module 3.1 Mammals gas exchange and SA:V ratio Flashcards
Why do large organisms need a special exchange system?
The body can not rid of waste products sufficiently enouh via exchange due to being more than 2 cells thick.
If the body did not get rid of these waste products, they would build up and become toxic to the body.
Does a small organism have a small or big SA:V ratio?
Large as their surface area is quite large compared to the volume. if large enough the organism can supply its own cell with oxygen via its surface area.
Compare metabolical activity of an active and inactive organism:
A more active organism will have a higher metabolic activity as it has to deliver more oxygen and nutrients to active cells. Or for animals such as mammals, it can be needed to keep themself warm. An inactive organism will have a much lower metabolic rate.
list features of a good exchange system:
Short diffusion pathway, a large surface area, a good blood supply. A larger surface area means there is more space for molecules to pass through, a short diffusion pathway means that molecules can pass through easier (thin barrier), good blood supply means a constant high concentration gradient, so diffsion occours faster.
Structure of the lungs: What does each structure do?
Trachea, bronchi, bronchioles, alveoli. The trachea funnels inhaled air into the lungs, in which the bronchi then are smaller passages in which takes air further into the lungs. these passages get smaller into bronchioles until reaching the lungs.
Name the muscles between the ribs: (2 types)
External intercostal muscles, Internal intercostal muscles.
Explain how our ribs and body moves/acts to ventilate air into and out of our lungs:
for inhale: External intercostal muscles contract. internal intercostal muscles relax, ribs move up, diaphram contracts (flattens), volume of thorax increases, pressure in the chest cavity decreases, air moves into the lungs. The opposite happens for when we exhale.
DEFINE: Ventilation and inspiration:
Ventilation: The process by which air is constantly being moved in and out of the lungs. Inspiration is when air i forced into the alveoli as the pressure of the atmosphere is greater than the pressure inside the lungs.
What are goblet cells? what is ciliated epithelium Where are they found?
Goblet cells are cells in which secrete mucus to trap pathogens. Ciliated epithelium are epithelium cells possessing cilia in which wafts mucus from goblet cells up the airway to be swallowed and digested. They are found in the trachea, bronchus and larger bronchioles.
What are squamos epithelium cells? What are they good for? Where is it found?
Squamos cells are flattened/ very thin cells approx. one cell thick in which can provide a very short diffusion pathway for gas exchange in the alveoli. They are found in the capillary to form the endothelium and the alveolar wall.
what do elastic fibres do? where are they found?
Elastic fibres are able to stretch and recoil, which can stretch out the alveolar wall during inspiration and reduce the size of the alveolar wall during expiration, helping push air out. They are also found in veins and arterys, helping to maintain pressure in the arterys. in veins it is very thin to prevent from reducing blood flow.
What is cartilage? Where is it found? What does it do?
Cartilage is a strong connective tissue. Found in the trachea and bronchi, ring of cartilage helps to support the airway and prevent collapse during inspiration. Bronchioles and smaller structures do not have cartilage.
What is a spirometer? what does is it measure?
A spirometer is an apparatus used for measuring the volume of air inhaled and exhaled out of the lungs.
What is vital capacity? How do you measure this in a spirometer? What factors can effect somebodys vital capacity?
Vital capacity is the maximum volume of air that can be moved by the lungs in one breath.You measure this by taking a deep breath ad then expiring as much air as possible. Factors in which can effect someones vital capacity include age, gender, height, size and level of fitness/exercise.
What is someones tidal volume? What unit is these volumes measured in?
Tidal volume is the volume of air moved in and out with each (normal) breath. These volumes are measured in dm3.
