System Integration and Communication in Living Systems

System Integration in Living Systems

C3.1.1 System Integration

• System integration is a necessary process in living systems.
• Coordination is needed for component parts of a system to collectively perform an overall function.

C3.1.2 Hierarchy of Subsystems

• Cells, tissues, organs, and body systems form a hierarchy of subsystems integrated in a multicellular living organism.
• This integration is responsible for emergent properties.
• Example: A cheetah becomes an effective predator through the integration of its body systems.

C3.1.3 Integration of Organs

• Integration of organs in animal bodies occurs through:
  • Hormonal signaling
  • Nervous signaling
  • Transport of materials and energy
• Distinction Between Nervous and Endocrine Systems:
  • Nervous system and endocrine system both send messages.
• Role of the Blood System:
  • The blood system transports materials between organs.

Multicellularity & Emergent Properties

• Multicellular organisms are made of many cells working together.

Levels of Organization

• Hierarchy:
  • Atoms and molecules → Organelles → Cell → Tissue → Organ → Organ system → Organism

Emergent Properties

• Emergent properties arise due to interactions.
• "The whole is greater than the sum of its parts." - Aristotle
• Multicellular organisms can complete functions that individual cells cannot undertake.

System Integration Explained

• System integration is the coordinated interaction of cells, tissues, and organs
• Each part plays a role in fulfilling the system's function.

Integration Example: Muscular and Circulatory Systems

• When exercising, muscles need ATP.
• Hint: Consider how the muscular and circulatory systems integrate to provide the necessary components for ATP production.

Cells

• Cells are specialized to perform specific tasks.
• Examples:
  • Neurons have long extensions to relay signals.
  • Fat cells, red blood cells, smooth muscle cells, chondrocytes, cardiac muscle cells, nerve cells, white blood cells, platelet cells, female sex cells, bone cells, skeletal cells, myeloblast cells, stem cells, intestinal cells, male sex cells, blastocyst cells

Tissues

• Made of similar cells that perform a shared function.
• Example: Muscle tissues contract, and there are three types (smooth, skeletal, cardiac).

Organs

• Structure made of multiple tissue types working together.
• Example: The heart contains cardiac muscle tissue for pumping, nervous tissue for impulse conduction, and connective tissue for structure.

Organ Systems

• Groups of organs orchestrating broader physiological functions.
• Example: The digestive system includes the mouth, stomach, and intestines, each performing its own function.

Emergent Properties Revisited

• Emergent properties arise from the interaction of component parts.
• Multicellular organisms are capable of completing functions that individual cells could not undertake.
• The whole is greater than the sum of its parts!

Signaling

• Effective integration of body systems depends on proper communication between different parts of the body.
• Communication occurs through:
  • Endocrine System
  • Nervous System

Endocrine Signaling

• Hormones: Chemical messengers produced by endocrine glands.
• Target specific cells via receptors (long-distance signaling).
• Long-lasting impacts (usually hours-days).
• Can take minutes to hours for effect to kick in.
• Example: pancreas secretes insulin which travel through blood and signals cells to take in glucose

Travel of Hormones

• Hormones travel through the circulatory system to reach targets.

Nervous Signaling

• Rapid electric signaling across neural networks allows for swift reactions to stimuli.
• Short-lived signals.
• Travel through neurons.
• Less than 1 second for effect.

Reaction to Stimuli

• Example: Immediate reaction to accidentally touching a hot surface.

Action upon touching hot surface

• The source of heat stimulates a finger (receiver).
• Afferent neuron axon (sensory) carries signals to the spinal cord.
• Efferent neuron axon (motor) carries signals from the spinal cord to the muscle (effector).

Endocrine vs. Nervous System

Wrap Up Questions

1. What is system integration? Provide an example.
2. What are differences between endocrine and nervous signaling?
3. Give an example of how endocrine glands work with other parts of the body.
4. Give an example of how the nervous system works with other parts of the body.
5. How can the endocrine and nervous systems work together?