·      Parasympathetic nervous system neurotransmitters acetylcholine  

·      Norepinephrine is released at postganglionic nerve endings 

·      Epinephrine is released from the adrenal medulla 

- Alpha 2 = found in adrenergic nerve endings 

- Beta 1 = located in the heart 

- Beta 2 = located in smooth muscles, lungs, uterus, skeletal muscle arteries and coronary arteries 

·      Adrenal medulla – release of epinephrine 

·      Arteries – vasoconstriction (exceptions are the coronary arteries and arteries to the skeletal muscle, which are dilated)

·      Heart – Increases heart rate and AV conduction, Increases contractility 

·      Intestines, GI motility and secretions – Decreased 

·      Postganglionic neurotransmitter – Norepinephrine released 

·      Pupil of the eye – Dilation (mydriasis) 

·      Respiratory passages, lower – Bronchodilation 

·      Urinary bladder – Relaxation 

·      Urinary sphincter – Contraction 

·      Alpha 1 Adrenergic Agonists

- alpha 1 receptor is stimulated 

- the action is contraction of smooth muscle, blood vessels constrict, increases BP 

·      Adrenergic Agonists 

- all alpha and beta receptors are stimulated 

- vasopressor, vasoconstriction, increases BP, cardiac stimulant, bronchodilator 

·      Alpha 1 Adrenergic Blocking Drugs 

- bonded with alpha 1 receptors and blocks them 

- action is relaxation of smooth muscles, vasodilation of blood vessels, decreases BP, relaxes smooth muscle of the uterus and increases urine flow 

·      Beta 1 Adrenergic Agonists 

- stimulates d-1 receptors in kidneys (low dose), stimulates beta-1 receptors (moderate dose) and stimulates alpha 1 receptors (high dose) 

- action is vasodilation and increased renal blood flow (low dose, increases force of contraction and cardiac output (moderate dose) and vasoconstriction increase in BP (high dose) 

·      Beta 2 Adrenergic Agonists 

- stimulates beta 2 receptors 

- relaxation of the smooth muscle in the lungs and relaxation of the uterus 

·      Beta Adrenergic Blocking Drugs 

- Selective Beta 1 Blockers 

            - the beta 1 receptor is blocked 

- decreases force of contraction, decreases cardiac output, decreases      heart rate, decreases conduction, decrease in cardiac output, decreases blood pressure

            - Non-Selective Beta Blockers 

                        - block beta 1 and beta receptors 

- decreases force of contraction, decreases cardiac output, decreases heart rate, decreases conduction, decrease in cardiac ouput, decreases blood pressure, can cause bronchoconstriction 

 

                - ephedrine

                - phenylephrine (Neo-Synephrineâ)

·      Adrenergic Agonists

                - epinephrine (Adrenalinâ)     

·      Alpha-1 Adrenergic Blocker

                - prazosin (Minipressâ)

                - terazosin (Hytrinâ)

                - doxazosin (Carduraâ)

·      Beta-1 Adrenergic Agonist

                - dobutamine 

·      Beta-2 Adrenergic Agonist

                - formoterol (Foradilâ)

               - albuterol (Proventilâ/Ventolinâ)

                - terbutaline (Brethineâ)

·      Beta Blocker

      - Nonselective

               - nadolol (Corgardâ)

               - propranolol (Inderolâ)

                - timolol (Blocadrenâ)

      - Selective

                - atenolol (Tenorminâ)

               - metoprolol (Lopressorâ)

·      Direct- Acting Cholinergic Agonists 

- stimulate/bind to the muscarinic receptors

- pupil constriction, decreases amount of fluid in eye, decreases intraocular pressure, prevent constipation and urinary retention

·      Indirect Acting Cholinergic Agonists 

- inhibit acetylcholinesterase 

- increases ACH 

·      Anticholinergics 

- bind to cholinergic receptor, blocking drug 

- increases HR, decreases GI secretions and motility 

                 - acetylcholine

                  - pilocarpine (Pilocarâ)

                  - bethanechol (Urecholineâ)

·      Indirect Acting Cholinergic Agents

                   - neostigmine (Prostigminâ)

·      Anticholinergic

                   - atropine

                  - dicyclomine (Bentylâ)

·      Arteries – Most arteries are not supplied by parasympathetic nerves

·      Heart – Decreases heart rate and AV conduction 

·      Intestines, GI motility and secretions – Increased 

·      Postganglionic neurotransmitter – Acetylcholine released 

·      Pupil of the eye – Constriction (miosis)

·      Respiratory passages, lower – Bronchoconstriction

·      Urinary bladder – Contraction 

·      Urinary sphincter – Relaxation 

 

- Muscarinic = found in cardiac, smooth muscle and glands

- Nicotinic₁ = found at ganglia of nerves 

- Nicotinic₂ = found at neuromuscular junction of skeletal muscle