Gas Exchange in Mammals Flashcards
What are the parts of the gas exchange system in mammals?
Trachea
ribcage
intercostal muscles
bronchus
bronchioles
lungs
diaphragm
alveoli
What happens during inspiration?
The external intercostal muscles contract and that pulls the ribcage upwards and outward. The diaphragm contracts and flattens. This increases the volume and decreases the pressure inside the thoracic cavity. The air then moves into the thoracic cavity down a pressure gradient.
What happens during expiration?
The internal intercostal muscles contract and that pulls the ribcage downward and inward. The diaphragm relaxes. This decreases the volume and increases the pressure inside the thoracic cavity. The air then moves out of the thoracic cavity down a pressure gradient.
How are the alveoli adapted for gas exchange?
Many alveoli increase the surface area for gas exchange. They are one cell thick which decreases the diffusion distance. They have many capillaries which maintain a steep concentration gradient for diffusion.
What is the tidal volume?
The volume of air in each breath
What is the ventilation rate?
The number of breaths per minute
What is the Forced expiratory volume?
The maximum volume of air that can be breathed out in 1 second.
What is the Forced vital capacity?
The maximum volume of air that is possible to breathe forcefully out of the lungs after a deep breath in.
What is tuberculosis?
When the person becomes affected by the bacteria the immune system destroys the infected tissue and damages the gas exchange surface.
How does tuberculosis affect the lungs?
It decreases the tidal volume and means less air can be inhaled with each breath. This means the patient breaths faster to get enough air and the ventilation rate increases.
What is fibrosis?
The building of scar tissue in the lungs means they become less elastic and can hold less air.
How does fibrosis affect the lungs?
It decreases the tidal volume and means less air can be inhaled with each breath. This means the patient breaths faster to get enough air and the ventilation rate increases.
What is asthma?
During an asthma attack the the bronchioles contract and this releases a large volume of mucus. The mucus blocks the airways and reduces the airflow in the lungs. This leads to less oxygen moving through the alveoli and into the blood.
How does asthma affect the lungs?
Decreases FEV
What is emphysema?
When foreign particles cause inflammation and destruction of the alveoli. The decrease n the surface area of the alveoli decreases the diffusion of oxygen into the blood.
