Block 1 - Epithelial Tissue

Question 1

What is the core of a microvilli made of?

Answer 1

Actin filaments bound by actin binding proteins (fimbrin or fascin)

Question 2

How are microvilli anchored to the membrane?

Answer 2

Lateral anchoring proteins eg. myosin 1

Question 3

What are stereocilia related to and where are they found?

Answer 3

Microvilli
Epididymis (absorption)
Inner ear cochlea (sense receptors)

Question 4

What is primary ciliary dyskinseia?

Answer 4

Genetic defect in ciliar proteins cause uncordinated or absent beating
Dextrocardia
Impair development of sinuses
No mucous removal in lungs
Infertility

Question 5

What are three types of junctions found on the lateral domain?

Answer 5

Occluding junctions, anchoring junctions, and communicating junctions

Question 6

Zonula Adherens

Answer 6

Lateral domain, cell to cell
Actin filaments
Cadherin

Question 7

What important role does cadherin play? What happens when it is lost?

Answer 7

Controls cell behavior and its loss is associated with acquisition of invasive behavior by tumor cells

Question 8

Macula adherens

Answer 8

"Desmosome"
Spot-like
Intermediate fillaments
Intracellular plaque - desmoplakin
Caherin transmembrane proteins

Question 9

What are intercellular channels made of? What type of junction are they?

Answer 9

Communicating junction
Pair of Connexons, each with 6 protein subunits
Occur in patches

Question 10

Where is collagen IV found in basement membrane?

Answer 10

Basal Lamina

Question 11

What type of collagen is in reticular lamina?

Answer 11

Thin collagen fibers, type III

Question 12

Focal Adhesions

Answer 12

Actin, basement membrane
Talin - peripheral protein
Integrin (C++ independent family”) -tm

Question 13

Hemidesmosome

Answer 13

Intermediate fillaments
Integrin
Desmoplakin

Question 14

What is glandular epithelium made out of?

Answer 14

Invagination of epithelial tissue (cuboidal cells normally(

Question 15

What is the difference between endocrine and exocrine glands?

Answer 15

Endocrine excrete materials into intercellular space and CT, diffusing into blood
Exocrine secrete into ducts of spaces lined with originating epithelium

Question 16

What are three types of excretion of exocrine glands?

Answer 16

Merocrine (mucous, serous, or mixed), apocrine, and holocrine

Question 17

What is product delivered to merocrine glands? How does the product leave the cell?

Answer 17

Membrane bound vesicles, which fuse with plasma membrane and release content via exocytosis

Question 18

What are differences between serous and mucous merocrine glands?

Answer 18

Serous have better developed RER and their cavity (serous acini) is rounded shape due to pyrimidal cells

Mucous glands stain light (barely any). Cells are columnar, therefore their cavity is columnar in shape

Question 19

How are mixed glands both mucous and serous?

Answer 19

Mucous cells create tube, serous cells cap forming demilunes. Submandibular gland

Question 20

How do apocrine glands secrete their material? Where can they be found?

Answer 20

Pinching of apical cytoplasm, forming secretory vesicles. Found in mammary glands.

Question 21

How do holocrine glands secrete material?

Answer 21

Apoptosis involving the whole cell, releasing material into lumen of gland

Question 22

What is the most common type of unicellular gland?

Answer 22

Goblet cells

Question 23

Where are unicellular glands most commonly found?

Answer 23

Non-secretory epithelium

Question 24

What is a duct?

Answer 24

The portion of a multicellular gland that connects the secretory portion to the surface of epithelium

Question 25

What are two types of secretory portions?

Answer 25

Alveolar (flask shaped)

Tubular (tube shaped)

Question 26

How are myoepithelial cells involved with glands?

Answer 26

Help expel material out of gland between basal lamina and secretory portion