Epithelial Tissue Flashcards
Epithelial tissue has two forms:
- covering and lining epithelium
2. glandular
ET covers
walls/organs of the closed ventral body cavity
ET lines
cavities
ET lining/covering examples:
digestive, urogenital, respiratory
ET glandular tissue:
fashions the glands of the body
What are the functions of the ET boundary (6)?
- protection
- absorption
- filtration
- excretion
- secretion
- sensory receptor
What are the special characteristics of Epithelium (5)?
- polarity
- specialized contacts
- supported by connective tissue
- avascular but innervated
- regeneration
Classification– What does the first and second name indicate about the ET layer?
first name indicates the number of cell layers
second layer describes the shape of the cell
What are the two first names for ET?
either simple (single layer) or stratified (multiple layers)
Function of simple ET?
the thin layer is mostly for secretion, filtration, and absorption
Function of stratified ET (provide example)?
common in areas of high abrasion where protection is needed
ex: skin surface and lining of mouth
Squamous ET description:
flattened and scale like
Simple squamous ET has what two coverings?
an inner covering: endothelium
a mid covering: mesothelium
Purpose of ET endothelium:
the inner covering provides a slick, friction-reducing lining
ex: blood vessels and heart
What is the purpose of ET mesothelium (provide where it is most commonly found)?
the mid covering lines ventral body and covers organs
ex: found in serous membranes
Simple cuboidal description:
the cells are box like and are as tall as they are wide
Function of simple cuboidal (provide example):
secretion and absorption
ex: kidney tubules, wall of small glands, and ovary surface
Simple columnar description:
the cells are a tall layer that is closely packed
Function of simple columnar:
absorption and secretion (mainly of enzymes and mucus)
Where can you find simple columnar (both nonciliated and ciliated)?
NONCILIATED: digestive tract, gallbladder, glands
CILIATED: small bronchi, uterine tubes, some regions of the uterus
What is a pseudostratified columnar layer?
they vary in height, giving the impression of multiple layers
ex: trachea
How do you classify stratified layers?
distinguish the top layer aka the apical layer