Unit 2 Discussion Board by https://padlet.com/cerenaermitanio/txpfskkjibjj9bra en-us 2022-03-03 21:31:37 UTC 2022-03-05 04:49:43 UTC hello@padlet.com https://padlet.net/icons/png/1f48a.png Divisions of the ANS cerenaermitanio https://padlet.com/cerenaermitanio/txpfskkjibjj9bra/wish/2077074503 The autonomic nervous system is divided into two parts: 1) the parasympathetic, or craniosacral, division and 2) the sympathetic, or thoracolumbar, division.

The parasympathetic division is associated with the cholinergic system, while the sympathetic division is associated with the adrenergic system. ]]> 2022-03-04 02:14:30 UTC https://padlet.com/cerenaermitanio/txpfskkjibjj9bra/wish/2077074503 ANS Neurotransitters cerenaermitanio https://padlet.com/cerenaermitanio/txpfskkjibjj9bra/wish/2077102195 In the sympathetic division, four neurotransmitters are released:
1) acetylcholine (ACH), which is released at the ganglia,
2) norepinephrine (NE), which is released at the adrenal medulla and neurons,
3) epinephrine (EPI), which is produced by the adrenal medulla, and
4) dopamine.

In the parasympathetic nervous system, the neurotransmitter acetylcholine (ACH) is released at both the ganglia and the postganglionic nerve endings.


]]> 2022-03-04 02:29:49 UTC https://padlet.com/cerenaermitanio/txpfskkjibjj9bra/wish/2077102195 ANS Receptors cerenaermitanio https://padlet.com/cerenaermitanio/txpfskkjibjj9bra/wish/2077191909 Adrenergic (sympathetic) receptors:
  • alpha 1:  found on glands, smooth muscles, eyes, most arteries and veins
  • alpha 2: found on the central (brain) and peripheral nervous systems
  • beta 1: found on the heart
  • beta 2: found on skeletal muscle arteries, coronary arteries, smooth muscle, uterus, and lungs
Cholinergic (parasympathetic) receptors:
  • muscarinic: located on cardiac, smooth muscle (visceral organs), and glands
  • nicotinic 1 (also known as nicotinic-nerve, Nn): located at ganglia of parasympathetic nerves and sympathetic nerves 
  • nicotinic 2 (also known as nicotinic-muscle, Nm): located at the neuromuscular junction of skeletal muscle

]]> 2022-03-04 03:21:53 UTC https://padlet.com/cerenaermitanio/txpfskkjibjj9bra/wish/2077191909 End Organ Responses cerenaermitanio https://padlet.com/cerenaermitanio/txpfskkjibjj9bra/wish/2077219071 Adrenergic (sympathetic) receptor effects when stimulated:
  • alpha 1:  smooth muscle contraction, vasoconstriction of arteries and veins, pupillary dilation from contraction of iris muscle
  • alpha 2: decreases release of norepinephrine from adrenergic nerve ending, relaxes contraction of smooth muscle, vasodilation of arteries and veins
  • beta 1: end organ is the heart; increase in heart rate, force of contraction and conduction 
  • beta 2 (by EPI only): bronchiolar smooth muscle undergoes bronchodilator, relaxation occurs at the uterus, and vasodilation occurs at the coronary and skeletal muscle blood vessels
Cholinergic (parasympathetic) receptor effects when stimulated:
  • muscarinic: decreases heart rate, bronchoconstriction, increase in digestion, GI secretions of the digestive system, constricts pupils
  • nicotinic 1 (also known as nicotinic-nerve, Nn): stimulates sympathetic and parasympathetic postganglionic neurons
  • nicotinic 2 (also known as nicotinic-muscle, Nm): skeletal muscle contracts

