Autonomics Flashcards
What is the Peripheral Nervous System broken down into?
Afferent and Efferent
What is the Efferent Nervous System broken down into?
Somatic and Autonomic
What is the Autonomic Nervous System broken down into?
Sympathetic and Parasympathetic
What receptor works in the sympathetic nervous system?
Nicotinic receptors
How are the neurotransmitters released in the sympathetic nervous system?
ACh is released from the synapse of the preganglionic fiber
Norepinephrine is released from the target organ
Which nervous system has short preganglionic fibers?
Sympathetic nervous system
Which nervous system has long preganglionic fibers?
Parasympathetic Nervous System
Which nervous system has long postganglionic fibers?
Sympathetic Nervous System
Which nervous system has short postganglionic fibers?
Parasympathetic Nervous system
The sympathetic nervous system can have two pathways. What is unusal about the second one (the more uncommon one/the exception)?
It does not use ganglionic fibers
It can directly innervate the adrenal medulla
The nicotinic receptors and ACh are directly in the Adrenal medulla, which releases epinephrine for the smooth muscle, cardiac muscle, and glands
What kind of receptors are involved in the parasympathetic nervous system?
Preganglionic fiber -> Nicotinic receptor -> postganglionic fiber -> Muscarinic receptor
Where do the cell nuclei originate for the parasympathetic nervous system?
In the brain stem and sacrum -> making it Cranial Sacral
What is another name for the parasympathetic nervous system?
Cranialsacral parasympathetic nervous system
What do sacral preganglionic fibers do?
stimulate the genital/urinary system
where do the cell nuclei in the sympathetic nervous system originae?
Thoracic nerves and lumbar nerves -> making it Thoracolumbar
Where do the lumbar nerves synapse at?
Celiac, Superior mesenteric, and inferior mesenteric
What is special about how the sympathetic nervous system synpases?
it can go up, down, or bypass the sympathetic chain
What is the sympathetic chain?
A chain of bundled nervous that run from the skull to the coccyx formed by the paravertebral ganglia
What are the general functions and characteristics of the Autonomic Nervous system?
- to preserve homeostasis and provoke reactions to protect the individual
- Afferent impulses from the viscera elicit reflex responses which generally cannot be controlled voluntarily
- Many fibers of the ANS are always active
- Sympathetic and Parasympathetic nervous systems are generally antagonistic
- Activation of the sympathetic system is generally associated with defense mechanisms
- Activation of the Parasympathetic system is associated with conservative and restorative processes
What do afferent impulses from the viscera in the Autonomic Nervous system do?
They elicit reflex responses which generally cannot be controlled voluntarily
What do the fibers that are always active in the ANS do?
They maintain a basal tone in most organs
e.g.: a certain level of constriction of blood vessel by the sympathetic nervous system. A parasympathetic tone in the G.I. tract
What is the exception to the antagonistic nature of the Sympathetic and Parasympathetic nervous systems?
Salivary glands, where both systems stimulate secretion
What defense mechanisms are involved in the activation of the sympathetic nervous system?
defense mechanisms involving the expenditure of energy, glycogenolysis, increased muscle tone, etc. (breathing , fight or flight)
What are examples of the conservative and restorative processes activation of the parasympathetic nervous system is associated with?
Decrease in blood pressure
decrease in body temperature
constricted airways
What is the neurotransmitter for the parasympathetic nervous system?
ACh
What neurotransmitter used in the sympathetic nervous system?
Norepinephrine
What is the target receptor in the parasympathetic nervous system?
Muscarinic Receptors
What does norepinephrine do in the sympathetic nervous system?
It mediates transmission of nerve impulses from autonomic postganglionic nerves to effector organs
What does ACh do in the parasympathetic nervous system?
it’s release is involved in transmission of nerve impulses from the autonomic postganglionic nerves to the effector organs
What does ACh do in the parasympathetic and sympathetic nervous systems?
it mediates all transmissions of nerve impulses across autonomic ganglia
What does acetylcholinesterase do?
