2.3: Respiratory Physiology Flashcards
True or False: Humans do not have a storage area for gases and must continually acquire oxygen and rid the body of carbon dioxide.
True
What are the 4 steps in Respiration?
- Breathing: includes inspiration (breathing air in) and expiration (breathing air out)
- External respiration: gas exchange with the environment at a respiratory surface
- Internal respiration: gas exchange between blood and tissue fluid
- Aerobic cellular respiration: production of ATP (adenosine triphosphate) in cells
Describe Step 1 in Respiration.
- Breathing: includes inspiration (breathing air in) and expiration (breathing air out)
Describe Step 2 in Respiration.
- External respiration: gas exchange with the environment at a respiratory surface
Describe Step 3 in Respiration.
- Internal respiration: gas exchange between blood and tissue fluid
Describe Step 4 in Respiration.
- Aerobic cellular respiration: production of ATP (adenosine triphosphate) in cells
Gas exchange takes place by the physical process of ______.
diffusion
For diffusion to be effective, the gas-exchange region must be what 3 things?
moist
thin
large in relation to the size of the body.
The effectiveness of diffusion is enhanced by extensive vascularization of the lungs, and delivery of oxygen to cells is promoted by an oxygen carrying molecule, such as ______.
hemoglobin
___1___ is a rich source of oxygen compared to ___2___; however, it does have a ___3___ effect on respiratory surfaces.
- Air
- water
- drying
A human loses about ______ of water per day when the air has a relative humidity of only 50%.
350 ml
View of alveolus, magnified to show external respiration
True or False: Humans have lungs that are elaborately subdivided into small passageways and spaces.
True
It has been estimated that human lungs have a total surface area at least ______ the skin’s surface area.
50x
To keep the lungs from drying out, ___1___ is ___2___ as it moves through passageways leading to the lungs.
- air
- moistened
______ happens as the lungs move air into the respiratory tract (inhalation) and out of the respiratory tract (exhalation).
Ventilation
Ventilation happens as the lungs move air into the ___1___ and out of the ___2___.
- respiratory tract (inhalation)
- respiratory tract (exhalation)
A ______ environment is created inside the lungs by the pleural space, which means that the pressure inside this space is less than that of the atmosphere.
negative pressure
During ______, the rib cage lifts superiorly and anteriorly to open up and expand the lungs.
inhalation
A muscle called the ___1___ is a dome-shape at rest. The ___1___ is flattened as it contracts, pulling the lungs open.
- diaphragm
As the thoracic cavity expands and lung volume increases, the density of the gases filling the lungs ______.
decreases
When the air pressure outside of the lungs is ______ than inside (where there is negative pressure), air will naturally flow into the lungs.
greater
During ______, the rib cage is lowered, the diaphragm rises, the thoracic pressure increases, and air will naturally move out of the lungs where the pressure is lower.
exhalation
True or False: The lungs completely empty during each breathing cycle.
False. The lungs DO NOT completely empty during each breathing cycle.
What is incomplete ventilation?
The lungs not completely emptying during each breathing cycle.
Because of the incomplete ventilation method, the air entering ___1___ with used air remaining in the lungs. This helps to ___2___ and ___3___.
- mixes
- conserve water
- maintain a constant temperature
______ primarily accounts for the exchange of gases between the air in the alveoli and the blood in the pulmonary capillaries.
Diffusion
Atmospheric air contains little ___1___, but blood flowing into the pulmonary capillaries is ___2___.
- carbon dioxide,
- almost saturated with this gas
GRADIENT DIFFUSION: Atmospheric air contains little carbon dioxide, but blood flowing into the pulmonary capillaries is almost saturated with this gas. Therefore, carbon dioxide naturally diffuses out of the blood into the alveoli and then ultimately exhaled. This pattern is the reversed for oxygen. Blood coming into the pulmonary capillaries is oxygen-poor, and the alveolar air is oxygen rich. This causes the oxygen to naturally diffuse into the capillaries.
Red blood cell with hemoglobin to bind and carry oxygen in the blood
______ helps to assist natural diffusion.
Hemoglobin
Most oxygen entering the blood combines with ___1___to form ___2___.
- hemoglobin (found in red blood cells)
- oxyhemoglobin
Each hemoglobin molecule contains ___1___ chains, and each chain is folded around an iron-containing group called ___2___, which is the iron that forms a loose association with oxygen.
- four polypeptide
- heme
True or False: Since there are less than 10 million hemoglobin molecules in each red blood cell, each cell can only carry about 40 million molecules of oxygen.
False. Since there are about 250 MILLION hemoglobin molecules in each red blood cell, each cell can carry MORE THAN ONE BILLION molecules of oxygen.
In the tissues, some hemoglobin combines with carbon dioxide to form ______.
carbaminohemoglobin
______, helps to remove carbon dioxide from the tissues.
carbaminohemoglobin
Approximately 30% of carbon dioxide is transported this way.
carbaminohemoglobin
Most of the carbon dioxide is transported in the blood in form of the ______.
bicarbonate ion
___1___ is an enzyme in red blood cells that combines carbon dioxide and water to form the ___2___.
- Carbonic anhydrase
- bicarbonate ion
Carbonic anhydrase is an enzyme in red blood cells that combines ___1___ and ___2___ to form the bicarbonate ion.
- carbon dioxide
- water
Approximate ___% of carbon dioxide is carried freely in the blood.
10%
