Unit 11 – Physiology of Human Body Systems
M3 – explain the need for ventilation systems in a multicellular organism
Multi-cellular organisms have a higher demand for substances and energy and the only way this
demand can be met is via respiration. The ventilation system brings oxygen through the respiratory
system, into the bloodstream and to the cells that require it.
As multi-cellular organisms we have a ventilation system as the air from the outside environment
has too big of a distance to diffuse through as well as holding a small surface area to volume ratio.
The cells that require substances would have to penetrate through all the skin cells before reaching
the cells that need the substances, and because of this they wouldn’t receive enough due to the skin
cells taking up most of it. Due to having such a large number of cells and all of them cells needing
oxygen, especially when they are working harder than usual, we need a respiratory system so them
cells are able to get a sufficient amount of oxygen near enough directly as it runs through the
bloodstream.
The nasal cavity is the main external opening of the respiratory system. The nasal cavity is lined with
hairs and mucus which help with trapping dust, so they don’t reach the internal organs. It is a hollow
space in the skull and nose, it warms and moisturises the air before it reaches the lungs.
The oral cavity is the second external opening of the respiratory system and can be used when the
nasal cavity isn’t fully functioning. Breathing through the oral cavity allows more air to enter as it’s
bigger in diameter but also has a shorter distance so the air can get to the lungs quicker. With the
oral cavity having a shorter distance to the lungs it isn’t as efficient as the nasal cavity at warming
and moisturising the air.
The pharynx is a long tube that acts as a passageway for air to get to the lungs and is divided into 3
parts. The nasopharynx connects with the nasal cavity, the oropharynx lies beneath the nasopharynx
and connects to the oral cavity. It acts as a passageway for air moving to and from the nasal cavity.
The hypopharynx is below the oropharynx and is where food and air crosses paths. So it’s function is
to guide food into the oesophagus and air into the larynx. This is assisted with the epiglottis, which
covers the larynx or oesophagus therefore stopping food or air incorrectly going down the wrong
tube.
The larynx connects the hypopharyx and trachea. It is used to breathe as it directs air to the lungs,
talk as it holds the voice box and swallow as directs food into the oesophagus. The larynx consists of
different cartilages which help it give it its shape; thyroid cartilage holds open the front of the larynx
and protect the vocal cords, cricoid cartilage which keeps the larynx held open.
…………………………………………………………………………………………………………………………………………………….
Thank you for previewing the example, feel free to buy the singular task, or the Unit 10 bundle xxx
M3 – explain the need for ventilation systems in a multicellular organism
Multi-cellular organisms have a higher demand for substances and energy and the only way this
demand can be met is via respiration. The ventilation system brings oxygen through the respiratory
system, into the bloodstream and to the cells that require it.
As multi-cellular organisms we have a ventilation system as the air from the outside environment
has too big of a distance to diffuse through as well as holding a small surface area to volume ratio.
The cells that require substances would have to penetrate through all the skin cells before reaching
the cells that need the substances, and because of this they wouldn’t receive enough due to the skin
cells taking up most of it. Due to having such a large number of cells and all of them cells needing
oxygen, especially when they are working harder than usual, we need a respiratory system so them
cells are able to get a sufficient amount of oxygen near enough directly as it runs through the
bloodstream.
The nasal cavity is the main external opening of the respiratory system. The nasal cavity is lined with
hairs and mucus which help with trapping dust, so they don’t reach the internal organs. It is a hollow
space in the skull and nose, it warms and moisturises the air before it reaches the lungs.
The oral cavity is the second external opening of the respiratory system and can be used when the
nasal cavity isn’t fully functioning. Breathing through the oral cavity allows more air to enter as it’s
bigger in diameter but also has a shorter distance so the air can get to the lungs quicker. With the
oral cavity having a shorter distance to the lungs it isn’t as efficient as the nasal cavity at warming
and moisturising the air.
The pharynx is a long tube that acts as a passageway for air to get to the lungs and is divided into 3
parts. The nasopharynx connects with the nasal cavity, the oropharynx lies beneath the nasopharynx
and connects to the oral cavity. It acts as a passageway for air moving to and from the nasal cavity.
The hypopharynx is below the oropharynx and is where food and air crosses paths. So it’s function is
to guide food into the oesophagus and air into the larynx. This is assisted with the epiglottis, which
covers the larynx or oesophagus therefore stopping food or air incorrectly going down the wrong
tube.
The larynx connects the hypopharyx and trachea. It is used to breathe as it directs air to the lungs,
talk as it holds the voice box and swallow as directs food into the oesophagus. The larynx consists of
different cartilages which help it give it its shape; thyroid cartilage holds open the front of the larynx
and protect the vocal cords, cricoid cartilage which keeps the larynx held open.
…………………………………………………………………………………………………………………………………………………….
Thank you for previewing the example, feel free to buy the singular task, or the Unit 10 bundle xxx
