The Nervous System Flashcards
What is the Nervous System
A network of cells and electrical and chemical signals that is our primary internal communication system
What are the 2 main functions of the Nervous System
To collect, process and respond to information in the environment
To co-ordinate the working of different organs and cells in the body
What are the 2 sub-divisions of the Nervous System
Central Nervous System (CNS)
Peripheral Nervous System (PNS)
What does the CNS include
Brain
Spinal Cord
What does the Brain do in the CNS
Centre of all conscious awareness
Cerebral Cortex distinguishes our higher mental functions from those of animals
Is divided into 2 hemispheres
What does the Spinal Cord do in the CNS
An extension of the brain
Passes messages to and from the brain and connects nerves to the PNS
Responsible for reflex actions
What does the PNS do
Transmits messages via neurons to and from the CNS
What are the sub-divisions of the PNS
Autonomic Nervous System (ANS)
Somatic Nervous System (SNS)
What does the Autonomic Nervous System do
Controls vital functions (e.g. breathing)
Deals with Fight or Flight response
Transmits information to and from internal bodily organs
Is automatic and involuntary
What are the 2 sub-divisions of the Autonomic Nervous System
Sympathetic Nervous System
Parasympathetic Nervous System
What does the Parasympathetic Nervous System
Body is at ease
Contracts pupils
Heart beats slower
Lungs constrict airways
Stimulates digestion
Reduces blood flow to skeletal muscles
What does the Sympathetic Nervous System do
Body is stressed/ emergency situations (fight or flight)
Dilates pupils
Heart beats faster and stronger
Relaxes airways (to breathe deeper)
Inhibits digestion
Increases blood flow to skeletal muscles
