respiratory histology/embryology Flashcards
What parts of the respiratory system make up the conducting zone
nasal cavity pharnyx larynx trachea bronchi bronchioles
what parts of the respiratory system make up the respiratory zone
respiratory bronchioles
alveolar ducts
alveolar sacs
alveoli
what are the parts of the upper respiratory system
nasal cavity and pharynx
what are the parts of the lower respiratory system
larynx
trachea
bronchioles
alveoli
What are the functions of the nose
warm (via rich capillary network)
humidify and filter incoming air (via ciliated mucus membrane)
What are the functions of the pharynx
passage way for food
passage way for air
what are the parts of the pharynx, and what kind of epithelium do they have
nasopharynx (pseudostratified columnar ciliated epithelium)
oropharynx (stratified squamous epithelium)
laryngopharynx (stratified squamous epithelium)
What are the three main cartilage of the larynx
epiglottis
thyroid cartilage
cricoid cartilage
what are the functions of the larynx
direct air to the trachea and food to the esophagus
false vocal cords close the trachea while swallowing
true vocal cords produce sound
What is the epithelium of the trachea like
ciliated pseudostratified columnar epithelium with goblet cells
what do the cilia of the trachea do
move mucus and trapped debris up the trachea and down into the esophagus
Right lung characteristics
shorter and wider than left three lobes (superior, inferior and middle) Two fissures (horizontal and oblique) displaced by the liver
left lung characteristics
longer and skinnier than right 2 lobes (superior and inferior) 1 fissure (oblique) displaced by the heart cardiac notch
what are the functions of the bronchial tree
distribute air through the lungs
filter incoming air
what is the path of air through the bronchial tree to the alveoli during inhalation
primary bronchi secondary bronchi tertiary bronchi bronchioles terminal bronchioles respiratory bronchioles alveolar ducts alveolar sacs alveoli
what is the alveoli
microscopic air sacs, the site of gas exchange
What are the four layers through which gases pass in the lungs into the blood
type 1 alveolar epithelial cell
basement membrane of alveolar cell
basement membrane of capillary cell
endothelial cell of capillary
what lines the alveoli, and what is its function
surfactant, it reduces surface tension and prevents closure
What is the basic transition of epithelial cells from the trachea to the alveoli
trachea and bronchi - ciliated pseudostratified columnar epithelium with goblet cells
bronchioles - simple cuboidal epithelium with clara cells
alveoli - simple squamous epithelium with surfactant
Gradual changes
What are the characteristics of the alveolar type 1 cells
line the majority of the alveoli
site of gas exchange
flat and thin
no mitosis
what are the characteristics of alveolar type 2 cells
do mitosis, create both type 1 and type 2 cells
produce surfactant
what are the properties of surfactant
90 percent lipids 10 percent protein
What is external respiratoin
gas exchange between capillaries and the environment
what is internal respiration
gas exchange between the blood and the cells
what are the three steps of external respiration
pulmonary ventilation (breathing)
gas diffusion across membranes and capillaries
transport of CO2 and O2 between alveoli and capillaries
what are the parts of the pleural cavity (place in which the lungs sit)
parietal pleura attached to the chest wall
visceral pleura attached to the lung
pleural fluid between the layers
diaphragm as the floor of the cavity
What are the cohesive forces of the lung and the chest cavity, and what do they ensure
the lung tries to collapse
the chest tries to expand
these cohesive forces ensure transmural pressure
what is pneumothorax
when air gets in the pleural space causing the chest and lung to become uncoupled and causes the lung to collapse
what is compliance of the lungs
measure of the expandibility of the lungs
what does low lung compliance cause
more work needed to expand the lung
what is resistance of the lungs
degree of ease of airflow
what affects resistance
number. length and diameter of the airways
what determines the diameter of the airways, and thus lung resistance
sympathetic = bronchodilation parasympathetic = bronchoconstriction
what determines the compliance of the respiratory system
compliance of the lungs
- surface tension of liquid in the lungs
- elastic recoil of the lungs
stiffness of the chest wall
what does emphysema cause in terms of respiratory compliance
emphysema causes an increase in compliance, meaning they easily inflate, but are hard to deflate
what does fibrosis cause in terms of respiratory compliance
fibrosis causes a decrease in compliance, making the lungs stiff and difficult to inflate
what causes us to inhale
diaphragm and external intercostals contract and cause the chest cavity to expand, increasing size of pleural cavity, lowering pressure of the pleural cavity, drawing air in
what causes us to exhale
passive - relaxation of the diaphragm of the external intercostals
forced - contraction of internal intercostals and abdominal muscles
decreases pleural cavity size
increases pleural pressure
forces air out
what is the main control center of respiration
medullary response center
what are the parts of the medulllary response center, and what are their functions
dorsal respiratory group - sets normal rhythm
ventral respiratory group - controls inspiration and expiration when demand increases
What do the pneumotaxic and apneustic centers or respiration control of the pons do
pneumotaxic - switch off inspiratory neurons
apneustic - prevents the pneumotaxic from switching off insiratory neurons
what is alveolar ventilation
the volume of fresh air introduced into the gas exchanging regions of the lungs per minute
MAV = rate x tidal volume - dead space
where does the majority of the air inspired go in the lungs
it goes to the smaller alveoli at the base of the lungs because of surfactant they are easier to expand. so the majority of the air goes into the base of the lungs
what cause O2 to move from the alveoli, into the capillaries
the partial pressure of O2 in the capillaries is lower (40 mmhg) that the partial pressure of O2 in the alveoli (100mmhg) pushing it into the blood
what causes CO2 to move from the capillaries into the alveoli
the partial pressure of CO2 in the capillaries is higher(45 mmhg) that the partial pressure of CO2 in the alveoli (40 mmhg) pushing it into the alveoli
what causes O2 to move from the blood into the tissues
the partial pressure of O2 in the blood is higher(100 mmhg) that the partial pressure of O2 in the tissues (40 mmhg) pushing it into the tissues
what causes the CO2 to move from the tissues into the blood
the partial pressure of CO2 in the blood is lower (40 mmhg) that the partial pressure of CO2 in the tissues (45 mmhg) pushing it into the blood
what helps the blood carry oxygen and carb0n dioxide
RBCs and their hemoglobin
what are the functions of RBCs
transport O2 and CO2 to and from the tissues
remove O2 and CO2 from the plasma, allowing gases to diffuse into the blood
how many O2 molecules can one hemoglobin carry
4
What are the two ways O2 travels in the blood
free in the plasma
bound to Hg on RBCs
what are the three ways CO2 travels in the blood
free in the plasma 7%
bound to Hg on RBCs 23%
as bicarbonate 70%
what allows the CO2 stored as bicarbonate to be transported out
Hg takes an H, and Cl- switches out for it
