BIOLOGY FOR LIFE
  • ⭐IB Bio Syllabus⭐
    • Unity and Diversity (A) >
      • A1 molecules >
        • A1.1: Water
        • A1.2: Nucleic Acids
      • A2 Cells >
        • A2.1: Origins of Cells
        • A2.2: Cell Structure
        • A2.3: Viruses
      • A3 Organisms >
        • A3.1: Diversity of Organisms
        • A3.2: Classification and Cladistics
      • A4 Ecosystems >
        • A4.1: Evolution and Speciation
        • A4.2: Conservation of Biodiversity
    • Form and Function (B) >
      • B1 Molecules >
        • B1.1: Carbohydrates and Lipids
        • B1.2: Proteins
      • B2 Cells >
        • B2.1 Membranes and Membrane Transport
        • B2.2 Organelles and Compartmentalization
        • B2.3 Cell Specialization
      • B3 Organisms >
        • B3.1 Gas Exchange
        • B3.2 Transport
        • B3.3 Muscle and Motility
      • B4 Ecosystems >
        • B4.1 Adaptation to Environment
        • B4.2 Ecological Niches
    • Interaction and Interdependence (C) >
      • C1 Molecules >
        • C1.1: Enzymes and Metabolism
        • C1.2: Cell Respiration
        • C1.3: Photosynthesis
      • C2 Cells >
        • C2.1: Chemical Signaling
        • C2.2: Neural Signaling
      • C3 Organisms >
        • C3.1: Integration of Body Systems
        • C3.2: Defense Against Disease
      • C4 Ecosystems >
        • C4.1 Populations and Communities
        • C4.2 Transfers of Energy and Matter
    • Continuity and Change (D) >
      • D1 Molecules >
        • D1.1: DNA Replication
        • D1.2: Protein Synthesis
        • D1.3: Mutation and Gene Editing
      • D2 Cells >
        • D2.1: Cell and Nuclear Division
        • D2.2: Gene Expression
        • D2.3: Water Potential
      • D3 Organisms >
        • D3.1: Reproduction
        • D3.2: Inheritance
        • D3.3: Homeostasis
      • D4 Ecosystems >
        • D4.1: Natural Selection
        • D4.2: Stability and Change
        • D4.3: Climate Change
    • Legacy Syllabus (2016) >
      • Core >
        • 1: Cell Biology >
          • 1.1: Introduction to Cells
          • 1.2: Ultrastructure of Cells
          • 1.3: Membrane Structure
          • 1.4: Membrane Transport
          • 1.5: The Origin of Cells
          • 1.6: Cell Division
        • 2: Molecular Biology >
          • 2.1: Molecules to Metabolism
          • 2.2: Water
          • 2.3: Carbohydrates and Lipids
          • 2.4: Proteins
          • 2.5: Enzymes
          • 2.6: DNA and RNA
          • 2.7: DNA Replication, Transcription and Translation
          • 2.8: Cell Respiration
          • 2.9: Photosynthesis
        • 3: Genetics >
          • 3.1: Genes
          • 3.2: Chromosomes
          • 3.3: Meiosis
          • 3.4: Inheritance
          • 3.5: Genetic Modification and Biotechnology
        • 4: Ecology >
          • 4.1: Species, Communities and Ecosystems
          • 4.2: Energy Flow
          • 4.3: Carbon Cycling
          • 4.4: Climate Change
        • 5: Evolution and Biodiversity >
          • 5.1: Evidence for Evolution
          • 5.2: Natural Selection
          • 5.3: Classification and Biodiversity
          • 5.4: Cladistics
        • 6: Human Physiology >
          • 6.1: Digestion and Absorption
          • 6.2: The Blood System
          • 6.3: Defense Against Infectious Disease
          • 6.4: Gas Exchange
          • 6.5: Neurons and Synapses
          • 6.6: Hormones, Homeostasis and Reproduction
      • Higher Level >
        • 7: Nucleic Acids >
          • 7.1: DNA Structure and Replication
          • 7.2: Transcription and Gene Expression
          • 7.3: Translation
        • 8: Metabolism, Cell Respiration & Photosynthesis >
          • 8.1: Metabolism
          • 8.2: Cell Respiration
          • 8.3: Photosynthesis
        • 9: Plant Biology >
          • 9.1: Transport in the Xylem of Plants
