MGSLG. (2020). Module 1 Unit 1
Responding to the environment and coordination of activities in the body
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Biological term |
Description |
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Afferent neuron |
Neuron that carries impulses to the CNS. |
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Alzheimer’s Disease |
Progressive mental deterioration that can occur in middle or old age, due to generalized degeneration of the brain. |
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Autonomic nervous system |
The part of the peripheral nervous system that controls involuntary actions. |
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Axon |
The long threadlike part of a nerve cell along which impulses are conducted from the cell body to other cells. |
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Central nervous system |
The part of the nervous system that consist of the brain and spinal cord. |
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Cerebrospinal fluid |
A watery fluid, continuously produced and absorbed, which flows in the ventricles (cavities) within the brain and around the surface of the brain and spinal cord. |
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Dementia |
A general term used for memory loss and loss of other intellectual abilities. |
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Dendrite |
A part of the neuron that conducts impulses towards the cell body. |
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Efferent neuron |
Neuron that carries impulses to the CNS. |
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Effectors |
Are muscles or glands that respond to the message from the nervous system (brain and spinal cord). |
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Medulla oblongata |
The part of the brain that controls the heart rate. |
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Meninges |
A collective name for the membranes that protect the brain. |
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Multiple sclerosis |
A disorder of the nervous system that is characterised by the breakdown of the myelin sheath of neurons. |
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Myelin sheath |
A fatty layer wrapped around the neuron, which acts as insulation. |
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Nerve |
Bundle of neurons. |
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Neuron |
One nerve cell. |
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Neurotransmitter |
Chemical that is released from a nerve cell which thereby transmits an impulse from a nerve cell to another nerve, muscle, organ, or other tissue. |
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Peripheral nervous system |
The part of the nervous system made up of cranial and spinal nerves. |
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Receptors |
Structures located in the sense organs. They convert a stimulus into an impulse. |
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Stem cells/meristematic cells |
Undifferentiated cells that can develop into any cell type. |
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Stimulus |
A detectable change (e.g. pain, heat, light, sound) that will be received by a receptor and converted into an impulse. |
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Synapse |
1. A junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter. |
Nervous co-ordination
- To survive, all organisms need to be able to sense changes in their environment and to control their responses to these changes
- The nervous system and the endocrine system are important communication systems that co-ordinate, intergrade and carry out the activity of body cells, tissues, organs and the organism
- They maintain a constant internal balance, while reacting to the changes that occur in both the external and internal environment
Reaction to stimuli in the environment
- The nervous system and sense organs play an important part in picking up stimuli, gathering information and responding quickly to changes from both the external and internal environment to maintain a constant state
- The nervous system in vertebrates performs five main functions:
- Gathers information using the senses
- Transmits information to processing areas of the brain
- Processes information
- Formulates responses to stimuli
- Sends information back through the network of effector organs to execute the response.
