Epithelium Flashcards
What is the very thin specialised epithelium of the blood vessels and vascular system called?
Endothelium
Found on epithelial cells:
What are the finger like projections that increase surface area for absorption called?
What moves mucus and other matter along the length of the epithelium?
Microvilli
Cilia
… are found lining the trachea, Vas Deferens and the oviduct.
Neither … or … are found in blood vessels, small endocrine ducts, lung alveoli, skin or oesophagus.
… are found lining the gastrointestinal tract and the nephrons of the kidney.
Cilia
Microvilli or cilia
A SINGLE later of epithelial cells is known as…
Simple
A common feature of epithelial cells is…
ABSENCE of blood vessels!
In a pseudostratified epithelium…
ALL cells are in contact with the basement membrane.
What functions are carried out by epithelia?
Sensory perception Absorption Secretion Transport Protection
The principle cells of the liver are…
What is one of their functions?
Hepatocytes
Metabolism, storage, secretion
What are the mucus secreting cells of the gastrointestinal tract and airways called?
Goblet Cells
What protein is deposited at the surface of the skin epithelium to form a protective barrier?
Keratin!
What best describes the epithelium of the skin?
Stratified squamous
Pseudostratified epithelium is found in the… and …
Simple columnar epithelium is found in the…
Vas Deferens, lining the bronchus
Oviduct
What is polarity?
Presence of an apical surface (free) and a basal surface.
Uneven distribution of organelles and membrane proteins!
What does avascularity mean?
There are NO blood vessels in the epithelium as there is NO space for them between closely packed cells.
How do epithelial cells receive nutrients and O2?
Nutrients are delivered by diffusion from blood vessels running in connective tissue which is BELOW the epithelium.
What specialised structures are present on the apical surface of epithelial cells?
examples of where they are they found?
Microvilli - digestive tract
Cilia - trachea
Function of microvilli + cilia?
M - increase surface area by increasing the absorptive capacity by 20x
C - help to move materials (mucus, eggs)
Where is simple squamous epithelial tissue found?
What is its function?
In the lung alveoli
Allows material to pass by diffusion and filtration in sites where protection is NOT important!
Where is keratinised stratified squamous epithelial tissue found?
What is its function?
What is the loose purple structure you can see on it?
Epidermis of the skin
Protection from mechanical + chemical damage
Keratin!
What is the mode of secretion for Merocrine glands?
Secretion by exocytosis (sweat glands)
What is the mode of secretion for Apocrine Glands?
A portion of plasma membrane BUDS off the cell which contains the secretion (mammary glands)
What is the mode of secretion for Holocrine Glands?
The ENTIRE cell disintegrates to secrete it’s product! (Sebaceous glands)
