -Sympathetic innervation of the heart: direct symp innervation of the SA node, AV node and the ventricular contractile fibers -Smooth muscle of the tracheobronchial tree: the smooth muscle beginning with the trachea all the way down to the bronchi/bronchioles as significant amounts of smooth muscle(symp regulates diameter of particularly the bronchioles
In the sympathetic division of the ANS how is the sequence events of innervation different for T5-L2?
-The preganglionic neurons exits the SC and enter the sympathetic chain ganglion, but they pass through without synapsing
In the sympathetic division of the ANS what four specific nerves do the preganglionic neurons from T5-L2 pass through before reaching the collateral ganglia?
-Greater splanchnic nerve -Lesser splanchnic nerve -Lumbar splanchnic nerve -Sacral splanchnic nerve
So where in the sympathetic division of the ANS do the preganglionic neurons synapse and terminate?
on the collateral ganglion -celiac ganglion -superior mesenteric ganglion -inferior mesenteric ganglion -hypogastric ganglion
How is the adrenal medulla innervated?
-from a preganglionic neuron along the greater splanchnic nerve—>celiac ganglion tract -even though a preganglionic neuron terminates on the celiac ganglion, an additional innervation continues down to the adrenal medulla and terminates on it *The adrenal medulla receives direct innervation from a sympathetic preganglionic neuron*
What is the significance of the way the adrenal medulla is innervated?
-by receiving direct innervation from a preganglionic neuron, the adrenal medulla is analogous to a sympathetic postganglionic neuron -So when it is excited, it behaves like and takes the place of a sympathetic postganglionic neuron
What is the effect of the adrenal medulla becoming innervated(excited)?
-It secretes catecholamines(NE/EPI/DOP) SECRETION FROM THE ADRENAL MEDULLA INTENSIFIES THE SYMPATHETIC RESPONSES THROUGHOUT THE BODY
What tissues/organs are innervated by the sympathetic ANS from T5-L2?
-small intestines -ascending colon -transverse colon -descending colon -sigmoid colon -rectum -anus -smooth muscle of the urinary bladder -genitals
What are the four cranial nerves innervated by the parasympathetic division of the autonomic nervous?
3,7,9,10
What is the result of the parasympathetic innervation of CN#3?
Oculomotor: innervates/helps regulate the diameter of the pupil
Where are the parasympathetic ganglia located?
They are usually located close to or in the wall of the target organ/tissue
