histology of epithelial cells

Question 1

what do all epithelial cells do

Answer 1

act as lining cells

Question 2

what are endothelial cells in regards to epithelial cells

Answer 2

endothelial cells are a specialised version of epithelial cells, as they are the cells that line the blood vessels making up the circulatory system

Question 3

what keeps all epithelial cells in place

Answer 3

an adhesion to its underlay called the basement membrane

Question 4

name the 4 major functions of epithelial cells

Answer 4

barrier/protection, absorption, lubrications, and movement

Question 5

what are the two types of passage through epithelial cell junctions (from the outside to inside environment) called

Answer 5

paracellular and transcellular

Question 6

what are tight junctions in epithelial cells and what do they do

Answer 6

the proteins that stick epithelial cells together in their lateral membranes - they control the passage of substances between cells

Question 7

in epithelial cell nomenclature what does the word simple mean

Answer 7

one cell thick

Question 8

in epithelial cell nomenclature what does the word stratified mean

Answer 8

layered

Question 9

in epithelial cell nomenclature what does the word pseudostratified mean

Answer 9

false layered - they appear layered but are actually one cell thick

Question 10

in epithelial cell nomenclature what does the word cuboidal mean

Answer 10

square cell

Question 11

in epithelial cell nomenclature what does the word columnar mean

Answer 11

tall cell

Question 12

in epithelial cell nomenclature what does the word squamous mean

Answer 12

flattened cell

Question 13

in epithelial cell nomenclature what does the word transitional mean

Answer 13

changeable/ dynamic

Question 14

where is the only place transitional cells are found

Answer 14

the bladder

Question 15

describe simple squamous epithelial cells

Answer 15

cells are flat and spread out, meaning they have a large surface area in contact with the exterior environment and the basement membrane - anchoring is strong

Question 16

give an example of where simple squamous epithelial cells would be found

Answer 16

anywhere where easy transmembrane movement is advantageous e.g. in the alveoli

Question 17

describe simple cuboidal epithelial cells

Answer 17

they have an increased cytoplasmic volume when compare to squamous cells, meaning they are capable of fulfilling some more complex roles such as secretion

Question 18

where are simple cuboidal epithelial cells found

Answer 18

in glands which specialise in secretion e.g. salivary glands

Question 19

describe simple columnar epithelial cells

Answer 19

cells that are taller than they are wide, with a nucleus that is polarised towards the basement membrane

Question 20

what is the function of simple columnar epithelial cells

Answer 20

they are very capable of dealing with wear and tear, and secreting large amounts of substances

Question 21

give an example of where simple columnar epithelial cells may be found

Answer 21

in the lining of the stomach - protects from the acid
in the lining of the intestines - secretions for lubrication

Question 22

describe stratified squamous epithelial cells

Answer 22

multi-layered epithelium in which the outermost layer are flat and scale-like - the lower layers may be different shaped but we name off of the most apical layer

Question 23

give an example of where stratified squamous epithelial cells can be found

Answer 23

surfaces that are subject to high levels of mechanical abrasion e.g. the skin

Question 24

name the two varieties of stratified squamous epithelial cells and how they differ

Answer 24

dry (keratinising stratified squamous epithelium) - called keratinocytes as they produce a tough protein called keratin that causes the top layer of cells to die, making the dry
wet (non-keratinising stratified squamous epithelium) - called non-keratinising epithelial cells as they produce a moist surface with the absence of keratin, keeping the cells alive

Question 25

what is another difference regarding wet and dry stratified squamous epithelial cells regarding nuclei

Answer 25

dry = no nuclei wet = nuclei

Question 26

describe pseudostratified columnar epithelial cells

Answer 26

all of the cells in the layer are in contact with the basement membrane but due to the misaligned nuclei the cells appear stratified

Question 27

where are pseudostratified columnar cells common and why

Answer 27

in the upper respiratory system as the flexibility of columnar cells allows the cells to move during the ins and outs of breathing

Question 28

describe transitional epithelial cells

Answer 28

a stratified epithelium in which the shape of the cells at the luminal layer may be difficult to discern due to the change in shape of cells

Question 29

what is the difference in appearance of transitional epithelial cells during relaxation and stretching

Answer 29

apical cells may appear rounded/cuboidal when the organ is relaxed, and flattened/squamous when it is stretched

Question 30

what do ciliated epithelial cells contain

Answer 30

hair like projections on their surface called cilia

Question 31

where are ciliated epithelial cells most common and what do they do

Answer 31

in the respiratory tract where they move mucus laden with dust or microbes away from the lungs to the upper regions so they can be coughed or sneezed out

Question 32

what do epithelial cells with microvilli contain

Answer 32

finger like protrusions on their surface called microvilli

Question 33

what is the major difference between cilia and microvilli

Answer 33

cilia move, whereas microvilli do not as their main role is absorption rather than locomotion

Question 34

what is a brush boarder referring to

Answer 34

where microvilli are extremely tightly packed so that they give the appearance of a fuzzy band

Question 35

where is the most common place to find epithelial cells with microvilli and why

Answer 35

in the intestine as the surface area increase allows for maximum absorption of nutrients from the gut

Question 36

what are goblet cells

Answer 36

modified columnar epithelial cells that synthesise and secrete mucous

Question 37

why do goblet cells receive their name

Answer 37

their shape resembles a drinking goblet

Question 38

where can goblet cells be found and why

Answer 38

in the respiratory and gastrointestinal tracts as they help with lubrication