Cells and Tissues: Epithelial Tissue

Question 1

key functions of epithelial tissues

Answer 1

Selective barriers
secretory
protection

Question 2

Tight junctions

Answer 2

Claudins and occlaudins attach adjacent cells, maintain cell polarity, make cells electrically tight i.e. skin

Question 3

Adherns Junctions

Answer 3

‘Belt desmosomes’, have a plaque layer joining actin (microfilament) to cadherins, catenins link the two, prevent from tension forces i.e. contractions

Question 4

Desmosome

Answer 4

Have plaque, keratin spans from one side desmosome to another across cytoplasm to maintain shape and stick cells together, cadherin links intercellular space, i.e. muscle cells

Question 5

Gap junctions

Answer 5

Direct channel between cells to pass messages, 6 connexIn’s form a connexOn, 2 gap juncs form a hemi channel, allow ~1kDa molecules i.e. cardiac tissue

Question 6

junctional complex

Answer 6

tight, adherens, desmosome

Question 7

microfilaments

Answer 7

ACTIN, bundles below membrane and cytoplasm,, strength, alter cell shape, tie cells together, muscle contraction

Question 8

Intermediate Filaments

Answer 8

KERATIN, strength, move materials through cytoplasm

Question 9

Hemidesmosome

Answer 9

Connect to the basement membrane, Intergrin links to laminin in the basement membrane and to Keratin intermediate filament

Question 10

Basal Lamina

Answer 10

secreted by epithelial cells, contains collagen, laminin, other proteoglycans, glycoproteins etc is a TOP

Question 11

reticular lamina

Answer 11

Produced by cells of underlying connective tissue fibroblasts, contains fiberous proteins fibroectin, collagen etc is a BOTTOM

Question 12

Epithelia contain nerves but not blood vessels making them?

Answer 12

Avascular

Question 13

How do epithelia recieve nutrients and remove waste

Answer 13

diffusion from vessels in connective tissue

Question 14

4 functions of basement membrane

Answer 14

supports overlying epithelium, surface for cells migrate during growth and wound healing, a physical barrier, filtrates substances in the kidney

Question 15

where is Covering and lining epithelia

Answer 15

form outer covering of skin and organs, inner lining of blood vessels, ducts and body cavities

Question 16

where is Glandular epithelia

Answer 16

secretory portion of glands

Question 17

two major types of epithelia

Answer 17

Epithelia, glands

Question 18

two kinds of glands (crine)

Answer 18

Exocrine (into ducts that go to surface - sweat, salivary, oil, wax glands, pancreas) is stratified cuboidal, Endocrine (into blood that go to surface - pituitary, pineal, thyroid)

Question 19

Simple arrangement pros and places

Answer 19

Single layer for secretion, absorbtion, filtration - avioli

Question 20

Stratified arrangement pros and places

Answer 20

2+ layers for protection i.e skin

Question 21

Pseudostratified arrangement pros and places

Answer 21

Appears to have multiple layers position of nuclei, not all cells reach apical surface, all cells with basement membrane, secretion i.e upper bronchi

Question 22

Squamous shape pros and places

Answer 22

flat and thin, diffusion - lungs

Question 23

Cuboidal shape pros and places

Answer 23

about as tall as they are wide, secretion and absorption - digestion

Question 24

Columnar shape pros and places

Answer 24

More tall than wide, secretion, absorption

Question 25

Transitional shape pros and places

Answer 25

Stratified epithelium, cells change shape from cuboidal-flat for organ shape, allow stretch - bladder

Question 26

simple squamous epithelium specialized subtypes

Answer 26

Mesothelium - lines pericardial, pleural, peritoneal cavities
Endothelium - lines inside of heart, blood and lymphatic cells

Question 27

simple cuboidal epithelium features

Answer 27

secretion and absorption, distance between nuclei is approx. hight of epithelium - pancreas ducts, kidney tubules

Question 28

simple columnar epithelium subtypes

Answer 28

Non-ciliated and ciliated

Question 29

Non-ciliated simple columnar epithelium

Answer 29

single layer with microvilli apical surface, have goblet cells, secretion and lubrication - gut stomach to anus, gall bladder

Question 30

Ciliated simple columnar epithelium (move materials)

Answer 30

single layer, goblet cells, cilia wave move mucus + foreign objects - some bronchioles, uterine tubes

Question 31

Stratified Squamous subtypes

Answer 31

Stratified Squamous Epithelium (non-keratinized),

Stratified Squamous Epithelium (keratinized)

Question 32

Stratified Squamous Epithelium (non-keratinized)

Answer 32

Protect from abrasion and microbes, require gland secretion - mouth, throat, tongue

Question 33

Stratified Squamous Epithelium (keratinized)

Answer 33

Keratinized dead surface cells on top of living cells, act as scaffolding to have trauma - skin

Question 34

Psuedo-stratified Columnar Epithelium subtypes

Answer 34

Pseudostratified Columnar Epithelium (ciliated and non-ciliated)

Question 35

Pseudostratified Columnar Epithelium (ciliated)

Answer 35

secrete mucus (goblet cells) and move it - most of upper airways

Question 36

Pseudostratified Columnar Epithelium (non-ciliated)

Answer 36

absorption and protection, Larger ducts of glands, epididymis, part of male urethra

Question 37

Glandular epithelia

Answer 37

single cell or group secrete into ducts, a surface or blood

Question 38

3 characteristics to describe structure of multicellular glands

Answer 38

1. structure of duct
2. structure of secretory area
3. relationship between the two