          • 9.2: Transport in the Phloem of Plants
          • 9.3: Growth in Plants
          • 9.4: Reproduction in Plants
        • 10: Genetics and Evolution >
          • 10.1: Meiosis
          • 10.2: Inheritance
          • 10.3: Gene Pools and Speciation
        • 11: Animal Physiology >
          • 11.1: Antibody Production and Vaccination
          • 11.2: Movement
          • 11.3: Kidney and Osmoregulation
          • 11.4: Sexual Reproduction
      • Options >
        • D: Human Physiology >
          • D.1: Human Nutrition
          • D.2: Digestion
          • D.3: Functions of the Liver
          • D.4: The Heart
          • D.5: Hormones and Metabolism
          • D.6: Transport of Respiratory Gases
  • IB Requirements
    • Learner Profile
    • Collaborative Sciences Project
    • External Assessment
    • Internal Assessment >
      • Research Design
      • Analysis
      • Conclusion
      • Evaluation
    • Extended Essay
  • Exam Revision
    • Revision Tools
  • Skills for Biology
    • Tools >
      • Experimental Techniques >
        • Addressing Safety
        • Measuring Variables >
          • Lab Drawings
          • Measurement Uncertainty
        • Techniques >
          • Microscopy
      • Technology >
        • Graphing with Excel
      • Mathematics >
        • Statistics >
          • Glossary of Statistic Terms and Equations
          • Descriptive Statistics >
            • Skew and the Normal Distribution
            • Outliers
            • Measures of Central Tendancy
            • Measures of Spread
            • Pearson Correlation
          • Inferential Statistics >
            • T-Test
            • ANOVA
            • Kruskal-Wallis
            • X2 Test for Independence
            • X2 Goodness of Fit
        • Graphing >
          • Interpreting Error Bars
    • Inquiry Processes >
      • Exploring & Designing >
        • Research Questions
        • Hypotheses and Predictions
        • Varaibles
        • Sampling
      • Collecting & Processing Data >
        • Data Tables
      • Concluding & Evaluating >
        • Error Analysis
  • SHS Course Info
    • Above & Beyond >
      • Biology Club
      • Pumpkin Carving
      • Scavenger Hunt
      • Science News
      • Wood Duck Project (legacy)
      • Invasive Crayfish Project (legacy)
    • Assessment >
      • Class Grading IB Bio I
      • Class Grading IB Bio II
      • Daily Quizzes (legacy)
      • Lab Practicals (legacy)
    • Class Photos
    • Recommendations
  • Contact
  • About
    • Philosophy
    • Resume
    • Reflection
    • Favorite Quotes
    • AEF Blog
  • Expeditions
    • Bahamas (2009)
    • Trinidad (2010)
    • Trinidad (2011)
    • Ecuador (2012)
    • Trinidad (2013)
    • Peru (2014)
    • Bahamas (2015)
    • Peru (2016)
    • Costa Rica (2017)
    • Costa Rica (2018)
    • Arizona (2022)
    • Florida (2023)
    • Belize (2024)
    • Costa Rica (2025)
  • Summer Ecology Research
  • Teacher Resources

C2.2  Neural Signaling

Guiding Questions:  
Guiding questions help students view the content of the syllabus through the conceptual lenses of both the themes and the levels of biological organization.
  • How are electrical signals generated and moved within neurons?
  • How can neurons interact with other cells?
​
​
Linking Questions:  
Linking questions strengthen students’ understanding by making connections between topics.  The ideal outcome of the linking questions is networked knowledge.
  • In what ways are biological systems regulated?
  • How is the structure of specialized cells related to function?

Resources:
  • ​Quizlet study set for this topic.  Coming soon!
C2.2.1— Neurons as cells within the nervous system that carry electrical impulses.  
  • State the function of the following neuron cell parts:  dendrites, axon and cell body.
