The Human
Nervous System
NERVOUS SYSTEM
CENTRAL
NERVOUS SYSTEM
BRAIN
PERIPHERAL
NERVOUS SYSTEM
SPINAL CORD
SOMATIC
NERVOUS
SYSTEM
SYMPATHETIC
NERVOUS SYSTEM
AUTONOMIC
NERVOUS
SYSTEM
PARASYMPATHETIC
NERVOUS SYSTEM
The Nervous System
 Nervous system is a delicate and complex communication
system made up of billions of connected nerve cells (neurons),
transmitting information around our body
 Consists of the brain, spinal cord and nerves throughout our
bodies
 There are 2 main subdivisions of the Nervous System- The
Central Nervous System (CNS) and the Peripheral Nervous
System (PNS)
 CNS= Brain and Spinal Cord
 PNS= all other nerves in our bodies
NERVOUS SYSTEM
CENTRAL
NERVOUS SYSTEM
BRAIN
SPINAL CORD
CNS- The Brain
 Known as the “Master Organ” because it overseas
everything we think, feel and do.
 Located in the skull and has a wrinkled appearance
 Can be subdivided into 3 regions: hindbrain (back),
midbrain (middle) and forebrain (front)
CNS- Spinal Cord
 The body’s information highway!
 Complex cable of nerve fibres stretching from the base of
the brain to the lower back
 Connects the brain to other parts of the body through its
connection with the PNS
 Receives sensory information from the PNS and transmits
it to the brain
 Transmits messages (responses) from the brain to the rest
of the body (via PNS)
Neurons (Nerves)
 Neurons are nerve cells and the basic units involved in all
behaviours
 They receive and send electrical signals between the CNS
and our bodies and also signal between themselves.
 Sensory (afferent) neurons- carry information from the
senses to Interneurons in the CNS for interpretation
 Interneurons- found only within the CNS and provide the
link between sensory and motor neurons
 Motor (efferent) neurons- transmit movement messages
from Interneurons in the CNS outwards to the muscles and
body for action.
 Activity:
Copy in your books a
diagram of a Neuron and
complete the mix n
Match worksheet
labelling the parts of a
neuron.
 Now build your very own
Neuron out of PipeCleaners!
Peripheral Nervous System (PNS)
 Peripheral meaning “border”
 All of the nerves outside the brain and spinal cord
 Carries messages to and from various muscles, glands and senses
throughout the body
 Further divided into 2 subsections: the Somatic and Autonomic
nervous system
NERVOUS SYSTEM
PERIPHERAL
NERVOUS SYSTEM
SOMATIC
NERVOUS
SYSTEM
AUTONOMIC
NERVOUS
SYSTEM
PNS- Somatic Nervous System
 A branch of the PNS that controls our voluntary movement
 Also called the Skeletal Nervous System because it connects the
skeletal muscles with the CNS allowing voluntary movement
 Carries Sensory Information TO the CNS
 Carries Motor Information FROM the CNS
 Messages can only travel in one direction, so the PNS has two
different pathways for carrying messages to and from the CNS
PNS- Autonomic Nervous System
 Carries messages between the CNS and the heart, lungs and
other internal organs and glands
 The ANS regulates and controls the functioning of internal
organs “automatically”
 EG- heart rate, breathing, digestion, salivation ect
 ANS functions independently of the CNS
 Has 2 subdivisions: Sympathetic Nervous System and
Parasympathetic Nervous System
NERVOUS SYSTEM
PERIPHERAL
NERVOUS SYSTEM
AUTONOMIC
NERVOUS
SYSTEM
SYMPATHETIC
NERVOUS SYSTEM
PARASYMPATHETIC
NERVOUS SYSTEM
Autonomic Nervous System:
Sympathetic Nervous System
 Arouses the body when you are experiencing an extreme
emotion or feel threatened
 Activates the “fight or flight” response
 Eg- Bungy Jumping, hearing footsteps in a dark alley
 Fight: Stay and “fight” the threatening situation
 Flight: Take “flight” and run away from the situation
Autonomic Nervous System:
Parasympathetic Nervous System
 Usually the dominant system maintaining a sense of
homeostasis (balance) in normal functioning.
 Calms or restores the body to the normal state of
functioning opposite to that of the Sympathetic NS
 Slow in returning the body back to normal because it takes
longer to remove the hormones initially released by the
Sympathetic NS for quick action.
NERVOUS SYSTEM
CENTRAL
NERVOUS SYSTEM
BRAIN
PERIPHERAL
NERVOUS SYSTEM
SPINAL CORD
SOMATIC
NERVOUS
SYSTEM
SYMPATHETIC
NERVOUS SYSTEM
AUTONOMIC
NERVOUS
SYSTEM
PARASYMPATHETIC
NERVOUS SYSTEM