SNS, also known as __________has ______ pre-ganglionic neuron and _______post ganglionic neuron
PNS, also known as___________ has _____ preganglionic neurons and ________ post ganglionic neurons
Acetylcholine is the NT present in_____
- 1. All sympathetic and parasympathetic preganglionic neurons
- 2. Somatic motor neurons
- 3. Parasympathetic postganglionic neurons
- 4. Sympathetic postganglionic neurons of sweat glands
Norepinephrine is NT _________
All other sympathetic postganglionic neurons except sweat glands
What are the 3 receptor sub-types in the PNS?
- Nicotinic ACh receptors
- Muscarinic receptors (stimulated by ACh)
- Adrenergic receptors (stimulated by Norepi)
Where are the muscarinic receptors in the PNS?
- Sweat glands
- Tissue innervated by
Name the adrenergic receptors, stimulated by Norepi?
Alpha and beta receptors on tissues (except sweat glands) innervated by the sympathetic postganglionic neurons.
Name the catecholamines?
Tyrasine is converted into ______ which is converted to ________ which is packaged into vessicles where it is transformed into _________ and finally___________.
List the nonselective adrenoreceptor agonists
nonselective alpha agonists (alpha1 and alpha2)
- Afrin (oxymetazoline (Afrin), tetrahydrozoline
- Used clinically for topical use where alpha 1 is present
alpha 1 selective agonists
- phenylephrine a1>a2>>>>>>B
alpha 2- selective agonists (autoreceptor)
- clonidine a2>a1>>>>>>>B
- guanabenz, guanfacine, alpha-methyldopa
What are the mixed alpha and beta-agonists?
- Norepinephrine a1=a2; B1>>B2
- Epinephrine a1=a2; B1=B2
What is the functional effect of alpha-1 sympathomimetic drugs on vascular smooth muscle?
contraction, vasoconstriction to increase BP
What is the functional effect of alpha-1 sympathomimetic drugs on pupilary dilator muscle?
Contraction (pupil dilation)
What is the functional effect of alpha-1 sympathomimetic drugs on pilomotor smooth muscle?
What is the functional effect of alpha-1 sympathomimetic drugs on the prostate?
What is the functional effect of alpha-1 sympathomimetic drugs on heart?
Increases force of contraction
What is the functional effect of alpha-1 sympathomimetic drugs on respiratory system?
Reduction of mucosal secretions- decongestants
What GI effects do alpha 2 and beta 2 agonists have?
a 2, b2: decrease in peristalsis via direct smooth muscle relaxation
a2: decreased digestive secretions
What are the GU effects of alpha 1 agonists?
- bladder: contraction of urethral sphincter-urinary continence
- erectile tissue: facilitates ejaculation
- uterus: B2: inhibits labor
Name alpha 2 agonists...
- Clonidine (CNS receptors- decreases BP
- Apraclonidine (ciliary receptors) reduces IOP
Name some B2 agonists and what they are used for?
Bronchodilation in ASTHMA and COPD
- Salmeterol (long duration of action)
- Ritodrine (for premature labor)
Name some indirect-acting Sympathomimetics?
(enhance catecholemine response)
- Methamphetamine (greater CNS effects)
- Methylphenidate (Ritalin) ADHD
- Pemoline (Cyclert) ADHD
Name some effects of alpha 1-antagonism on BP
- decrease PVR and lower BP
- ex. phentolamine, phenoxybenzamine
Name some effects of an alpha 2 antagonist?
- treatment of diabetic neuropathy, enhance male sexual fx, reverse clonidine withdrawal
- ex. Yohimbine
Name some B- antagonists for ocular tx?
- Timolol (ocular hypotensive)
What is the functional effect of alpha 2 agonism on blood pressure?
What about on platelets, adrenergic nerver terminals, vascular smooth muscle and fat cells?
