3.3.2 gas exchange systems Flashcards
(31 cards)
what are some adaptations of the trachea?
1) smooth muscular and elastic tissue enables control of diameter of airways.
2) mucus produced by goblet cells, which traps particles, viruses and bacteria.
3) cilia move to push mucus up and out airways.
what is the purpose of the cartilage rings?
prevents airways collapsing due to pressure changes. also, c shaped to allow for swallowing.
what are alveoli specialisations to improve gas exchange?
- endothelium wall of capillary is thin for short diffusion distance.
- RBC compressed against capillary wall for short diffusion distance.
- surfactant layer inside alveoli to prevent collapsing and sticking together.
- alveoli walls contain elastic tissue, enabling recoil for exhalation.
- epithelial wall of alveolus thin for short diffusion distance (one cell thick).
- narrow capillary lumen to slow down RBCs allowing more time for diffusion.
- network of capillaries allow constant blood flow, maintaining concentration gradient.
- large number of alveoli, providing a large surface area.
- squamous epithelial/endothelial cells.
what is respiration?
a series of chemical reactions to produce ATP.
what is breathing?
the movement of air in and out the lungs/body.
what is gas exchange?
the diffusion of gases between environment and transport systems/cells.
what’s the process of inhalation?
1) external intercostal muscles contract and raise ribs.
2) diaphragm contracts, flattens and pushes down digest organs.
3) volume of chest cavity increases.
4) pressure in chest cavity drops below atmospheric pressure.
5) elastic tissue between alveoli is stretched.
6) increase lung volume.
7) air moves into lungs.
what is the process of exhalation?
1) external intercostal muscles relax and ribs fall.
2) diaphragm relaxes and is pulled up by displaced organs.
3) volume of chest cavity decreases.
4) pressure in lungs increase and rises above atmospheric pressure.
5) recoil of elastic tissue between alveoli.
6) decrease lung volume.
7) air moves out of lungs.
what happens when the internal intercostal muscles contract?
ribs move down and in.
what happens when the external intercostal muscles contract?
ribs move up and out.
what happens to breathing during strenuous conditions?
- rate of inhalation and exhalation increases.
- depth of breath increases (intercostal muscle contraction and stronger diaphragm contraction).
what is pulmonary ventilation?
total volume of air that is moved into lungs per minute.
what is the equation for pulmonary ventilation?
pulmonary ventilation rate = tidal volume x breathing rate
what is tidal volume?
volume of air normally taken in at rest in one breath.
what is breathing rate?
number of breaths taken in a minute.
what is vital capacity?
maximum volume of air exhaled after forceful inhalation.
what is residual volume?
volume of air that cannot be expelled from lungs.
what is the equation for tidal (total) lung capacity?
tidal (total) lung capacity = tidal capacity + residual volume
what happens during exercise to pulmonary ventilation?
pulmonary ventilation rate increases.
- increase depth of tidal volume (using vital capacity).
- increase ventilation rate.
why does ventilation rate fall slowly after expertise?
- repay oxygen debt.
- anaerobic respiration causes increase in lactic acid, therefore lactic acid is oxidised in liver by extra oxygen.
what is the external structure of insects and what a pro and con of such?
exoskeleton: prevents water loss// acts as a barrier against gas exchange.
what is the gas exchange system in insects?
tracheal system.
what is the path of gas exchange in insects?
spiracle > trachea > tracheole > cells
what is present in insect tracheoles?
water as water diffuses out of cell by osmosis, which slows diffusion rate.
