B1.2 - Nerves And Hormones Flashcards
Why are the sense organs? (5)
- Eyes.
- Ears.
- Tongue.
- Nose.
- Skin.
What type of cells detect stimuli?
Receptors.
What are the receptors in the eyes sensitive to?
Light.
What are the receptors in the ears sensitive to? (2)
- Sound.
2. Changes in position.
What are the receptors in the nose sensitive to?
Smell (a chemical stimuli).
What are the receptors in the tongue sensitive to?
Taste (a chemical stimuli).
What are the receptors in the skin sensitive to? (4)
- Touch.
- Pressure.
- Pain.
- Temperature changes.
What do light receptor cells contain? (3)
- A nucleus.
- Cytoplasm.
- A cell membrane.
Which neurones carry signals from the receptors to the CNS?
Sensory neurones.
Which neurones carry signals from the CNS to the effectors?
Motor neurones.
Which neurones carry signals from sensory neurones to motor neurones?
Relay neurones.
What can effectors be and what do they do? (2)
- Muscles, which contract.
2. Glands, which secrete hormones.
What does the CNS include? (2)
- The brain.
2. The spinal cord.
What do neurones transmit information as?
Electrical impulses.
What does the brain do in the CNS?
It coordinates a response.
What does the nervous system do?
It allows you to react to your surroundings and coordinate your behaviour.
What are the characteristics of reflex actions? (2)
- Automatic.
2. Fast.
What is a synapse?
A junction between two neurones.
What happens at a synapse?
The nerve signal is transferred by chemicals which diffuse across the gap between two neurones.
What part of the CNS could impulses travel through in a reflex action? (2)
- Spinal chord.
2. An unconscious part of the brain.
What internal conditions are controlled in the body? (4)
- Blood sugar levels.
- Temperature.
- Ion content.
- Water content.