Cells And Tissues

Question 1

What is the function of epithelial cells?

Answer 1

To cover the surface of the skin and line the cavities

Question 2

What is found in the cytoskeleton of an epithelial cell?

Answer 2

Microfilaments - which are there to support and strengthen. Contain the protein actin
Flexible and can change the shape of the cell

Intermediate filaments
Support and strengthen and are responsible for the cell structure
Contain protein known as keratin

Question 3

How is an epithelial cell arranged?

Answer 3

Sheets of single layer or multiple layers

Question 4

What are the names of the sides of an epithelial cell?

Answer 4

The top = free or apical ( closer to the exterior/ lumen)
The side = lateral
The bottom = basal or attached (closer to the connective tissue)

Question 5

How are epithelial cells arranged?

Answer 5

In single or multiple layers of sheets

Question 6

What are the four main junctions that hold the epithelial cell together?

Answer 6

Desmosone ( Spot weld)
Adherens
Tight
Gap

Question 7

Role of Desmosone junction?

Answer 7

• connect the intermediate filaments of neighbouring cells together
• protein of cadherins spans the gap in between to connect.

Question 8

Role of adherens?

Answer 8

• connect microfilaments of neighbouring cells.
• protein cadherins spans the gap to connect and also
• catenin protein for this type of connection

Question 9

Role of tight junction?

Answer 9

• stop things passing through
• the stands are tightly weaved and they contain two proteins
  Claudin and oclaudin.

Question 10

Role of the gap junction?

Answer 10

- formed in membrane of two cells
Passage between two cells. 
-made from connexon protein 
6 connexon proteins = hemichanel
Two hemichanel = hemidesmosone
Forms a gap junction

Question 11

What is the basement membrane?

Answer 11

What the cells sit on and the foundation of the epithelium.

Question 12

What connects the cells to the Base Membrane?

Answer 12

Hemidesmosone found on the basal surface

Question 13

How many layers does the BM have?

Answer 13

Two
The basal Lamina closer to the epithelium barrier
And the reticula lamina closer to the connective tissue

Question 14

What protein helps the epithelium attract the Basement Membrane?

Answer 14

Laminin protein

Question 15

What is the role of the the inter grins protein and how does it relate to the laminin protein?

Answer 15

Interim protein = attach the laminin and the intermediate filaments within the cytoplasm of the epithelium cell.

Question 16

What is found in the reticula lamina?

Answer 16

Strong reticular fibres made from collagen networks.

Question 17

What connects the reticula lamina to the connective tissue?

Answer 17

Fibronection

Question 18

What other role does the BM have?

Answer 18

The migration of cells across the surface

Question 19

What are two main classification of epithelial tissue?

Answer 19

Glands - endocrine and exocrine

Covering and lining - outer covering and inner lining

Question 20

What are the three main arrangements of epithelial tissue?

Answer 20

Simple
Stratified
Pseudo stratified

Question 21

What are the three main shapes of epithelial tissue?

Answer 21

Squamous - flat
Cuboidal - good for secretion and absorption, tall as it is wide
Columnar - good for secretion and absorption taller than it is long

Question 22

What is the role of microvilli?

Answer 22

Increases the surface area leading to more absorption on a simple columnar epithelium.

Question 23

What is the difference between cilliated and non?

Answer 23

It means one has microvilli and the other doesn’t

Question 24

What are the three main classifications of glands?

Answer 24

Acinar
Tubular
Coiled tubular

Question 25

What is the common function for squamous cells?

Answer 25

Filtration - shirt distance for substances to move across - protective layering - small size means it requires less energy to make more of it - can be keratinised or non

Question 26

What is similar about connective and epithelium tissue?

Answer 26

Both supplies by the nerves

Question 27

Main difference between epithelium and connective tissues?

Answer 27

Epithelium is avascular and connective is vascular

Question 28

What makes up Connective tissue?

Answer 28

Cells and extra cellular matrix Extra cellular matrix contains - proteins - water - polysaccharides (sugars)

Question 29

What happens when proteins and polysaccharides in connective tissue interact?

Answer 29

Form a molecule known as hylaruronic acid. Which makes the water jelly like - viscosity

Question 30

What is released in order for cells to pass through the tissue?

Answer 30

Hylauronidase

Question 31

When the protein core/linking protein interact with the Sulphated (GAGs) sugars what is formed.

Answer 31

Proteoglycan

Question 32

What are the three connective tissue fibres?

Answer 32

Collagen - strength and support, resistes pulling force - elastic fibres - elasticity and fibrilin - Reticular fibres - made from collagen and layer of glycoprotein - form networks

Question 33

What is Marfuns syndrome?

Answer 33

Mutation in the fibrillin protein. Arteries more likely to rupture Height problems Tall and long limbs:

Question 34

What happens if the fibres are more than the cells in connective tissue?

Answer 34

They become more dense leading to regular fibres e.g tendons, ligaments and aponeurons And irregular fibres e.g heart valves and joint capsules.

Question 35

What happens if the fibres are less than the cells?

Answer 35

Loose - areolar connective tissue - has all 3 fibres - Fat - stored energy and support - Loose reticular tissue - stroma supports functioning organs