Peripheral Nervous System Part one
What is the peripheral Nervous System? While the CNS consists of the brain and spinal cord, the PNS consists of the nerves extending outside of the CNS. The purpose of the PNS is to send information to and from the brain to the rest of the body.
Afferent nerves vs. efferent nerves Afferent nerves send messages back to the central nervous system (brain and spinal cord) Efferent nerves transmit messages from the central nervous system (brain and spinal cord) to the rest of the body
Sympathetic nerves (fight or flight) Facilitate mobilization for quick action. The chemical being used by the body is norepinephrine or epinephrine. Affects the body by: Increasing heart rate Constriction of blood vessels Widening airways and passages in the lungs
Parasympathetic nerves (feed and breed) Direct restorative and conservative processes Chemical being used by the body is acetylcholine Affects the body by: Increases movement and secretion in the gi tract Decreases heart rate Increases mucus production in the lungs Dilation of blood vessels
Beta Receptors There are two different kinds of these in the body B1- cardiac receptors B2- respiratory Receptors Epinephrine and/or Norepinephrine activate these receptors before something could happen… Stress Fear Exercise
What happens when these beta receptors are activated? Increase blood pressure Increase heart rate Beta 2 Airway dilation
Sympatholytic Agents also called Adrenergic Blocking Agents Inhibit signals of norepinephrine or epinephrine These are primarily used for treatment of hypertension and heart arrhythmias
Sympathomimetic Agents also known as adrenergic agents Direct acting: mimic the effects of norepinephrine and epinephrine by combining with receptors in the sympathetic nervous system. Indirect Acting: facilitate the release of norepinephrine or block the reuptake of norepinephrine in the nerve.
Examples of direct acting Sympathomimetic Agents Drug: Receptors it binds to: Treatment for: Also known as: Phenylephrine Alpha-1 Nasal decongestion Clonidine (Catapress) Alpha-2 Blood pressure Albuterol (ProAir, Ventolin) Beta-2 Breathing Beta-Agonist Levalbuterol (Xopenex) Salmeterol (Serevent) Asthma These are mimicking the effects of norepinephrine and epinephrine.
Beta blockers also called Beta Antagonists Beta blockers interfere with the binding to the receptor of epinephrine and other stress hormones, and weaken the effects of stress hormones, thus, mediating the “flight or fight” response. Brand Generic Inderal Propranolol Tenormin Atenolol Lopressor Metoprolol Corgard Nadolol Betapace Sotolol Sectral Acebutolol Zebeta Bisoprolol
Deck The Halls with Beta Blockers -lol –lol –lol –lol….. I’ll learn Lopressor is Metoprolol Betapace is sotolol, sectral-Acebutolol Deck the Halls with Beta blockers -lol –lol –lol –lol….. I’ll learn Tenormin is Atenolol These are used for hypertension And on occasion, public speaking