Autonomic Nervous System

α2 agonist Clonidine

- Inhibitory Drug (Given for Blood Pressure) -Stimulates receptors in the brain that monitor cetacholamine levels in the blood -Fools the brain into believing that the catecholamines levels are higher than they really are -Causes the brain to reduce its signals to the adrenal medulla -> lowers catecholamine production and blood vessels

Adrenergic Blocking Agents

-Broad or Specific -Broader at higher doses (Higher doses act on more receptors) -Masks signs of hypoglycemia/hyperglycemia

Neurotransmitters and Receptors (Preganglionic Neruons)

-Conduct impulses from the brain/spinal chord to the ganglion Both SNS and PNS preganglionic neurons release Acetylcholine (Ach) as their neurotransmitter; Receptors are Cholinergic (Nicotinic)

Neurotransmitters and Receptors (Postganglionic Neurons)

-Conduct impulses from the ganglion to the effector organ or tissue ALL PSN postganglionic neurons release Ach as their nuerotransimitter; Receptors are Cholinergic (Muscarinic) MOST SNS postganglionic neurons release Norepinephrine as their neurotransmitter; Receptors are Adrenergic (α or β) Exception: the SNS postganglionic neurons innervating the sweat glands release Ach as their nuerotransmitter; Receptors are cholinergic (muscarinic)

Actions of Epinephrine

-Increases formation of new glucose in the liver (gluconeogenesis) -Increases release of stored glucose from liver and mucle -Decreases sensitivity of tissues to insulin -Causes sweating even when the person isnt hot

Sympathetic Nervous System or SNS

-Involved in FLIGHT or FIGHT response -Sympathetic neurotransmitters (norepinephrine) are released from neurons at synapses (spaces between neuron and effector organ tissue) and the ADRENAL MEDULLA -Norepinephrine and epinephrine (Catecholamines) are released from ADRENAL MEDULLA directly into the bloodstream

Parasympathetic Nervous System

-Involved with CONSERVING energy; Localized -Parasympathetic neurotransmitter is Acetylcholine -Returns body to normal homeostasis

β1: Beta 1

-Located in the heart and kidneys -Causes increased heart rate and force of myocardial contraction and secretion of renin (

α1: Alpha 1

-Located on Smooth Muscle of Blood Vessels in gut and skin -Causes contraction of blood vessels when stimulated (Raises blood pressure and shunts blood to lungs, brain, liver, skeletal muscle and heart) -Associated with EXCITATION AND STIMULATION -Most of the α receptors on effector organ cells

α2: Alpha 2

-Located on actual nerves that stimulate the effector organ cells -Located on Smooth Muscle of GI Tract (pancreas, intestine, and adipose tissue) -Causes RELAXATION when stimulated which decreases digestion -Primarily inhibitory (makes sure not too much epinephrine is going to the effector organ)

β2: Beta 2

-Located on bronchial smooth muscle (lungs); Located on blood vessels in skeletal muscle where they cause RELAXATION, which increases blood flow to muscles -Causes the muscle to relax when stimulated which opens up the airways -Vasodilation of renal arteries

Release of Acetylcholine

-Lowers heart rate and contractility -Lowers Blood Pressure -Constricts pupils (focus on several smaller/closer things) -Tearing (secretions) -Increases blood flow to viscera (organs) and skin -Peristalsis of the GI Tract (mouth watering, relaxation of sphincters, pancreas secretes digestive enzymes)

Release of Norepinephrine and Epinephrine (Cont.)

-Shunts blood away from the skin and viscera (organ) to the skeletal muscles, brain, and heart (FIGHT or FLIGHT) -Inhibits perastalsis in the GI Tract -Inhibits contraction of the bladder and rectum -Causes flushing in the face and neck -Causes piloerection (hair raising) and horripilation (goose bumps)

Release of Norepinephrine and Epinephrine

-Stimulate heartbeat (increase rate and strength of contraction) -Raises blood pressure (increases thru vasoconstriction) -Dilates pupils (Better Far Vision) -Dilates the trachea, bronchi and bronchioles (Increases oxygenation to the body) -Glycogenolysis (breakdown of glycogen to glucose)

Autonomic Nervous System Characteristics

1. Both Central (In the Brain/Spinal Chord) and Peripheral ( Out in rest of the body) Nervous System components -Regulated by the Hypothalamus -Nerve Tracts in the Spinal Chord and Terminate at Effector Organs (organs in the body that have receptors for these nerve endings) 2. Subconscious; cannot be readily controlled

Autonomic Nervous System Characteristics (Cont.)

3. Regulates, Adjusts and Coordinates Vital Visceral (Organ) Functions -Vital Signs (BP, HR, RR) -Metabolism (glucose metabolism, insulin, reproductive hormones, growth hormones) -Digestion (GI Tract movement, Acidity of GI Tract) -Elimination (Bladder movement, sphincter tightness)

Autonomic Nervous System Characteristics (Cont.)

4. Affects/Affected By EMOTIONS -Fear,Anger -Skin Changes -Pupillary Changes -Palpitations (heart pounding) 5. Two-Neuron System (Pre-ganglionic nerves meet the post-ganglionic nerves) -Ganglion: Mass of nervous tissue comprised of neuron cell bodies lying outside the brain or spinal chord -Myelinated: insulated with a layer of connective tissue to speed the conduction Preganglionic neurons (myelinated) exit the spinal chord Postganglionic nerons (unmyelinated) transmit to the effector organ

β2 Agonists

Albuterol, salmeterol, isoproterenol, metaproterenol, terbutaline (selective for pulmonary receptors) Isoproterenol and Terbutaline both β1 and β2

Anticholinergic Drugs (Block Cholinergic Receptors)

Atropine -DRIES SECRETIONS for SURGERIES -increases HR for bradycardia -dilates pupils for eye exams -Competitive antagonist to Ach Ipratropium (Atrovent) -bronchodilation (opening airways) by inhibiting cholinergic receptors

ANS Visceral (Organ) Regulation

Blood pressure and blood flow changes, as a result of: -Vasoconstriction of vessels (Shunts blood away from organs that dont need it to areas that do and conserves heat) -Vasodilation of skeletal muscle vessels (occurs around organs that we need and releases heat)

ANS Visceral (Organ) Regulation (Cont.)

Body Temperature Changes Respiration Changes -Bronchodilation - opening the large airways (in the lung) -Bronchoconstriction - small amount normally Digestion -Decrease in blood flow to GI Tract -Peistalsis (movemnt of food and fluid thru the GI Tract) -Upset stomach

Combivent

Combination of albuterol (β2 agonist) and ipratropium (anticholinergic)

Catecholamines

Epinephrine (80%) and Norepinephrine (20%) -Epinephrine is 10x stronger -Epinephrine is only secreted from adrenal medulla

ANS Visceral (Organ) Regulation (Cont.)

Metabolism Changes - Catabolic (break down) -Gluconeogenesis (creation of glucose from non-carbohydrate sources), glycogenolysis (the break down of stored glucose) -Fat break down (lipolysis) -Insulin resistance Elimination Changes -Urinary (Bladder relaxes) -Bowel (Decrease in peristalsis)

Cholinergic Drugs (Activate/Stimulate Cholinergic Receptors)

Pilocarpine (Isopto Carpine) -Topical eye drops for glaucoma -Constricts pupils to treat Promotes action of normal hormone Pyridostigmine (Mestinon) -inhibits the break down of Ach in myasthenia

Adrenergic blockers and agonists

See Chart on Pg 86

Two Branches of ANS

Sympathetic and Parasympathetic