B6: Brain and Mind

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  • Created by: Emma
  • Created on: 04-06-13 20:57
What is a stimulus?
A change in an organism's environment.
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What does the Central Nervous System (CNS) do?
It coordinates an animal's response. The CNS (brain and spinal cord) is connected to the body by the peripheral nervous system (PNS). It is sometimes referred to as the processing centre.
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What does the peripheral nervous system consist of?
Sensory neurons and motor neurons.
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What do sensory neurons do?
Sensory neurons carry impulses from receptors to the CNS.
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What do motor neurons do?
Motor neurons carry impulses from the CNS to effectors.
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Receptors and effectors can form part of complex organs. Give examples.
Muscle cells in a muscle, light receptor cells in the retina of the eye and hormone secreting cells in a gland.
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How do receptors and effectors work in a muscle?
Impulses travel along motor neurons and stop at the muscle cells (effectors), causing the muscle cells to contract.
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How do receptors and effectors work in the eye?
The lens focuses light onto receptor cells in the retina. The receptor cells are then stimulated and send impulses along sensory neurons to the brain.
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How do receptors and effectors work in hormone secreting cells?
An impulse travels along a motor neuron and stops at the hormone secreting cells in glands (effectors). This triggers the release of the hormone into the bloodstream.
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What are neurons?
Neurons are specifically adapted cells that carry an electrical signal when stimulated. They are elongated to make connections between different parts of your body and have branched endings so a single neuron can act on many other neurons/effectors.
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What is an axon?
A long fibre surrounded by a cell membrane formed by cytoplasm in motor neurons.
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What is the purpose of a fatty sheath surrounding an axon?
It insulates the neuron from neighbouring cells and increases the speed at which the nerve impulse is transmitted.
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What are synapses?
Synapses are the gaps between adjacent neurons.
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(1/2)State the steps in which impulses are transferred between neurons.
(1/2) 1. A nerve impulse reaches the synapse through the sensory neuron. 2. The impulse triggers the release of chemicals, called neurotransmitters, into the synapse. 3. (cont.)
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(2/2) State the steps in which impulses are transferred between neurons.
(2/2) (cont.) 3. Neurotransmitters diffuse across the synapse and bind with receptor molecules on the membrane of a motor neuron. 4. A nerve impulse is sent through the motor neuron.
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What is a reflex action?
A reflex action is a fast, automatic, involuntary response to a stimulus.
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(1/2) What is the basic pathway for a reflex arc?
(1/2) 1. A receptor is stimulated (e.g. by a sharp pain). 2. This causes impulses to pass along a sensory neuron into the spinal cord. 3. The sensory neuron synapses with a relay neuron, by-passing the brain. 4. (cont.)
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(2/2) What is the basic pathway for a reflex arc?
(2/2) (cont.) 4. The relay neuron synapses with a motor neuron, sending impulses to the effectors. 5. The effectors respond (e.g. muscles contract).
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How do simple reflexes help animals to survive?
Simple reflexes ensure that an animal automatically responds to a stimulus in a way that helps it to find a mate, shelter from predators and find food.
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Name the simple reflexes of newborn babies.
Stepping reflex, grasping reflex, rooting reflex and sucking reflex.
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What causes a conditioned reflex action?
A conditioned reflex action is caused by building an association between the stimulus that naturally triggers the response (primary stimulus) and the new stimulus (secondary stimulus).
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How can you modify reflex actions?
In some situations your brain can override or modify a reflex action by sending a signal, via a neuron, to the motor neuron in the reflex arc. This allows you to keep hold of a hot plate even though your body's natural reflex response is to drop it.
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How do we use neuron pathways to learn?
1. Each time you have a new experience, a different neuron pathway is stimulated. 2. Every time the experience is repeated afterwards, the pathway is strengthened. 3. Pathways that aren't used regularly are eventually deleted.
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What skills are dealt with in the cerebral cortex?
Intelligence, memory, language and consciousness (a sense of right and wrong.)
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Describe the differences in short-term and long-term memory.
Short-term memory stores information for a limited period of time, and long-term memory stores an unlimited amount of information.
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What things make us more likely to remember information?
Repetition, if there is a strong stimulus associated with it, or if you can see a pattern in it.
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How do some drugs and toxins affect the nervous system?
By changing the speed at which nerve impulses travel to the brain. They can also send false signals to the brain, prevent nerve impulses from travelling across synapses or overload the nervous system with too many nerve impulses.
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What is serotonin and what does it do?
Serotonin is a chemical transmitter used in the central nervous system. It has mood-enhancing effects (it's associated with feeling happy).
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Other cards in this set

Card 2

Front

What does the Central Nervous System (CNS) do?

Back

It coordinates an animal's response. The CNS (brain and spinal cord) is connected to the body by the peripheral nervous system (PNS). It is sometimes referred to as the processing centre.

Card 3

Front

What does the peripheral nervous system consist of?

Back

Preview of the front of card 3

Card 4

Front

What do sensory neurons do?

Back

Preview of the front of card 4

Card 5

Front

What do motor neurons do?

Back

Preview of the front of card 5
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