Download Biology Nervous System - Educational Research Center

International Arab Baccalaureate
IAB Scope
Dimension
Facet
Benchmark
Domain
The nervous system is a
primary organ system in the
body found in all vertebrates
and invertebrates.
Function
The nervous system controls
body functions and cognitive
abilities and facilitates
responses to external stimuli
from other body systems or the
environment.
Composition
The nervous system consists of
a central nervous system and a
peripheral nervous system that
are made of specialized cells
called neurons.
Epistemic
System
Nervous System
Human Body Systems
Theme/
Branch
Biology
Sample
Learning Outcomes
The student realizes that:
− the human body includes a nervous system like all vertebrates and
invertebrates.
− the human nervous system extends from the brain to various parts of the body.
The student realizes that the nervous system:
− controls most of our voluntary and nonvoluntary body functions.
− controls cognitive abilities such as reasoning, learning and memory.
− collects and processes information gathered internally and externally.
− reacts to various stimuli such as sensory input.
− coordinates the actions of the body.
− transmits signals between various parts of the body.
The student realizes that:
− the nervous system contains a network of specialized cells called neurons,
along with supportive cells called Glial cells.
− the nervous system includes sensory neurons, motor neurons, and interneurons
that conduct nervous messages.
− a neuron is a specialized cell that typically includes a cell body, dendrites and
an axon.
− the cell body of a neuron contains a nucleus and cell organelles.
− the dendrites and the axon are extensions from the cell body.
− typical axons are surrounded by myelin sheath.
− the nerve consists primarily of the axon of the neurons surrounded by a myelin
sheath.
Biology
Nervous System / 1
Dimension
Sample
Learning Outcomes
Benchmark
Composition
The nervous system consists of
a central nervous system and a
peripheral nervous system that
are made of specialized cells
called neurons.
Internal
Structure
Neurons connect by synapses
to form complex networks
that allow for the propagation
of signals leading to different
functions.
Epistemic
System
Nervous System
Theme/
Branch
Human Body Systems
IAB Scope
Facet
The student realizes that:
− the nervous system consists of a central nervous system and a peripheral
nervous system.
− the peripheral nervous system consists of sensory neurons, ganglia and the
nerves connecting them.
− the central nervous system consists of the brain and the spinal cord.
− the brain consists of cerebrum, cerebellum and medulla oblongata.
− the central nervous system can be divided in two areas: grey matter and white
matter.
− the grey matter contains high proportion of cell bodies of neurons.
− the white matter includes all the nerves.
The student realizes that:
− dendrites receive the messages and transmit them to the cell body.
− axons transmit the message away from the cell body.
− axons from the nerve fibers are found in the white matter.
− an axon is linked to consecutive neurons or to effector cells by synapses.
− an action potential is a sudden and rapid reversal of voltage across the plasma
membrane.
− an action potential results in release of neurotransmitters from the axon
terminals into the synapse.the nervous message propagates from one neuron to
another via the synapse.
− synaptic transmission describes how a presynaptic neuron and a postsynaptic
one interact with each other in the presence of an effective stimulus.
− neurons function in networks that relay messages across the body.
− the speed of propagation depends on internal factors such as its nature, cross
section.
Biology
Nervous System / 2
External
Structure
Dimension
Cognitive
Nervous System
Epistemic
System
Theme/
Branch
Human Body Systems
IAB Scope
Facet
Analytical
reasoning
Sample
Learning Outcomes
Benchmark
The nervous system receives
input and reacts to external
stimuli from the environment
as well as other systems in
the body.
Describing and explaining
trends, patterns and
relationships in data
pertaining to common
processes that occur within
the nervous system and that
are responsible for its
functioning.
The student realizes that:
− the somatic nervous system receives external stimuli that determine how it
interacts with its environment under certain conditions.
− the nervous system and the endocrine system are related such that both achieve
communication among different body organs.
− the speed of propagation depends on external factors such as temperature,
alcohol, drugs and certain medicines.
− the striated contractile muscle fibers of the skeletal muscle are arranged in
parallel with each other, where the neuromuscular spindles are found.
− the nervous system is responsible for social and behavioral functions, and
dysfunctions result in severe psychiatric pathology.
The student is able to:
− explain the functioning of the reflex arc.
− explain the role of ion channels and sodium-potassium pumps in the
establishment of the resting potential and the action potential.
− describe hyperpolarization in terms of its inhibitory effect on a neuron.
− describe the all-or-none characteristic and threshold potential of a nerve
impulse.
− describe a synapse and explain how acetylcholine is used to transmit a signal
across the synapse.
− explain the relationship between the myelin sheath and nerve impulse
transmission.
− explain how the central nervous system is protected from injury.
− tease out the presence of specific enzymes in the synaptic cleft to explain the
fast and short lasting function of neurotransmitters at the level of the synapse.
− identify the action potential as presented in a line graph with electrical potential
differences plotted as a function of time.
Biology
Nervous System / 3
Dimension
System
Cognitive
Criterial
Reasoning
Nervous System
Theme/
Branch
Human Body Systems
IAB Scope
Facet
Relational
Reasoning
Sample
Learning Outcomes
Benchmark
The student is able to:
− compare the structure of the sensory neuron, motor neuron and interneuron.
−
compare a nerve to a muscle fiber.
Using criteria to classify,
− distinguish between action potential and resting potential.
and to distinguish between,
different parts/processes within − compare and contrast the sympathetic autonomic nervous system and the
parasympathetic one according to their opposing functions.
the nervous system
− compare and contrast curare (antagonist) and nicotine (agonist) according to
the similarity of their spatial configuration with that of acetylcholine.
The student is able to:
− relate the location of myelinated and unmyelinated nerve fibers to white and
grey matter within the central nervous system.
Determining the relationships
− relate the types of stimuli and threshold levels to action potentials and to the
between external/internal
intensity of responses (summation).
stimuli and the nervous system
− associate the regulation of the cardiac rhythm with the autonomic nervous
response.
system.
− associate the occurrence of action potential to the presence of an effective
stimulus.
Biology
Nervous System / 4
Dimension
System
Theme/
Branch
Facet
Cognitive
Nervous System
Human Body Systems
Critical
Reasoning
Logical
Reasoning
Sample
Learning Outcomes
Benchmark
Independently researching
and collecting relevant
information concerning
nervous system activity or
pathology, to describe and
explore these processes and
their causes.
Inferring, justifying and
deducing from relevant data
the occurrence of
phenomena and processes
that are related to the
functioning of the nervous
system.
The student is able to:
− investigate the sympathetic and parasympathetic activities of the autonomic
nervous system.
− research facts and develop hypotheses about the causes of Parkinson’s disease.
− design an experiment to investigate conditions affecting the reflex arc.
− research synaptic plasticity to explore how synaptic strengthening underlies
learning and memory.
The student is able to:
− infer from data the effects of common stimulants, depressants, or other
chemicals on excitatory and inhibitory responses of neurons.
− deduce from the results of an experiment that the presence of myelin on nerve
fibers increases the conduction speed of the nervous message.
− justify why the electrical and chemical changes occur during an action
potential.
− justify the prolonged action of dopamine at the level of the synapse.
− deduce that the action potential can be detected by an oscilloscope, an
electronic test instrument that allows the observation of constantly varying
signal voltages.
− infer that the destruction of motor neurons of the spinal cord by the
poliomyelitis virus leads to paralysis in the corresponding muscles.
Please refer to the PSE taxonomy for behavioral and metacognitive facets.
IAB Scope
Biology
Nervous System / 5