Exam 3 Review Flashcards
conducting airways – they do not participate in gas exchange.
Trachea to the terminal bronchioles
participate in gas exchange
Alveoli
• Alveoli participate in gas exchange
Connected to respiratory bronchioles (___) and alveolar ducts (____)
simple cuboidal epithelium. Simple squamous
alveoli, alveolar sacs, respiratory
bronchioles, alveolar ducts and a terminal bronchiole
• the functional unit of the lung
• wrapped in elastic C.T.
Pulmonary lobule
Alveoli are composed chiefly of _____ allowing for exchange of gases with pulmonary capillaries.
type I alveolar cells,
secrete surfactant that prevents collapse of the alveoli during exhalation.
Type II alveolar cells:
carry deoxygenated blood from
the right heart to the lungs for oxygenation
Pulmonary arteries
branch from the aorta and deliver
oxygenated blood to the lungs (primarily the muscular
walls of the bronchi and bronchioles)
Bronchial arteries
Ventilation-perfusion coupling: matches perfusion
(____) of areas in the lungs to ventilation
(___) in that area
blood flow. airflow
surface tension moves two
pleaural layers together.
Mechanical coupling:
Function of what:
Filter, warm, moisten incoming air Smell incoming air Resonating chamber
Nose
Function of what:
duct that drains secretions of the sinuses and tears into the nose. Increases turbulence
mixing air for moisture
and warmth
The Three nasal conchae (or turbinates):
It functions as:
a passageway for air and food
a resonating chamber
a housing for the tonsil
Pharynx
composed of 9 pieces of cartilage: connects the
laryngopharynx with the trachea (the “windpipe”). • prevents food and water from entering
the lower respiratory system • Resonating chamber
Larynx
The trachea is composed of 4 layers:
• a mucous secreting epithelium: mucosa
• three layers of CT (submucosa, hyaline cartilage, and adventitia).
Earth’s atmosphere is composed of
Nitrogen (N2) 78%
Oxygen (O2) 21%
Carbon Dioxide (CO2) 0.04%
Water Vapor variable, but on average around 1%
The gases of the atmosphere
have a____ and a_____
(5 x____)
mass. weight. 1018 kg
The atmosphere exerts a significant____ on every object on the planet through _____(force applied per unit area, P = F/A.) Measured by a barometer
force. air pressure
At sea level, the air pressure is:
760 mmHg = 1 atmosphere
At high altitudes, the atmospheric pressure is____;
descending to sea level, atmospheric pressure is____.
less. greater
apply equally to the gases of the atmosphere,
the gases in our lungs, the gases dissolved in the blood,
and the gases diffusing into and out of the cells of our
body.
Gas laws
applies to containers with flexible walls – like
our thoracic cage.
Volume and pressure are inversely related.
o If there is a decrease in volume – there will be an increase in pressure.
o V ∝∝ 1/P
Boyles laws
applies to a mixture of gases.
The pressure of each gas is directly proportional to the percentage of that gas in the total mixture: PTotal = P1 + P2 + P3 …
O2 = 21% of atmosphere, the partial pressure exerted by the contribution of just O2 (written pO2 or PAO2) = 0.21 x 760 mmHg = 159.6 mmHg at sea level.
Dalton’s law
Gas molecules diffuse from regions of
High pressure (concentration) to lower p (c)
deals with gases and solutions.
Increasing the partial pressure of a gas “over” (in contact with) a solution will result in more of the gas dissolving into the solution.
The patient in this picture is getting more O2 in contact with his blood - consequently, more oxygen goes into his blood.
Henry’s law
Reducing the vol in a container will ____ the pressure. Increasing the vol in a container will ____ the pressure.
Increase. Decrease
movement of air between the atmosphere and
the alveoli: inhalation and exhalation.
Ventilation
___ is the exchange of gases.
Respiration
(pulmonary) gas exchange between the alveoli and the blood.
External respiration
(tissue) gas exchange between the systemic capillaries and the tissues of the body.
Internal respiration
Changing the volume of the thoracic cavity (and the lungs – remember the mechanical coupling of the chest wall, pleura, and lungs), changes the____
pressure in the lungs.
primary muscle of respiration – all the others are accessory.
Diaphragm
The 3 other factors also affect the ease with which we ventilate:
Surface tension of alveolar fluid, Lung compliance, and Larger diameter of an airway
accounts for 2/3 of lung elastic recoil. Surfactant prevents the complete collapse of alveoli at exhalation, facilitating reasonable levels of work.
Surface tension of alveolar fluid:
means the lungs and chest wall expand easily.
Lung compliance
-> less airway resistance->greater flow of air
Resistance proportional 1/d4 same as blood vessels Regulated by smooth muscle
Larger diameter of an airway
About 70% of the tidal volume reaches the xxx
zone – the other 30% remains in the xxx zone
(called the xxx ).
respiratory. conducting. anatomic dead space
Dalton’s Law : The pressure of a specific gas is the
Partial pressure Pp
Gas xxx (like the AC
membrane) from greater partial pressure to lower partial
pressure.
Greater the difference=faster diffusion.
diffuses across a permeable membrane
moves from the alveoli into the blood
O2
moves into the lungs.
CO2
In the blood, a tiny amount of O2 is dissolved in the plasma. Most O2 (about 98.5%) is carried
Attached to Hb