Epithelium

Question 1

where is epithelium found

Answer 1

it covers the surface of the body, lines cavities and tubes, forms many glands and even some organs(liver)

Question 2

what are the many functions of the epithelium

Answer 2

act as a mechanical barrier(skin, chemical barrier(stomach), absorption(intestine), secretion(salivary gland), containment(urinary bladder)

Question 3

epithelial cells are found in wide range of cell sizes/shapes and functions, but what are the common features

Answer 3

adhesion between cells is strong = minimal intercellular space, good for covering surfaces
all have at their basal layer a basal lamina= layer of extracellular matrix components cells are attached to
all non-vascular, nutrients diffuse across basal lamina
cells usually polarised

Question 4

what are the 4 headings used to classify covering epithelial cells

Answer 4

shape, no. of layers, cell surface/tissue surface/specialisations, presence of specialised cell types

Question 5

what are the different cell shapes of covering epithelial cells

Answer 5

squamous(flattened, like a fish scale)
cuboidal(cube shaped)
columnar(like a column, relatively tall + thin)

Question 6

what are the different no. of layers of covering epithelial cells

Answer 6

simple = 1 layer
stratified = two or more layers
pseudostratified = tissue appears to have multiple layers, but all cells are actually in contact with basal lamina

Question 7

what are the different cell surface/tissue surface/specialisations of epithelial cells

Answer 7

prominent microvilli (brush border)
cilia
layers of keratin protein on tissue surface(keratinised)

Question 8

what specialised cell types can be found on epithelial cells

Answer 8

goblet cells (single cell mucous glands)

Question 9

what is glandular epithelia

Answer 9

they produce secretory products, eg sweat, milk, oil, mucous etc.

Question 10

what are the 2 classifications of glands

Answer 10

endocrine(ductless glands) product secreted towards basal end of cell
exocrine(ducted glands) = secreted toward pical end of cell, either toward lumen, into duct, or onto body surface