Lecture 07

Brain 4

  1. Nervous System
    1. Functions
      1. React
      2. Desire
      3. Plan
    2. Divisions
      1. Central Nervous System
      2. Peripheral Nervous System
    3. Terminology
  2. Peripheral Nervous System
    1. Somatic Nervous System
    2. Autonomic Nervous System
      1. Sympathetic Division
      2. Parasympathetic Division
  3. Central Nervous System
    1. Brain
    2. Spinal Cord
      1. Spinal Reflex
      2. Why Spinal Reflexes are Fast

Overview

In humans (as in almost all animals), neurons do not exist in a haphazard arrangement. Instead, they are organized in an elegant system that speeds the flow of information in and out of a central command. The central nervous system, consisting of the brain and spinal cord, serves as this central command, and almost all of the 100 billion neurons in the human body are found there.


The peripheral nervous system contains the remaining neurons (a few million). The peripheral nervous system has several subdivisions that govern the control of muscles, glands, and organs.


The spinal cord contains a few billion neurons. It generally relays information to and from the periphery to the brain. But spinal reflexes that do not require any brain involvement also exist. These reflexes are of two types: Monosynaptic reflexes that to not involve interneurons (knee jerk reflex) and polysynaptic ones that involve sensory, motor, and interneurons within the spinal cord (pain reflex).


Specifics

  1. Identify the structures that comprise the central and peripheral nervous system, and distinguish nerves and tracts, and white matter and gray matter.
  2. Be familiar with the divisions of the peripheral nervous system, and discuss their functions.
  3. Understand the dynamics of a spinal reflex, and the role brain processes do and do not play.


Peripheral Nervous System

DivisionsPrimary Function
Somatic Nervous System 
Autonomic Nervous System 

Sympathetic Division of the ANS

 

Parasympathetic Division of the ANS