The Nervous System Flashcards
What is the nervous system?
Essentially a biological information highway and responsible for controlling all biological processes and movements in the body
It can also recieve information and interpret via electrical signals which are used
What is the human nervous system spilt into?
- Central Nervous System (CNS)
- Peripheral Nervous System (PNS)
(detects and sends electrical impulses used in the nervous system)
What does CNS consist of?
- Brain
- Spina cord
Why is CNS important?
It is responsible for recieveing and interpreting signals from the PNS
Also sends out signals to it via nerves either consciously or unconsciously
How many nerves that branch CNS To PNS (outisde CNS)?
43
These are motor neurones that carry signals away from CNS to PNS
What does the PNS consist of?
Mainly of neurones (nerve cells) that are bundles of fibres or axons that connect to one another and connect to CNS and other parts of the body
What do nerves do?
Transmit signals from brain called motor neurones
What is motor neurones responsible for?
Muscle contraction
What are sensory neurones?
Nerves that carry messages from PNS to CNS
What are relay neurones?
Connect sensory neurones to the motor neurones
What is the PNS further divided into?
- Somantic Nervous System
- Autonomic Nervous System
What is the somantic nervous system (SoNS) part of?
Perpherial Nervous System (PNS)
What is the somantic fibres responsible for?
Voluntary movement of body
i.e. movement you consciously think about doing
What does the SoNS recieve?
Messages from the sensory neurones
What type of impulses does the autonomic nervous system incorporate?
All impulses done involutarily
They govern all vital bodily functions e.g breathing , heart rate , digestion , sexual arousal and stress response
What does autonomic nervous system further spilt into?
- Synpathetic nervous system
- Parasymthetic nervous system
(keep one another in check in form of negative feedback as a release of insulin and glucagon in sugar control of blood)
When is the sympathetic nervous system activated?
In cases of emergerncies to mobilse energy and often considered “fight or flight response”
What is the parasympathetic nervous system responsible for?
“rest and digest” or “feed and breed” system
It is activated when organisms in relaxed state
What do both sympathetic and parasympathetic nervous system have in common?
Both systems have opposite actions
where one system activates a physiological response and other inhibits it
Diagram of divisions of nervoys system
Summarise how the nervous system is sub-dividied
- The nervous system is specialised network of cells
- CNS is made up of brain and spinal cord
- The brain is the centre of all conscious activties
- The spinal cord is an extension of brain and responsible for refle actions
- It passes messages to and from the brain connect nerves to PNS
- PNS transmit messages via millions of neurons to nerve system -> ANS - > SNS
- ANS governs vital functions in body such as breathing , heart rate and digestion
- SNS controls muscle movement (fight or flight) and recieve info from sensory receptor
Where is the PNS?
Outside of the CNS
What does the PNS transfer?
Signals to CNS via neurones
subdivided into autonomic nervous system and
somantic nervous system
What bodily functions does autonomic nervous system govern?
- Breathing
- Hear rate
- Digestion
