the nervous system Flashcards
A01
Outline the nervous system
The nervous system is a specialised network of cells in the human body & is our primary internal communicator
The nervous system has two main functions:
* To collect,process & respond to info in the enviroment
* To co-ordinate the working of different organs & cells in the body
What two subsytems is the nervous system divided into
- Central nervous system(CNS)
- Peripheral nervous system(PNS)
Outline the role of the central nervous system (CNS)
CNS is made up of the brain & spinal cord
* The brain is centre of all conscious awareness
The brains outer layer,the cerebral cortex-covers the brain
The brain is divided into two hemispheres
- The spinal cord is an extension of the brain-its responsible for reflex actions e.g pulling your hand away from a hot plate
The peripheral nervous system(PNS)
The PNS transmits messages via nerve cells throughtout whole body from the brain & relays messages to back to brain
The peripheral nervous system is subdivided into:
* Autonomic nervous system(ANS) governs vital functions in body such as breathing,heart rate,digestion
* Somatic nervous system(SNS) governs muscle movement & recieves info from sensory receptors
Outline Autonomic Nervous system ( ANS)
One of systems subdivided by PNS
ANS governs vital functions in the body such as breathing, heart rate, digestion
The ANS is divided into 2 sections:
* The sympathetic nervous system
* The Parasympathetic nervous system
Outline Sympathetic nervous system
its one of the subsystems divided by ANS
The sympathetic nervous system is associated with the fight or flight’ response
it prepares body for physcial activity e.g fighting
it is utilised when body is in an alert state
It increases bodily activities:
It can accelerate heart rate
* sweat increases
* breathing rate increases
* constricts blood vessels ,
* causes pupil dialtion
* raises blood pressure
It can accelerate heart rate, breathing rate increases widen bronchial passages for increased breathing capacity( needed when running: decreasing activity of the large intestine ( no time for toilet) constricts blood vessels , causes pupil dialtion & raises blood pressure
Outline Parasympathetic nervous system
its one of the subsystems divided by ANS
The Parasympathetic nervous system is known as rest & digest system
it helps to conserve bodys activity levels & energy by decreasing activity to be used later
It regulates bodliy functions like digestion & urination
It slows heart & breathing rate, lowers blood pressure as body enters state of relaxation
Relaxation enables body to go into ‘standby’ recovery mode , the more time spent in a PNS state, healthier the person will be
