Epithelial - Glandular

Question 1

Features of glandular epithelium (3, plus examples)

Answer 1

epithelial cells
produce and release a secretion
differ in composition from tissue fluid or blood
eg. mucus, gastric secretions, sebum

Question 2

How are exocrine glands formed?

Answer 2

invagination/infolding of epithelial cells, subsequent growth in underlying connective tissue

Question 3

What do exocrine glands do? (3, plus examples)

Answer 3

secrete material via duct
columnar or cuboidal
into lumen of an organ OR onto free surface of epithelium
eg. sweat glands, salivary glands

Question 4

3 modes of secretion by glandular epithelium

Answer 4

merocrine, apocrine, holocrine

Question 5

Describe merocrine

Answer 5

secretion contained within vesicles, released into duct

Question 6

Describe apocrine

Answer 6

secretion contained within cytoplasm (apex), cell membrane buds off to form carrier vesicles

Question 7

Describe holocrine

Answer 7

secretion contained within cytoplasm, cell ruptures to release secretion

Question 8

What is hyperplasia? (3)

Answer 8

increase in cell number due to increase in proliferation
increase in tissue size
increase in demand, inflammatory response

Question 9

What is atrophy? (3)

Answer 9

decrease in cell size
‘shrinking’ of an organ
loss of tissue, eg. skeletal, cardiac, brain

Question 10

What is metaplasia? (3)

Answer 10

transformation of one type of epithelium to another
response to change in environment
reversible if original environment restored

Question 11

What is hypertrophy? (3)

Answer 11

increase in cell size
increase in cellular protein content
bulking of skeletal muscle

Question 12

What is dysplasia? (3)

Answer 12

increase in number of immature cells within tissue
characterized by abnormal shape, unequal size
early form of pre cancer

Question 13

How does a cell go from normal to cancer?

Answer 13

normal, hyperplasia, dysplasia, cancer

Question 14

What do cell junctions do? (4)

Answer 14

connect cells and surrounding structures
anchor cells to each other (except blood)
protect tissue from mechanical stress
facilitate communication

Question 15

What are the types of junctions? (5)

Answer 15

tight, adherens, desmosomes, hemidesmosomes, gap

Question 16

Tight junctions (function, location)

Answer 16

fusion of plasma membrane proteins of adjacent cells
prevent materials passing through
located apically (close to cell surface)

Question 17

Adherens (function, location)

Answer 17

‘zipping up’ adjacent cells in hook-like manner
leave small spaces between so cells can stretch
located mid-way down cell wall below tight junctions

Question 18

Desmosomes (function)

Answer 18

link adjacent cells, similar to adherens
connect protein filaments into cytoskeleton of cells
for high mechanical stress

Question 19

Hemidesmosomes (function, location)

Answer 19

half a desmosome
connect cells to basal lamina
found on bottom of basement cells

Question 20

Gap junctions (function)

Answer 20

aligned channel protein pores between cells

communication and transport of nutrients and wastes