respiration Flashcards
what is the primary function of respiration?
gas exchange
where does gas exchange occur in mammals?
in the lung
what type of air gets inhaled during respiration?
o2 rich air
what type of air gets exhaled during respiration?
co2 rich air
what transports o2 and co2 in the body
blood
what happens to the air that flows through the nose?
clean the air of big dust particles and warms the air
what air flows through the nose, it passes through what?
the nasal septum and the nasal turbinates
what is the passage of air after it leaved the nose?
- pharynx
- larynx
- trachea until it finally reaches the lungs via the bronchi
what do the lungs and airways share the chest cavity with?
the heart, great vessels and esophagus
what do the airways consist of?
series of tube that branch and become narrower, shorter and more numerous as they penetrate into the lungs
what does the trachea divide into
2 main bronchi (one for each lung)
what does the main bronchi divide into?
lobar and segmental bronchi
how many lobar bronchi does the right lung have? why?
3 due to its 3 lobes
how many lobar bronchi does the left lung have? why?
2 due to its 2 lobes
what does the segmental bronchi divide into?
divide further into smaller branches
what is the smallest airway that does not contain alveoli?
terminal bronchioles
what is the pleura?
Thin cellular sheet attached to the thoracic cage interior and folds back upon itself, attached to the lung surface
what is the viscera pleura attached to?
surface of the lungs
what is the parietal pleura attached to?
interior throacic cage
wat is the pressure in the pleural space?
negative pressure
what are the airways divided into?
into 2 zones; conducitng and respiratory zones
what does the conducting airways consist of?
conducting airways consist of the airways from the mouth and nose openings, all the way down to the terminal bronchioles
what is conducted through the conducting airways?
air from the atmosphere to the respiratory part of the lungs
do the conductiive airways contribute to gas exchange
no
what is the condutive airways said to composed?
anatomical dead space
where does the repiratory part of the lungs begin?
begins where the terminal bronchioles divide into respiratory bronchioles,
what is found beyond the respiratory bronchioles?
the alveolar ducts lined with alveoli
what is the alveiolar region of the lungs for?
site of gas exchange
which zone takes makes up the greatest part of the lung?
respiratory zone due to high branching
what is The smallest physiological unit of the lungs
acinus
where is the acinus located?
distal to the terminal bronchioles
what are the 4 main functions of the conductive airways?
- defense against bacterial infection and foreign particles
- Warm and moisten inhaled air
- production of sound and speech by movement of passing air
- regulation of air flow
how can the conductive airways protect against bacteria?
the epithelial lining of the bronchi has hair-like projections and mucous is secreted to line the respiratory passage causing for foreign particles to stick to it and the cila sweeps mucous into the pharynx
what is the name given to the defense system of the conductive airways?
mucociliary defense system
how is airflow regulated in the conductive airways?
contaction or relaxation of the airwats to alter resistance to flow
how many alveoli are their in the human lung?
roughly 300 million
each alveolus may be associated with how many capillaries?
1000 capillaries
what type of blood is brought to the lungs via pulmonary circulation?
mixed venous blood
what happens to the mixed venous blood that comes to the lungs?
it gets oxygenated and then returns to the heart (left)
what does the broncial circulation involve?
supplies oxygenated blood from the systemic circulation to the tracheobroncial tree
what does the bronchiole circulation allow?
for the airways to get oxygenated
where does the pulmonary A. originate from?
from the left ventricle
branches of the pulmonary A. run with what?
the airways
what happens when the pulmonary A. branches. reaches the alveoli?
arterioles divied into capillaries within the alveolar walls
what does the pulonary arteries constitute?
the respiratory surface of the lungs where the gas exhange takes place
where does the oxygenated blood in the lungs come from?
alveolar capillaries
by what does the oxygenated blood of the lung leave to return to the left heart?
pulmonary veins
what supplies the airway walls of the lungs?
bronchial A that branch off of the aorta
is the bronchiole ciruculation part of the systemic circulation?
yes
how many different types of alveolar cells are there?
