EXAM 2 Respiratory System Flashcards
major cause of morbidity and mortality in premature infants
Immaturity of the respiratory tract
when does surfactant production typically begin?
around week 20
_________ allows lungs to expand
Surfactant
what will happens to infants without surfactant?
unable to respire after birth
when are sufficient alveoli present in fetuses to permit survival
25th-28th week of gestation
at 3-7 years of age, how much surfactant does the child have?
300 million
how much surfactant does an adult have?
700 MILLION
how much alveoli are there at birth?
20-50 million
when do we develop our maximum number of alveoli?
around age 20
Lack of stiff structural support for airways makes children more susceptible to what two things?
atelectasis (lung collapse) and obstruction
Neonates are predominately what type of breathers?
nose breathers
why is there more resistance to airflow in infants?
Infant airways are smaller than adults
what is mucous effect on air flow?
increases resistance to airflow
a sign of increased respiratory resistance in babies
nasal flaring
Presenting sign for hypoxia in babies
nasal flaring
what can negatively affect airflow in babies?
Small amounts of mucus, edema, or airway constriction
Most respiratory disorders in infants result in what two things?
REDUCED LUNG COMPLIANCE AND INCREASED AIRWAY RESISTANCE.
The ability of the lungs to stretch
COMPLIANCE
6 signs of Reduced compliance or increased resistance
- Increased respiratory rate
- Grunting
- Nasal flaring
- Retractions
- Stridor
- Wheezing
what is tachypnea
Increased respiratory rate
sound caused by increased turbulence of air moving through the trachea and proximal airways
stridor
three things that make up upper airway
- Nasopharynx
- Oropharynx
- Laryngopharynx
4 things that make up lower airway
- Larynx
- Trachea
- Bronchi
- Acinus
nasal cavity functions (6)
- Conducts gases to and from lungs
- Filters, warms, humidifies air
- Turbinates are convoluted and vascular
- Rigid (bone/cartilage) to prevent collapse
- Vibrissae (large hairs) trap foreign particles
- Cilia sweep mucous into nasopharynx
four paranasal sinuses
Maxillary, frontal, ethymoid, and sphenoid
two things the parasal sinuses contribute to
speech resonance and heat and water vapor exchange
in sinuses, what action removes bacteria and debris?
Mucociliary
Primary role for sinuses
speech resonance
where is the Eustachian Tube located?
Runs from middle ear to posterior pharynx
what Allows pressure equalization of middle ear?
Eustachian Tube
what closes Eustachian tubes during swallowing
Pharyngeal muscles
what predisposes children to otitis media?
Eustachian Tube angle and shorter length
genetic abnormality that lacks functional cilia. Patient presents with frequent upper respiratory infections, pulmonary infections, and infertility
Kartagener syndrome
Conducting Airways function
- Direct air to respiratory exchange zones of the lung
- Warm, filter, and humidify air
Number of bifurcations
around 20 divisions
w2here does gas exchange happen?
at terminal end
primary defense mechanism in Ciliated columnar epithelial cells
Mucociliary transport
Ciliary function is impaired by (7)
- Smoking
- ETOH
- Hypo or hyperthermia
- Cold or hot air, low humidity
- Anesthetics, corticosteroids, noxious gases
- Viral infection (common cold)
- Excessive mucous production
hoe much mucous to goblet cells produce per day?
100 mL/day
where does mucous come from?
goblet cells
unique antibody that is produced and secreted on ALL mucosal surfaces
Secretory IgA
do children or adults have more goblet cells?
children
functions of larynx
- Sound protection
- Valve to prevent air from escaping the lungs
- Prevent foreign substances from entering the trachea and lungs
- Expel foreign substances (coughing)
Serves as a separation between lower and upper respiratory tract.
larynx
To hold air in we clamp off _____.
vocal folds
critical for clearing lungs
cough
a horseshoe shaped bone from which the larynx is suspended
hyoid bone
Strangled people have this bone crushed
hyoid bone
- One of few bones not connected to other bones, suspended by sensory ligaments and muscles
hyoid bone
3 types of cartilage in larynx
thyroid, cricoid, arythenoid
A V-shaped cartilage containing the vocal folds
Thyroid
A ring shaped cartilage connected to the trachea, supports the arythenoid cartilages posteriorly
cricoid
vocal folds connect on posterior side of this cartilage
Arythenoid
Vocal cords are strung between what two cartilages?
arythenoid cartilage and cricoid cartilage.
