T2 - the cardiovascular and respiratory systems Flashcards
True or False? The lungs allow gas exchange in humans.
True. The lungs are the gas exchange surface in humans.
What is the function of the trachea?
The trachea, or windpipe, connects the nose and mouth to the lungs/bronchi.
What are the alveoli?
Alveoli are tiny air sacs surrounded by a network of capillaries, serving as the site of gas exchange between the air and the blood.
Describe the role of the bronchi.
The bronchi (singular bronchus) branch off the trachea and carry air into the right and left lungs. They contain mucus to trap dust and pathogens.
Which process takes place at the alveoli?
The process that takes place in the alveoli is gas exchange.
True or False? Alveoli and surrounding capillaries are surrounded by multiple layers of cells to minimise diffusion distance.
False. Alveoli and surrounding capillaries are surrounded by single layers of cells to minimise diffusion distance.
What are the features of alveoli that make them an efficient exchange surface?
Alveoli are an efficient gas exchange surface because: They have a large total surface area, They provide a short diffusion distance, They have a good blood supply and good ventilation, maintaining a steep concentration gradient, They are lined with a layer of moisture in which gases can dissolve.
How is a steep concentration gradient for both oxygen and carbon dioxide maintained in the alveoli?
A steep concentration gradient for both oxygen and carbon dioxide is maintained in the alveoli as follows: Good ventilation means that a high concentration of oxygen and a low concentration of carbon dioxide is maintained inside the alveoli, A good blood supply ensures that blood is constantly flowing; this means that the blood immediately next to each alveolus is always low in oxygen and high in carbon dioxide.
How does a dense capillary network directly surrounding the alveoli help to increase the rate of gas exchange?
A dense network of capillaries directly surrounding the alveoli helps to maximise the rate of gas exchange by providing: a short diffusion distance between the alveoli and the red blood cells, a large surface area over which gas exchange can occur.
Why is a faster rate of gas exchange important during exercise?
A faster rate of gas exchange is important during exercise as a greater amount of oxygen is required for a higher rate of respiration in muscle tissues. There is also a higher quantity of carbon dioxide being produced which needs excreting from the body via the lungs.
True or False? The blood entering the capillaries in the lungs has a high concentration of carbon dioxide.
True. The blood entering the lungs has returned from the body where oxygen has been exchanged for the carbon dioxide produced in respiration. The carbon dioxide is then carried to the lungs where it is exchanged for oxygen again.
What is the function of the heart?
The heart is an organ that pumps oxygenated blood from the lungs to the rest of the body and deoxygenated blood from the body to the lungs.
Describe the pathway of deoxygenated blood through the heart from the body.
Deoxygenated blood from the body: Enters the right atrium through the vena cava, Flows through the atrio-ventricular valve into the right ventricle, Is pumped through the pulmonary semilunar valve into the pulmonary artery, To the lungs for oxygenation.
Why does the left ventricle have a thicker muscle wall than the right ventricle?
The left ventricle has a thicker muscle wall to pump oxygenated blood at high pressure throughout the body, while the right ventricle pumps deoxygenated blood at lower pressure to the lungs.
What role do valves play in the heart?
Valves in the heart prevent the backflow of blood, ensuring that blood flows in only one direction through the heart chambers and vessels.
