Chapter 8: Transport in Mammals

Overview

• Focus on the transport system in mammals.
• Differences from transport systems in fish and insects.

Key Questions

• What is a transport system?
• Why do we need a transport system?

Unicellular vs Multicellular Organisms

• Unicellular Organisms
  • Made of one cell.
  • Can easily diffuse substances (e.g., oxygen) directly into the cell.
• Multicellular Organisms
  • Made of many cells.
  • Central or deeper cells have difficulty receiving substances directly due to distance.

Problem in Multicellular Organisms

• Deep cells in multicellular organisms have difficulty receiving oxygen or nutrients.
• Without transport systems, cells may die due to lack of essential substances.

Evolution of Transport System

• Developed to address the issue of transporting substances over large distances within an organism.
• Process:
  1. Creation of internal spaces or cavitations.
  2. Filling these spaces with a liquid medium.
  3. Housing the liquid in tubes or vessels to prevent leakage.

Components of the Transport System

1. Medium (Blood)
   • Carries essential substances like oxygen and nutrients.
2. Blood Vessels
   • Contain and direct the flow of blood, preventing leakage.
3. Pump (Heart)
   • Moves the blood through vessels, ensuring continuous flow.

Functionality

• The transport system facilitates the movement of substances like oxygen close to cells for efficient diffusion.
• Minimizes distance for diffusion, making it easier for cells to receive nutrients and expel waste.

Summary

• The transport system is crucial for multicellular organisms to overcome limitations of direct diffusion due to cell layers.
• Ensures efficient delivery of substances and removal of waste, maintaining cell viability.