Decrease BP via autoreceptor neg feedback
- 1. platelets: aggregation
- 2. adrenergic nerve terminals: inhibits transmitter release (via negative feedback)
- 3. vascular smooth muscle: contraction
- 4. fat cells: inhibition of lipolysis
Name some nonselective B-agonist or selective B1 drugs and their affinity for B receptors?
What is their function on Blood Pressure?
Increase CO and raise BP
- Isoproterenol (Isuuprel) (not used) B1=B2>>>>alpha
- Xamoterol (not used)
- Dobutamine B1>B2>>>>alpha
Name some B2 selective agonists?
Metaproterenol, terbutaline, albuterol, salmeterol, formoterol, pirbuterol, bitolterol
Name the functional effects of the B1 sympathomimetic drugs on heart?
- Increases force and rate of contraction
Name the functional effects of the B2 sympathomimetic drugs on blood pressure?
On respiratory, uterine, vascular smooth muscle?
Causes peripheral vasodilation which decreases BP.
Promotes smooth muscle relaxation.
(Metaproterenol, terbutaline, albuterol, salmeterol......
Name the dopamine agonists and their action at the D1, D2 receptors?
- 1. dopamine D1=D2>B>>alpha
- 2. fenoldopam D1>>D2
What is functional effect of D1 agonism on smooth muscle?
Dilates renal blood vessels
What is the functional effect of D2 agonism on nerve endings?
- Modulation of transmitter release
- (Parkinson's and schizophrenia)
What is the major role of adrenoreceptor agonism?
Blood pressure regulation
What are the ocular effects of alpha 1 agonists?
- 1. mydriasis (pupil dilation to accomodate far vision)
- 2. Reg of intraocular pressure
- alpha 1, alpha 2: increase humoral outflow
- B1: increase production of aquaous humor (antagonize B1)
What do glaucoma agents do?
agonize alpha 1, alpha 2 and antagonize B1
Name the cholinergic receptor subtypes?
- Muscarinic and Nicotinic
- M1: CNS, autonomic ganglia
- M2: cardiac muscle
- M3: smooth muscle, glandular tissue
- M4: CNS
- M5: CNS
- Nm: skeletal muscle at NMJ
- Nn: autonomic ganglia, adrenal medulla, CNS
What do AcHEsterace inhibitors do?
- Useful for diseases of the NMJ (Myasthenia Gravis)
- ex. pyridostigmine, neostigmine
- Useful for glaucoma: increase outflow of aquaous humor
- ex. physostigmine (Isopto)
Tx abdominal distension
Alzheimers and other cognitive dz.
What are some AE's of AchE inhibitors?
Nausea, vomiting, diarrhea, anorexia, flatulence, abdominal cramping
What are some CI for AcHE inhibitors?
- AV Block (unstable, severe cardiac dz)
- Uncontrolled epilepsy
- Active PUD
What do nicotinic antagonists (and agonists) do?
- prevent muscle cell depolarization at NMJ
- Paralysis for anesthesia
- Ex. Pancuronium, vecuronium, rocuronium
What are muscarinic agonists used for?
- Diagnosis of asthma
- GI/GU motility
- Decrease IOP
What are muscarinic antagonists used for?
What AE's do muscarinic antagonist cause?
- Motion sickness, bronchodilation, overactive bladder, bradycardia, mydriasis
- Blurred vision
- Dry mouth
- urinary retention
What is the muscarinc effects Mneumonic?
- S: salivation, sweating, secretions
- L: lacrimation
- U: urination
- D: diarrhea
- E: emesis
- s: salivation, sweating, secretions
- l: lacrimation
- u: urination
- g: GI upset
- b: bradycardia, bronchoconstiction, BM
- a: abdominal cramps, anorexia
- m: miosis
What is the anti-cholinergic mneumonic?
- Can't PEE
- Can't SEE
- Can't SPIT
- Can't SHIT
- blurry vision
- dry mouth
- stasis of urine
Name the enzyme that breaks down catecholimines (EPi/NorEpi?