13. Cystic Fibrosis Flashcards
What is the upper airway tract?
4 structures
Nose- sense of smell, filtering, humidifying, heating and cooling
Mouth- sense of taste, some filtering
Pharynx- passage of food to esophagus and directs air to lower airways
Larynx- holds vocal folds, used for making sounds and speech
Slide 4
What is the nasal cavity?
Types of flow?
Lines by epithelium cells releasing mucus (salty, sticky, and has lysozymes)
Inhalation- laminar flow, mucus traps particles, moist to humidity air, blood supply in nasal cavity heats up air
Exhalation- turbulent flow, moisture in air recaptured by mucus
Slide 5
What is the lower airway tract?
Made up of the trachea and the lungs
Surrounded by the pleural sac within thoracic cavity
Trachea- has 4 layers:
Mucosa- respiratory epithelium and lamina propria
Submucosa- connective tissue and submucosal glands
Cartilage
Adventita
Slides 6-9
Slide 15
What is the secondary respiratory lobule?
The functional unit of the lung Supplied by a terminal bronchiole Contains 3-13 acini Surrounded by interlobular septa which the veins and lymphatics pass through About 1-2.5cm across
Slide 10
What are acinus?
Defined as portion of the lung distal from the terminal bronchiole supplied by respiratory bronchiole
Represents generations ~15-23
Includes respiratory bronchioles, alveolar ducts, and alveoli
About 10000 alveoli per acini
About 30000 acini per human lung
Slide 11
What are alveoli?
Where O2 and CO2 diffuse between the air and blood
Made up of 2 types of pneumocytes:
Type 1- squamous cells, 0.15-0.30μm thick, most of surface, place of diffusion
Type 2- cuboidal cells, secrete surfactant to decrease surface tension within alveoli and keeps them open
Pores of Kohn- unknown function
Slides 12-13
What are the 2 blood supplies of the lung?
Pulmonary artery- deoxygenated to exchange O2 and CO2
Bronchial artery- oxygenated blood to supply lung tissue
Lung holds 9% of blood supply
What are basal cells?
What are ciliated cells?
What are goblet cells?
What are ionocytes?
Basal cells- found along respiratory epithelium (except alveoli), regenerate and can differentiate into other respiratory cells
Ciliated cells- found throughout respiratory epithelia (except alveoli) and covered in cilia, cilia beat ti move mucus towards pharynx
Goblet cells- found in nasal passage, trachea, bronchi, and larger bronchioles, secrete mucin 5B (Muc5B)
Ionocytes- new cell discovered, rare not too sure of role
Slide 16
What is mucociliary clearance? Slide
Exists both in upper and lower airway
Upper- moves mucus from the front of nasal cavity to pharynx
Lower- distal airways towards pharynx (only in conducting airways
Both result in swallowing it spilling out of the mucus
Periciliary liquid (PCL)- sol later
Mucus- gel layer
Airway surface liquid (ASL)- PCL+mucus
Nasal cavity, trachea, and bronchi have mucus secreting glands (submucosal gland)
Slides 17-18
What is periciliary liquid (PSL) regulation?
What is PCL secretion?
PCL is tightly regulated in the airways, but isn’t fully understood
Hypothesis is epithelial cells can cause fluid secretion and absorption by regulation of ion transportation
No PCL = collapsed cilia = no movement of mucus
Slide 19
Slide 23
What is PCL secretion?
What is PCL absorption?
Secretion:
Cl is moved from basolateral side to apical, NKCC brings Cl into cell using K and Na gradient, cystic fibrosis transmembrane conductance regulator (CTFR) opens and Cl moves into luminal space, Na moves paracellular to lumen, H2O moves paracellular due to osmotic gradient, ENaC is inhibited by CTFR to stop Na movement back into cell
Absorption:
CTFR closes leading to ENaC opens, calcium activated chloride (CaCC) channel closes and anti transporter closes, Na moves into cell and to basolateral side, Cl move paracellular due to electrochemical gradient, H2O moves paracellular to basolateral side
Slides 20-21
How is mucus produced?
Muc5B mainly made and released from submucosal glands (SMG)
Muc5AC is released from goblet cells
What is cystic fibrosis?
What is the cystic fibrosis transmembrane conductance regulator (CFTR)?
Most common fatal genetic disease affecting children
Autosomal recessive mutation in the gene producing cystic fibrosis transmembrane conductance regulator (CFTR) channel
Over 1700 different mutations to the CFTR cm gene, not all result in CF
CFTR channel is a ABC transporter class ion channel (ATPase Binding Cassette) Cl and HCO3
Slides 24-25
What are the cystic fibrosis classes?
Class III, IV, V, VI are mostly curable by daily taking medications and treatments
Classes I and II are still unsolved problems -> CF researchers are currently focusing on finding solutions
Slides 26-28
What are the cystic fibrosis symptoms and lung complications?
Symptoms- salty skin, persistent coughing, shortness of breath, frequent lung infections, poor growth or weight gain in spite of a good diet, frequently greasy, bulky, foul smelling stool, difficulty passing stool
Lung problems in late childhood
Airway plugging, chronic airway infections, bronchiectasis (abnormal and permanent dilation of airways), pneumothorax, respiratory failure (unable to perform oxygenation or CO2 elim), and more
Slides 29-30
