The Human Nervous System (AQA GCSE Combined Science: Trilogy: Biology): Flashcards
Exam code: 8464
1/220Still learning
Know0
- FrontStructure & Function
Central nervous system (CNS)
Was this flashcard helpful?
Cards in this collection (22)
Central nervous system (CNS)
The brain and spinal cord.
What are the two main parts of the human nervous system?
Central nervous system (CNS) – the brain and spinal cord
Peripheral nervous system (PNS) – all the nerves in the body
Neurone
A nerve cell that carries information as electrical impulses.
What is the function of the nervous system?
It enables humans to react to their surroundings and to coordinate their behaviour.
Information travels through the nervous system as impulses.
Information travels through the nervous system as electrical impulses.
Put the stages of a nervous response in the correct order:
stimulus, effector, receptor, response, coordinator
stimulus → receptor → coordinator → effector → response
What is the role of the CNS in a nervous response?
It acts as the coordinator, receiving information from receptors and coordinating the response of effectors (muscles contracting or glands secreting hormones).
Reflex action
An automatic and rapid response that does not involve the conscious part of the brain.
True or False?
Reflex actions involve the conscious part of the brain.
False.
Reflex actions are automatic and do not involve the conscious part of the brain, which is what makes them so rapid.
Why are reflex actions important?
They are automatic and rapid, which helps to protect the body from harm and minimise damage.
Name the three types of neurone found in a reflex arc.
Sensory neurone
Relay neurone
Motor neurone
State the function of the sensory, relay and motor neurones.
Sensory neurone – carries impulses from a receptor to the CNS
Relay neurone – found inside the CNS; connects the sensory and motor neurones
Motor neurone – carries impulses from the CNS to an effector
Put the parts of a reflex arc in the correct order.
stimulus → receptor → sensory neurone → relay neurone → motor neurone → effector → response
Synapse
A gap (junction) between two neurones, where the impulse is passed on by chemicals (neurotransmitters) diffusing across.
Reaction time
The time taken to respond to a stimulus (usually less than a second).
What is the aim of the reaction time required practical?
To plan and carry out an investigation into the effect of a factor on human reaction time.
Describe the ruler drop method for measuring reaction time.
One person holds a ruler vertically between the other person's open thumb and finger (at the 0 cm end).
The ruler is dropped without warning and caught as quickly as possible.
The further down the ruler is caught, the slower the reaction time.
Name three factors that can affect a person's reaction time.
Age, use of drugs (e.g. caffeine), background noise and stress.
Give three control variables for the ruler drop investigation.
Use the same dominant hand each time
Drop the same ruler from the same height and orientation
Use the same person catching the ruler
How can the accuracy and reliability of the reaction time results be improved?
Repeat the test and calculate a mean.
Using a computer removes human error and can measure in milliseconds, which is more precise.
A set of reaction time results contains an anomaly. What should be done with it, and how is the fastest reaction identified?
The anomalous result should be excluded when calculating the mean.
The lowest reaction time corresponds to the fastest reaction.
The further down the ruler is caught, the the person's reaction time.
The further down the ruler is caught, the slower the person's reaction time.
Sign up to unlock flashcards
or