Anatomy & Physiology - Connective Tissue (Ch. 4)

Connective Tissue Overview

• Connective tissue provides protective and structural support, filling internal spaces, supporting other tissues, and transporting materials.
• It occurs throughout the body and is never exposed to the outside environment.

Characteristics of Connective Tissues

• Composed of three basic components: specialized cells, extracellular protein fibers, and the ground substance (fluid).
• The matrix formed by extracellular fluid and ground substance constitutes the majority of the tissue volume and influences specific functions.

Functions of Connective Tissues

• Establishes structural framework for the body.
• Transports fluids and dissolved materials.
• Protects delicate organs and supports surrounding tissues.
• Stores energy reserves primarily as triglycerides.
• Defends against invading microorganisms.

Classification of Connective Tissues

• Classified based on physical appearance into:
  • Connective tissue proper: connects and protects (includes loose and dense types).
  • Fluid connective tissues: primarily for transport (includes blood and lymph).
  • Supporting connective tissues: provide structural strength (includes cartilage and bone).

Types of Fibers in Connective Tissues

• Collagenous fibers: Long, unbranched, and strong, resisting force in one direction (e.g., tendons).
• Reticular fibers: Form networks, resist forces in multiple directions, stabilize functional cells.
• Elastic fibers: Branched and wavy, allow tissues to return to original length after stretching (e.g., elastic ligaments).

Loose Connective Tissue

• Serves as packing material, filling spaces between organs and stabilizing specialized cells.
• Types of loose connective tissues include:
  • Areolar Tissue: Least specialized, elastic, supports blood vessels.
  • Adipose Tissue: Contains adipocytes, provides padding, insulates, and stores energy (includes white and brown fat).
  • Reticular Tissue: Supports framework, complex network, located in reticular organs like liver and spleen.

Dense Connective Tissues

• Tightly packed with a high density of collagenous or elastic fibers.
• Types of dense connective tissues include:
  • Dense Regular Connective Tissue: Parallel collagen fibers, provides strong attachment and reduces muscle friction (e.g., tendons and ligaments).
  • Dense Irregular Connective Tissue: Interwoven collagen fibers, provides strength against forces from various directions, found in organ capsules and the dermis.
  • Dense Elastic Tissue: Contains elastic fibers, allows for stretch and recoil.

Fibrocytes in Connective Tissue Proper

• Second most abundant fixed cell found in connective tissue proper, differentiated from fibroblasts.
• Maintain the connective tissue fibers, ensuring structural integrity.

Test your knowledge on connective tissues with this flashcard quiz from Anatomy & Physiology Chapter 4. Explore the characteristics, functions, and importance of connective tissues in the body. Perfect for students looking to reinforce their understanding of this essential topic.