Human Histology: Nervous Tissue Overview

Introduction to Histology

• Histology is the study of microscopic tissue structure, providing insights into cell and tissue functions and pathology.
• Crucial for diagnosing diseases by identifying normal tissue architecture and abnormalities, such as inflammation or cancer.

Types of Tissues

• Epithelial Tissue:

  • Types include Simple, Stratified, Pseudostratified, and Transitional.
  • Functions: Protection, Secretion, Absorption, and Filtration.

• Connective Tissue:

  • Types include Loose, Dense, Cartilage, Bone, and Blood.
  • Functions: Provides support, stores energy, and transports materials (e.g., vitamins and minerals).

• Muscle Tissue:

  • Types include Skeletal, Cardiac, and Smooth.
  • Functions: Responsible for Movement, Posture, and Heat production.

• Nervous Tissue:

  • Composed of Neurons and Neuroglia; coordinates and controls body activities.

Branches of Histology

• General Histology: Study of the structure and function of tissues.
• Special Histology: Focuses on microscopic structures of organs (e.g., heart, digestive system).
• Pathological Histology: Examines diseased tissues.

Nervous Tissue Components

• Neurons: Primary functional units that transmit electrical signals and process information.
• Neuroglia (Glial Cells): Supportive cells that maintain the neuronal environment, providing protection and nutrients.

Neuron Structures and Functions

• Dendrites: Branch-like structures that receive signals from other neurons.
• Axon: Long projection that transmits impulses away from the neuron to other neurons or effector cells.

Types of Neuroglia and Their Functions

• Astrocytes:

  • Provide structural support, regulate blood flow, maintain the blood-brain barrier, and support the chemical environment for neurons.

• Oligodendrocytes (CNS) and Schwann Cells (PNS):

  • Produce myelin sheath, insulating axons and enhancing signal transmission speed.

• Microglia:

  • Act as the immune cells of the central nervous system, protecting against pathogens and debris.