Overview of Histology: Tissues and Functions

Epithelial Tissue
- Covers body surfaces, lines cavities and forms glands.
- Functions: protection, absorption, secretion, sensation.
- Types: squamous, cuboidal, columnar; can be simple or stratified.
Connective Tissue
- Supports, binds, and protects other tissues and organs.
- Types: loose connective, dense connective, adipose, cartilage, bone, blood.
- Contains extracellular matrix, which provides structural and nutritional support.
Muscle Tissue
- Responsible for movement.
- Types:
  - Skeletal: voluntary, striated, multi-nucleated.
  - Cardiac: involuntary, striated, mono-nucleated, intercalated discs.
  - Smooth: involuntary, non-striated, mono-nucleated.
Nervous Tissue
- Composed of neurons and glial cells.
- Function: transmit electrical impulses, support and protect neurons.

Tissue Preparation
- Fixation: preserves tissue structure (e.g., formaldehyde).
- Embedding: infiltrating tissues with paraffin or resin for sectioning.
- Sectioning: cutting thin slices (5-10 µm) using a microtome.
Staining
- Enhances contrast in tissue samples.
- Common stains:
  - Hematoxylin and Eosin (H&E): general purpose, stains nuclei blue and cytoplasm pink.
  - Special stains (e.g., Masson's trichrome) for specific structures.

Light Microscopy
- Uses visible light to magnify specimens.
- Commonly used for stained tissue sections.
Electron Microscopy
- Higher resolution using electron beams.
- Types: Transmission Electron Microscopy (TEM) for thin sections; Scanning Electron Microscopy (SEM) for surface details.

Diagnosis of diseases: cancer pathology, infections, and inflammatory conditions.
Research: studying cellular structure and function.
Education: teaching anatomy and physiology through tissue examples.

Tissue homeostasis: balance of cell turnover and tissue integrity.
Histopathology: examination of tissues to identify disease.
Regenerative medicine: using histology to understand tissue repair and regeneration processes.

Microscopic anatomy: histology is the study of tissues, the building blocks of organs.
Essential for understanding: anatomy and physiology of organisms

Epithelial: covers surfaces, lines cavities, forms glands.
- Functions: protection, absorption, secretion, sensation.
- Types: squamous (flat), cuboidal (cube-shaped), columnar (tall and narrow).
  - Can be simple (one layer) or stratified (multiple layers).
Connective: supports, binds, and protects other tissues.
- Types: loose connective (flexible), dense connective (strong), adipose (fat storage), cartilage (flexible support), bone (hard support), blood (fluid transport).
- Contains: extracellular matrix providing structural and nutritional support.
Muscle: responsible for movement.
- Types:
  - Skeletal: voluntary (conscious control), striated (striped), multi-nucleated (multiple nuclei).
  - Cardiac: involuntary (unconscious control), striated, mono-nucleated (single nucleus), intercalated discs (structures connecting muscle cells).
  - Smooth: involuntary, non-striated (smooth), mono-nucleated.
Nervous: transmits electrical impulses.
- Composed of: neurons (nerve cells) and glial cells (support and protect neurons).

** Tissue Preparation**:
- Fixation: preserves tissue structure (e.g., formaldehyde).
- Embedding: infiltrating tissues with paraffin or resin for sectioning.
- Sectioning: cutting thin slices (5-10 µm) using a microtome.
Staining: enhances contrast.
- Common Stains:
  - Hematoxylin and Eosin (H&E): general purpose, stains nuclei blue and cytoplasm pink.
  - Special stains (e.g., Masson's trichrome) for specific structures.

Light Microscopy: uses visible light to magnify specimens, commonly used for stained tissue sections.
Electron Microscopy: higher resolution using electron beams.
- Transmission Electron Microscopy (TEM): for thin sections.
- Scanning Electron Microscopy (SEM): for surface details.

Diagnosis of Diseases: cancer pathology, infections, and inflammatory conditions.
Research: studying cellular structure and function.
Education: teaching anatomy and physiology through tissue examples.

Tissue homeostasis: balance of cell turnover and tissue integrity.
Histopathology: examination of tissues to identify diseases.
Regenerative medicine: using histology to understand tissue repair and regeneration processes.