Test 2 Respiratory/Pulmonary Flashcards
What is a cause of morbidity and mortality in premature infants?
immaturity of the respiratory tract
What begins after week 20?
Surfactant(a detergent) production: fluid that lines the alveoli- purpose to lower surface tension and pressure and make you able to contract lungs)
At what weeks of gestation are sufficient alveoli present to permit survival?
25th to 28th week
About how many alveoli does one have at birth? 3-7 years old? and final adulthood?
birth-20-50million
3-7 years ~ 300million
adult ~ 700million
Lack of stiff structural support for airways makes infants more susceptible to what?
atelectasis(lung collapse) and obstruction
Why are infant airways much more resistant to air flow than adults?
infant airways are smaller
ex: imagine breathing through a coffee straw and a mcdonalds straw
Are neonates predominantly mouth-breathers or nose-breathers?
nose-breathers
Therefore obstruction of the nose or nasopharynx increases upper airway resistance and increases work of breathing
Who is more likely to suffer from pneumonia, newborn or adults and why?
newborn bc of lack of alveoli
What is a sign of increased respiratory resistance more so in infants?
Nose flaring
What are things that can dramatically reduce airflow?
mucus, edema, or airway constriction
Most respiratory disorders in infants result in what?
reduced lung compliance (ability to stretch and recoil) or increased airway resistance
There are six signs of reduced compliance or increased resistance. What are they?
Increased respiratory rate (tachypnea)
Grunting (audible noise during expiration)
Nasal flaring
Retractions (skin being sucked in around ribs during inspiration)
Stridor (sound caused by increased turbulence of air moving through the trachea and large airways)
Wheezing (sound caused by increased turbulence of air moving through the smaller airways)
Infants have more ____ cells that cause them to create more mucous that can obstruct their airways.
goblet cells
What are the two major airways made up of?
Upper airway:
Nasopharynx
Oropharynx
Laryngopharynx
Lower airway: Larynx Trachea Bronchi Acinus
The nasal cavity has 6 functions. Summarize.
CONDUCTS gases to and from lungs
FILTERS,WARMS,HUMIDIES air
TURBINATES are convoluted and vascular
(Efficient heat exchanger.
Water (mucous) evaporates from surface to humidify air)
Rigid (bone/cartilage) to PREVENTS COLLAPSE
VIBRISSAE(large hairs) trap foreign particles
MUCOSAL EPITHELIAL CILIA sweep mucous into nasopharynx, which is then swallowed or expectorated
What are the four paranasal sinuses?
Maxillary(cheeks get infection with sinus infection), frontal(not everyone has them), ethymoid, sphenoid(last two more posterior)
What do the paranasal sinuses contribute to?
speech resonance, heat and water vapor exchange (warming and humidifying air)
ex: when someone has a cold their voice changes
What removes bacteria and debris in the sinuses?
mucociliary action
What allows pressure equalization of the middle ear?
eustachian tube
ex: like when you’re on a plane
At what time do the eustachian tubes open?
open during swallowing
The eustachian tubes are in different positions in children than adults. At what position does it sit? What risk increases with this position?
Horizontal position and shorter length in children. This causes more ear infections bc fluids can’t drain as easily
What do your conducting airways(what are responsible for moving air) consist of?
oral and nasal pharynx and larynx is what takes up air
trachea, segmental bronchi and bronchioles (nonrespiratory)
branches of bronchioles and alveolar ducts(respiratory)
Kartagenrous syndrome is what?
No functional cilia which means sterile(no cilia in fallopian tubes), sinus infections, etc. Cant beat mucous away
What are the conducting airways made of?
Ciliated columnar mucosal epithelial cells
Cilia above the esophagus are beating ____ and below(like in the lungs) are beating mucous ____. why?
down. up. want to swallow the mucous
What is a primary defense mechanism of the airways?
Mucociliary transport: Moves inhaled particles and mucous to the esophagus for swallowing or coughing
Ciliary function is impaired by what?
Smoking Ethanol Hypo or hyperthermia Cold or hot air, low humidity Anesthetics, corticosteroids, noxious gases Viral infection (common cold) Excessive mucous production
What do goblet cells produce?
Produce mucous (100 mL/day)
what is sIgA?
antibody secreted on mucousal surfaces that organisms can bind to and prevent infection
List the functions of the larynx.
Sound production
Valve to control air movement out of the lungs, including to expel foreign substances, e.g. coughing
Prevent foreign substances from entering the trachea and lungs
a horseshoe shaped bone from which the larynx is suspended
hyoid bone
What are the three cartilages of the larynx?
THYROID: a V-shaped cartilage containing the vocal folds (attach anteriorly, one you can feel)
CRICOID: a ring shaped cartilage connected to the trachea, supports the arytenoid cartilages posteriorly(isthmus of thyroid gland runs here)
ARTHENOID: vocal folds connect on posterior side
these vibrate when air passes over them, forming sound (longer folds create lower sounds, tighter folds create higher sounds)
vocal folds
Vocal folds must remain ____ so when air passes over them and they vibrate.
tight
Longer vocal folds means higher or lower pitch? Tighter folds create which?
lower the pitch ;
higher sounds
Where does the trachea divide into the right and left mainstream bronchi?
carina
How many lobes does the right lung have?
3
How many lobes does the left lung have?
2
Describes the largest unit of the lung to the smallest.
