Autonomic Nervous System Eunice Lee Debora Jeong Joshua Iannotti Period 4
Organization of Nervous System
Central Nervous System 1. Brain A) Forebrain (1) Sensory info (receive/process) (2) Thinking, perceiving, producing B) Brainstem (1) Hindbrain Balance equilibrium (2) Midbrain Auditory and visual responses Motor functions 2. Spinal Cord A) connects brain to peripheral nervous system
Peripheral Nervous System 1. Sensory Nervous System A) sends info to CNS i.e. when someone pokes your finger 2. Motor Nervous System A) sends info from CNS i.e. when you want to lift your finger B) Autonomic vs. Somatic (1) Somatic: 1. voluntary motor 2. skeletal muscles (2) Autonomic: 1. involuntary motor 2. smooth and cardiac muscles 3. Parasympathetic vs. Sympathetic
Reflex Arc Definition: a neural pathway that controls a reflex i.e. jolting backward when touching something hot
TWO types of Reflex Arc 1. Autonomic Reflex Affects inner organs (visceral= deep) Triggered by visceral afferent signaling Sensory neuron -> connecting neuron -> motor neuron i.e. peristalsis, sweating 2. Somatic Reflex Affects muscles Starts with force acting onto a surface i.e. hammer on patella Then energy is received and sensory neuron senses force Then sends signal to motor neuron which sends a signal to the brain to jerk the knee
AutonomicSomatic
Autonomic: Sympathetic vs Parasympathetic
Body PartSympatheticParasympathetic EyeDilatesConstricts HeartRate increasesRate decreases BladderRelaxesContracts Salivary GlandsStops productionIncreases production LungsDilate bronchiolesConstrict bronchioles LiverRelease glucoseN/A Adrenal GlandSecrete epinephrine/ norepinephrine N/A Intestines/ StomachDecreases activities of muscles and glands Increases gland secretions, motility KidneyVasoconstriction/ decreased urine output N/A GenitalsEjaculationErection Arrector pili MuscleContractRelax GallbladderRelaxesContracts
Ultimate Outcome for each System: Autonomic vs. Somatic Autonomic: Maintaining homeostasis: Control glands Control smooth and cardiac muscle Somatic: Self-Preservation: Control skeletal muscles
Ganglionic Fibers Axons sent into nerves Synapse with neurons in ganglia first PREGANGLIONIC FIBERS ARE… POSTGANGLIONIC FIBERS ARE…
Sympathetic System Preganglionic fibers -Reach spine and leave spine (rami) -Synapse in sympathetic ganglia -Shorter Postganglionic fibers -Extend from sympathetic ganglia -Longer
Parasympathetic System Preganglionic fibers -Carried by vagus nerves -From brain and spinal chord ganglia -Longer -Myelinated Postganglionic fibers -Continue from ganglia organs -Shorter -Unmyelinated
Sympathetic Neurotransmitters Preganglionic fibers secrete AcH (Acetylcholine) Cholinergic Postganglionic fibers secrete NE (Norepinephrine) Andrenergic
Parasympathetic Neurotransmitters Preganglionic fibers secrete AcH Postganglionic fibers secrete AcH and Nitric Oxide
RECEPTORS Nicotine AcH Receptor -Strong Muscle contractions -Both sympathetic and parasympathetic Adrenergic Receptors -Postganglionic neurons -Just sympathetic Muscarinic AcH Receptors -Receives AcH -Weak Muscle contractions -Just Parasympathetic
Termination of Receptors AcHe (Acetylcholinesterase) breaks down AcH NE is removed NE has prolonged effect
Bibliography r/Pharm_PNS_new.pdf r/Pharm_PNS_new.pdf 4/ans.htm 4/ans.htm Receptors-and-the-autonomic-nervous-system/ Receptors-and-the-autonomic-nervous-system/