Cystic Fibrosis

Question 1

What are components of the lungs ?

Answer 1

Trachea > bronchi > bronchioles > alveoli

Question 2

What is the structure of the trachea and bronchi

Answer 2

• have C-shaped rings of cartilage on front half, provide support and flexibility
• lumen contains ciliated epithelium and smooth muscle, allows tubes to contract and relax (may need to constrict to prevent dust or pollen from entering

Question 3

What is ciliated epithelium and its role?

Answer 3

• Epithelial tissue with cilia (hairs) on it
• contain goblet cells between the epithelia ,which secrete mucus to trap dirt and pathogens
• Once trapped the cilia wafts mucus up and out of the mouth to be swallowed into the stomach

Question 4

What are properties of thebronchioles?

Answer 4

Consist mainly of smooth muscle and epithelial cells, usually don’t contain cartilage

Question 5

What are properties of alveoli?

Answer 5

• Lined with squamous epithelial tissue and consist of elastic fibres
• adapted for gas exchange with: forming network increasing SA; good blood supply, surrounded by blood vessels; short diffusion distance for gas, only 2 cells thick (sq. Epithelia and endothelium)

Question 6

What is the CF gene?

Answer 6

A section of DNA on chromosome 7 carrying the code for the CFTR protein

Question 7

What is cystic fibrosis caused by?

Answer 7

A mutation in the CFTR protein
- which normally codes for carrier protein in cell membranes transporting chloride ions in and out of cells of the respiratory tract and into the mucus
- makes mucus watery and easy to get rid of due to osmosis
- mutant CFTR isn’t as efficient at transporting chloride ions, making mucus thick and sticky

Question 8

What are some issues that may arise in the respiratory system due to CF?

Answer 8

• build up of mucus in lungs traps bacteria, increasing risk of infection
• build of mucus in the airways decreases SA of alveoli, reducing rate of gas exchange

Question 9

What are some issues that may arise in the reproductive system due to CF

Answer 9

• cervical mucus prevents sperm from reaching the egg
• sperm ducts become blocked with mucus; sperm produced cannot leave testes

Question 10

What are some issues that may arise in the digestive system due to CF

Answer 10

• the pancreatic duct connecting the pancreas to the small intestine becomes blocked w mucus, so digestive enzymes don’t reach small intestine -> fewer nutrients are absorbed
• mucus can cause cysts to form on pancreas, damaging insulin producing cells and causing diabetes