Flashcards in Respiratory AP Deck (59)
What happens during inflammation?
Response to cellular injury, mediators (cytokines, etc) released. Area increased permeability, vasodilation. WBCs rush to area, clot and scar formation
What are the parts of the upper respiratory system?
Nose, nasal cavity, mucus membranes, sinuses, pharynx, larynx, cartilages (thyroid, cricoid, epiglottis)
What does the epiglottis do?
Closes the larynx during swallowing
What are the parts of the lower respiratory system?
Trachea, primary bronchus (L/R), tracheobronchial tree, terminal bronchioles, respiratory bronchioles, alveolar ducts, alveoli
Which cells produce mucus?
When does the mucus membrane end?
Ends at terminal bronchioles. Respiratory bronchioles is the first place where gas exchange can happen
What is the carina?
Bifurcation to the L and R primary bronchus, landmark for ETT placement
What is the difference between the L and R bronchus?
R bronchus is wider and straighter
1. Increased risk of aspiration into LRL
2. Risk of intubation into R lung
What do the respiratory bronchioles do?
First site of gas exchange, 35% of gas exchange happens here
What are alveoli?
Site of gas exchange (65%), lined with epithelial cells in contact with capillaries
What are the Pores of Kohn?
Tiny openings allow air circulation, gas + pressure equalization, connecting alveoli in collateral ventilation
What is collateral ventilation in the alveoli?
Facilitated by Pores of Kohn, allows alveoli to still function as gas exchange unit even if some are collapsed or shunted
What are the types of alveolar cells?
Type 1: Gas exchange, diffusion
Type 2: Produce type 1 cells, surfactant. Highly metabolic and sensitive to decreased CO and perfusion
Type 3: Alveolar macrophages transport trapped particles into lymphatic vessels
What is surfactant?
Hydrophobic phospholipid molecule repels water and decreases surface tension in alveoli. Produced by type 2 cells, prevents fluid seeping in from capillaries
What is the half life of surfactant?
14 hrs, therefore body must keep producing
What is the hilius?
Area where tubular parts of the bronchus enters the lungs and visceral pleura folds over into parietal pleura
What is the pleural membrane consist of?
1 continuous membrane including visceral pleura and parietal pleura, folding over at the hilius
What is visceral lung pleura attached to?
What is parietal lung pleura attached to?
Thoracic wall, helps to ventilate and regulate pressure
What is the pleural cavity and what does it do
Space in between visceral and parietal pleura containing 30-50cc serous fluid. Functions to decrease friction and protect from thoracic infections
How are the lungs supplied with blood?
1. Bronchial arteries carry oxygenated blood and nourish trachea to terminal bronchioles and lung tissues
2. Pulmonary arteries carry deoxygenated blood but it's enough to nourish alveolar ducts, alveoli, and respiratory bronchioles
What does lymphatic circulation do in the lungs?
1. Remove foreign particles, cell debris
2. Remove excess fluid to keep interstitial space dry
Nodes in the hilius
How does the diaphragm inhale/exhale?
Innervated by phrenic nerves C3-C5, moves down with inspiration and relaxes with expiration. Pressure changes create respiration
What are other muscles of respiration besides diaphragm?
External intercostals (inspiration, T2-T11), internal intercostals (expiration), abdominal wall muscles, accessory muscles
How does the CNS control breathing?
1. Nerve supply (Phrenic C3-C5)
3. Brain stem
4. Central and peripheral chemoreceptors
Which nerves control diaphragmic breathing?
Which cranial nerves control gag reflex?
CN IIIIV Glossal pharyngeal
CN X Vagal
How does the ANS control respiration?
Bronchial muscles constrict (PNS) or dilate (SNS)
How does the brain stem control respiration?
1. Medulla and pons regulate rate / rhythm
2. Stretch receptors in airways stimulated by changes in lung volume and prevent over inflation (Herring Breuer reflex)