It quickly breaks down and destroys ACh
Where are muscarinic receptors found?
the cells of effector organs
Where are nicotinic receptors found?
in all autonomic ganglia
How is dopamine converted to NE?
- Tyrosine hydrolyzes to Dopa
- Dopa is converted to Dopamine
- Dopamine is converted to NE
Where is the alpha2 receptor?
On the postganglionic fiber
What do DOMA, NMN, MOPEG, and VMA have in common?
They are all ways to metabolize NE
They break it down
What role does alpha2 have?
it takes NE back into the cell
What is the target tissue of the α1 receptor?
Vascular smooth muscle, skin, renal, and splanchnic
Gastrointestinal tract, sphincters Bladder, sphincter radial muscle, iris
What is the target tissue of the α1 receptor?
Vascular smooth muscle, skin, renal, and splanchnic
Gastrointestinal tract, sphincters
Bladder, sphincter
radial muscle, iris
What is the target tissue of the α2 receptor?
GI tract, wall
Presynaptic adrenergic neurons
What is the target tissue of the β1 receptor?
Heart
Salivary glands
Adipose tissue
Kidney
What is the target tissue of the β2 receptor?
Vascular smooth muscle of skeletal muscle
GI tract, wall
Bladder, wall
Bronchioles
What is the target tissue of the nicotinic receptor?
Skeletal muscle, motor end plate
Postganglionic neurons, SNS and PNS
Adrenal Medulla
What is the target tissue of the muscarinic receptor?
All effector organs, PNS
Sweat glands, SNS
What are the adrenoreceptors?
- α1
- α2
- β1
- β2
What are the cholinoreceptors?
- Nicotinic
- Muscarinic
What are the agonists of the α2 receptor?
Clonidine
What are the antagonists of the α2 receptor?
Yohimbine
What does the β1 receptor do to the heart in the sympathetic nervous system?
It increases heart rate by increasing AV nodal conduction, contractility, and the SA node
What does the β2 receptor do to the bronchioles in the sympathetic nervous system?
it dilates the airways
What does the β2 receptor do to the bladder in the sympathetic nervous system?
it relaxes the detrusor muscle in the wall and keeps you from being able to pee
What does the α1 receptor do to the bladder in the sympathetic nervous system?
it contracts the sphincter and keeps you from peeing
What does the α receptor do to the male genitalia in the sympathetic nervous system?
it causes ejaculation
What does the α1 receptor do to the eye in the sympathetic nervous system?
it dilates the pupil (mydriasis) (effects the radial muscle, iris)
What does the β receptor do to the eye in the sympathetic nervous system?
It dilates the ciliary muscle and affects far vision
What does the Muscarinic receptor do to the skin in the sympathetic nervous system?
It increases thermoregulatory in sweat glands
What does the α1 receptor do to the skin in the sympathetic nervous system?
It increases stress in the sweat glands and contracts the Pilomotor muscle and causes goose bumps
What does the Muscarinic receptor do to the heart in the parasympathetic nervous system?
it decreases heart rate by decreasing contractility, AV nodal conduction, and SA node heart rate.
What does the Muscarinic receptor do to the bronchioles in the parasympathetic nervous system?
It constricts the airways
What does the Muscarinic receptor do to the bladder in the parasympathetic nervous system?
it contracts the wall, detrusor muscle and relaxes the sphincter allowing you to pee
What does the Muscarinic receptor do to the male genitalia in the parasympathetic nervous system?
it causes erection
What does the Muscarinic receptor do to the Eye in the parasympathetic nervous system?
It constricts pupil (miosis) in the radial muscle in the iris and contracts the ciliary muscle affecting near vision
What would happen if the Muscarinic receptor was blocked in the bladder?
you would not be able to pee
If a medicine was given that blocked the he β receptor in the heart, what would happen?
heart rate would decrease
If a medicine was injected into the penis that blocked the alpha receptor, what would happen?
Ejaculation would be prevented.
If a patient was given a drug that stimulated the β1 receptor, what would happen in the heart?
Heart rate would increase
If a patient was given a drug that blocks the Muscarinic receptor, what would happen in the bronchioles?
the airways would be unable to constrict