The Nervous System Flashcards
What is the nervous system
A specialised network of cells in the human body and it is our primary internal communication system
What are the two main functions of the nervous system
To collect, process and respond to information in the environment
To coordinate the working of different organs and cells in the body
What are the two divisions of the Human Nervous System
Central Nervous System (CNS)
Peripheral Nervous System (PNS)
What are the two subdivisions in the Central nervous system
The brain-All conscious and most unconscious processing
Spinal chord- Recieves and transmits information from the brain and body
What is the importance of the brain (3)
- It is the centre of all conscious awareness
- The brains outer layer, the cerebral cortex, is highly developed in humans and it is what distinguishes us from other species
- The brain is also divided into two hemispheres
What is the importance of the Spinal Chord (3)
- It is an extension of the brain
- It is responsible for reflex actions
- Passes messages to and from the brain and connects nerves to the PNS
an example of a reflex action is pulling ur hadn away when in contact with something hot
What is the importance of the PNS (2)
It transmits messages via millions of neurones to and from the CNS
It is subdivided into two
Neurones= nerve cells
Name the two sub divisions of the PNS
Autonomic and somatic nervous systems
What does the Autonomic Nervous System (ANS) do
Governs vital functions in the body such as breathing, heart rate digestion sexual arousal and stress response
Involuntary system (not under conscious control)
What does the SNS (somatic nervous system) do
Controls muscle movement and recieves information from sensory receptors
Voluntary system (under conscious control)
Are there any further divisions of the ANS and if so name them
Yes there are two more subdivisions and they work in parallel
Sympathetic and Parasympathetic
What does the Sympathetic nervous system do?
Increases bodily activities
typically involved in responses that prepare the body for fight or flight.
Impulses travel from the sympathetic nervous system to organs in the body to help us prepare for action when we are faced with a dangerous situation.
What is the role of the Parasympathetic nervous system
Decreases bodily activitves
activates in rest
The role is to relax the body, and return us to our ‘normal’ resting state. Consequently, the parasympathetic nervous system slows down our heart rate and breathing rate, and reduces our blood pressure. Furthermore, any functions that were previously slowed down during a fight or flight reaction are started again.
Q1- Describe two or more functions of the peripheral nervous system (4 marks)
The PNS transmits messages, via millions of neurons to and from the CNS
The autonomic nervous system governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses.
The somatic nervous system controls muscle movement and receives information from sensory receptors.
additional information: the sympathetic nervous system works alongside the endocrine system to bring about physiological arousal in the fight or flight response.
The parasympathetic nervous system works alongside the endocrine system to return the body to its resting state in the rest and digest responses.
How thick is the cerebral cortex
2mm-4mm thick