  • Identify the cell body, axon and dendrites in diagrams of typical sensory and motor neurons. ​
C2.2.2— Generation of the resting potential by pumping to establish and maintain concentration gradients of sodium and potassium ions.
  • Define membrane potential. 
  • Define resting potential.
  • Outline three mechanisms that together create the resting potential in a neuron.
  • State the voltage of the resting potential.
  • Outline the six steps of sodium-potassium pump action.
​C2.2.3— Nerve impulses as action potentials that are propagated along nerve fibers.
  • Define nerve impulse.
  • Define action potential.
C2.2.4— Variation in the speed of nerve impulses.
  • Outline the correlation between conduction speed of nerve impulses and axon diameter.
  • Explain the difference in nerve impulse speed for myelinated and unmyelinated fibers.
  • State the correlation between conduction speed of nerve impulses and animal size. ​
C2.2.5-- Synapses as junctions between neurons and between neurons and effector cells.
  • Define synapse, synaptic gap and effector.
  • List examples of effector cells.
  • State that a signal can only pass in one direction across a typical synapse.
  • State the role of neurotransmitters.​​​
C2.2.6- Release of neurotransmitters from a presynaptic membrane.
  • Outline the mechanism of synaptic transmission occurring at a presynaptic cell, including the role of depolarization, calcium ions, exocytosis and diffusion.
  • State that calcium functions as a chemical signal triggering exocytosis of neurotransmitter from a presynaptic cell.
C2.2.7- Generation of an excitatory postsynaptic potential.
  • Outline the mechanism of synaptic transmission occurring at a post-synaptic cell, including the role of neurotransmitters, diffusion, receptors, gated ion channels, threshold potential and action potential. 
  • State that acetylcholine is one of the most common neurotransmitters in both invertebrates and vertebrates and is used as the neurotransmitter in many synapses including between neurons and muscle fibers.
  • Outline the digestion of acetylcholine by acetylcholinesterase.
AHL ​C2.2.8- Depolarization and repolarization during action potentials. 
  • State that an action potential is only initiated if the threshold potential is reached. 
  • Define depolarization. 
  • Outline the mechanism of depolarization during an action potential using voltage gated sodium channels.
  • Define repolarization. 
  • Outline the mechanism of repolarization during an action potential using voltage gated potassium channels.
AHL ​C2.2.9- Propagation of an action potential along a nerve fiber/axon as a result of local currents.
  • Describe the movement of sodium ions in a local current.
  • State that local currents cause each successive part of the axon to reach the threshold potential.
  • Explain how the movement of sodium ions propagates an action potential along an axon.
  • Outline the cause and consequence of the refractory period after depolarization.
AHL ​C2.2.10- Oscilloscope traces showing resting potentials and action potentials.
  • Outline the use of oscilloscopes in measuring membrane potential.
  • Annotate an oscilloscope trace to show the resting potential, action potential (depolarization and repolarization), threshold potential and refractory period.
  • Deduce the number of nerve impulses per second from an oscilloscope trace.
AHL ​​​C2.2.11- Saltatory conduction in myelinated fibers to achieve faster impulses.
  • Describe the structure of a myelinated nerve fiber.

  • Outline how the myelination of neurons allows for saltatory conduction, in which the action potential can effectively jump from node of Ranvier to node of Ranvier. 
  • ​State that in myelinated neurons, the Na+ and K+ ion channels are clustered down the axon at nodes of Ranvier.
AHL ​​​C2.2.12- Effects of exogenous chemicals on synaptic transmission.
  • Define exogenous chemicals.
  • Outline the effects of neonicotinoids on synaptic transmission. 
  • Outline the effects of cocaine on synaptic transmission.
AHL ​​​C2.2.13- Inhibitory neurotransmitters and generation of inhibitory postsynaptic potentials.
  • ​Outline the inhibitory mechanism of the neurotransmitter GABA.
  • Outline the consequence of hyperpolarization by inhibitory neurotransmitters.
AHL ​​​C2.2.14- Summation of the effects of excitatory and inhibitory neurotransmitters in a postsynaptic neuron.
