lesson 3: Histology Flashcards
What is histology?
Study of tissues in relationship between their structure and function
What is a tissue?
Organized groups of cells that together perform a specific function
What are the two components that all tissues have?
- Cells
- Extracellular matrix (ECM)
What are the four types of tissues?
- Epithelial tissue
- Connective tissue
- Muscle tissue
- Nerve tissue
What are the characteristics of epithelial tissue?
- Cells: ++++
- ECM: +
- Surface lining
- Secretion of substances
What are the characteristics of connective tissue?
- Cells: many types
- ECM: ++++++
- Connection between tissues
- Protection
What are the characteristics of muscle tissue?
- Cells: contractile cells
- ECM: ++
- Contraction
What are the characteristics of nerve tissue?
- Cells: nerve cells
- ECM: ++
- Nerve impulse transmission
What is the first step in the preparation for tissue to be examined?
Tissue extraction
What is the purpose of fixation in tissue preparation?
To prevent degradation
What is used for fixation in tissue preparation?
Methanol
What is the purpose of staining in tissue preparation?
To enhance visual contrast
What does hematoxylin stain?
Acid structures (nucleus)
What does eosin stain?
Basic structures (cytoplasm)
What is the final step in the preparation for tissue examination?
Observation under the microscope (OM or EM)
What are the two main types of staining?
- General staining
- Differential staining
What does general staining help to identify?
- Cell shape
- Nuclei number and shape
What does differential staining help to identify?
Types of bacteria
What color indicates G+ bacteria in differential staining?
Blue
What color indicates G- bacteria in differential staining?
Pink
What does Masson staining highlight?
- Collagen (blue)
- Muscle fibers (red)
