Respiratory System EXAM III Flashcards
Why is it necessary to move CO2 out of the blood?
because it makes the blood acidic.
What is the purpose of the airways in the body?
to transmit, warm and humidify inspired air.
What are the airways lined with?
ciliated pseudostratified columnar epithelium with goblet cells.
What is the purpose of the cilia in the airways?
help to remove particles.
What is the purpose of the goblet cells in the airways?
to produce mucus that entraps and helps to remove debris.
What are the airways held open with?
bone in the upper airways and cartilage in the lower airways.
What is the path of air through the respiratory system?
a) nasal cavity
b) pharynx
c) larynx
d) trachea
e) Bronchus
f) Bronchioles
g) alveoli
What does the larynx include?
epiglottis, vocal cords, and glottis.
What does the trachea include?
cartilaginous rings, trachealis muscle.
ends in a bifurcation or split.
When is the trachea closed off?
during swallowing.
When is the esophagus closed off?
during breathing.
Why is there a sphincter at the top of the esophogus?
to reduce air flow to the stomach.
Describe the bronchi.
have cartilage, are a continuation of the trachea into the lungs.
Describe the bronchioles.
smooth muscle with no cartilage that are innervated by the autonomic nervous system.
Continuation of the bronchi.
Last place where the gas exchange does not occur.
What are the alveoli?
sac-like structures where gas exchange occurs. the functional portion of the lung.
What are the pores of Kohn?
pores that keep the alveoli from collapsing.
Describe the type I alveolar cells/pneumocytes.
made up of simple squamous epithelium.
used for gas exchange.
very thin.
Describe the type II alveolar cells/pneumocytes.
produce surfactant–a phospholipoprotein that reduces surface tension, keeps . the alveoli from collapsing, breaks H2O association.
What are alveolar macrophages?
found in the lumen of the alveolus and can wander.
perform nonspecific immunity.
Describe the diaphragm.
the primary muscle for inspiration. The phrenic nerves (C3-C5) stimulate the diaphragm.
What are the external intercostal muscles?
located between the ribs. Elevate the ribs upward and outward to expand.
What are the scalenus and sternocleidomastoid?
raise the sternum and elevate the ribs. Only used in strenuous breathing.
Describe the function of the abdominal muscles.
increase abdominal pressure and pressure on the thorax by pushing the abdomen.
What are the internal intercostal muscles?
pulls the ribs down and in, decreasing the volume of the thoracic cavity. Used only in active expiration.
What is the atmospheric pressure at sea level?
760 mmHg
How does the atmospheric pressure change as the altitude increases?
the pressure decreases.
What is the intrapulmonary pressure (intra-alveolar pressure)?
pressure within the alveoli. Equal to the atmospheric pressure. 760 mmHg
What is the intrathoracic pressure (intrapleural pressure)?
pressure within the thoracic cavity. Located between the lungs and teh chest wall.
usually around 756 mmHg.
What is the transmural pressure gradient?
the difference between the alveolar and pleural pressure.
What is the gist of Boyle’s law?
volume and pressure are inversely related.
Describe intrapleural fluid cohesiveness.
keeps teh thoracic walls and lungs in close proximity and lubricates.
What is ventilation an example of?
bulk flow of gases.
What conditions must be met for air to flow into the lungs?
the pressure at the alveolar level must be less than the atmospheric pressure.
What conditions must be met for air to flow out of the lungs?
the alveolar pressure must be greater than atmospheric pressure.
What do the muscles of respiration alter?
the volume of the thoracic cavity, which in turn alters the volume of the lungs.
What kind of process is inspiration?
an active process, meaning that the activity of muscles is required.
What happens when the thoracic cavity expands?
the volume in the interpleural space increases, decreasing the pressure to 754 mmHg, which also decreses the intra-alveolar pressure to 759 mmHg, so air flows down the pressure gradient.
Inspiration.
What kind of process is expiration?
a passive process, in the resting state.
What does expiration rely on?
the elastic fibers in the lungs for recoil. The alveolar pressure is 761 mmHg, which is greater than atmospheric pressure, 760 mmHg.
What is the pressure difference at the end of inhalation?
the alveolar pressure is equal to the atmospheric pressure.
What does a decrease in radius do to the air flow?
it diminishes the flow.
Describe asthma.
a smooth muscle problem in which the resistance to flow increases.
Describe bronchitis.
inflammation of the lining of the bronchi, in which the resistance to flow increases.
Describe emphysema
the collapse of smaller airways.
breakdown of alveolar walls leading to larger alveoli, but fewer alveoli. (less total surface area).
What happens to the arterioles when the bronchioles dilate?
they also dilate.
What does CO2 control?
the dilation of bronchioles. As blood flow increases, CO2 in the alveoli increases, which leads to increased dilation of bronchioles to improve airflow.
What is compliance?
how stretchy or willing to expand the lung is. Helps to determine recoil.
the more elastic the tissue, the more likely the alveoli will collapse.
What influences compliance?
the alveolar surface tension.
What does surface tension of water normally do?
would cause the alveoli to collapse.
How does the alveolar surface tension affect compliance?
it opposes expansion.
What does surfactin do?
helps to prevent the collapsing of alveoli.
Breaks water interactions and surface tension.
What is surfactant produced by?
type II alveolar pneumocytes.
When are type II alveolar pneumocytes produced?
at 8 months of gestation.
What is the law of laplace?
P=2T/r, where P=inward collapsing pressure, T=surface tension, r=radius of alveoli.
What does the law of laplace state?
the tendency to collapse is directly related to the surface tension and inversely related to the radius of the alveolus. **Surfactant reduces tension.
What does it mean that alveoli are interdependent?
if one starts to collapse, the other help to hold it open by equalizing the pressures.
What happens if babies are born before 8 months of gestation?
they suffer newborn respiratory distress syndrome.
How much of the body’s energy is used for resting breathing?
3%
What happens when there is a decrease in pulmonary compliance?
there is an increase in the work required.
up to 30% of energy consumption.
What happens if there is an inrease in airway resistance?
there is an increase in the work required.
Up to 30%
What happens if there is a decrease in elastic recoil?
there is an increase in the work required
Up to 30% of energy consumption.
involved in exhale.
Describe the increased need of energy with exercise.
increase in work required.
up to 30% of energy consumption.
energy needed for breathing larger volumes of air at a faster rate.
What is the normal volume of air in the lungs?
2 to 2.5 liters
What is the maximum capacity of air in the lungs?
males: 5.7 Liters.
Females: 4.2 liters.