Human Anatomy - Epithelial tissue Flashcards
What is a tissue?
A group of closely associated cells that perform related functions and are similar in structure.
What are the four tissue types?
What are their general functions?
Epithelial - covering
Connective - support
Nervous - control
Muscle - movement
Epithelial Tissue
______ a body surface or ____ a body cavity.
Forms parts of most ______.
Covers
Lines
Glands
What are the different functions of epithelial tissue?
protection
absorption, filtration and ion transport
excretion, secretion
Forms slippery surface
What are the special characteristics of epithelium?
- Cellularity
- Specialized contacts
- Polarity
- Supported by connective tissue
- Avascular but innervated
- Regeneration
Describe cellularity as it pertains to epithelial tissue.
Epithelial tissue is almost entirely composed of cells.
Describe specialized contacts as it pertains to epithelial tissue.
Cells of epithelial tissue are joined by special junctions.
These gap junctions allow for communication and for the cells to work as functional unit.
Describe polarity as it pertains to epithelial tissue.
Cell regions of the apical surface differ from the basal surface
How does epithelium receive nutrients without a dedicated blood supply?
Epithelia receive nutrients from underlying connective tissue.
Capillaries go through connective tissue but not through epithelium
Describe regeneration as it pertains to epithelial tissue.
Lost cells are quickly replaced by cell division.
How is epithelium classified?
First name of the tissue indicates the number of cells:
Simple - 1
Stratified 2 or more
Last name of the tissue describes the shape of the cells:
Squamous - flat
Cuboidal - cube-shaped
Columnar - column-shaped
How does structure relate to function? Protection = \_\_\_\_\_\_\_\_ Transport = \_\_\_\_\_\_\_\_ Filter = \_\_\_\_\_\_\_\_\_ Stomach = \_\_\_\_\_\_\_\_
Stratified
Simple
Simple
Simple
Endothelium and mesothelium are both what type of epithelium?
Simple squamous
What is endothelium?
Slick lining of hollow organs in the circulatory system and in the inner layer of the heart.
Inner covering
What is mesothelium?
Lines peritoneal, pleural and pericardial cavities.
Covers the visceral organs of those cavities.
Middle covering.
What is the function of simple squamous epithelium?
Passage of materials by passive diffusion, osmosis and filtration.
Secretion in serous membranes.
Where is simple squamous epithelium located?
Renal corpuscles
Alveoli of lungs
Lining of heart, blood and lymphatic vessels (endothelium)
Lining of ventral body cavity and serosae (mesothelium)
What is the function of simple cuboidal epithelium?
Secretion and absorption
What is the location of simple cuboidal epithelium?
Kidney tubules
Secretory portions of small glands
Ovary surface
What lines the duct of a lumen?
Simple cuboidal epithelium
Describe simple columnar epithelium.
Single layer of column shaped epithelial cells.
Some bear cilia on their apical surface.
May contain goblet cells.
What is the function of simple columnar epithelium?
Absorption
Secretion of mucus, enzymes and other substances
Ciliated type propels mucus or reproductive cells
Where is simple columnar epithelium located?
Non-ciliated forms
- line GI tract, gallbladder, ducts of some glands
Ciliated form:
- lines small bronchi, uterine tubes, uterus
What is the purpose of cilia?
Move material across the surface of cells.
What do goblet cells do?
Secrete mucin