NERVOUS
REGULATION
NERVOUS REGULATION
 WHAT ARE ALL THE LIFE PROCESSES?
 H.N.T.R.S.G.E.R.M.R
 WHICH ONES HAVE WE COVERED?
 H.N.T.R.S.G.E.
 WHAT ARE WE UP TO?
 R  REGULATION / RESPONSE
 WHAT IS THIS EXACTLY?
 THE ENVIRONMENT, BOTH INTERNAL AND EXTERNAL,
IS CONSTANTLY CHANGING…ORGANISMS MUST
RESPOND TO THESE CHANGES AND
REGULATE/CONTROL THESE RESPONSES
ACCORDINGLY
NERVOUS REGULATION
 REGULATING AND
RESPONDING TO CHANGES
REQUIRES THE
COORDINATION OF EVERY
BODY SYSTEM…BUT THE
MAJOR ONES TO CONSIDER
ARE THE:
 MUSCULOSKELETAL 
CHECK
 NERVOUS  CARRY
MESSAGES
 ENDOCRINE  CHEMICAL
MESSAGES
NERVOUS REGULATION
 HOW DOES THE NERVOUS SYSTEM WORK?
 THE PATHWAY OF A MESSAGE
STIMULUS  RECEPTOR  IMPULSE  EFFECTOR  RESPONSE
 DEFINITIONS?





STIMULUS
RECEPTOR
IMPULSE
EFFECTOR
RESPONSE
NERVOUS REGULATION
 REVIEW QUESTIONS:
 FUNCTIONAL UNITS OF:
 LUNGS  ??
 KIDNEYS  ??
 NERVOUS SYSTEM  ??
 NEURONS!!!
 WHAT’S THE TRICK TO KNOWING HOW
SOMETHING FUNCTIONS?
NERVOUS REGULATION
 NEURONS
NERVOUS REGULATION
 NEURONS






CELL BODY
DENDRITES
AXON
SCHWANN CELLS
MYELIN SHEATH
TERMINAL BRANCHES
 TYPES OF NEURONS
 SENSORY
 INTERNEURON
 MOTOR NEURON
NERVOUS REGULATION
 HOW DO NEURONS FIT INTO THE MESSAGE
PATHWAY?
STIMULUS  RECEPTOR  IMPULSE  EFFECTOR  RESPONSE
NERVOUS REGULATION
 IMPORTANT TO NOTE THAT ADJACENT NEURONS
NEVER ACTUALLY TOUCH!!
 INSTEAD THERE IS A
SYNAPSE!!!
 THE GAP, OR SPACE,
BETWEEN ADJACENT
NEURONS
 THE MESSAGE MUST BE
ABLE TO CROSS THIS
GAP!!
 WE WILL COME BACK TO
THIS SHORTLY!!
NERVOUS REGULATION
 UNDERSTANDING THE MESSAGE, OR
IMPULSE, INVOLVED IN NERVOUS
SYSTEM COMMUNICATION IS VERY,
VERY, VERY, VERY, VERY, VERY,
VERY, VERY, VERY, VERY, VERY,
VERY, VERY, VERY, VERY, VERY,
VERY, VERY, VERY, VERY, VERY,
VERY, VERY, VERY, VERY, VERY,
VERY, VERY, VERY, VERY, VERY, VERY
COMPLEX!!
NERVOUS REGULATION
 THE NERVE IMPULSE IN SIMPLE
TERMS:
 A STIMULUS CHANGES THE
PERMEABILITY OF THE CELL
MEMBRANE, WHICH THEN ALLOWS
SODIUM AND POTASSIUM TO
CHANGE SIDES WITH REGARD TO
THE MEMBRANE, CHANGING THE
RELATIVE “CHARGE”…CREATING
AN ELECTRICAL SIGNAL THAT
TRAVELS DOWN THE CELL
NERVOUS REGULATION
 SOME COOL STUFF ABOUT NERVOUS SYSTEM
IMPULSES
 THRESHOLDS
 REFRACTORY PERIODS
 NEUROTRANSMITTERS
 DRUGS!!
NERVOUS REGULATION
NERVOUS REGULATION
 NERVOUS REGULATION IN PROTISTS
NERVOUS REGULATION
 NERVOUS REGULATION IN HYDRAS
 CELLS ARE ALL
LINKED TOGETHER
FORMING A
“NERVE NET”
 NO FORMAL
SYSTEM
NERVOUS REGULATION
 NERVOUS REGULATION IN EARTHWORMS
 CENTRAL VS.
PERIPHERAL
NERVOUS
SYSTEM
 GANGLIA
 MULTIPLE
NERVE CELLS
THAT FUNCTION
SIMILAR TO A
BRAIN
NERVOUS REGULATION
 NERVOUS REGULATION IN GRASSHOPPERS
 SIMILAR TO EARTHWORM
 INCORPORATES SOME MORE SPECIAL SENSE
ORGANS (EYES, ANTENNAE)
NERVOUS REGULATION
 LET’S GET TO THE GOOD STUFF!!
WHAT ABOUT HUMAN BRAINS?!?!?
 CHAPTER 15, HUMAN NERVOUS SYSTEM…HERE
WE COME 