Topic 3A: Exchange and Transport systems Flashcards
Why do larger organisms need specialized exchange surfaces?
Larger organisms have a smaller surface area to volume ratio, so they need specialized surfaces for efficient gas exchange and nutrient absorption.
What is the relationship between surface area and the efficiency of exchange?
A larger surface area allows more molecules to be exchanged at once, increasing efficiency (e.g., in gas exchange).
What is the function of folds and villi in exchange surfaces?
They increase the surface area, enhancing the rate of exchange of gases, nutrients, and waste.
Why do multicellular organisms require transport systems?
To transport substances efficiently over longer distances to cells deeper within the body, due to limited diffusion rates.
What is gas exchange?
Gas exchange is the process of taking in oxygen and releasing carbon dioxide across an exchange surface, such as lungs or gills.
What factors affect the rate of gas exchange?
~Surface area
~Concentration gradient
~Thickness of the exchange surface
Why do exchange surfaces often have a thin membrane?
A thin membrane reduces the diffusion distance, making gas exchange faster.
What is the role of alveoli in the lungs?
Alveoli are tiny air sacs in the lungs where gas exchange occurs; they provide a large surface area and a thin barrier for efficient diffusion.
How is the concentration gradient maintained in gas exchange?
By constantly bringing in oxygen and removing carbon dioxide, maintaining a high concentration of oxygen in the alveoli and a low concentration of carbon dioxide.
How are the lungs adapted for efficient gas exchange?
The lungs have a large surface area (alveoli), a thin exchange surface (single-cell layer), and a good blood supply to maintain a concentration gradient.
What is vital capacity?
The maximum amount of air that can be exhaled after a maximum inhalation.
What is tidal volume?
The volume of air taken in or expelled during normal breathing (about 500 ml in an average adult).
How do bronchi and bronchioles contribute to gas exchange?
They distribute air to the alveoli, where gas exchange occurs. The bronchioles contain smooth muscle to regulate airflow.
How does asthma affect gas exchange?
Asthma causes the airways to narrow and swell, leading to difficulty in breathing and reduced oxygen intake.
How does chronic obstructive pulmonary disease (COPD) affect gas exchange?
COPD damages the alveoli, reducing the surface area for gas exchange, leading to a decrease in oxygen intake and carbon dioxide removal.
What are the main causes of emphysema, a form of COPD?
Smoking and long-term exposure to irritants cause the destruction of alveolar walls, reducing surface area for gas exchange.
How does pulmonary fibrosis affect the lungs?
It causes thickening and scarring of lung tissue, increasing the diffusion distance and reducing the efficiency of gas exchange.
What is lung cancer and how does it affect gas exchange?
Lung cancer involves the uncontrolled growth of cells in the lungs, which can block airways, damage alveolar structures, and impair gas exchange.
How can spirometry be used to diagnose lung diseases?
Spirometry measures lung volumes and airflow, helping to diagnose conditions like asthma, COPD, and restrictive lung diseases.
What does a reduced FEV1 (Forced Expiratory Volume in 1 second) indicate?
A reduced FEV1 can indicate airway obstruction, commonly seen in conditions like asthma and COPD.
What is the FEV1/FVC ratio and what does it indicate?
The FEV1/FVC ratio is the proportion of the forced vital capacity (FVC) that can be exhaled in 1 second. A low ratio suggests obstructive lung disease.
What can peak flow measurements tell us about lung function?
Peak flow measures the maximum speed of expiration and can help track asthma symptoms or monitor lung function in other conditions.
How is a dissection of a gas exchange system useful for understanding its function?
Dissection allows observation of the structure of organs involved in gas exchange (e.g., lungs, gills), helping to understand their function in vivo.
What are the key features of gills in fish that allow efficient gas exchange?
Gills have a large surface area, thin walls, and a countercurrent flow system, which maintains a concentration gradient for gas exchange.
Why is countercurrent flow important in fish gills?
Countercurrent flow allows the oxygen concentration in the water and blood to remain at different levels, ensuring efficient gas exchange.
How are tracheal systems in insects adapted for gas exchange?
Insects have a network of tubes (tracheae) that bring air directly to cells, reducing the need for a circulatory system to transport gases.
What is gas exchange?
The process of absorbing oxygen and releasing carbon dioxide through diffusion across a surface.
What is Alveolus?
Tiny air sacs in the lungs where gas exchange occurs between the air and blood.
What is Tidal volume?
The volume of air taken in or expelled with each normal breath.
What is Vital capacity?
The maximum amount of air that can be exhaled after a maximum inhalation.
What is Asthma?
A respiratory condition where the airways become inflamed and constricted, making it difficult to breathe.
What is Chronic obstructive pulmonary disease (COPD)?
A group of lung diseases that block airflow and make it difficult to breathe, often caused by smoking.
What is Emphysema?
A form of COPD where the alveolar walls are damaged, reducing surface area for gas exchange.
What is Pulmonary fibrosis?
A lung disease that causes scarring and thickening of lung tissue, impairing gas exchange.
What is Spirometry?
A test that measures lung function, including the volume of air a person can inhale and exhale.
What is FEV1 (Forced Expiratory Volume in 1 second)?
The amount of air a person can forcefully exhale in one second.
What is FVC (Forced Vital Capacity)?
The total volume of air that can be forcefully exhaled after a full inhalation.
What is Peak flow measurement?
A test that measures the maximum speed at which a person can exhale air from their lungs.
What is Countercurrent flow?
A mechanism in fish gills where water and blood flow in opposite directions to maintain a concentration gradient for oxygen diffusion.
What is Tracheal system?
A network of tubes in insects that allows for direct gas exchange with cells, bypassing the need for a circulatory system.
