3: Histology Flashcards
What are characteristics of epithelial tissue?
-Highly cellular, minimal extracellular matrix
-Polarity, tissue has an apical and basal surface
-Attachment to basement membrane
-Avascular
-High regenerative capacity
What are the 4 types of tissue?
- Nervous
- Muscle
- Epithelial
- Connective
What are the 3 functions of epithelial cells?
- Physical protection
- Selective permeability
- Secretion
How do epithelial cells receive nutrients if they are avascular?
Diffusion from basement membrane
What is the apical surface? What is unique about it?
The top layer of epithelial tissue. It is unattached
What is the basal surface?
Where the epithelial tissue attaches to a basement membrane
What is a tight junction? What does it do? Where is it common?
An intercellular junction made of proteins that prevents anything from entering between cells. Common at the apical surface
What is a gap junction? What does it do? Where is it common?
An intercellular junction that is localized (does not span the whole outside of a cell). It’s primary function is communication. It is common in cardiac muscle.
What are anchoring junctions?
Intercellular junction important for support and to resist mechanical stress.
What anchoring junctions is localized and at the lateral level?
Desmosomes
What anchoring junction is all the way around a cell at a lateral level?
Adherens
What anchoring junction is at the basal surface?
Hemidesmosomes
What kind of tissue is fat?
Loose connective tissue
What are the functions of a simple squamous epithelium?
Diffusion, filtration
What are common locations of simple squamous epithelium?
Lung air sacs (alveoli), lining of blood vessels, serous membranes
What are common functions of simple cuboidal epithelium?
Absorption, secretion
What are common locations of simple cuboidal epithelium?
Kidney tubules, glands
What are common functions of simple columnar epithelium?
Absorption, secretion, movement (if ciliated)
What are common locations of simple columnar epithelium?
Lining of stomach, small intestine, large intestine (non-ciliated), lining of uterine tubes (ciliated)
What are common functions of pseudostratified columnar epithelium?
Protection, movement (if ciliated)
What is the common location of pseudostratified columnar epithelium?
Lining of respiratory tract
What are the functions of stratified squamous epithelium?
Protection