Structural Organization-Structural Organization In Animals Topic

Structural Organization in Animals [JEE Notes]

1. Basics of Structural Organization:

  • Tissues:

  • Definition: A group of cells with a similar structure and function. -(4 Types of Tissues)

    • Epithelial Tissue (covering and lining)
    • Connective Tissue (support and protection)
    • Muscular Tissue (movement and contraction)
    • Nervous Tissue (coordination and regulation)
  • Organs:

    • Definition: A structure made up of different tissues that perform specific functions. -(Examples of Organs)
      • Heart
      • Lungs
      • Stomach
      • Liver
  • Organ Systems:

  • Definition: A group of organs that work together to perform a specific function. -(Major Organs Systems in Animals)

    • Digestive System: Converts food into energy.
    • Respiratory System: Takes in oxygen and expels carbon dioxide.
    • Circulatory System: Pumps blood throughout the body.
    • Excretory System: Removes waste products.
    • Nervous System: Controls and coordinates the body’s activities.
    • Endocrine System: Regulates the body’s functions through hormones.
    • Musculoskeletal System: Provides support and movement.

2. Animal Tissues:

  • Epithelium:

  • Structure:

    • Cells closely packed together with little extracellular material.
    • Covers and lines the surfaces of organs and cavities.
  • Types:

  • Simple Epithelium: Single layer of cells.

  • Stratified Epithelium: Multiple layers of cells.

  • Glandular Epithelium: Secretes substances such as mucus or enzymes.

  • Connective Tissue:

  • Structure:

  • Cells widely separated by an extracellular matrix.

  • Types:

  • Loose Connective Tissue: Loosely arranged cells in a gel-like matrix.

  • Dense Connective Tissue: Tightly packed cells in a dense matrix.

  • Adipose Tissue: Cells specialized to store fat.

  • Cartilage: Flexible connective tissue with specialized cells called chondrocytes.

  • Bone: Hard connective tissue with specialized cells called osteocytes.

  • Muscle Tissue:

    • Structure:
    • Cells specialized for contraction.
    • Contains contractile proteins actin and myosin.
    • Types:
      • Skeletal Muscle: Voluntary movement of bones
      • Smooth Muscle: Involuntary movement of internal organs.
      • Cardiac Muscle: Pumping of the heart.
  • Nervous Tissue:

  • Structure:

    • Neurons: Specialized cells that conduct electrical signals.
    • Neuroglia: Support cells that provide nutrients and protection for neurons.

3. Organ Systems and Functions

  • Digestive System:

    • Structure:
    • Mouth, esophagus, stomach, small intestine, large intestine, rectum, anus.
    • Accessory Organs: Liver and Pancreas
    • Functions:
    • Breaks down food into nutrients that can be absorbed by the body.
    • Eliminates undigested materials as waste.
  • Respiratory System:

    • Structure:
      • Nose, pharynx, larynx, trachea, bronchi, bronchioles, and lungs.
    • Functions:
    • Takes in oxygen from the atmosphere.
    • Removes carbon dioxide from the bloodstream.
  • Circulatory System:

    • Structure:
    • Heart, Blood Vessels (arteries, veins, capillaries), Blood components (Red Blood Cells, White Blood Cells, Platelets, Plasma)
    • Functions:
      • Pumps blood throughout the body.
      • Transports oxygen, nutrients, hormones, and waste products.
  • Excretory System:

    • Structure:
    • Kidneys, Ureters, Urinary Bladder, Urethra
    • Functions:
    • Removes nitrogenous waste products from the bloodstream.
    • Regulates water and electrolyte balance.
  • Nervous System:

  • Structure:

    • Central Nervous System (Brain, Spinal Cord)
    • Peripheral Nervous System (Sensory neurons, Motor neurons, Autonomic Nervous System)
  • Functions:

    • Controls and coordinates the body’s activities.
    • Receives, processes, and responds to stimuli.
  • Endocrine System:

    • Structure:
    • Various Glands (Pituitary, Thyroid, Adrenal, Pancreas, etc.)
    • Functions:
    • Regulates the body’s functions through hormones.
    • Controls processes like growth, metabolism, reproduction.
  • Musculoskeletal System:

    • Structure:
      • Bones, Joints, Muscles
    • Functions:
      • Provides support and protection for the body.
      • Facilitates movement and locomotion.

References:

  • NCERT Biology Class 11: Chapter 1 -“The Living World”
  • NCERT Biology Class 11: Chapter 2-“Biological Classification”
  • NCERT Biology Class 12: Chapter 3-“Human Reproduction”.
  • NCERT Biology Class 12: Chapter 5-“Principles of Inheritance and Variation”