Exam 1 Review (MC)

Question 1

The cleaving of non helical terminal ends of pro-collagen, converting it into tropocollagen occurs where?

Answer 1

Immediately after secretion

Question 2

Name the molecular complex that primarily serves to prevent paracellular transport

Answer 2

Zonula occludens

Question 3

The basal lamina is associated with which type of collagen?

Answer 3

type IV

Question 4

Desmocollins and desmogleins belong to which group of CAMs?

Answer 4

Cadherins

Question 5

What are catenins?

Answer 5

they serve as a major interface between cadherins that hold adjacent cells together and their actin cytoskeletons

Question 6

What are molecular complexes that anchor cells together and reinforce the physical integrity of tissues and cells?

Answer 6

zonula adherens

Question 7

What are connexons?

Answer 7

Components of a gap junction that consist of 6 Connexins that form a hollow, hexagonal structure

Facilitate movement of molecules (usually ions in order to allow cells to “communicate”)

Often arranged in “clustered patches”

Question 8

explain the difference between hemidesmosomes and desmosomes

Answer 8

hemidesmosomes: link the basal domains of cells to the ECM via the intracellular tonofilaments
desmosomes: link basolateral domains of cells to ECM and other adjacent cells

Question 9

Which family of CAM’s is associated with carbohydrate binding?

Answer 9

Selectins

Question 10

What is another name for selectins? why?

Answer 10

lectins, bc they bind to carbohydrates

Question 11

define extraversion

Answer 11

the movement of leukocytes from the blood to the tissues

selectins are involved in this

Question 12

What best differentiates simple vs. compound glands?

Answer 12

ductal branching

Question 13

Who recognized, without using a microscope, 21 kinds of “membranes” that could now be considered tissues?

Answer 13

Marie Francois Xavier Bichat

Question 14

What were some of Virchow’s major contributions to histology and pathology?

Answer 14

He coined the phrase “omnis cellulae e cellulae” which is alluded to in the cell theory

also used histology to help explain pathological processes

Question 15

Who are the 2 people credited for discovering that all living things were made of cells?

Answer 15

Schwann and Schleiden

Schwann = zoologist
Schleiden = botanist

Question 16

What type of epithelium is associated with the striated ducts of compound glands?

Answer 16

Cuboidal transitioning to columnar

Question 17

Describe the molecular structure of the cell membrane

Answer 17

diphospholipid bilayer with intermembranous proteins associated with it

Question 18

Aqueous materials can pass through the plasma membrane via ________

Answer 18

channels and transporters

Question 19

What stains are included in the most common staining technique for light microscopy?

Answer 19

H&E

Hematoxylin and Eosin

Question 20

Explain what the H&E stains stick to

Answer 20

Hematoxylin: stain nuclear material and some cytoplasmic components, such as RER, dark blue to light blue or purple

Eosin: is an acid dye, so it stains cytoplasmic components and much of the extracellular material a yellowish to pinkish color

Question 21

Hematoxylin is a basic dye (true or false)

Answer 21

False

it acts like a basic dye due to the mordant that is used to help it bind to tissues

Question 22

What are the 2 types of stains that depend on the Schiff reaction?

Answer 22

PAS and the Fuelgen reaction

Question 23

What does PAS stain?

Answer 23

glycogen/carbs

Question 24

What does Fuelgen stain?

Answer 24

nucleic acids/DNA

Question 25

What is a schiff reaction?

Answer 25

it depends on the formation of aldehyde groups following exposure to HCl or periodic acid.

Question 26

What is a metachromatic stain? give examples of different metachromatic stains

Answer 26

a stain whose color changes after it has reacted with something in the specimen ex. toluene blue turning red after reacting with mast cells

Question 27

How can the resolution of a microscope be increased?

Answer 27

changing the wavelength of the light source (electrons instead of light does this) increasing the refractive index of the medium you're looking through (oil)

Question 28

What are the different granule contents that can be found in mast cells? what do they do?

Answer 28

Histamine: inflammatory response (packaged/stored by proteoglycans) ECF-A (eosinophil chemotactic factor): attracts eosinophils and neutrophils SRS-A (slow reacting substance of anaphylaxis): similar to histamine but has a more sustained effect Heparin: poor anticoagulant that is thought to help clear plasma lipids

Question 29

what is a plasma cell? what is an easy way to identify them in in photomicrograph?

Answer 29

a cell that produces antibodies look for the tell tale "clockface" distribution of heterochromatin that is spherical and typically offset.

Question 30

Define proteoglycan and it's structure

Answer 30

they are the secreted products of resident cells ex. fibroblasts, chondroblasts, etc structure: extracellular protein complexes of glycosaminoglycans

Question 31

what is a proteoglycan aggregate?

Answer 31

composed of GAGS attached to a core protein the core protein is attached to a hyalurana molecule via linker proteins

Question 32

Why do collagen fibers have a 64 nm gap between one another?

Answer 32

in order to separate the head and the tail of adjacent tropocollagen molecules

Question 33

How is type 1 collagen synthesized? (6 steps)

Answer 33

1. type 1 collagen is synthesized as a prepropeptide 2. the pre-sequence is cleaved after it is translocated to the ER lumen of the fibroblast to create a procollagen 3. procollagen is secreted into the extracellular matrix 4. peptidases cleave the non-helical ends ,that prevent polymerization, to form tropocollagen 5. tropocollagen monomers spontaneously assemble into collagen fibers 6. collagen fibers 64 nm apart are deemed collagen

Question 34

How are elastic fibers synthesized?

Answer 34

elastin is synthesized as a prepropeptide that is secreted as a propeptide extracellular enzymes, also secreted by the fibroblast, make the propeptide into tropoelastin tropoelastin monomers are assembled into amorphous fibers or sheets with the aid of fibrillins

Question 35

What is the epithelial layer associated with interlobular ducts of compound glands?

Answer 35

pseudostratified columnar

Question 36

What is the epithelial layer associated with intercalated ducts of compound glands?

Answer 36

cuboidal transitioning to columnar | same epithelial type is associated with striated ducts of compound glands

Question 37

what is the equation used to calculate diopters?

Answer 37

1 meter / the focal length of the lens (in meters)

Question 38

Compare parenchyma vs stroma in compound glands

Answer 38

Parenchyma: high cellularity Stroma: connective tissue

Question 39

Laminin has binding sites for what 4 molecules?

Answer 39

Type IV collagen proteoglycan integerin nitogen