2 L6 Cells in Tissues 1

Question 1

4 key types of tissue

Answer 1

Muscle - Epithelial - Nervous - Connective -

Question 2

Describe the general makeup of cells in tissues

Answer 2

Internal cytoskeleton- network of filaments for shape, support and movement
Cells secrete ECM for support, structure, regulation of cell communication and behaviour

Question 3

True or False- ECM is crucial in maintaining differentiated shape of cells

Answer 3

True- cells without ECM don’t do their function

Question 4

Where is epithelial tissue found

Answer 4

Lines organs and cavities within the body - Covers the external body

Question 5

What is the function of epithelial tissue

Answer 5

Protective barrier - Absorptive and Secretory functions

Question 6

True or False- Epithelial tissue has polarity

Answer 6

True- on the apical and basal surfaces

Question 7

What are 2 important properties of epithelial tissue

Answer 7

Avascular- gets nutrients via diffusion
Regenerative- stem cells allow regeneration

Question 8

What are the 3 cell shapes of epithelium

Answer 8

Squamous, Cuboidal, Columnar

Question 9

What are the 4 ways to describe cell layers of epithelium

Answer 9

Simple - Stratified - Pseudostratified - Transitional

Question 10

What are the 2 surface specialisations of epithelium

Answer 10

Cilia and Microvilli

Question 11

What is the purpose of glands

Answer 11

To allow for focussed production of a secreted product

Question 12

Describe tight junctions

Answer 12

Tightly bound junction at apical surface

Question 13

Describe zonula adherens

Answer 13

Strengthens attachment to neighbouring cells at apical region

Question 14

Describe gap junctions

Answer 14

Allow for communication between neighbouring cells

Question 15

Describe desmosomes

Answer 15

Anchors neighbouring cells together

Question 16

Describe hemidesmosomes

Answer 16

Anchors cell to basement membrane

Question 17

What pathway do tight junctions control

Answer 17

Control the paracellular pathway

Question 18

What are the 2 transmembrane proteins associated with tight junctions

Answer 18

Occludin - Claudins

Question 19

What is the purpose of claudins

Answer 19

Different claudins allow for different permeability in different tissues

Question 20

What does zonula adherens do

Answer 20

Links cytokeratins of adjacent cells by connecting actin filaments

Question 21

What is the transmembrane protein associated with zonula adherens

Answer 21

E-cadherins (transmembrane proteins)

Question 22

What do desmosomes do

Answer 22

Links cytokeratins of adjacent cells through cytokeratin (intermediate filaments)

Question 23

What is the transmembrane protein associated with desmosomes

Answer 23

Cadherins e.g. desmoglein

Question 24

What do hemidesmosomes do

Answer 24

On basal surface of cell and anchor to basement membrane by binding to cytokeratin

Question 25

What is the transmembrane protein associated with hemidesmosomes

Answer 25

Integrins

Question 26

What is the transmembrane protein associated with gap junctions and what do they do

Answer 26

Connexins- form channels called connexons that can open and close to allow the passage of small ions/molecules

Question 27

Claudin 16 malfunction

Answer 27

Affects Mg ions in kidney- kidney failure (low Mg reabsorption)

Question 28

Claudin 1

Answer 28

Waterproof qualities in skin

Question 29

Desmoglein 3

Answer 29

Pemphigus vulgaris (autoimmune disease) attacks desmoglein 3 and causes cells fall apart, skin sloughs off

Question 30

E cadherins

Answer 30

Linked to metastasis of cancer cells

Question 31

Descrive microvilli

Answer 31

Fingerlike projections of plasma membrane with core of parallel actin bundles

Question 32

Describe what light and electron microscopy allow you to see when viewing microvilli

Answer 32

Light microscopy- brush border Electron microscopy- individual microvilli with shape maintained by actin microfilaments

Question 33

What are the 2 types of cilia

Answer 33

Motile and non-motile

Question 34

Non-motile cilia

Answer 34

Sensory information

Question 35

Motile cilia

Answer 35

Beat in rhythm to move substances across surface of epithelium

Question 36

What filaments are cilia composed of

Answer 36

Microtubules

Question 37

What is the purpose of the basement membrane

Answer 37

To bind epithelial cells to connective tissue. Is formed and maintained by these

Question 38

What does the BM control

Answer 38

Growth and Differentiation

Question 39

How does the BM regulate permeability

Answer 39

By forming a barrier that allows nutrients to pass through to epithelia

Question 40

What is best way to view the BM using light microscope and why

Answer 40

Immunichemistry- lets you see specific components. H & E staining doesn't show much

Question 41

What 3 layers of BM are visible under electron microscopy

Answer 41

Lamina lucida, Lamina densa, Lamina fibrorectularis

Question 42

Why does the BM have basal folding

Answer 42

To increase the SA of basal surface of cell