Wednesday, February 9, 2011

Nervous System

  • Central Nervous System (CNS) - brain and spinal cord
  • Peripheral Nervous System (PNS) - everything outside the brain and spinal cord with represented the input and outputpathways
  • Sensory System - nervous system "input device"
  • Motor System - output system
- carries orders to all 3 types of muscle and to the body's glands
  • Somatic Nervous System - controls skeletal muscle and usually voluntary movements
  • Automatic Nervous System - controls smooth and cardiac muscle in your orgons
  • Parasymphathetic - resting and digesting
- deals with normal functioning

  • Sympathetic - fight or flight
- body's alert system

  • Nervous tissue - contains no epithelium, no connective tissue and no muscle tissue




Four types of (CNS) :
  • Astrocytes - metabolic and structural support cells
  • Microglia - remove debris
  • Epedymal - covering and lining cavities
  • Oligodendrytes - make a lipid insulation called myelin
Two types of (PNS) :
  • Schwann cells - makes myelin for PNS
  • Satellite cells - support cells

Neurons - Control function of the nervous system

  • dendrites - receive information from the environment of from other cells
  • axon - generates and send signals to other cells
  • axon terminal - connects to a receiving cell
  • synapse - combination of axon terminal and receiving cell
  • neuromuscular synapse or junction - the receiving cell is skeletal muscle
  • sensory neuron - input neurons
  • motor neuron - output neurons
  • inter neurons - neurons that carry info. between neurons
  • Neurons - an exitable cells

- carries a small electrical charges

  • Polarized - not stimulating, resting cell
  • Depolarized - more positive than resting cells
  • Repolarization - the inside of the cells becomes more negative again, returning to rest
  • Hyperpolarized - more negative than at rest
  • action potential - whole series of permeability changes
  • local potential - the size of the stimulus determines the excitement of the cell
  • impulse conduction - action potential travels down the axon from tha cell body to the terminal
  • nodes of Ranvier - bare spots between adjacent glial cells
  • neurotransmitters - sends signal
  • spinal cord - located in a hollow tube running inside the vertebral column

No comments:

Post a Comment