2j Coordination and Response Flashcards
What is the CNS?
Central Nervous System
is the spinal cord and brain
What is the PNS?
Peripheral Nervous System
is the collection of neurons connected to the CNS
What are neurons?
Neurons carry electrical impulses to carry messages from place to place
What do hormones do?
- Long term effects - slower responses
- Travels in the blood
- Released from endocrine glands
- Some examples are ADH and adrenaline
- Responsible for fight and flight
What do Neurons do?
Short term effects - faster response
- Responsible for transmitting information about sounds and smells
- Responsible for transmitting information about pain
- Travel in the nerves - pass messages as electrical signals
- Found in the brain and spinal cord
- Involved in reflex actions
Why is the axon long?
Because it is responsible for carrying the electrical impulses around the body
What happens in the synapses so they are able to pass an impulse from one neurone to the next?
1) Electrical impulse comes towards the synapse
2) Neurotransmitters are stored there, the electrical impulses travel there and become neurotransmitters
3) Neurotransmitters are released from the end of one neurone which diffuses from the synapse
4) When the neurotransmitters reach the next neurone they cause a new electrical impulse to be sent
What are the 3 types of neurones called?
Sensory neurone
Relay neurone
Motor neurone
What is a sensory neurone?
Carry out nerve impulses from receptor cells in the body towards the CNS
What are relay neurones?
Make connections between neurones inside your brain and your spinal cord
What are motor neurones?
Carry nerve impulses from your brain to your muscles / glands (effectors)
What is the sense organ?
It is the receptor
- eye
- skin
- nose
- tongue/taste buds
- ears
What are the names of the 5 senses?
- Sight
- Touch
- Taste
- Smell
- Hearing/balance
What is the stimulus detected by the sense organs?
Sight/eye - light
Touch/skin - Particles (temperature/pressure)
Smell/nose - chemicals in the air
Taste/tongue/taste buds - chemicals in the food
Hearing/balance/ears - Frequencies, vibrations
What is a stimulus?
A change in the surroundings
What is a receptor?
An organ or cell detecting a stimulus
What is an effector?
A muscle or gland
What is a response?
A reaction to the change
A person hears music playing and decides to change the radio station. How does the person respond and coordinate?
1) A radio plays a song and sends out the sound wave (stimulus)
2) A receptor cell in the ear senses the stimulus
3) An electrical impulse is sent along a sensory neurone
4) The impulse reaches the brain via the spinal cord
5) The brain processes the information
6) The brain sends out an impulse along a motor neurone
7) The impulse reaches an effector cell in the muscle in the finger
8) The finger moves towards the radio to change the channel (response)
What is a reflex?
A rapid and automatic response to a stimulus - no brain involvement
What is the order of the reflex arc?
1) A stimulus is a change in the environment of an organism
2) This is detected by a receptor such as the eye
3) Impulses from a receptor pass along a sensory neurone…
4) to the central nervous system (the co-ordinator)
5) The message is passed from a sensory neurone to a relay neurone
6) Then the message passes between a rely neurone and…
7) a motor neurone
8) The motor neurone carries an impulse to an effector…
9) which can be a muscle or a gland…
10) A muscle responds by contracting, a gland responds by releasing chemical substances
What is the eye?
The eye is the sensory organ which allows us to see. It contains receptor cells which pick up information about light, they convert this information into an electrical signal and then send the information to the brain
What is the role of the iris?
The eye needs to control the amount of light coming into the eye. It does this by changing the size of the iris
What does the pupil do?
Light travels from an object into the eye through the pupil