The Human Nervous System

The Human Nervous System

NERVOUS SYSTEM

CENTRAL NERVOUS SYSTEM

PERIPHERAL NERVOUS SYSTEM

AUTONOMIC NERVOUS

SYSTEM

PARASYMPATHETIC NERVOUS SYSTEM

SYMPATHETIC NERVOUS SYSTEM

SOMATIC NERVOUS SYSTEM

BRAIN SPINAL CORD

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 Pipe-Cleaners!

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

AUTONOMIC NERVOUS

SYSTEM

SOMATIC 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

PARASYMPATHETIC NERVOUS SYSTEM

SYMPATHETIC 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

PERIPHERAL NERVOUS SYSTEM

AUTONOMIC NERVOUS

SYSTEM

PARASYMPATHETIC NERVOUS SYSTEM

SYMPATHETIC NERVOUS SYSTEM

SOMATIC NERVOUS SYSTEM

BRAIN SPINAL CORD