Histo

Question 1

Step 1 of preparation of histologic sections

Answer 1

tissue collection

Question 2

Step 2 of preparation of histologic sections

Answer 2

Fixation and trimming

in 10% formalin

Question 3

step 3 of preparation of histologic sections

Answer 3

Dehydration

series of alcohols increasing to 100%

Question 4

step 4 of preparation of histologic sections

Answer 4

Paraffin embedding

Question 5

Step 5 of preparation of histologic sections

Answer 5

Sectioning with microtome

3-4 micrometers

Question 6

step 6 of preparation of histologic sections

Answer 6

Straightening sections on water bath

Question 7

step 7 of preparation of histologic sections

Answer 7

transferring sections to slide

Question 8

step 8 of preparation of histologic sections

Answer 8

staining and coverslipping

Question 9

Blue stain for mainy genetic materials (DNA and RNA)

Answer 9

Haematoxylin

Question 10

Pink stains for mainly proteins

Answer 10

Eosin

Question 11

Key Characteristics of the epithelium

6

Answer 11

• Covers all external and internal surfaces of the body
• Has polar orientation (One side faces lumen and other side is anchored to another tissue)
• Contains no blood vessels
• can have apical modifications
• minimal extracellular space between cells
• forms a basement membrane

Question 12

how are epithelium described

2

Answer 12

• Morphology (shape and arrangement)
• Function (Glandular or non-glandular)

Question 13

types of epithelia regarding structure

2

Answer 13

• Simple epithelium (single layers of cells)
• Stratified epithelium (Multiple layers of cells)

Question 14

simple squamous characterisitcs

3

Answer 14

• One layer of flat and thin cells
• best suited for passive transport of substances across the cytoplasm
• provide very little protection and thus are not found on surfaces subject to high stress

alveoli, vessels, body cavities

Question 15

Simple cuboidal epithelium

2

Answer 15

• one layer of thicker, deeper cells that look like squares
• usually associated with secretion and/or absorption

thyroid, kidney, lung, ovary, ducts and secretory portions of many gland

Question 16

simple columnar epitheial

3

Answer 16

• one layer of tall, long and thin cells
  markedly polarized
• often have apical modifications (cilia, microvilli etc.)
• usually associated with secretion and/or absorption

intestine, female repro tract, many exocrine glands

Question 17

Simple pseudostratified epitheial

4

Answer 17

• One layer, but due to the arrangement of the nuclei, appears to be multilayered
• all cells rest on the basement membrane
• secretion and movement of particles along the tubular organs
• also called respiratory epithelium

trachea, bronchi, epididymis, vas deferens

Question 18

Stratified squamous epithelium

4

Answer 18

• multiple layers of thin, flat cells
• most common multilayered epithelia. cover most of the external and some internal bodyparts
• protect underlying tissues and prevent their desiccation
• some keratinise. In SA, only occurs on outside and not where where tissue remains moist, LA can occur in mouth, etc

Question 19

stratified cuboidal epithelium

3

Answer 19

• multpile layers of cube like cells
• not abundant
• found covering areas of trasnition between simple and stratisifed epithelia

Question 20

stratified columnar epitheial

3

Answer 20

• multiple layers of tall, thin cells
• not abundant
• found covering areas of transition between simple and stratisfied epithelia

Question 21

transitional epithelium

5

Answer 21

• appearance changes from thick stratified columnar to thin stratisfied squamous
• some of the surface cells are binucleated
• often seen in urinary tract as they have to expand and contract to accomodate liquid contents of the bladder/ureters
• Only found in the urogenital system.
• subject to marked cariation of internal pressure (cell type depends on degree of distinction

AKA urothelium

Question 22

how are epithelial glands classified

4

Answer 22

1. method of secretion (endocrine vs. exocrine)
2. type of secretion
3. shape
4. cell numbers

Question 23

Endocrine glands

4

Answer 23

• ductless and have no connections to external or internal surfaces
• produce hormones
• near blood vessels
• high diversity in morphology

Question 24

where do Exocrine glands secrete to

Answer 24

• secrete its product to a lumen or free surface

Question 25

Types of secretory product consistency from exocrine glands | 3

Answer 25

- serous (clear, watery fluid) - mucous (more viscous fluid) - mixed (mixture of above)

Question 26

types of secretion of exocrine glands | 3

Answer 26

- merocrine (exocytosis, cell membrane remains intact and fuses to expel contents) - holocrine (cell membrane ruptures and "commits suicide" - Apocrine (cell pinches off surface with secreted product)

Question 27

Apical modifications | 3

Answer 27

- cilia (actively motile, long cell processes) - Microvilli (non-motile small projections specialised for abosrption. increase surface area) - stereocilia (long microvilli)

Question 28

what are the 3 types of Cell junctions | 3

Answer 28

- adherent junctions (cells anchor together to insure tissue cohesion) - tight junctions (control what eneters the body) - gap junctions (for communication between cells)

Question 29

Adherent junctions

Answer 29

linking of junctions provides stifness of tissue - cell to cell: desmosomes - cell to extracellular matrix: hemidesmosomes

Question 30

tight junctions | 3

Answer 30

- controll the entrance of compunds (nutrients etc.) to the blood vessels from the intestinal lumen. - limit the paracellular movement of water and other molecules - 2 pathways for compunds to transverse epithelial sheet: paracellular (between cells) and transcellular (across cells)

Question 31

Gap junctions | 1

Answer 31

- aqueous channels (pore like) that allow small molecules to pass between two adjacent cells | less than or equal to 1000Da in molecular weight

Question 32

how are exocrine glands classified

Answer 32

classified regarding the number of cells (multi/unicellular)and shape, type of secretory product and type of secretion