GHM PBL 2

Question 1

Describe the pathophysiology of cystic fibrosis

Answer 1

• Inherited (AUTOSOMAL RECESSIVE)
  -Mutation to CFTR gene (Cystic Fibrosis Transmembrane Conductance Regulator Gene)
  -CFTR gene codes for CFTR protein - regulates movement of Cl- + Na+ across epithelial cell membrane
  -Mutation (to one / both copies of gene) - ion transport defective, therefore, build up of thick MUCUS throughout body, mostly in lungs + digestive system
• build of mucus in lungs, increased risk of lung infection, breathing probems

-excess mucus binds to enzymes of pancreas, reduces their function, leading to MALABSORPTION

Question 2

What type of transporter is CFTR ?

Answer 2

ABC transporter

Question 3

What specifically causes thick mucus in CF?

Answer 3

Lack of salts in between cells
Prevents water following

Question 4

Describe the effect of CF gene mutation on sweat glands, lungs an gut

Answer 4

SWEAT GLANDS:
Usually CFTR transports Cl- ions out of sweat glands (along with Na+ + H2O) into blood. However, due to mutation, Cl- stays and therefore, Na+ and H2O stay as well. This causes Cl-, Na+, H2O to be excreted as sweat, therefore, excessive salty sweat

LUNGS:
Prevents Cl- and therefore, H2O from leaving cells and going to lungs. This makes mucus in lungs thick

GUT:
Thick mucus interferting with pancreatic juice (enzymes) + ability to digest food

Question 5

Describe growth faltering in cystic fibrosis

Answer 5

CFTR mutation results in pituitary gland releasing less growth hormone

Growth hormone + insulin growth facotr surpressed due to malabsorption (malabsorption of proteins + fats lead to poor growth + malnutrition), inflammation (repeated lung infections due to CF)

Question 6

Describe how CF affects pancreatic juice and pancreatic enzymes

Answer 6

CF results in pancreatic insufficiency

PANCREATIC JUICE: liquid secreted by pancreas, contains digestive enzymes

In CF, pancreatic enzymes get stuck in mucus of pancreas, do not reach small intestine

No enzymes to break down food, much of proteins, carbs, etc not absorbed for use by body (MALABSORPTION)

MALABSORPTION = POOR GROWTH, MALNUTRITION = GROWTH FALTERING

Question 7

Describe recurrent chest infection in CF patients

Answer 7

CF leads to build up of thick mucus in lungs
Increases chances of accumularing for bacteria + pathogens
Leads to inflammation of lungs
This causes macrophages + nutrophils to release elastatse + ROS (in response to chest infection caused by CF) - this is what causes inflammation
Vit C helps get rid of ROS

Question 8

Describe how CF can lead to GERD / GORD

Answer 8

Thick mucus causes blockage in digestive system
Leads to delayed gastric emptying
Increase risk of acid reflux

Question 9

State a complication of CF

Answer 9

Distal Intestinal Obstruction Syndrome

• Mucus in intestine combines with faeces, builds up, produces a mass
  -Leads to Partially / fully obstructed bowel