3 types
what are the 3 types of alveolar cells?
- epithelial type 1 and 2 cells
- endothelial cells
- alveolar macrophages
what do the alveolar epithelial cells form all together?
form a complete epithelial layer sealed by tight junctions
what is produced by alveolar epithelial type 2 cells?
pulmonary surfactant
what is the main function of pulmonary y surfactantf?
decreases the surface tension of the alveoli
what dot do the alveolar endothelial cells constitute?
constitute the walls of the pulmonary capillaries
what is the thickness of the endothelial cell walls?
as thin as 0.1 micron
what is the function of alveolar macrophages
These remove foreign particles that may have escaped the mucociliary defense system of the airways and found their way into the alveoli
how could the lung tissue be described?
elastic but unable to expand or contract by itself
how does air enter the lungs?
its sucked into the lungs
what allows to suck air into the lungs?
the respiratory muscles of the chest walls
what are the different types of respiiratory muscles?
inspiratory and expiratory muscles
what is the main inspiratory muscle?
the diaphragm
what innervated the diaphragm?
the phrenic n
C3-C5
What does contraction of the diaphragm cause?
its dome to descend and the chest to expand longitudinally and elevates the lower ribs because of the vertically oriented attachments of the diaphragm to the costal margins
the contraction of the external intercostal muscle allows what to happen?
raises the ribs during inspiration
what happens as the ribs elevate during inspiration?
the anterior-posterior and transverse dimensions of the chest enlarge
what muscles may assist in inspiration?
external intercostal diaphragm parasternal intercartilagenous mucle SCM scalenes
when do the accessory muscles of inspiration have the greatest involvement?
during ventilation
asthma
or in cases of obstructed airways
how are the neck muscles involved in inspiration?
elevate and fix the uppermost part of the rib cage, elevate the sternum, and slightly enlarge the anterio-posterior and longitudinal dimensions of the chest
is expiration active or passive during quite breathing?
passive
when does expiration become an active process?
higher levels of ventilation (exercise), or in pathological states when expiratory resistance increases and the movement of airflow out of the lungs is impeded
what are the muscles involved in active expiration?
internal intercostal muscles
abdominal muscles
what happens when expiratory muscle contract?
compress the abdominal content, depress the lower ribs, and pull down the anterior part of the lower chest
what happens to the diaphragm when expiratiory muscles are contracting?
gets pushed upwards
what are the muscles of expiration essential for?
- coughing
- singing
- talking
- vomiting
what can result in an enormous increase in pressure in the thoracic cage and abdomen?
Forced maximal contraction of the expiratory muscles against a closed glottis
what happens if valsalva’s maneuver is sustained?
this would lead to a decrease in venous return to the heart, thus a decrease in cardiac output due to constantly high pressure
summarize the events that happen in inspiration
- contraction of diaphragm and intercostal muscles
- expansion of throacic cage
- intrapleural pressure gets negative
- transpulmonary pressure increases
- expansion of lungs
- alveolar pressure < atmospherir
- air flows into the lungs
summarize the events that happen in expiration
- diaphragm and intercostal muscles stop contracting
- chest wall moves in
- intrapleural pressure returns to preinspiratory values
- transpulmonary pressure decreases
- lungs recoil
- air in lungs is compressed
- alveolar pressure > atmospheric pressure
- air flows out of the lungs
what does a spirometer measure?
measures volumes of inhaled or exhaled gas
what can the spirometer be used to measure?
measure tidal volume, vital capacity, inspiratory capacity, expiratory reserve volume, and inspiratory reserve volume
what cannot be measured using the spirometer?
It cannot be used to measure functional residual capacity, total lung capacity, or residual volume.
how does the spirometer function?
Basically a tube linked to a chamber with movable piston of known dimension.
○ We record the movement of the piston.
what does the vital capacity go from
super low to super high
what does the inspiratory capacity go from
low to super high
what does the functional residual capacity go from
hyper low to low