Structure and functions of living organisms - Humans Gas Exchange Flashcards
What is the role of diffusion in gas exchange
It allows the oxygen and C02 to pass in and out the blood stream into/from the alveoli
2.46 describe the structure of the thorax, including the ribs, intercostal muscles, diaphragm, trachea, bronchi, bronchioles, alveoli and pleural membranes
https://www.savemyexams.com/igcse/biology/edexcel/19/revision-notes/2-structure-and-function-in-living-organisms/gas-exchange/structure-of-the-breathing-system/
What is the role of intercostal muscles and the diaphragm in ventillation
The intercostal muscles and ribs move up and out/down and in and the diaphragm contracts /relaxes to create more/less space in the thorax, therefore lowering/raising the pressure inside.
How are alveoli adapted for gas exchange
1)They have a large surface area due to the walls inside them
2)They have a short diffusion pathway between the alveoli (1 cell thick) and the capillaries containing blood (1 cell thick) meaning that the CO2 and O2 can easily diffuse in and out of the alveoli
practical: investigate breathing in humans, including the release of carbon dioxide and the effect of exercise
This would be done by two people taking part in a varying length of time doing exercise. After each time the participants will breath in to a beaker and place the beaker covering the candle and see how long and time how long it takes for the candle light to go out. repeat this while increasing the time spent exercising proportionally
How to make this experiment more reliable and accurate: practical: investigate breathing in humans, including the release of carbon dioxide and the effect of exercise
Reliable: Repeat three times to remove any anomalies
Accuracy: Have the same length candle sticks, same types of candles, keep the room temperature and environment the same
What are the biological consequences of smoking in relation to the lungs for Bronchitis:
The cilia are destroyed by the chemicals inside a cigarette. This means that the mucus is not swept away from the lungs and remains to clog the air passages. Making it hard for oxygen to pass in and out of the lungs.
What are the biological consequences of smoking in relation to the lungs for Emphysema:
The tar inside the smoke from cigarettes destroys the walls inside the alveoli giving it a smaller surface area and therefore a lower rate of diffusion in and out of the bloodstream causing a decrease in the (amount) of oxygen that goes into the blood stream and is used in respiration for energy
What are the biological consequences of smoking in relation to the lungs for Lung Cancer:
A carcinogen (a chemical such as tar in cigarettes), causes cells to mutate and divide rapidly and loose their function, forming a tumor( a mass of cells formed from a mutated cell which has divided uncontrollably). This places pressure on organs.
What are the biological consequences of smoking in relation to the lungs for Carbon monoxide poisoning:
Carbon monoxide binds to the hemoglobin in red blood cells (forming carboxyhemoglobin). Meaning that the oxygen cannot bond to the hemoglobin in the red blood cells and therefore cannot be used in respiration to create energy for the body
What are the biological consequences of smoking in relation to the lungs for Coronary heart disease:
Fatty deposits start building up in the walls of the coronary arteries (arteries that supply the heart with oxygen). This can lead to clots forming in these arteries meaning that no blood can pass through them. If no oxygen can get to the heart, it can cause a heart attack. the size of the heart attack varies depending on how much of the heart cannot receive blood because of the blockage