  • Describe the effects of excitatory and inhibitory neurotransmitters on the ability of a postsynaptic cell to reach its threshold potential. 
  • Define summation.
  • Interpret graphical representations of the summation of combinations of excitatory and inhibitory neurotransmitters.
AHL ​​​C2.2.15- Perception of pain by neurons with free nerve endings in the skin.
  • Describe the mechanism by which environmental stimuli are able to activate nerve endings in the skin, including the role of receptor proteins, ions channels, and threshold potential.
  • List stimuli which can trigger a pain response. 
  • Outline the flow of information during the pain response. ​
AHL ​​​C2.2.16- Consciousness as a property that emerges from the interaction of individual neurons in the brain.
  • Define emergent property.
  • State that new properties emerge at each level of biological organization.
  • Outline consciousness as an emergent property.
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Picture
  • ⭐IB Bio Syllabus⭐
    • Unity and Diversity (A) >
      • A1 molecules >
        • A1.1: Water
        • A1.2: Nucleic Acids
      • A2 Cells >
        • A2.1: Origins of Cells
        • A2.2: Cell Structure
        • A2.3: Viruses
      • A3 Organisms >
        • A3.1: Diversity of Organisms
        • A3.2: Classification and Cladistics
      • A4 Ecosystems >
        • A4.1: Evolution and Speciation
        • A4.2: Conservation of Biodiversity
    • Form and Function (B) >
      • B1 Molecules >
        • B1.1: Carbohydrates and Lipids
        • B1.2: Proteins
      • B2 Cells >
        • B2.1 Membranes and Membrane Transport
        • B2.2 Organelles and Compartmentalization
        • B2.3 Cell Specialization
      • B3 Organisms >
        • B3.1 Gas Exchange
        • B3.2 Transport
        • B3.3 Muscle and Motility
      • B4 Ecosystems >
        • B4.1 Adaptation to Environment
        • B4.2 Ecological Niches
    • Interaction and Interdependence (C) >
      • C1 Molecules >
        • C1.1: Enzymes and Metabolism
        • C1.2: Cell Respiration
        • C1.3: Photosynthesis
      • C2 Cells >
        • C2.1: Chemical Signaling
        • C2.2: Neural Signaling
      • C3 Organisms >
        • C3.1: Integration of Body Systems
        • C3.2: Defense Against Disease
      • C4 Ecosystems >
        • C4.1 Populations and Communities
        • C4.2 Transfers of Energy and Matter
    • Continuity and Change (D) >
      • D1 Molecules >
        • D1.1: DNA Replication
        • D1.2: Protein Synthesis
        • D1.3: Mutation and Gene Editing
      • D2 Cells >
        • D2.1: Cell and Nuclear Division
        • D2.2: Gene Expression
        • D2.3: Water Potential
      • D3 Organisms >
        • D3.1: Reproduction
        • D3.2: Inheritance
        • D3.3: Homeostasis
      • D4 Ecosystems >
        • D4.1: Natural Selection
        • D4.2: Stability and Change
        • D4.3: Climate Change
    • Legacy Syllabus (2016) >
      • Core >
        • 1: Cell Biology >
          • 1.1: Introduction to Cells
          • 1.2: Ultrastructure of Cells
          • 1.3: Membrane Structure
          • 1.4: Membrane Transport
          • 1.5: The Origin of Cells
          • 1.6: Cell Division
        • 2: Molecular Biology >
          • 2.1: Molecules to Metabolism
          • 2.2: Water
          • 2.3: Carbohydrates and Lipids
          • 2.4: Proteins
          • 2.5: Enzymes
          • 2.6: DNA and RNA
          • 2.7: DNA Replication, Transcription and Translation
          • 2.8: Cell Respiration
          • 2.9: Photosynthesis
        • 3: Genetics >
          • 3.1: Genes
          • 3.2: Chromosomes
          • 3.3: Meiosis
          • 3.4: Inheritance
          • 3.5: Genetic Modification and Biotechnology
        • 4: Ecology >
          • 4.1: Species, Communities and Ecosystems
          • 4.2: Energy Flow
          • 4.3: Carbon Cycling
