Introduction to the Nervous System

Introduction to the Nervous System Two autonomical divisions of the Nervous System - ans1. Central nervous system (CNS) -Brain: processes sensory data and sends motor commands and is the seat of higher functions such as intelligence, memory, and emotion -Spinal cord: Relays information to/from the brain and processes some information on its own 2. Peripheral nervous system (PNS) -All the neural tissue outside of the CNS which is responsible for communication between the CNS and the rest of the body (peripheral nerves) Define somatic - ansOf/to the body Define visceral - ansComing from organs What does afferent mean? - ansCarrying to, afferent goes to CNS, sensory pathway Predict how the sympathetic reflexes controlling blood vessels would respond to a sudden decrease in blood pressure - ansConstricts the blood vessels so the pressure increases Asthma can be treated by inhaling a drug that mimics the actions of noradrenaline on the sympathetic nervous system. Describe how this drug could be ussed to target the patient's respiratory system - ansDirectly creates bronchial openings What does efferent mean? - ansGoing away from the CNS, motor pathway, further divided into ANS and SNS (involves cerebellum-conscious things) What is the ANS also known as... - ansVisceral nervous system (involuntary regulations) Two classes of neural cells - ans1. Neurons -For information transfer, processing, and storage 2. Neuroglia -Cells found in CNS and PNS that surround and protect neurons -Unlike most neurons, glial cells retain ability to divide Sympathetic nervous system - ansNerves from thoracic (T) and lumbar (L) region. Neurotransmitters are acetycholine and norephine. Mainly triggers flight or fight response. Stimulation has more widespread and long lasting responses Parasympathetic nervous system - ansNerves from brainstem and sacral (S) regions. Neurotransmitters are acetycholine. Bladder emptying. Rapidly released and the effects are short lived and localized. Conserving energy and replenishing energy reserves. Feed or breed. Rest or digest. Explain why the sympathetic and the parasympathetic divisions of the ANS are often described as being opposing in function - ansSympathetic division stimulates, have has more long and widespread effects. Parasympathetic division inhibits (conserving energy), rapid and short lived Explain why sympathetic stimulation tends to have more widespread and longer lasting effects than parasympathetic stimulation - ansNorephine that is released takes longer to dissipate through the bloodstream. In parasympathetic, acetycholine degrades rapidly Examples of the role of reflexes in ANS function - ansWhen the body goes into fight or flight mode, the sympathetic nervous system dilates the arteries and increases the rate at which the heart contracts. Other examples are pupil dilation, gut motility, and heart rate