Lecture Notes on Tissues

Introduction

• Lecture covers Chapter on Tissues
• Emphasis on subscribing to educational channel for updates

Definition of Tissue

• Collection of cells performing similar function
• Made of cells with the same origin, performing a common function

Types of Tissues in Plants

1. Meristematic Tissue

   • Found in regions of continuous cell division
   • Types:
     • Apical Meristem: Located at the tips (roots and shoots)
     • Intercalary Meristem: Located at internodes and leaf bases
     • Lateral Meristem: Involved in increasing the girth of the plant

2. Permanent Tissue

   • Derived from meristematic tissues; do not divide further
   • Types:
     • Simple Permanent Tissue: Composed of similar types of cells
       • Parenchyma: Involved in storage, photosynthesis & basic tissue formation
       • Collenchyma: Provides flexibility & mechanical support
       • Sclerenchyma: Provides structural support; thick-walled, dead cells
     • Complex Permanent Tissue: Composed of different types of cells
       • Xylem: Transports water and minerals; composed of tracheids, vessels, xylem fibers, and xylem parenchyma
       • Phloem: Transports food; composed of sieve tubes, companion cells, phloem fibers, and phloem parenchyma

Stomata

• Tiny openings for gas exchange
• Guard cells control the opening and closing

Animal Tissues

1. Epithelial Tissue

   • Covers body surfaces and lines internal organs
   • Functions in protection, secretion, and absorption
   • Types:
     • Squamous Epithelium: Thin and flat; involved in diffusion and filtration
     • Cuboidal Epithelium: Cube-shaped; involved in secretion and absorption
     • Columnar Epithelium: Tall, column-like; involved in secretion and absorption

2. Connective Tissue

   • Provides support, binds together, and protects tissues and organs
   • Types:
     • Loose Connective Tissue: Includes areolar and adipose tissues
     • Dense Connective Tissue: Includes tendons (connect muscles to bones) and ligaments (connect bones to other bones)
     • Skeletal Tissue: Includes bone and cartilage
     • Fluid Tissue: Includes blood and lymph

3. Muscle Tissue

   • Specialized for contraction
   • Types:
     • Skeletal Muscle: Voluntary, striated, attached to bones
     • Cardiac Muscle: Involuntary, striated, found in heart
     • Smooth Muscle: Involuntary, non-striated, found in walls of internal organs

4. Nervous Tissue

   • Specialized for communication
   • Composed of neurons
   • Functions in receiving, processing, and transmitting information

Miscellaneous

• Importance of understanding tissue organization and function for both plants and animals
• Reminder to revisit and review complex concepts, and to subscribe to educational resources for better understanding

Conclusion

• Summary of types and functions of tissues in plants and animals
• Encourages continuous learning and review through educational channels and resources