          • 4.4: Climate Change
        • 5: Evolution and Biodiversity >
          • 5.1: Evidence for Evolution
          • 5.2: Natural Selection
          • 5.3: Classification and Biodiversity
          • 5.4: Cladistics
        • 6: Human Physiology >
          • 6.1: Digestion and Absorption
          • 6.2: The Blood System
          • 6.3: Defense Against Infectious Disease
          • 6.4: Gas Exchange
          • 6.5: Neurons and Synapses
          • 6.6: Hormones, Homeostasis and Reproduction
      • Higher Level >
        • 7: Nucleic Acids >
          • 7.1: DNA Structure and Replication
          • 7.2: Transcription and Gene Expression
          • 7.3: Translation
        • 8: Metabolism, Cell Respiration & Photosynthesis >
          • 8.1: Metabolism
          • 8.2: Cell Respiration
          • 8.3: Photosynthesis
        • 9: Plant Biology >
          • 9.1: Transport in the Xylem of Plants
          • 9.2: Transport in the Phloem of Plants
          • 9.3: Growth in Plants
          • 9.4: Reproduction in Plants
        • 10: Genetics and Evolution >
          • 10.1: Meiosis
          • 10.2: Inheritance
          • 10.3: Gene Pools and Speciation
        • 11: Animal Physiology >
          • 11.1: Antibody Production and Vaccination
          • 11.2: Movement
          • 11.3: Kidney and Osmoregulation
          • 11.4: Sexual Reproduction
      • Options >
        • D: Human Physiology >
          • D.1: Human Nutrition
          • D.2: Digestion
          • D.3: Functions of the Liver
          • D.4: The Heart
          • D.5: Hormones and Metabolism
          • D.6: Transport of Respiratory Gases
  • IB Requirements
    • Learner Profile
    • Collaborative Sciences Project
    • External Assessment
    • Internal Assessment >
      • Research Design
      • Analysis
      • Conclusion
      • Evaluation
    • Extended Essay
  • Exam Revision
    • Revision Tools
  • Skills for Biology
    • Tools >
      • Experimental Techniques >
        • Addressing Safety
        • Measuring Variables >
          • Lab Drawings
          • Measurement Uncertainty
        • Techniques >
          • Microscopy
      • Technology >
        • Graphing with Excel
      • Mathematics >
        • Statistics >
          • Glossary of Statistic Terms and Equations
          • Descriptive Statistics >
            • Skew and the Normal Distribution
            • Outliers
            • Measures of Central Tendancy
            • Measures of Spread
            • Pearson Correlation
          • Inferential Statistics >
            • T-Test
            • ANOVA
            • Kruskal-Wallis
            • X2 Test for Independence
            • X2 Goodness of Fit
        • Graphing >
          • Interpreting Error Bars
    • Inquiry Processes >
      • Exploring & Designing >
        • Research Questions
        • Hypotheses and Predictions
        • Varaibles
        • Sampling
      • Collecting & Processing Data >
        • Data Tables
      • Concluding & Evaluating >
        • Error Analysis
  • SHS Course Info
    • Above & Beyond >
      • Biology Club
      • Pumpkin Carving
      • Scavenger Hunt
      • Science News
      • Wood Duck Project (legacy)
      • Invasive Crayfish Project (legacy)
    • Assessment >
      • Class Grading IB Bio I
      • Class Grading IB Bio II
      • Daily Quizzes (legacy)
      • Lab Practicals (legacy)
    • Class Photos
    • Recommendations
  • Contact
  • About
    • Philosophy
    • Resume
    • Reflection
    • Favorite Quotes
    • AEF Blog
  • Expeditions
    • Bahamas (2009)
    • Trinidad (2010)
    • Trinidad (2011)
    • Ecuador (2012)
    • Trinidad (2013)
    • Peru (2014)
    • Bahamas (2015)
    • Peru (2016)
    • Costa Rica (2017)
    • Costa Rica (2018)
    • Arizona (2022)
    • Florida (2023)
    • Belize (2024)
    • Costa Rica (2025)
  • Summer Ecology Research
  • Teacher Resources