4-Pulmonary System Overview Flashcards
important elements of respir sys
full list
- mechanism for centrally regulating ventilation
- air pump
- surface for gas exchange
- mechanism for gas transport
- circulatory system
- mechanism for reg distribution of blood
important functions
condensed
- gas exchange/metabolism
- acid base balance
- phonation
- defense mech/handle bioactive materials
upper airway structures
- nasal cavity
- paranasal sinuses
- pharynx
- larynx
upper airways function
- air conditioning for respir sys
- source of resistance to airflow
- warm inspired air to body temp
- humidify/saturate with water inspired air for gas exchange
- filter/entrap/clear particulates
- defense by nasal epithelium secretions
inc secretions = inc resistance
airway generations
0 = trachea
1-10 = bronchi (with cartilage)
11-16 = bronchioles (no cart)
17-19 = respiratory bronchioles
20-22 = alveolar ducts
23 = alveolar sacs
16 terminal bronchioles
bronchus characteristics
- mucus blanket
- goblet cells
- smooth muscle
- mucus glands
- cartilage
G1-10
bronchioles characteristics
- ciliated epithelium
- thin smooth muscle
- elastic tissue
- NO cartilage
- goblet cells (up to terminal bronchioles then no)
G11-19
alveolus characteristics
- NO smooth muslce
- NO cart
- just elastic tissue
non adrenergic non cholinergic nerves
NANC
when activate = relaxation of bronchiolar smooth muscle via NO and vasoactive intestinal peptide
adrenergic activation
abundant B2 adrenoreceptors to relax/bronchodilate
muscarinic acetylcholine receptors
parasymps stim to contract bronchiolar smooth muscle and inc glandular secretions
irritant receptors
activation in trachea and bronchi = reflex contraction of smooth muscle + stim mucosal glands in resp to irritant
mucus production system
- gel layer
- sol layer
- goblet cells (prod mucus esp inc when smoke or pollutants)
- submucosal glands (mucus and serous cells, present where cartilage at, controlled by ANS)
periciliary fluid
makes up sol layer of mucus blanket
-made by ciliated epi cells
-maintained by chloride secretion and sodium absorption
transports mucus with pollutants out of respir system after gets trapped in gel layer
cystic fibrosis
mutation in CFTR
-abnormal Cl secretion = disinhibit Na channel so sol layer becomes dehydrated (water move out of periciliary mucus)
freq lung infection and damage, xs thick mucus, salty skin/sweat, poor growth
survival age 40
treating cystic fibrosis
goal to prevent/control infections + remove mucus from lungs
-use meds to target mutations or infection or bronchodilators
-PT to improve mucus clearance and fix posture, percussion
respiratory unit consists of
- bronchiole
- alveolar ducts
- atria
- alveoli
site of gas exchange
pores of kohn
pores b/t adjacent alveoli so collateral ventilation occurs if lung partially deflated
-bad though for passage of fluid and bacteria
cell types on alveolar surface
- type I = make up the wall/surface area, flat cells with large cytoplasmic extensions, fewer than II
- type II = larger/thicker cells, produce surfactant
- macrophages = engulf and destroy foreign material
respiratory membrane
fused basement membranes of capillary and alveolaus but leaky
-site of gas exchange
respiratory membrane made of
- layer of fluid lining the alveolus with surfactant
- alveolar epithelium
- epithelial basement membrane
- interstitial space
- capillary basement membrane
- capillary endothelial membrane
lung interstitium composition
- lymphatics
- capillaries
- immune cells
- fibroblasts
- connective tissue (collagen/elastin)
interstitial lung disease
interstitium enlarged with inflamm cells and edema fluid or increased extracellular matrix
-will interfere with gas exchange
pleural membranes
single continous membrane that folds back on itself
-lines lungs with visceral pleura and chest cavity with parietal
pleural space
normally intrapleural space is virtual and pressure should be more neg than intrapulmonary (alveolar space)
has small amount of pleural fluid
pleural fluid function
important for transmitting the force produced by chest expansion to the long parenchyma
creates suction/vacuum b/t two surfaces = sub atmospheric pressure
pleural fluid flow
- made by microvessels of the parietal pleura
- removed from pleural space by stomata
- lymphatic channels
pleural effusion
excess of pleural fluid that disrupts mechanical coupling b/t chest wall and lung
-lung pulls away from chest wall
-atelectasis (partial collapse of lung), compression
precipitating conditions pleural effusoin
- inc microvascular hydrostatic pressure
- dec colloid oncotic pressure
- inc microvascular permeability
- impaired lymph drainage
- diaphragmatic defects
symptoms of pleural effusion
often no symptoms unless effusion is moderate/large or inflammed
-SOB
-chest pain with deep inhalation, pleuritic pain
-fever
-cough
treat underlying cause or thoracentesis
pneumothorax
air in pleural cavity = partial or complete lung collapse
-spontaneous or trauma (penetrating, blunt)
usually asymptomatic unless larger then dyspnea and pleuritic chest pain
treat with catheter aspiration or tube thoracostomy after get x ray
tension pneumothorax
progressive inc in pleural pressure due to one way flow or air
-air goes in but not out
-very serious > severe hypotension/shock from dec venous return (vena cava is compressed)
tidal volume
volume of air associated with normal resting breathing (1/2 L)
inspiratory reserve volume
amount of volume between normal resting inspiration and maximal
combines with tidal volume for inspiratory capacity
residual volume
vol in lungs after maximal expiration
combines with expiratory reserve = functional residual capacity
vital capacity
total volume between maximal inhalation and exhalation
