Control in the body - The Nervous System Flashcards
What are the 2 systems of control in the body?
Hormones
The nervous system
How are hormones and the nervous system different in effecting the body?
The nervous sytem is quick and has effects on the body
Hormones are slow acting but have a long alsting effect on the body
Give the order at which the body always follows in a nervous response
Stimulus
↓
Receptor
↓
Sensory Neurone
↓
CNS (co-ordinator)
↓
Motor neurone
↓
Effector
↓
Response
What is a stimulus?
A change in your environment which the human body is capable of detecting
What are the 5 sense organs?
Eyes, ears, nose, tounge, skin
What do sense organs conatin?
Receptors
What are receptors?
Groups of cells which are sensitive to a stimulus, they change stimulus energy (eg light energy) into electrical impulses
What sort of things can stimulus’ be?
- Light
- Sound
- Touch
- Pressure
- Pain
- Chemical
- A change in position or temperature
Name each sense organ and what sort of receptor they contain
Eyes - light receptors (sensitive to light, these cells have a nucleus, cytoplasm and cell membrane)
Ears - sound receptors (sensitive to sound) - also ‘balance’ receptors; sensitive to changes in position
Nose - smell receptors (sensitive to chemical stimuli)
Tongue - taste receptor (sensitive to bitter, salt, sweet and sour plus th taste of savoury things) - chemical receptor
Skin - sensitive to touch, pressure, pain and temperature change
Sensory neurone
The nerve cells that carry signals as electrical impulses away from the receptors in the sense organs to the central nervous system
Relay neurones
The nerve cells that carry signals from the sensory neurones to motor neurones
Motor neurones
The nerve cells that carry signals from the central nervous system to the effector muscles or glands
Effectors? How do each of them respond?
Muscles and glands (these are effectors) - they respond in different ways.
Muscles contract in response to a nervous impulse, where as glands secrete hormones
The central nervous system?
Where all the infromation from the sense organs is sent, and where reflexes and actions are coordinated
What do neurones (nerve cells) do?
Transmit the information (as electrical impulses) very quickly to and from the CNS
