End of chapter 3 questions Flashcards
the structures below are found in the human brochial tree.
1. alveoli
2. trachea
3. bronchioles
4. bronchi
which of the following shows the route taken by air after it is breathed in through the mouth?
A. 2-3-4-1
B. 1-4-3-2
C. 2-4-3-1
D. 4-1-2-3
C. 2-4-3-1
Which of the following is NOT a feature of an efficient gas exchange surface?
A. thick walls
B. moist lining
C. close proximity to blood capilaries
D. large surface area
A. thick walls
chemicals in cigarrete smoke lead to the breakdown of the walls of the alveoli. what is the name given to this disease?
A. bronchitis
B. emphysema
C. coronary heart disease
D. lung cancer
B. emphysema
a student wrote the following about the lungs.
when we breathe in, our lungs inflate, sucking air in and pushing the ribs up and out, and forcing the diaphragm down. this is called respiration. in the air sacks of our lungs the air enters the blood. the blood then takes the air around the body where it is used by the cells. the blood returns to the lungs to be cleaned. when we breathe out, our lungs deflate, pulling the diaphragm up and the ribs down. the stale air is pushed out of the lungs.
the student did not have a good understanding of the workings of the lungs. Re-write thier description, using correct biological words and ideas.
when we breathe in, the external intercostal muscles between our ribs contract, pulling the ribs up and out. the diaphragm muscles contract, flattening the diaphragm. this increases the volume of the chest cavity, lowering the pressure there, and causing air to enter from outside the body, through the nose or mouth. this is called ventilation. in the air sacks of the lungs, oxygen enters the blood. the blood then takes oxygen around the body, where it is used by cells. the blood returns to the lungs, where carbon dioxide leaves the blood and enters the air sacks, when we breathe out, the external intercostal muscles relax and the rib move down and in. the diaphragm muscles relax, and the diaphrsgm returns to a dome shape. these changes decrease the volume of the chest cavity, increasing the pressure in the cavity, pushing air out of the lungs.
a man had a pneumothorax on the left side & his left lung collapsed.
explain why a pneumothorax caused the left lung to collapse.
pneumothorax: puncture in chest wall letting air into the pleural cavity
when the volume of the chest is increased by the movements of the ribs and the diaphragm, the drop in pressure in the chest cavity draws air into the pleural cavity through the puncture in the chest wall, instead of through the mouth or nose into the lung.
a man had a pneumothorax on the left side of his chest.
explain why the right lung was not affected.
pneumothorax: puncture in chest wall letting air into the pleural cavity
each lung is isolated from the other by being in a seperate pleural cavity, so a pneumothorax on one side will not affect the opposite lung.
pneumothorax: puncture in chest wall letting air into the pleural cavity
if a patient’s lung is injured or infected, a surgeon can sometimes ‘rest’ it by performing an operation called an artificial pneumothorax. what do you think might be involved in this operation?
a tube is inserted through the chest wall into the pleural cavity on the side of the injured lung. this stops ventilation in that lung, while the other lung will be ventilated normaly.
Briefly explain the importance of the following.
A. the trachea wall contains C-shaped rings of cartilage.
B. the distance between the air in an alveolus and the blood in an alveolar capilary is less than 1/1000th of a millimetre.
C. the lining of the trachea contains mucus-secreteing cells and cells with cillia
D. smokers have a lower concentration of oxygen in thier blood than non-smokers
E. nicotine patches and nicotine chewing gum can help someone give up smoking.
F. the lungs have a surface area of about 60 m2 and a good blood supply.
A. the rings support the trachea so that it does not collapse during inhalation.
the gap in the ‘C’ allows food to pass down the oesophagus, which runs next to the trachea without catching on the rings.
B. the short distance allows easy diffusion of oxygen into the blood, and diffusion of carbon dioxide out of the blood.
C. the mucus traps bacteria and dirt particles. the cillia beat backwards and forwards to sweep these out towards the mouth, preventing them from entering the lungs.
D. smoke contains carbon monoxide, which displaces oxygen from the haemoglobin of the red blood cells of the smoker.
E. the addictive drug in tabacco smoke is nicotine. smokers who are trying to give up can use patches or gum to provide the nicotine they normally get from cigarettes, reducing the craving to smoke.
F. the large surface area is provided by the alveoli. it allows for efficient diffusion of oxygen into the large blood supply, and efficient removal of the waste product, carbon dioxide.
explain the differences between bronchitis and emphysema.
bronchitis is a lung disease caused by irritation of the linings of the airways to the lungs, and may be made worse by bacteria infecting the bronchial system.
emphysema is a lung disease where the walls of the alveoli brak down and then fuse together, reducing thier surface area. (both diseases may be caused by smoking.)
