Mammal Gas Exchange

➢ Inhaled air enters the nasal cavity, where it is cleaned, warmed and humidified on its way through the pharynx.

Respiration begins with inhalation, which is an active motion that makes the diaphragm contract. When the diaphragm contracts it moves downward making the chest cavity increase. This causes air to enter in through the nose and/or mouth. The nose is the primary organ where the air enters and exits the body. The nasal cavity is lined with cilia and mucus that traps bacteria and foreign particles. The pharynx is a tube structure positioned behind the oral and nasal cavities. This allows air to pass from the mouth and nose to the lungs. The air travels through a thin like flap called the epiglottis which prevents food and drink from going into the lungs which is commonly known as going down the wrong pipe. The larynx, also known as the voice box, is a passage for the air to enter the trachea. The trachea is the tube that connects the throat to the Bronchi. The Bronchi splits

The human lung is a series of blind end tubes, hollow tubes that that allow for the conduction of air. The conduction of air starts from the nasal cavity or oral cavity, continues to flow through the trachea and bronchus and finally reaches the bronchioles that lead into the alveolus that allows for gas exchange to occur (Phalen et al. 1983). This system can be broken down into two different region; a conducting region and a region of gas exchange. The conduction portion of the respiratory system begins in the nasal cavity and the oral cavity and continues to the bronchioles. The transition from the bronchioles to the alveolar duct results in the transition from the conducting region of the respiratory

This is what enables the diffusion of oxygen into the blood and carbon dioxide out of the blood. Multi-cellular organisms have a greater number of cells and therefore a higher energy demand than single cellular organisms, this demand can only be met by allowing the cells to respire, a ventilation system therefore brings oxygen molecules which are a raw product of respiration into the haemoglobin of the blood to then be transported to tissues. Volume ratio is very low so if there was no ventilation system and the organism instead relied on the exchange of materials through the exposed skin it would be very difficult for the body to meet the high energy demand as less oxygen and carbon dioxide would be

Water has a significantly lower oxygen concentration than air, thus, it is harder to ventilate as it is far more thick. Because of this, fish must have a far more efficient gas exchange system which will allow them to obtain enough oxygen from the water. This is why fish have adapted to using the movements of their gill cover, swimming or the countercurrent flow to maintain the diffusion gradient of gases across the gas exchange surface. Whereas, mammals and terrestrial insects have tidal ventilation, which means that the air goes into the system the same way it comes out. Because of this, with each breath not all of the old air exits the body, hence, not all the air entering the body is new. For this reason, mammals and terrestrial insects are unable to extract the maximum amount of oxygen out of the air. Compared to fish, which have a far more efficient form of utilising the oxygen they extract than mammals and insects, as the fish have adaptations such as using the countercurrent flow, which makes the fish more efficient at obtaining oxygen into their bloodstream than insects or

Gaseous exchange for mammals occur in the organs called the lungs. The external opening (mouth and nasal passages) is connected by a system of airways which end in thin-walled alveoli

It exchanges oxygen and carbon dioxide between body tissues, outside air, and the blood. The main parts of the respiratory systems in the order of how they come in from the outside environment are: the nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles and finally the alveoli. The nasal cavity cleans, warms and moistens the air due to its cilia lining. The pharynx is the meeting place of the oral and nasal cavities and the larynx is the voice box. The trachea, or the windpipe, is a ciliated and mucus lined tube with cartilage rings supporting it on the outside. The trachea branches off into the two bronchi that lead into the lungs and then branch off into even smaller tubes called bronchioles that take the air to the alveoli. The alveoli are tiny air sacs found in the lungs where gas exchange occurs through

The respiratory system of a koala is very similar to humans. Their gas exchange is done by breathing into the lungs and breathing out the exchange of carbon dioxide. The oxygen that was breathed in, then goes into the bloodstream in the heart and is transferred through the body and exchanged. Their system includes a nose, nostrils, a respiratory tract, and lungs. The only difference between koalas and other mammals are that they lack "swell bodies" which are glands that regulate air flow between the left and right nasal cavities but it does not effect them as much.

Air goes in through the nose and passes down the trachea, larynx, pharynx, to the bronchus.

Polyglottos have comparatively small, non-inflatable lungs and nine air sacs that play a vital role in ventilation but are not directly involved in the exchange of

Mammals use a ventilation system to carry out gas exchange. Diffusion of the respiratory gases occurs because the body needs to get rid of the carbon dioxide (a product of cell respiration) through exhalation and needs to absorb oxygen as oxygen is vital for cell respiration to make ATP. Oxygen in the air is ventilated into the body by inhalation (moving air from the atmosphere into the lungs) through either the mouth or he nasal cavity, after which it travels down the trachea (throat) towards the lungs. The first thing the air comes in contract with is the bronchi, which are The airways of the lungs, after a person takes in a breath of air, the air travels through the nose or mouth, down into the trachea, The trachea then divides two main

Preventing the loss of water will ensure that gas exchange remains moist as it is required for efficient gas exchange. Another adaptation that insects have is the structural adaptation where their tracheae are highly branched to help increase the surface are to volume ratio. When the surface area to volume ratio is increased it becomes larger and this makes their gas exchange more efficient as it is a requirement of a gas exchange membrane. Insects have another structural adaptation where they have thin tracheoles. By having thin walls respiratory gases, oxygen and carbon dioxide can dissolve into the fluid and diffuse easily into the surrounding tissues. The surface of the insects tracheal tubes are lined with chitin in a spiral fold. Chitin, also known as taenidia, is a strong and light-weight material which acts as a reinforcing wire that keeps the insect's airways open while the body moves and allows some flexibility. Having chitin present in an insect's gas exchange membrane ensures that their gas exchange surface is well ventilated and that their concentration gradient is maintained. Gas exchange could be prevented without the taenidia as external forces such as body movements or gravity would compress the

This means that they are not limited to living only in an aquatic habitat or a terrestrial habitat unlike fish. Fish can only live in an aquatic habitat and have no special adaptations to live in a terrestrial habitat. A fish's gas exchange system requires water to support the fish's filaments and to hold the lamellae apart so that surface area can be kept large. If a fish were to live in a terrestrial habitat they would be permanently exposed to air. This air would then make the filaments and the lamellae stick together which would then greatly decrease the surface area to volume ratio. As a result, the efficiency of gases diffusing would reduce. Fish's gills would desiccate without the water to keep them moist so the respiratory gases would not be able to dissolve so it can diffuse into the blood. However, due to the process of counter-current flow, fish can take in more of the oxygen that is in water. This leads to a greatly efficient gas exchange. Mammals can avoid desiccation of their gas exchange system as the air they breathe in is warmed and moistened by the nasal passages as it enters the nostrils and the mouth. This allows the mammals to live in terrestrial or aquatic

As the years have passed animals have evolved from very simple animals to more advanced animals. Their individual respiratory systems have developed depending on their habitat. Even though the Orcinus lives in water and the Trochilidae lives on land their respiratory systems are worth observing, as we can see how specific organisms can develop different ways in which their respiratory systems evolved. By looking at the way they have evolved from past ancestors and how they are respectively similar. Looking forward into the way these to species have evolved we can create a deeper understanding of the respiratory system and how it has changed throughout the years. This paper will focus on how different their respiratory systems affect them with

Respiration is one of the most important processes done every day by every organism on earth. It involves two systems that are essential for living; the gas exchange and circulatory systems. While the basic concept is the same, animals don’t all use the way to diffuse oxygen (O2) into the blood. Animals also have different ways of using the O2 to keep their body functioning. Both Humans and Leopard Seals have lungs, but the way they survive and their use of their lungs and the O2 is different.