The Nervous System Flashcards
What does the nervous system do
It uses signalling molecules to communicate messages
Messages are sent as an electrical impulse along a neuron
What are nervous systems
They keep body systems working together they require control
What are the two types of nervous systems
Central Nervous System (CNS) – brain and spinal cord
Peripheral Nervous System (PNS) – neurons connecting the CNS to the rest of the body
What are receptors
Changes are detected by special cells called receptors.
What is the stimulus response mechanism
Stimulus > Receptor > Control Centre > Effector > response
What are the senses in our body
Receptors are special nerve cells found in various body parts, including those related to our senses – skin, eyes, ears, nose and tongue
What are the different receptors
Thermoreceptor, mechanoreceptor, chemoreceptor, photoreceptor, nociceptor (pain)
What is the thermoreceptor
Its stimulus is temperature and its location is the skin
What is the mechnoreceptor
Its stimulus is vibration (sound), touch and pressure. And its location is the ear and skin
What is the chemoreceptor
Its stimulus is chemicals and its location is the nose and tongue
What is the photoreceptor
Its stimulus is light and its location is the eyes
What is the nociceptor
It is the pain receptor. Its stimulus is damage to cells and its location is the skin
What are the three main parts of neurons and explain each of them
Dendrites - receive info from receptors or other neurons
Cell body - contains nucleus and provides energy for cell
Axon - conducts impulse from dendrites to axon terminals, often covered in myelin
What is an impulse
An impulse (message) always travels one way along a neuron from dendrite to axon terminals
What are groups of neurons called?
nerves
What is the synapse
The synapse is the gap between each neuron
What is needed for the message to be passed from one neuron to the next,
neurotransmitter
What are reflex arcs
Reflex arcs are a special pathway in the nervous system that result in reflex actions.
What is a reflex action.
A reflex action is a response to a stimulus that occurs so rapidly it requires no conscious thought. This happens in order to protect the body from harm.
