ANS- Prodigy FCs Flashcards
What are the two main subdivisions of the autonomic nervous system?
Sympathetic and Parasympahtetic
Where do sympathetic postganglionic neurons originate?
In the peripheral sympathetic ganglia or one of the sympathetic chain ganglia
Parasympathetic nerve fibers from cranial nerve IX innervate what gland?
The parotid gland
Parasympathetic fibers from cranial nerve VII serve what areas? (3)
The nasal, submandibular, and lacrimal glands.
Parasympathetic nerve fibers located within cranial nerve III innervate what two areas?
The ciliary muscle of the eye and the pupillary sphincter.
B2 Relaxation of the ciliary muscle > lens flattens > far vision (SNS)
CN 3 > M1 - constriction of ciliary muscle > lens protrudes > near vision (PNS)
A1 - Contracts pupillary muscle/ sphincter > Dilates the pupil (SNS)
CN3 > M1? - relaxes the pupillary sphincter > constricts the pupil (PNS)
Parasympathetic nerves are supplied via the vagus nerves to what areas of the body? (11)
Esophagus
Heart
Lungs
Stomach
Liver
Gallbladder
Pancreas
Small intestine
Proximal colon
Upper ureters
Kidneys
Where do parasympathetic nerve fibers exit the CNS?
Cranial nerves 3, 7, 9, 10
S2-S4
At what point do preganglionic sympathetic fibers exit spinal nerves?
Immediately following the spinal nerve’s exit from the spinal canal (T1-L2)
Where are the cell bodies of sympathetic preganglionic neurons found?
In the intermediolateral (IML) horn of the spinal cord.
How do sympathetic nerves differ from skeletal motor nerves?
Skeletal motor nerves are comprised a 1 single neuron
Sympathetic pathways are comprised of 2 neurons which are termed preganglionic and postganglionic neruons
Approximately 75% of all parasympathetic nerve fibers can be found in what cranial nerve?
Cranial nerve X (vagus)
- Does the parasympathetic nervous system contain both preganglionic and postganglionic neruons?
- How do they differ from the sympathetic pathways?
- Yes
- Most preganglionic parasympathetic fibers travel uninterrupted the entire way to the effector organ.
All preganglionic neurons (sympathetic and parasympathetic) are cholinergic and therefore secrete what neurotransmitter?
Acetylcholine
Name the two main receptors that acetylcholine activates.
Nicotinic and Muscarinic
What are the two major types of adrenergic receptors?
Alpha and Beta
Almost all of the parasympathetic postganglionic neurons are cholinergic and therefore secrete what NT?
Acetylcholine
What beta receptor is responsible for thermogenesis?
Beta 3
Are nerve fibers that secrete NE considered cholinergic or adrenergic?
Adrenergic
Are nerve fibers that secrete acetylcholine considered cholinergic or adrenergic?
Cholinergic
Are the sympathetic nerve fibers that terminate in the adrenal medulla preganglionic or postganlionic? What NT do they secrete?
Preganglionic, Acetylcholine
Where are parasympathetic postganglionic neurons located?
Within the wall of the effector organ (or very close to it)
- The majority of sympathetic postganglionic neurons are adrenergic and therefore secrete what substance?
- Sympathetic postganglionic nerve fibers serving what 3 areas are cholinergic?
Norepi
- Cutaneous arterioles
- Sweat glands
- Piloerector muscles
Sacral parasympathetic fibers are distributed to what areas of the body? (5)
- Descending colon
- Urinary bladder
- Rectum
- Lower portions of ureters
- External genitalia
What beta receptor is responsible for increasing cardiac contractility and increased HR?
B1
What alpha receptor is responsible for vasoconstriction?
Alpha 1
(and post-synaptic alpha-2 in VSM)
What alpha receptor results in inhibition of NT release when stimulated?
Presynaptic alpha-2
What beta receptor is responsible for uterine and intestinal relaxation?
Beta 2
What beta receptors are located in the lungs that result in bronchodilaton when stimulated?
Beta 2
What beta receptor is responsible for glycogenolysis, lipolysis, and bladder wall relaxation?
Beta 2
(I thought lipolysis was beta 3?)
What is the effect of sympathetic nervous system activation on heart muscle?
Increased inotropy
What is the effect of sympathetic stimulation on the gallbladder and bile ducts?
Relaxation
What effect does sympathetic stimulation have on the liver?
Causes the liver to release gluose/Glycogenolysis
How does activation of the sympathetic nervous system affect the gut?
Decreased peristalsis and decreased tone within the lumen
How does activation of the SNS affect the lungs?
Bronchodilation and mild constriction of blood vessels
(more air, less blood? maybe? lol)
What happens when beta 2 receptors within the coronary arteries are stimulated?
They vasodilate
How does stimulation of the SNS affect sweat glands?
Increase sweat release
What are the renal effects of SNS stimulation?
Decreased UOP and increase in RENIN secretion
Renin - released from juxtaglomerular apparatus
Converts angiotensinogen to angiotension 1
How does activation of the SNS Affect heart rate?
Increased chromotropy
How does stimulation of the sympathetic nervous system affect the nasal, parotid, submandibular, gastric, pancreatic, and nasal glands?
Vasoconstriction and minimal secretion
How does activation of the SNS Affect systemic arterioles of the abdominal viscera and skin?
Vasoconstriction
What effect does activation of the SNS have on fat cells?
lipolysis
How does stimulation of the SNS affect the piloerector muscles?
Causes them to contract
How does SNS activation affect skeletal muscle?
