Cells and tissues: epithelium

Question 1

Epithelium key functions

Answer 1

selective barrier, secretory onto free surface, protective. no blood vessels

Question 2

Cell Junctions

Answer 2

Tight
adherens
gap
desmosomes
hemidesmosomes

Question 3

Tight junction

Answer 3

apical end of cell, join cytoskeletons of adjacent cells. electrically tight. stomach intestines, bladder. made of claudins and occludins

Question 4

Adherens Junction

Answer 4

prevent cell separation from tension like contraction. Leaves gap, spanned by cadherins. plaque with catenins that links cadherins to actin

Question 5

Gap Junction

Answer 5

6 connexin proteins form pizza
connexon/hemichannels form tunnels between cells for small molecules. calcium may pass through

Question 6

Desmosome Junction

Answer 6

has plaque, resists shearing forces, cadherin spans gap and binds to desmoplakin, binds to keratin

Question 7

Hemidesmosome

Answer 7

connects to basement membrane. integrin binds to laminin in BM and plaque/keratin

Question 8

Microfilaments

Answer 8

Made of actin,
bundles beneath cell membrane and cytoplasm.
strength, structure shape, and cytoplasm to membrane,
contraction
tie cells together

Question 9

intermediate filaments

Answer 9

structural strength made of keratin

Question 10

Junctional complex

Answer 10

tight junction, adherens, and desmosome found close together

Question 11

Basement membrane

Answer 11

made of basal lamina and reticular lamina, junction between connective and epithelium. nutrients diffuse from connective to epithelial because no blood vessels, only nerves in epithelium. barrier and surface for cells to migrate when healing

Question 12

basal lamina

Answer 12

secreted by epithelium, made of collagen, laminin, proteoglycans, glycoproteins

Question 13

reticular lamina

Answer 13

produced by connective tissue (fibroblasts), fibronectin, collagen

Question 14

melanoma diagnoses

Answer 14

can change depending on how far it has moved through BM

Question 15

two kinds of epithelia

Answer 15

Covering and lining (inner and outer)
glandular (exocrine and endocrine)

Question 16

arrangement of epithelium

Answer 16

simple: 1 layer
stratified: multiple layers
pseudostratified: looks like multiple layers, but is not

Question 17

Epithelial Shapes

Answer 17

squamous: flat
cuboidal: cubes
columnar: taller than wide
transitional: urinary bladder (stratified where cells change from cuboidal to flat for stretching)

Question 18

simple squamous

Answer 18

delicate; filtration; diffusion; secretion
mesothelium: pericardial, pleural, peritoneal cavities (sacs)
endothelium: inside of heart, blood and lymphatic vessels

Question 19

simple cuboidal

Answer 19

secretion and absorption. regular boxes

Question 20

ciliated simple columnar

Answer 20

elongated, bigger cells. can have microvilli, assits motility, of mucous and foreign objects or oocytes

Question 21

non-ciliated simple columnar

Answer 21

elongated, bigger cells. secretion, absorption, and lubrication, dispersed with goblet cells whcih secrete mucous. can have microvilli

Question 22

stratified squamous

Answer 22

protective and deals with trauma
keratinised: dry trauma, skin
non-keratinised: wet trauma, mouth, throat, vagina,etc.

Question 23

stratified cuboidal

Answer 23

fairly rare, protection, lining limited secretion and absorption. part of male urethra. ducts adult sweat glands and oesophageal glands

Question 24

stratified columnar

Answer 24

protection and secretion. lines parts of urethra large excretory ducts like in oesophagus and anal mucous membrane. also in eye

Question 25

ciliated pseudo-stratified columnar

Answer 25

some cilia, secrete mucous from gobelt cells. secrete and move. not all cells reach apical surface but all cells connected to bm found in trachea

Question 26

non-ciliated pseudo stratified columnar

Answer 26

no goblet cells, no cilia. not all cells reach apical surface but all cells connected to bm. absorption and protection. Larger ducts (epididymis and make urethra)

Question 27

transitional epithelium

Answer 27

urinary bladder (stratified where cells change from cuboidal to flat for stretching)

Question 28

Cavities

Answer 28

pleural: lung sac
pericardial: heart sac
peritoneal: guts sac

Question 29

serosa/serous membrane

Answer 29

lines body cavity and (mesotheliam and connective tissue

Question 30

Membrane mods

Answer 30

microvilli: increase surface area for absorption, don’t move
cilia: motile, move things along in one direction

Question 31

Glands

Answer 31

single or group of cells that secrete onto surface, into duct, or into blood. glandular epithelia is always for secretion

Question 32

Endocrine glands

Answer 32

directly into blood via interstitial fluid, long distance strog effects. found in pituitary, pineal, thyroid, parathyroid

Question 33

exocrine gland

Answer 33

into ducts that empty on surface of covering or ling epithelium. loal effects, like sweat, saliva, oil, wax

Question 34

exocrine glands classifications

Answer 34

single cell like goblet for mucous
multi cellular

Question 35

multicellular glands

Answer 35

simple: duct doesn’t branch, but the gland cells may branch
compound: duct branches

Question 36

multicellular gland secretion area classes

Answer 36

tubular
coiled tubular
branched tubular
alveolar (acinar)
Branched alveolar
tubulo alveolar