GAS EXCHANGE Flashcards
What are 3 adaptations of exchange surfaces?
Thin walls for fast diffusion, large surface area for more diffusion, good blood supply to keep blood supply steep.
Explain the movement of breathing in:
- Diaphragm contracts and moves down
- External intercostal muscles contract causing ribs to move upwards
- your lung volume increases
- pressure inside the thorax decreases
Explain the movement of breathing out:
- Diaphragm relaxes moving upwards
- External intercostal muscles relax cause ribs to move down
- Lung volume decreases
- Pressure in the thorax increases
What is the inside of the thorax and outside of lungs separated by?
The pleural membranes
What is inside the pleural cavity?
The pleural fluid.
What is the purpose of the pleural membrane, cavity and fluid?
To provide lubrication.
What is the effect of exercise on breathing rate?
Faster and deeper. (In order to take in more oxygen and release more Co2)
What separates the trachea and oesophagus?
The epiglottis
What is the pharynx?
The junction between the trachea and oesophagus.
Name three chemicals in cigarettes.
Tar, Nicotine, Carbon monoxide
What are the effects of nicotine?
loss of appetite and increased heart rate.
How many carcinogens do cigarettes contain?
43
What is the effect of carbon monoxide?
It combines irreversibly with haemoglobin reducing the blood’s capacity to carry oxygen.
Explain emphysema:
Destruction of the alveoli reducing the surface area of alveoli, therefore limiting gas exchange. Patient may feel short of breath.
Explain bronchitis:
The cilia lining in the trachea becomes paralysed by the hot smoke meaning the passage narrows and causes a smoker’s cough.