Lobular bronchi segmental bronchi (forming bronchopulmonary segments) bronchopulmonary segments terminal bronchioles (smallest units)
Where do alveoli form on?
respiratory bronchioles
alveoli = ____
gas exchange
adults have how many alveoli per lung?
about 300 million total
what occurs on the surface of alveoli?
O2 and CO2 exchange
What are the 3 types of alveolar cells?
Type I: squamous epithelial cells (“pneumocytes”)-Majority of cells, form gas exchange surface
Type II: produce surfactant-
Phospholipid-containing liquid that lowers surface tension (eases opening) and facilitates gas exchange
Type III: alveolar macrophages (“dust” cells)-
Phagocytize particles / microbes that reach alveoli
What are the 3 types of alveolar cells?
Type I: squamous epithelial cells (“pneumocytes”)-Majority of cells, form gas exchange surface(surfactant covering these cells)
Type II: produce surfactant-
Phospholipid-containing liquid that lowers surface tension (eases opening) and facilitates gas exchange
Type III: alveolar macrophages (“dust” cells)-
Phagocytize particles / microbes that reach alveoli(can cause black lung-found in coal miners. our bodies don’t have enzymes that can phagocytize coal
What are the visceral pleura and parietal pleura?
visceral plura- Thin, continuous membranes covering the lungs
parietal plura-Thin, continuous membranes covering the thoracic cavity
the sacs that surrounds the lungs
What are the membranes separated by?
small amount of serous fluid to lubricate (around 15 ml)
Intrapleural space at maintained at _____ which keeps it expanded (i.e., a vacuum, which keeps lungs pressed against thorax wall)
negative pressure
PS. if negative pressure would be disrupted could cause a collapsed lung
What makes up the autonomic nervous system?
parasympathetic and sympathetic
What nerve stimulates the parasympathetic nervous system?
Vagus nerve
what does the vagus nerve(cranial nerve 10) stimulate?
constriction of bronchial smooth muscle (bronchoconstriction)– this is rest and digest so don’t need as much air flow
what causes the relaxation of bronchial smooth muscle?
Sympathetic innervation (T1-T4) and epinephrine / norepinephrine (adrenal gland medulla)
What is the sympathetic nervous system mediated by?
beta-2 adrenergic receptors
what is the defense against excessive secretions or foreign/irritating substances?
cough reflex
if the cough reflex decreases what risk increases?
risk of aspiration
May be caused by cough suppressant medicines, brainstem injury, age
what is a cough initiated by?
tracheobronchial cough receptors in carina (bifurcation of right and left mainstem bronchi) and coordinated in brainstem (medulla oblongata)
how is a cough produced?
when vocal folds and epiglottis close tightly against air trapped in lungs
Expiratory muscles (intercostal and abdominal) contract and increase pressure against closed vocal folds and epiglottis
Vocal folds and epiglottis suddenly open
High pressure air escapes, ejecting debris, mucus
What arises from the thoracic aorta (oxygenated arterial blood)?
bronchial artery system
What supplies oxygenated blood to bronchi and supporting lung structures?
bronchial artery system
What arises from the pulmonary artery and divides into right and left pulmonary arteries?
Pulmonary artery system
What delivers unoxygenated blood from the right ventricle?
pulmonary artery
The pulmonary artery system is a huge capillary network for what?
gas exchange
*Fewer capillaries in elderly and infants (therefore less efficient gas exchange)
The pulmonary artery system is a ____ pressure arterial system.
low
Blood flow may _____ to adjust for gas exchange needs
be increased or reduced
Oxygenated blood exits through ______
pulmonary vein into left atrium
What are the 2 mechanisms that increase capillary perfusion?
- Recruiting (opening) previously closed capillaries
–Normally only 25% of pulmonary capillaries are perfused - Increasing arteriolar
blood flow
Pulmonary arterioles \_\_\_\_\_\_ in response to alveolar hypoxia (insufficient O2 or excess CO2), re-routing blood flow to alveoli that are well-ventilated
constrict
What are the 3 factors that regulate fluid balance across lung tissue?
- Hydrostatic pressure (blood pressure vs tissue pressure)
- Colloid osmotic (oncotic) pressure (related to protein concentration on either side of a membrane)
- Capillary permeability (leakiness between endothelial cells lining capillaries)
What is the process of ventilation?
Ventilation is the process of moving air into and out of the lungs
What is the purpose of ventilation?
Purpose is to allow O2 absorption from inspired air and removal of CO2 to expired air
What are 3 things that influence ventilation?
- Age (e.g., reduced with older age)
- Body size and shape (e.g., reduced with obesity)
- Body position (e.g., reduced with supine position)
What are 4 lung volumes? What are 4 lung capacities?
- Tidal
- Inspiratory Reserve
- Expiratory Reserve
- Residual Volume
- Vital Capacity
- Inspiratory Capacity
- Functional Residual
- Total Lung Capacity
The volume of air breathed in and out without conscious effort in a “normal” breath (~500 cc)
tidal volume (TV)
The volume of air above TV that can be inhaled with maximum effort after a normal inspiration (~3 L)
Inspiratory reserve volume (IRV)
The volume of air above TV that can be forcibly exhaled with maximal effort after normal exhalation (~1.2 L)
Expiratory reserve volume (ERV)
The volume of air left in the lungs after a maximum exhalation (~1.2 L)
Residual volume (RV)
The total volume of air that can be exhaled after a maximum inhalation (VC = TV + IRV + ERV, ~4.7 L)
Vital Capacity (VC)
