ANS VS PNS Melanie Pacheco Signey Mojica Karina Benitez Valeria Valdez

Nervous System Peripheral Nervous System (PNS) Somatic Nervous System Automatic Nervous System (ANS) Sympathetic Nervous System Parasympathetic Nervous System Central Nervous System (CNS)

C ENTRAL N ERVOUS S YSTEM Organs divided into two major groups:  Brain and Spinal Cord Responsible for sending and receiving information

P ERIPHERAL N ERVOUS S YSTEM Includes: 1) Cranial nerves that come from the Brain 2)Spinal Nerves that come from the Spinal cord Subdivided into: 1) Somatic Nervous System 2) Autonomic Nervous System

S OMATIC N ERVOUS S YSTEM Voluntary Muscle Movements Muscular movements and sensation Contains two major types of Neurons: 1) Sensory Neurons(Afferent) 2) Motor Neurons(Efferent) The neurons of SNS project from the CNS into the muscles and sensory organs. It is a direct path with synapses to connect nearby neurons.

A UTOMATIC N ERVOUS S YSTEM Controlled and part of PNS Involuntary Muscle Movements Regulates glands, cardiac, and smooth muscle by returning them back to homeostasis; just like the reflex arc Divided Into: 1) Sympathetic Nervous System: “Fight or Flight” 2) Parasympathetic Nervous System: “Rest and Digest”

AUTONOMIC V.S SOMATIC

R EFLEX A RC Stimulus: a change in the environment Response: react to the change in the environment Receptors: cells specialized to react to a specific stimulus

C ONT. Reflexes Help Maintain Homeostasis By Controlling:  Heart Rate  Breathing Rate  Blood Pressure  Digestion

S YMPATHETIC D IVISIONS o Location: thoratic and lumbar spinal cord o Helps the body when it is in need of energy, under stress, and in emergency situation o Does this by: o increases blood pressure o decrease digestion o Increase heart beat o (fight or flight process) o Structure used: o Adrenal gland o Gray rami o Sympathetic trunks o Sympathetic chain ganglia

S YMPATHETIC G ANGLIA C HAIN Deliver information to the body Located in the spinal cord and extend from the upper neck down to the coccyx.

P REGANGLIONIC F IBERS Nerve fibers that connect the central nervous system to ganglia Sympathetic preganglionic fibers tend to be shorter than parasympathetic fibers and sympathetic fibers tend to form more synapses than parasympathetic fibers.

P OSTGANGLIONIC F IBERS  In the autonomic nervous system, fibers from the ganglion to the effector organ are called postganglionic fibers.  Postganglionic fibers in the sympathetic division are adrenergic and use norepinephrine as a neurotransmitter.  Postganglionic fibers in the parasympathetic division are cholinergic and use acetylcholine as a neurotransmitter.

P ARASYMPATHETIC D IVISION Location: in sacral region of the spinal cord Allows the body to go back to the resting state Counterbalances sympathetic division Returns to homeostasis Structures used:  Parathyroid gland  Submandibular gland  Sublingual gland

Neurotransmitters Receptors

R EGULATION Reflex centers receive sensory impulses from the viscera, and use autonomic nervous pathways to stimulate a motor response from the muscles or gland. The hypothalamus helps regulate the body temperature, hunger, and electrolyte pathways. The limbic system and cerebral cortex controls the autonomic nervous system during emotional stress.

T ERMINATION Acetyl Cholinesterase decomposes the acetylcholine and the acetylcholine affects the post synaptic membrane Then norepinephrine is released from cholinergic fibers that go back to the presynaptic neurons.

Works Cited "Central Nervous System and Peripheral Nervous System: MedlinePlus Medical Encyclopedia Image." U.S National Library of Medicine. U.S. National Library of Medicine, n.d. Web. 17 Mar "Example: Somatic Reflex Arc." Example: Somatic Reflex Arc. N.p., n.d. Web. 19 Mar "Grey and White Matter." Difference Between Grey and White Matter | Difference Between | Grey vs White Matter. N.p., n.d. Web. 17 Mar "Human Anatomy." Human Anatomy. N.p., n.d. Web. 19 Mar "Nervous." Dictionary.com. Dictionary.com, n.d. Web. 19 Mar "Neurology - Divisions of the Nervous System." YouTube. YouTube, 14 Oct Web. 19 Mar "Neuroscience For Kids." - Autonomic Nervous System. N.p., n.d. Web. 19 Mar "Organization of the Nervous System." The Peripheral Nervous System. N.p., n.d. Web. 19 Mar "Peripheral Nervous System Anatomy." Peripheral Nervous System Anatomy. N.p., n.d. Web. 18 Mar "Reflex Arc." Reflex Arc. N.p., n.d. Web. 19 Mar