Nervous System Flashcards
What does the nervous system and hormones do?
Enable us to respond to external changes
Help us control conditions inside our body
What are some forms hormones are used in?
Contraception and fertility treatments
What else produces hormones and responds to external stimuli?
Plants
What does the nervous system do?
Enables humans to react to their surroundings and coordinate their behaviour
What detects stimuli?
Receptors
What do receptors in the eye detect?
Light
What do receptors in the ears detect?
Sound
What do receptors in the ears also detect?
Changes in position and enable us to stay balanced
What do receptors in the nose and on the tongue detect?
Chemicals and enable us to taste and smell
What do receptors in the skin detect?
Touch
Pressure
Pain
Temperature changes
What do light receptors have?
Nucleus
Cytoplasm
Cell membrane
What happens to information from receptors?
It’s passed along neurones in nerves to the brain and the brain coordinates a response
What are reflex actions and what do they involve?
Automatic and rapid
Involving sensory, relay and motor neurones
What happens in a simple reflex action?
- Impulses from a receptor pass along a sensory neurone to the central nervous system (CNS)
- At a synapse between a sensory neurone and a relay neurone in the CNS, a chemical is released causing an impulse to be released along a relay neurone
- A chemical is then released at the synapse between a relay and motor neurone in the CNS, causing impulses to be sent along a motor neurone to an organ, bringing about a response
What is an effector and what do they do?
Muscle - contracts
Gland - secreting chemical substances
