Biopsychology AO1 - up to fight or flight Flashcards
What is the Nervous System?
A specialised network of cells in the human body that is our primary internal communication system
What types of signals is the Nervous System made up of?
Chemical and Electrical
What are the 2 main functions of the Nervous System?
1) To collect, process and respond to information in the environment
2) To co-ordinate different organs and cells in the body
What are the 2 sub-systems of the Nervous System?
The Central Nervous System
The Peripheral Nervous System
What does the CNS stand for?
Central Nervous System
What does the PNS stand for?
Peripheral Nervous System
What is the CNS made up of?
Brain and Spinal cord
What is the function of the Brain in the CNS?
It is the centre of all conscious awareness
It is divided into 2 hemispheres (Left and Right)
What is the function of the Spinal Cord in the CNS?
It is an extension of the brain
It passes messages to and from the brain
It connects to the PNS
It is responsible for reflex actions
What does the CNS do?
Connects nerves to the PNS to pass messages
What does the PNS do?
Transmits messages to and from the CNS via millions of neurons
How many subdivisions does the PNS have?
2
How many components are in the CNS?
2
What are the 2 subdivisions of the PNS?
The Autonomic Nervous System
The Somatic Nervous System
What does the Autonomic Nervous System do?
Governs vital functions in the body
e.g. breathing, heart rate, digestion, sexual arousal, stress responses
What does the Somatic Nervous System do?
Governs muscle movement and receives information from Sensory Receptors
How many states can the Autonomic Nervous System be in?
2
What are the 2 states the ANS can be in?
Sympathetic
Parasympathetic
What is the ANS’ resting state?
Parasympathetic
When does the ANS change to a sympathetic state?
When adrenaline levels rise (fight or flight)
Define Nucleus
The control centre of cells containing chromosomal data
What does a Dendrite do?
Receives nerve impulses (signals) from adjacent neurons
What is an Axon?
Where electrical signals pass along
What does the Myelin Sheath do?
Insulates and protects the axon from external influences that might affect the transmission of the nerve impulse
What is the Myelin Sheath?
A fatty layer surrounding the Axon
What do the nodes of Ranvier do?
Speed up the transmission of the impulse by forcing it to ‘jump’ across the gaps
What do Terminal Buttons do?
Send signals to adjacent cells by communicating across the synaptic gap
Name all the parts of a neuron:
Nucleus
Dendrites
Axon
Myelin Sheath
Nodes of Ranvier
Terminal Buttons
*How many neurons are in the Human Nervous System?
Around 100Billion
*What percentage of neurons are in the brain?
80%
What is the purpose of neurons?
To provide the nervous system with a means of communication by transmitting chemical and electrical signals
How many types of neuron are there?
3
What are the 3 neurons called?
Sensory Neurons
Relay Neurons
Motor Neurons
What order do signals pass through the neurons in?
Sensory –> Relay –> Motor
What direction do Dendrites carry the signal?
Towards the cell body
What direction does the Axon carry the signal?
Away from the cell body
What are the segments of Myelin Sheath called?
The Nodes of Ranvier
How does Electrical Transmission work?
- When a neuron is activated by a stimulus, the inside of the cell becomes positively charged for a split second
- An action potential occurs
- This creates an electrical impulse that travels down the axon to the end of the neuron
Where are Sensory Neurons located?
They are found in clusters called Ganglia in the Peripheral Nervous System
Where are Relay Neurons located?
They are in the brain and visual system