]]> 2022-03-04 03:39:04 UTC https://padlet.com/cerenaermitanio/txpfskkjibjj9bra/wish/2077219071 Adrenergic Drug Classes (Sympathetic Division) cerenaermitanio https://padlet.com/cerenaermitanio/txpfskkjibjj9bra/wish/2077354838 Sympathomimetics: mimics the sympathetic system 
  •  alpha-1 adrenergic agonists: stimulate the alpha-1 andenergic receptors, causing:
    • contraction of smooth muscle and blood vessels, increasing blood pressure, vasoconstriction of nasal passage
    • ex: phenylephrine (Neo-Synephrine®)
  • adrenergic agonists: stimulates all alpha and beta receptors, causing:
    • increase in blood pressure by vasopressor-vasoconstriction, stimulation of heart, bronchodilation 
  • ex: epinephrine (Adrenalin®)
  • beta-1 adrenergic agonists: stimulate different receptors depending on dosage--
    • low dose: stimulates dopaminergic receptors, causing vasodilation & increased renal blood flow
    • moderate dose: stimulates beta-1 receptors, increasing force of contraction and cardiac output
    • high dose:  stimulates alpha-1 receptors, causing vasoconstriction & increase in blood pressure
    • drug example: dobutamine
  • beta-2 adrenergic agonists: stimulate beta-2 receptors
    • causes relaxation of the smooth muscle of uterus and lungs (bronchodilation)
      • drug examples:
        • albuterol (Proventil®, Ventolin®)
        • terbutaline (Brethine®)
        • formoterol (Foradil®)

Sympatholytics: drugs that work against the sympathetic system
  • alpha-1 adrenergic blocking drugs bind to alpha-1 receptors and blocks them, causing
    • relaxation of smooth muscle, vasodilation of blood vessels (decreases blood pressure), and relaxes smooth muscle of uterus and increases urine flow
    • drug examples
      • prazosin (Minipress®)
      • terazosin (Hytrin®)
      • doxazosin (Cardura®)
  • selective beta-1 blockers:  binds to beta-1 receptors and blocks them
    • decreases force of contraction, cardiac output (lower blood pressure), heart rate, and conduction
    • drug examples
      • atenolol (Tenormin®)
      • metoprolol (Lopressor®)
  •  non-selective beta blockers: blocks beta-1 and beta-2 receptors
    • decreases force of contraction, heart rate, conduction, and cardiac output, thus lowering blood pressure (may also cause bronchoconstriction)
    • drug examples:
      • nadolol (Corgard®)
      • propranolol (Inderol®)
      • timolol (Blocadren®)
]]> 2022-03-04 05:22:49 UTC https://padlet.com/cerenaermitanio/txpfskkjibjj9bra/wish/2077354838 Cholinergic Drug Classes (Parasympathetic Division) cerenaermitanio https://padlet.com/cerenaermitanio/txpfskkjibjj9bra/wish/2077375318 Parasympathomimetics: drugs that mimic the parasympathetic system
  • direct-acting cholinergenic agonists: stimulates muscarinic receptors; mimics ACH but effect depends by drug
    • acetylcholine: constricts pupil
    • pilocarpine (Pilocar®): constricts pupils, decreases fluids in eye and intraocular pressure
    • bethanechol (Urecholine®): stimulates muscarinic receptors of bladder & GI, preventing constipation and urinary retention
  • indirect-acting cholinergic agonists: inhibits acetylcholinerase, the enzyme that breaks down ACH in synapses; increases ACH
    • ex: neostigmine (Prostigmin®)
Parasympatholytics: drugs that work against the parasympathetic system
  • Anticholinergics: binds to a cholinergic receptor and blocks it (competitive antagonism:
    • examples
      • atropine: increases heart rate, decreases vagus nerve activity, slows digestion and urination
      • dicyclomine (Bentyl®): decreases GI secretions and motility
      • ipratropium bromide (Atrovent®): bronchodilation

]]> 2022-03-04 05:40:02 UTC https://padlet.com/cerenaermitanio/txpfskkjibjj9bra/wish/2077375318