LBL 5 Connective Tissue and Secretions

Question 1

Name three protein fibres in the respiratory system

Answer 1

Collagen
Elastin
Reticulin

Question 2

Name the three types of specialised cells in the respiratory system

Answer 2

Macrophages
Clara cells
Mast cells

Question 3

Name three types of tissue found in the respiratory system

Answer 3

Cartilage
Smooth muscle
Lymphoid tissue

Question 4

What stain is used to distinguish between elastin fibres and other connective tissue fibres?

Answer 4

Verhoeff-Van Gieson stain
Stained by iron-haematoxylin compound (Verhoeff)
Van Gieson is a counter-stain

Question 5

Name the properties of elastin

Answer 5

Highly elastic protein fibre, found in the alveoli
Elastin fibres are made up of multiple sub-units of tropoelastin (will cross link with each other)
Encoded by the ELN gene
Contains fibrillin
Longest lived human proteins (half-life of 80 years)

Question 6

What reticulin fibres made of?

Answer 6

Collagen (type III) secreted by reticular cells (type of specialised fibroblast)

Question 7

Where are reticulin fibres found?

Answer 7

Liver
Lung
Lymph

Question 8

What is used to stain Reticulin?

Answer 8

They are argyrophilic so they use silver stains

Examples: Gordon & Sweet’s, Jones Methenamine Silver

Question 9

Properties of Mast Cells (Fat cells)

Answer 9

Precursor of Myeloid progenitor
Numerous in regions where it is in contact with the outside world
Travels through the blood before migrating out of the blood vessel
Contain granules of heparin and histamine
Activated by the binding of IgE

Question 10

Properties of Asthma

Answer 10

Increases airway resistance
Causes bronchial inflammation 
Airway hyper-responsiveness 
More goblet cells, smooth muscle and the basement membrane is thicker
Treated with steroids

Question 11

Examples of where cartilage is found

Answer 11

Trachea

Bronchi

Question 12

Properties of Cartilage

Answer 12

Avascular and aneural tissue
Produced by chondrocytes
3 types: Elastic, Hyaline and Fibrocartilage

Question 13

Properties of Elastic Cartilage

Answer 13

Principle protein type is elastin
Contains some Type II collagen
Very flexible
Found in the epiglottis

Question 14

Properties of Hyaline Cartilage

Answer 14

Principle protein is Type II collagen
Covered in fibrous membrane
Chondrocytes exist in lacunae
Found in trachea, ribs and joints

Question 15

Properties of Fibrocartilage

Answer 15

Contains Type I collagen
Found where 2 bones have fused together (secondary cartilaginous joints)
Can form scar tissue of collagenous structures
Attaches tendons/ligaments to bone

Question 16

What is the word for Cartilage disease?

Answer 16

Chondropathies

Examples: Achondroplasia (inherited), Knee Injuries (trauma), Osteoarthritis (wear and tear)

Question 17

Properties of mucus

Answer 17

Secreted by goblet cells
95% water with some smattering inorganic ions and protein
Contains mucin: helps form a gel, highly diverse (20 different mucin genes), respiratory mucus contains large amounts of Mucin 5A and 5B

Question 18

What gene causes the mutation for Cystic Fibrosis?

Answer 18

CFTR gene (autosomal recessive)

Question 19

What does cystic fibrosis cause?

Answer 19

Thick mucous prevents the muco-ciliary escalator from functioning.
Increases the likely hood of infections