Defense against excessive secretions or foreign/irritating substances
Cough Reflex
receptors for cough reflex are located in the ____.
carina
Diminishing cough reflex results in?
increases risk of aspiration
how can cough reflex be diminished?
by cough suppressant medications, brainstem injury, age
where is cough reflex coordinated?
brainstem (medulla oblongata)
how is 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.
nerve that stimulates constriction of bronchial smooth muscle
Vagus nerve
branch of Autonomic Nervous System that results in BRONCHIODILATION
SYMPATHETIC
branch of Autonomic Nervous System that results in - BRONCHIOCONSTRICTION
PARASYMPATHETIC
what causes relaxation of bronchial smooth muscle
epinephrine/norepinephrine (adrenal gland medulla)
bronchiodilation in sympathetic nervous system is mediated by what type of receptors?
beta-2 adrenergic receptors
stimulation of these will result in sympathetic response
beta-2 adrenergic receptors
where does the Trachea divide into right and left mainstem bronchi
carina
how many lobes does the right lung have?
3
how many lobes does the left lung have?
2
bronchiole branching (start from trachea)
trachea -> right and left mainstem bronchi -> Lobular bronchi -> segmental bronchi -> bronchopulmonary segments -> the terminal bronchioles (smallest units)
why can pneumonia be in a certain lobe and not in the others?
Bacteria can be isolated in segments, Lobular bronchi divide into bronchial segments
where are alveoli found?
terminal bronchioles branch off to smaller respiratory bronchioles which have alveoli
Adults have _____ alveoli per lung
350 million
Adults have _____ alveoli total
700 million
how many square meters of surface area for gas exchange in adult?
75 square meters
3 types of alveolar cells
Type 1: squamous epithelial cells (pneumocytes)
Type 2: produce surfactant
Type 3: alveolar macrophages
alveolar cell type- Majority of cells, form gas exchange surface
Type 1: squamous epithelial cells
alveolar cells that produce surfactant
Type 2
alveolar cells that phagocytize particles/microbes that reach alveoli
type 3: alveolar macrophages
Purpose of surfactant
to change surface tension
Patient with collapsed alveoli will have what sounds when listening to them breathe
crackle sounds
why is there crackling sounds in patients with collapsed alveoli?
not enough surfactant in alveoli to allow them to smoothly open up
Thin, continuous membranes covering lungs
visceral pleura
Thin, continuous membranes covering thoracic cavity
parietal pleura
visceral pleura and parietal pleurae separated by what?
serous fluid
purpose of serous fluid?
to lubricate
Intrapleural space maintained at what type of pressure?
negative pressure
accumulation os serous fluid causes what symptom in patients?
shortness of breath
Blood supply to the lungs and bronchia through what 2 systems?
Bronchial artery system
Pulmonary artery system
system that Supplies blood to bronchi and supporting lung structures
Bronchial artery system
Bronchial artery system arises from ___.
thoracic aorta
Pulmonary artery system arises from ___.
Pulmonary artery
it is critical that the Pulmonary artery system is maintained at what kind of pressure?
low
artery system that has Huge capillary network for gas exchange
Pulmonary artery system
why is ability for exchange gas less efficient in elderly and infants?
Fewer capillaries
Oxygenated blood exits through pulmonary vein into ____.
left atrium
Normally only what % of pulmonary capillaries are perfused
25%
why do we have high levels of carbon dioxide in alveoli
We have high levels when we do not ventilate alveoli.
3 ways that we can recruit the other 75% of all the capillaries we have in respiratory tree
- recruiting (opening) previously closed capillaries
- dilating capillaries that are open
- increasing pulmonary artery pressure
- As children approach puberty, risk of developing middle ear infections (otitis media) falls. Why?
More acutely angled Eustachian tube
- Your patient complains of a 3-day history of nasal drainage and nagging cough. They request a powerful cough suppressant, what is a possible significant negative consequence of its use?
Increased risk for respiratory infection.
Pulmonary arterioles ______in response to alveolar hypoxia
constrict
Fluid balance across lung tissue is regulated by:
hydrostatic pressure, colloid osmotic pressure, capillary permeability
what is hydrostatic pressure?
blood pressure vs tissue pressure, - pushes fluid to alveoli
what is Colloid Osmotic Pressure (oncotic)
related to protein concentration on either side of a membrane,pulls water back into vessel
when does colloid pressure change?
when protein concentration changes in blood
leakiness between endothelial cells lining capillaries
Capillary Permeability
what is ventilation?
Ventilation is the process of moving air into and out of the lungs
purpose for ventilation
Purpose is to provide for oxygen absorption from inspired air and removal of carbon dioxide to expired air.
Ventilation is influenced by
age, body shape and size, body position
