Mammalian Tissue Structure Flashcards
What is histology?
The study of microscopy structure of cells and tissue, allowing correlations between cellular structures + function to be examined
What are tissues?
Collections of cells arranged in specific fashion
What is histopathology?
Branch of histology that focuses on identification + study of disease
How is histology of tissue analysed?
Tissues dehydrated + embedded in wax
Thin sections of tissue cut from “wax-block”
Mounted on microscope slides
Dyes added
Why must the tissues be dehydrated + embedded in wax?
Tissue has to be “fixed” in formalin to prevent degradation
+ conserve structural attributes
Why is the tissue cut into thin slices?
To allow light to transverse through tissue
Why is dye added to the tissue?
To highlight specific features as tissue has little inherent contrast
What dyes are used?
Haematoxylin
Eosin
What does haematoxylin dye do?
Used for basophilia
Turns DNA/RNA blue/purple
What does eosin dye do?
Used for basophilia
Turns proteins within + outside cell pink
What are adipose tissue?
All same cells
What are compound tissues?
Mix of cells with different functions
What are the two types of cell barriers?
Epithelium
Endothelium
What are the 4 categories of tissues?
Connective
Muscular
Nervous
Epithelium
What are the 3 primitive (germ cell) layers?
Mesoderm
Ectoderm
Endoderm
What primitive layer is connective tissue developed from?
Mesoderm
What primitive layer is muscular tissue developed from?
Mesoderm
What primitive layer is nervous tissue developed from?
Ectoderm
What primitive layer is epithelium developed from?
All 3
What is epithelia?
Tissues that serve as protective layers +/or secretory components of body organs + systems
What is the structure of epithelia?
Formed into tightly cohesive cellular sheets
Cover/line body surfaces
What does epithelia have a high capacity for?
Regeneration
eg. wound healing
What is epithelia’s structure related to function?
Structure vital for the passage of O2, digested food + secretions through epithelia
What are epithelia’s attributes?
Limited intracellular space Mitotic capability Basement membrane Single or multiple layers of cells Free apical surfaces
Why does epithelia have limited intracellular space?
Specialised junctions hold cells close together
Effective barrier + blocks infiltration of fluids between cells
Why does epithelia have single or multiple layers of cells?
Thin = diffusion important Thick = protection from abrasion
Why does epithelia have free apical surfaces?
During development or maturity of cell