Anatomy and Physiology Lecture Notes: Autonomic Nervous System

Introduction

• Professor Long's lecture for AMT 1 students
• Focus on the autonomic nervous system (ANS) as part of efferent division
• Importance for students entering healthcare
• Key concepts include drugs called sympathomimetics

Overview of the Efferent Nervous System

• Efferent nervous system: brain and spinal cord to effectors (muscles)
• Two divisions: Somatic Nervous System and Autonomic Nervous System (ANS)
  • Somatic Nervous System
    • Controls voluntary skeletal muscle
    • Requires conscious thought
  • Autonomic Nervous System
    • Functions automatically without conscious control
    • Controls smooth and cardiac muscles
    • Key for regulating heart rate, digestion, respiration, blood flow, and reproductive functions

Autonomic Nervous System (ANS)

• Two parts: Sympathetic and Parasympathetic Nervous Systems
• Sympathetic Nervous System (SNS)
  • "Fight or Flight"
  • Increases heart rate, blood pressure, breathing rate, and mental activity
  • Dilates respiratory tract and certain blood vessels
  • Decreases digestive, urinary, and reproductive functions
• Parasympathetic Nervous System (PNS)
  • "Rest and Digest"
  • Decreases heart rate, breathing rate, blood pressure
  • Increases digestive function, urine production, and reproductive activity
  • Aids in calming and maintaining bodily functions at rest

Mechanisms and Effects

• Sympathetic Nervous System
  • Short preganglionic and long postganglionic neurons
  • Releases adrenaline (norepinephrine) at target organs
  • Active during high stress or physical activity
  • Effects include increased respiration, cardiac output, mental activity, and blood flow to essential areas
  • Decreases digestive and urinary functions
• Parasympathetic Nervous System
  • Long preganglionic and short postganglionic neurons
  • Releases acetylcholine at all synapses
  • Supports rest and recovery functions
  • Increases blood flow to digestive organs, promotes digestion and waste removal

Functional Overview

• Sympathetic: activates systems needed for immediate action
• Parasympathetic: conserves energy and supports bodily maintenance
• Both systems work to balance body functions based on current needs

Important Notes for Exams

• Know alternate names: "Thoracolumbar" for SNS, "Craniosacral" for PNS
• Understand neurotransmitter differences: adrenaline vs. acetylcholine
• Distinguish between neuron lengths and myelination in both systems
• Recognize effects on body systems and regulatory mechanisms

Summary

• Concludes material for the first semester of Anatomy and Physiology
• Emphasizes understanding autonomic nervous system for healthcare applications
• Reminds students to review and prepare for final assessments

This concludes the lecture notes for Professor Long's anatomy and physiology course on the autonomic nervous system. Ensure to familiarize yourself with the key concepts and functions discussed for a comprehensive understanding of the ANS.