Transport in Animals

TRANSPORT IN ANIMALS

Overview of Circulatory Systems

  • Single-Loop Circulatory System

    • Example: Fishes
    • Components:
    • One Ventricle
    • One Atrium
    • Gill Capillaries

  • Double-Loop Circulatory System

    • Examples: Most reptiles, crocodilians, birds, and mammals
    • Components:
    • Two Atria
    • Two Ventricles completely divided
    • Lung Capillaries
    • Ventricle Structure:
    • With partial division: Found in most reptiles
    • Fully developed: Found in crocodilians, birds, and mammals

Importance of Transport in Organisms

  • Vital substances that need to be transported within the body:
    • Oxygen
    • Carbon Dioxide
    • Nutrients
    • Waste Products
    • Hormones
    • White Blood Cells (factors that fight disease)

Transport Mechanisms in Unicellular Organisms

  • Mechanism:
    • Diffusion: Movement of substances from areas of high concentration to low concentration
    • Limitation:
    • In unicellular organisms, due to small and thin structures, diffusion is sufficient.
    • However, with thicker bodies, diffusion alone is inadequate, risking starvation of cells.

Circulatory Systems in Multicellular Organisms

  • Key Components of Circulatory Systems:
    • Blood: The transport medium
    • Blood Vessels: The pathways for blood circulation
    • Heart: The pump for blood circulation
    • Valves: Ensure one-directional flow of blood
  • Function of Circulatory Systems: Operate to collect and transport various substances to different body parts.

Types of Circulatory Systems

  • Open Circulatory System:

    • Exists in many invertebrates such as crustaceans, snails, and insects
    • Characteristics:
    • Blood pumped at relatively low pressure into a body cavity called haemocoel
    • Blood directly bathes internal organs, moving slowly through tissues
    • Less efficiency, suitable for small organisms.

  • Closed Circulatory System:

    • Found in larger animals including segmented worms, sea urchins, and all vertebrates
    • Characteristics:
    • Blood remains enclosed in a continuous network of blood vessels
    • Tissue fluid present between blood vessels and cells, enhancing efficiency
    • Enables rapid, high-pressure blood circulation to specific tissues.

The Human Circulatory System

  • Closed Circulatory System: Referred to as the cardiovascular system.

  • Components:

    • Cardio: Relates to the heart
    • Vascular: Relates to blood vessels

  • Double Circulation Structure:

    • Right Side: Pumps deoxygenated blood to the lungs (pulmonary circulation)
    • Left Side: Pumps oxygenated blood to the rest of the body (systemic circulation)

Functionality of the Circulatory System

  • Pulmonary Circulation:

    • Blood is pumped to the lungs for gaseous exchange
    • Oxygen collected; carbon dioxide removed

  • Systemic Circulation:

    • Blood pumped at high pressure to body tissues
    • Delivers oxygen and nutrients, removes carbon dioxide and waste products

Importance of Tissue Fluid Formation

  • Tissue Fluid:

    • Formed when blood plasma is pushed out of capillaries
    • Provides a medium for substance movement between blood and cells

  • Oxygen Transport:

    • Rapid oxygen transport to all body cells facilitates cellular respiration
    • Cellular respiration releases energy necessary for activities and heat production.

Activity Prompt

  • Instruction: "PLEASE COMPLETE ACTIVITY 1 ON PAGE 80"
  • Additional Material: Watch the recommended video for further understanding and context.