Nervous Communication Flashcards
(26 cards)
How do animals respond to external stimuli to aid survival?
Avoid harmful environments such as those being too hot or too cold
How do animals respond to internal stimuli to aid survival
Make sure conditions are optimal for internal stimuli
What is a stimulus?
Any change in the internal or external environment
What is the response to a stimulus
Stimuli, receptors, effectors, response
Why are receptors referred to as specific
Respond to specific stimuli
What are receptors
Proteins on cell surface membrane
How do receptors communicate with effectors
- hormonal system
- nervous system
What are the three main neurones of the nervous system
- Sensory neurone
- Motor neurone
- Relay neurone
What is the nervous system made up of?
A complex network of neurones
What do sensory neurones do?
Transmits electrical impulses from receptors to the CNS
What do motor neurones do
Transmits electrical impulses from the CNS to effectors
What do relay neurones do
Transmits electrical impulses between sensory neurones and motor neurones
When an electrical impulse reaches the end of a neurone, how does it get to the next neurone?
Neurotransmitters takes the information to the next neurone, creating an electrical impulse
What are the two systems of the nervous system
- The central nervous system (brain and spinal cord)
- the peripheral nervous system (neurones that connect the CNS to the rest of the body)
What are the two systems of the peripheral nervous system
- somatic nervous system (controls conscious activities e.g. running)
- autonomic nervous system (controls unconscious activities e.g digestion)
What are the two divisions of the autonomic nervous system?
- The sympathetic nervous system (gets body ready for action, fight or flight)
- The parasympathetic nervous system (calms body, rest and digest)
What is a reflex
An unconscious response
Why are reflexes important
They help to protect the body because they’re rapid and unconscious
What is a reflex arc
Pathway of neurones linking receptors to effectors
Why is the nervous response localised, short-lived and rapid
Localised= electrical impulse reaches end of neurone, neurotransmitters secreted directly onto target cells
Short-lived= neurotransmitters quickly removed once job is done
Rapid= electrical impulses really fast, so allows animals to react quickly to stimuli
What is a reflex arc
- receptors detect a change in stimulus
- sensory neurones sends electrical impulses to relay neurone
- relay neurone transmits electrical impulse from sensory to motor neurone
- motor neurone sends electrical impulses to effector
What is positive and negative tropism
Positive = grow towards stimulus
Negative= away from stimulus
How do plants increase their chance of survival?
- sense direction of light and grow towards it
What parts of the plants are phototropic and gravitropic?
Shoot= positively phototropic, negatively gravitropic
Roots= negatively phototropic, positively gravitropic
