Deck 4: Epithelial Tissue

Question 1

Functions of the basement membrane include which of the following?

A) Contractility
B) Molecular filtering
C) Active ion transport
D) Excitability
E) Modification of secreted proteins

Answer 1

Molecular filtering

Question 2

Using immunohistochemistry a population of cells is shown to be positive for the protein connexin. From this we can infer that the cells are connected by what type of junction?

A) Tight (occluding) junctions
B) Zonula adherens
C) Gap junctions
D) Hemidesmosomes
E) Desmosomes (macula adherens)

Answer 2

Gap junctions

Question 3

An individual genetically unable to synthesize normal occludin is likely to have epithelia with defective regulation in which of the following?

A) Material crossing the epithelium between the cells (paracellular movement)
B) Communication between the cells
C) Attachment to the basement membrane
D) Strong attachment to neighboring cells
E) Movement of membrane proteins in the apical domains of cells

Answer 3

Material crossing the epithelium between the cells (paracellular movement)

Question 4

An intermediate filament protein found in cytoplasm of most epithelial cells is which of the following?

A) Actin
B) Vimentin
C) Laminin
D) Myosin
E) Keratin

Question 5

Which of the following cellular features is used in naming types of epithelia?

A) Shape of cells in the basal layer
B) Number of cell layers
C) Presence of a basal lamina
D) Size of the nuclei
E) Nature of the cell junctions that are present

Question 6

The release of lipid droplets from cells is which type of secretion?

A) Merocrine
B) Serous
C) Apocrine
D) Mucous
E) Holocrine

Question 7

Exocrine glands in which the acini all produce a secretion of heavily glycosylated, hydrophilic proteins are an example of which type of gland?

A) Serous gland
B) Mixed gland
C) Mucous gland
D) Tubuloacinar gland
E) Simple gland

Question 8

With a 5-year history of chronic respiratory infections, a 23-yearold, non-smoking man is referred to an otolaryngologist. A bronchial biopsy indicates altered structures in the epithelial cells. Which of the following, if altered to reduce function, is most likely involved in this patient's condition?

A) Hemidesmosomes
B) Cilia
C) Basolateral cell membrane folds
D) Microvilli
E) Tight junctions

Question 9

An 11-month-old girl is referred to a pediatric gastroenterology clinic due to a history of generalized weakness, slow growth, and refractory diarrhea. For the past month she has been hospitalized regularly to receive parenteral nutrition. Examination of the epithelium lining her small intestine confirms that the failure to absorb nutrients is most likely due to a significant decrease in which of the following?

A) Microvilli
B) Gap junctions
C) Cilia
D) Cell layers
E) Basement membrane thickness

Question 10

A 42-year-old woman of Mediterranean descent presents with multiple oral blisters and a few cutaneous blisters on her back and buttocks. The superficial bullae are fragile, some have unroofed to form ulcerated lesions, and there is a positive Nikolsky sign. Blood tests reveal antibodies to a subfamily of cadherins and immunohistochemical staining of a biopsy from the oral mucosa shows distribution of the antigen throughout the epithelium. In what structures is the defect that is causing this patient's condition?

A) Desmosomes
B) Tight junctions
C) Hemidesmosomes
D) Gap junctions
E) Reticular lamina