3.2 Human Gas Exchange Flashcards
(20 cards)
Outline the structures in the human gas exchange system.
- alveoli
- bronchioles
- bronchus
- trachea
- lungs
Describe the adaptations of the alveoli.
- many alveoli so increases the surface area : volume
- thin wall so short diffusion distance
- extensive capillary network maintains a steep concentration gradient
Describe the mechanism of inhalation.
- air moves into the lungs
- diaphragm contacts
- external intercostal muscles contact
- volume increases and pressure decreases in the thoracic cavity
Describe the mechanism of exhalation.
- air moves out the lungs
- diaphragm relaxes
- internal intercostal muscles contract
- volume decreases and pressure increases in thoracic cavity
What are some risk factors that increase the incidence of lung disease?
- smoking
- exposure to pollution
What is a correlation.
Correlation is an association or relationship between variables.
What is a causation.
A causation occurs when one variable is influenced by another.
What is ventilation/ breathing?
Movement of air into and out of lungs
Respiration is …
Chemical reaction to release energy in the form of ATP
Gaseous exchange is..
Diffusion of oxygen from the air in the alveoli into the blood/ diffusion of carbon dioxide from the blood into the air in the alveoli
What does extensive capillary network mean
Walls of the capillary are only one cell thick SO short diffusion distance
- allowing for a constant flow of blood through capillaries
How does gas exchange occurs in the alveoli
- High concentration of O2 in the alveoli so oxygenated air diffuses from the alveolar epithelium and into the blood into the capillaries
- High concentration of CO2 in the capillaries so CO2 diffuses from capillaries to alveolar epithelium and is then exhaled
Narrowing of the bronchiole effect one gas exchange:
- Decreases gas exchange as narrowing of the lumen
Smaller lumen SO less air leaving and entering the alveoli → concentration gradient is smaller
Effect breaking down of alveoli walls has on gas exchange
- Smaller surface area
- Thicker walls → can’t expand as much so ventilation decreases
- increases the SA:V ratio so longer diffusion distance
Pulmonary ventilation formula
Pulmonary ventilation = total volume (at rest) X ventilation rate (how quick ur breathing)
What is tidal volume
Volume of air that enters and leaves ur lungs at normal resting rate
Vital capacity
Max volume of air inhaled/exhaled
Residual volume
Volume of air left in lungs after the STRONGEST EXHALATION
total lung capacity
Vital capacity + residual capacity
What does a spirometer measure
Lung Capacity
