Transport and Gas Exchange Flashcards
Respiration
The transport of oxygen to cells producing energy. Three processes: ventilation, gas exchange, cellular respiration
Ventilation
The exchange of air between lungs and atmosphere (through breathing)
Gas Exchange
Gas exchange: The exchange of oxygen and carbon dioxide in the alveoli (lungs) and in the bloodstream (by diffusion)
Cellular Respiration
The release of ATP from organic molecules (enhanced by oxygen – aerobic respiration)
Trachea
Tube that allows air to travel into and out of the lungs to and from the atmosphere
Lungs
Take in fresh air (oxygen) from atmosphere and get rid of carbon dioxide from blood
Bronchi
Tubes (right and left) that carry air into lungs (from trachea) and out of lungs
Bronchioles
Smaller tubes that carry air to and from the alveoli (from the bronchi) - ↑SA
Alveoli
Clusters of air sacs (↑SA) at ends of bronchioles - Gas exchange with the blood (O2 and CO2)
pneumocytes
Cells that make up the lining of each alveolus, (lining is VERY THIN - only one cell layer thick)
type I pneumocytes
squamous (flattened) and extremely thin to minimize diffusion distance and increase surface area for gas exchange; these cells are amitotic (do not divide)
type II pneumocytes
cuboidal with granules (store components to make surfactant); function is to secrete pulmonary surfactant - a liquid substance that reduces surface tension (ensuring all alveoli expand at the same rate and none of them collapse in on themselves due to unequal pressure) Note: these cells can divide and make both type I and type II pneumocytes if needed
Diffusion
net movement of anything from a region of higher concentration to a region of lower concentration; driven by a concentration gradient
Concentration gradient
Drives diffusion; results from the unequal distribution of particles between two solutions
Surfactant
a fluid secreted by the cells of the alveoli that serves to reduce the surface tension of pulmonary fluids; contributes to the elastic properties of pulmonary tissue, which prevent the alveoli from collapsing.
Surface area to volume ratio
cell membrane needs enough surface area to adequately exchange gases; as the sell grows -> surface area to volume decreases, reducing the rate of gas exchange
Squamous
flattened cell: type 1 pneumocytes
Cuboidal
cubed cell; pneumocytes type II
Inspiration
breathing in
a. Diaphragm muscles contract (flatten
downwards) and external (on outside)
intercostal muscles contract (pull ribs up
and out)
b. Thoracic cavity volume and lung volume
increase (pressure of air in lungs drops
below atmospheric pressure – air rushes in
through the mouth or nasal passage to equalize)
Expiration
(breathing out)
- Diaphragm muscles relax (curves upward), abdominal wall muscles contract (pushing diaphragm up), external intercostal muscles relax (ribs fall), and internal (on inside) intercostal muscles contract (pulling ribs back down)
- Thoracic cavity volume and lung volume decrease (pressure of air in lungs rises above atmospheric pressure – air rushes out to equalize)
External intercostal muscles
outside of ribs; contract during inspiration pulling the ribs up and out
Internal intercostal muscles
inside of ribs; contract during exhalation to pull the ribs back down
Diaphragm
underneath the lungs; function- assist during in/exhalation; contract downward and flatten during inhalation, relax and curve upwards during exhalation
Abdominal muscles
includes the diaphragm, contract and relax to assist with your breathing
Negative pressure mechanism
negative pressure is created when you inhale causing it to be like a vacuum in your chest cavity; draws air into the lungs
Atmospheric pressure
the pressure of the atmosphere
Thoracic cavity
chest cavity
Emphysema
a chronic/progressive disease where the walls of the alveoli are damaged (feeling of shortness of breath) - a form of COPD (chronic obstructive pulmonary disease)
- Healthy alveoli turn into large, irregularly shaped structures with gaping holes, ↓ elasticity (so ↑
total lung volume at rest)
- ↓ SA, ↓O2 can reach the bloodstream
- Causes: tobacco/marijuana/fumes/coal dust/air pollution
Elasticity
the rebound of the lungs after having been stretched by inhalation
Lung Cancer
is a cancerous growth (uncontrolled cell division) within the lungs
- Lung tissues become dysfunctional can lead to internal bleeding, coughing up blood, wheezing, respiratory distress, and weight loss
- Causes: carcinogens (smoking, asbestos)/air pollution/ certain infections/genetic predispositions
Malignant
Malignant cancer cells can take over healthy tissues of the bronchioles & alveoli
Metastatic/metastasize
cancer cells spread (metastasize) to the brain/bones/liver/adrenal gland
Carcinogen
Something that can cause you to have cancer
Ventilation Rate
The amount of air inhaled in a specified time period
Tidal Volume
the amount of air that moves in or out of the lungs with each respiratory cycle; around 500 mL in an average healthy adult male; approximately 400 mL in a healthy female
Spirometer
measures volume of gas inhaled/ expelled per breath
pressure
pressure drops below atmospheric pressure during inhalation; pressure rises above atmospheric pressure during exhalation (rushes out to equalize)
volume
thoracic cavity and lung volume increase during inhalation; they decrease during exhalation
