Tissues 2-3

Question 1

What are the three different cell shapes of epithelium?

Answer 1

Squamos, cuboidal and columnar

Question 2

What is the function of tight junctions?

Answer 2

Allow cells to establish and maintain apical-basolateral polarity by preventing the mixing of proteins and lipids between different compartments.

Question 3

What is the function of belt junctions?

Answer 3

Separate plasma membranes into apical and basolateral demains as they have different lipid and protein compositions.

Question 4

What two cell types is protective epithelium made up of?

Answer 4

Keratinising (dead) and non-keratinising (alive) cells

Question 5

Where do endocrine glands secrete into?

Answer 5

Bloodstream

Question 6

Where do exocrine glands secrete into?

Answer 6

Ducts

Question 7

Exocrine glands will have a high concentration of what?

Answer 7

Rough ER

Question 8

What is constituted secretion?

Answer 8

Released as it is made

Question 9

What is cell turnover?

Answer 9

A balance between cell proliferation and cell death. When it becomes unbalanced, polyps or cancers can develop.

Question 10

How often does the lining of the gut get replaced?

Answer 10

Every 3-10 days.

Question 11

How often is fat, heart and bone tissue replaced?

Answer 11

Every 8-10 years.

Question 12

How does applying pressure affect cell proliferation?

Answer 12

Increases it.

Question 13

What are the functions of the ECM?

Answer 13

• Physical support
• Determines mechanical and physiochemical properties
• Influences growth, adhesion and differentiation
• Essential for develop, tissue function and organogenesis

Question 14

What is affected in OI?

Answer 14

Collagen type 1

Question 15

What is affected in congenital muscular dystrophy?

Answer 15

Laminin 2

Question 16

What is affected in Hurler’s syndrome?

Answer 16

ECM catabolism

Question 17

What causes liver cirrhosis?

Answer 17

Excess ECM deposition

Question 18

What causes osteoarthritis?

Answer 18

ECM loss

Question 19

How many types of collagen is there?

Answer 19

28

Question 20

What type of collagen is present in all basement membranes?

Answer 20

Type IV

Question 21

What is the basic structure of collagen?

Answer 21

Triple helix made up of three alpha chains. X-Y-Gly repeat. X is often proline. Y is often hydroxyproline.

Question 22

What are the effects of hydroxylation of proline and lysine?

Answer 22

Hydrogen bond formation between the three alpha chains. Form covalent cross linkages, providing tensile strength and stability.

Question 23

What is scurvy caused by and what are the effects?

Answer 23

Vitamin C deficiency results in under hydroxylated collagen, reducing stability of tissue.

Question 24

What is the structure of an elastic fibre?

Answer 24

Elastin core surrounded by microfibrils (rich in fibrilin)

Question 25

What amino acids are elastic fibres rich in?

Answer 25

Alanine and lysine

Question 26

What is a major risk for patients with Marfan’s syndrome?

Answer 26

Aortic ruptures due to lack of elasticity in blood vessels.

Question 27

What is the basement membrane?

Answer 27

Flexible, highly specialised, thin mats of ECM underlying epithelial sheets.

Question 28

Where is the basement membrane found?

Answer 28

Surrounds muscle, fat and peripheral nerve.