Increase in glycogenolysis and increase in strength
How does activation of the SNS affect the adrenal medulla secretion?
Increased epi and norepi release (80%/20%)
How does activation of the SNS affect coagulation?
increased coagulation
How does activation of the SNS affect the penis?
Ejaculation
How does SNS stimulation affect the detrusor and trigone muscles of the bladder?
Relaxation of the detrusor muscle (pee = contraction of this muscle)
Contraction of the trigone muscle (prevent pee form coming out)
How does SNS activation affect basal metabolism?
increases it up to 100%
How does stimulation of the SNS Affect the pupil?
Mydriasis
How does stimulation of the SNS affect the apocrine glands?
Causes them to release odiferous, thick secretions
How does activation of the PSNS affect systemic arterioles?
No effect
How does activation of the PSNS affect the penis?
Erection
How does PSNS stimulation affect the detrusor and trigone muscles of the bladder?
Causes detrusor to contract and trigone to relax (so you can pee)
How does PSNS stimulation affect the pupil?
Miosis
How does PSNS stimulation affect the gallbladder and bile ducts?
Contraction
How does PSNS stimulation affect the kidney?
No effect
How does PSNS stimulation affect adrenal medulla secretion?
No effect
Is there any parasympathetic activity in fat cells?
Nope
Does activation of the PSNS have any effect on skeletal muscle?
Nada
How does PSNS stimulation affect the piloerector muscles?
No effect
Is there any parasympathetic effect on coagulation?
Negative
How does PSNS activation affect basal metabolism?
It doesn’t!
How does PSNS stimulation affect the sweat glands?
It produces sweat on the palms of the hands
How does PSNS stimulation affect the lacrimal, parotid, nasal, submandibular, pancreatic, and gastric glands?
Increased secretion
Does stimulation of the PSNS have any effect on apocrine glands?
no0o0o0
How does PSNS stimulation affect the gut?
Increased muscle tone of the GI tract and increased peristalsis
How does PSNS stimulation affect the bronchi?
Bronchoconstriction
How does PSNS stimulation affect the liver?
Slight increase in glycogen synthesis (storage of glucose)
How does PSNS stimulation affect the heart muscle?
Decreased inotropy
How does PSNS stimulation affect the HR?
decreases it via the vagus nerve and M2 receptors
How does PSNS stimulation affect the coronary arteries?
dilation ? I thought SNS did this…maybe not… that’s why people have MI’s related to stress
What 2 hormones are released into the bloodstream in mass quantities when stimulation of sympathetic nerves to the adrenal medulla occurs?
Epi (80%) and NE (20%)
All sympathetic NTs are synthesized from what substance?
Where does this synthesis take place?
Tyrosine
Synthesized in the post-ganglionic sympathetic nerve ending
(makes sense since postganglionic sympathetic neurons are the ones to release NE)
Where do sympathetic nerve fibers orginate?
In the spinal cord and spinal nerves between T1-L2.
>Then pass into the sympathetic chain
>Then on to the organs and tissues they innervate
The ANS is responsible for regulating what functions? (7)
Arterial pressure control
GI secretions
GI motility
Bladder emptying
Sweating
Body temp
Involuntary regulation of smooth and cardiac muscle
Are postganglionic neurons of the PSNS considered to be cholinergic or adrenergic?
Cholinergic
Where are the muscarinic receptors located?
On all effector cells stimulated by the postganglionic cholinergic neurons of either the PNS or SNS
Cardiac pump function is affected by the SNS and PSNS in what 3 ways?
Heart rate (Chronotropy)
Force of contraction (Inotropy)
Modulation of coronary blood blow
The anterior hypothalamus is involved with the regulation of what?
Temperature regulation
What is the supraoptic hypothalamus responsible for regulating?
Water metabolism
What is the primary area for relay of afferent chemoreceptor and baroreceptor information from the vagus and glossopharyngeal nerves?
The nucleus tractus solitarius (within the medulla)
Increased afferent impulses from the glossopharyngeal and vagus nerves inhibit the peripheral sympathetic nervous system resulting in…
peripheral SNS vascular tone is inhibited
>Vasodilation.
Vagal tone is increased
>Bradycardia
What is the thoracolumbar nervous system?
The efferent SNS
>starts in the IML gray column of T1-L2/3
The fusion of the inferior cervical and first thoracic sympathetic nervous system ganglia is called what?
What does it provide innervation to?
Stellate ganglia/Cervicothoracic ganglia
-Provides sympathetic innervation to the head, neck, upper extremities, heart, and lungs.
Which NT is present in the CNS and primarily involved in the coordination of motor activity in the brain?
Dopamine
What is the predominant pathway for inactivation of the endogenous catecholamines?
What about exogenous catecholamiens?
Reuptake - Endogenous
Metabolism by liver and kidneys - Exogenous
What is the predominate metabolite of norepinephrine found in the urine?
Vanillylmandelic acid
What are the characteristics of muscarinic stimulation? (6)
- Bradycardia
- Decreased contracility
- Miosis
- Bronchoconstriction
- Increased gastric secretion
- GI hypermotility
When given in low doses, which two muscarinic antagonists may produce paradoxical bradycardia?
Atropine and scopalamine
Which commonly used drug is a centrally acting selective partial alpha-2 adrenergic agonist?
What does it cause?
Clonidine
>causes a decrease in central sympathetic outflow
Which narcotic has been reported to produce HTN crisis, convulsions, and coma in patients taking MAO inhibitors?
Meperidine
