Autonomics lecture 1 Flashcards
The autonomic nervous system is comprised of 2 neurons in a chain, what are they?
- Pre-ganglionic
- Post ganglionic
In you ganglion what are all the ACh receptors?
-Nicotinic
What type of receptor do you find in the sympathetic portion of sweat glands?
-ACh muscarinic
Pre ganglionic cell bodies in the sympathetic nervous system are ______?
-Thoracolumbar
Where do axons from the sympathetic nervous system extend to?
-pre and para vertebral ganglia (tend to be short)
Where do you find post ganglionic cell bodies?
-Para and pre vertebral ganglia
Where to post ganglionic axons extend to?
-Effector tissues/organs
Sympathetic pre-ganglionic also innervate adrenal medulla causing the adrenals cells to release what into the bloodstream?
-Norepinephrine and epinephrine
In parasympathetic nervous systems the pre-ganglionic cell bodies are what?
-Craniosacral
Where do pre-ganglionic axons extend to?
-Ganglia located near or in effector tissues/organs
What neurotransmitter is used by both the sympathetic and parasympathetic pre-ganglionic fibers?
-ACh
ACh acts through what receptors located on post- ganglionic fibers?
-Nicotinic receptors
T/F Drugs that alter ACh levels affect both the sympathetic and parasympathetic systems
True
Motor neurons innervating skeletal muscle also cat via what receptors?
-Nicotinic receptors
What do post ganglionic sympathetic use for neurotransmitters?
- DA
- NE
- EPI
What does DA activate?
-D1
Post ganglionic parasympathetic use what for a neurotransmitter?
-ACh
What does ACh act on in post ganglionic effector tissues and somatic muscles?
- -Muscarinic in effector
- Nicotinic in somatic muscles
Where do you find M1 receptors?
-Stomach
What is the agonist for M1, M2, and M3 receptors?
- ACh
- Bethanechol
- Pilocarpine
What is the response from an M1 receptor?
-Increase acid secretion
What are the antagonists for M1, M2, and M3 receptors?
- Atropine
- scopalamine
What do M2 receptors act on?
- Sinoatrial node
- Atria
- AV node
- Centricle
What are the responses from M2 receptors?
- Decrease HR
- Decrease AP duration and contractility
- Decrease conduction velocity
- Decrease Contractility
What does M3 act on?
- GI smooth muscle
- Secretory glands
What are the responses for M3 receptors?
- Contract
- Increase secretions
What are the receptors for the parasympahetic nervous system?
- M (muscarinic)
- N (nicotinic)
What is the agonist for Nm and Nn receptors?
-ACh
What is the antagonist for Nm?
- Succinylcholine
- Tubocurarine
What is the antagonist for Nn?
- Mecamylamine
- Trimethaphan
What tissues do Nm receptors act on?
-Neuromuscluar junction
What tissues do Nn receptors act on?
- Autonomic ganglia
- Adrenal medulla
- CNS
What are the two classes of nueromuscular blockers?
- Depolarizing (Succinylcholine)
- Non-depolarizing (Tubocurare)
What does Tubocurare do?
-Competes with ACh at nicotinic receptors
What does succinylcholine do?
-Act as a nicotinic agonist and depolarizes/desensitizes the neuromuscular endplate making the neuron unresponsive to another ACh challenge
What does a block of AChE do?
- Affect both parasympathetic and sympathetic systems
- Affects tissues innervated by post-ganglionic fibers
- Affects signaling at the neuromuscular junction
If you have an increase in ACh what happens to you heart?
-Decrease HR
What is Sarin?
-A cholinesterase inhibitor (causes an increase in ACh)
What does an increase in ACh do to salivation?
-Increase
What does and increase in ACh do to eyes?
- Makes them watery
- blurred vision (dilated pupils)
What does an increase in ACh do to sweating?
-Increase sweating
What does an increase in ACh do to the GI?
-Give you diarrhea
What is a cholinesterase inhibitor that has a short duration of action and is used for glaucoma, and is an antidote for atropine?
-Physostigmine
What does physostigmine do?
- It is a short duration
- Used for glaucoma
- Antidote for atropine
What is Donepezil (aricept)?
-Cholinesterase inhibitors
What does Donepezil (aricept) to?
- Extended duration of actions
- Used to treat Alzheimer’s
What does Botulinim toxin do?
- Prevents release of ACh
- Relax intraocular muscles
- Treats muscle dystonia (spasms)
- Remove wrinkles
What are cholinergic agents used in dentistry?
- Cevimelin (Evoxac)
- PIlocarpine (salagen)
What is Cevimeline used for?
-Treat xerostomia in Sjogren’s syndrome
What is Pilocarpine used for?
-Used to treat xerostomia after radiotherapy
