Unit 11 assignment 5
Task 1
1.1) Outline the structure and functions of the respiratory system in humans. Use
a labelled annotated diagram for this and write an account.
The respiratory system is responsible for supplying the body with the oxygen that it
needs to function and respire. The biological system is made up of specific organs
which carry out gas exchange when animals or plants breathe. The speed that this
process happens is very dependent on the size of the organism and their environment.
Some animals and plants have specific adaptations to increase the speed that this
process can be carried out.
The lungs also work with the circulatory system to pump oxygenated rich blood around
the body, which makes its way back around with waste such as carbon dioxide for us to
exhale out.
The respiratory system consists of; Nasal cavity/oral cavity, Pharynx, trachea, carina of
trachea, left and right main bronchus, Bronchi, lungs and diaphragm. Air is taken in from
either one of the cavities into the Pharynx which allows movement of air from the
nose/mouth to the larynx. The trachea or windpipe allows the air to move down into the
bronchi through the main bronchus and the air is taken into the bronchioles which allow
gas exchange with blood: they have several branches which branch out into the alveoli
and alveolar infundibulum.
The alveoli act as the bridge between the lungs and the bloodstream, the oxygen in the
air that was inhaled is absorbed from here and carbon dioxide that is a waste product is
removed from here.. Although these are tiny microscopic air sacs, they are also known
as the workhouses of the respiratory system.
The air is taken in by the shift in pressure and volume in the ribcage. The diaphragm
aids in the main processes of inspiration and expiration.
, Unit 11 assignment 5
1.2) Explain what is meant by respiration and breathing.
Respiration is a chemical reaction that takes place in plants cells and animal cells, for
energy to be released from glucose so that all the other processes needed can happen.
This is the opposite to photosynthesis. On the other hand, breathing is a physical
process involving the movement of air in and out of the lungs to facilitate gas exchange.
1.3) Outline how inspiration and expiration are brought about.
Ventilation is the movement of air into and out of the lungs. This process includes both
inspiration and expiration.
Inspiration is when lung pressure is decreased below atmospheric pressure, causing air
to move into the lungs
Expiration is when lung pressure is increased above the atmospheric pressure which
causes air to be pushed out of the lungs.
This all works by a scientific law known as Boyle’s law, which states that as the volume
of the container (lungs) increases the pressure of the container decreases. They have
an inverse relationship.
1.4) Explain in detail why a multicellular organism like man/woman needs a
ventilation system.
The ventilation system in human beings is highly important as it is needed for us to
obtain oxygen for our body, and get rid of the waste product like carbon dioxide
Humans especially need this as they have a small surface area to volume ratio and a
large diffusion distance. Smaller organisms such as insects can breath through their
skin, however because we are much larger organisms diffusion is very inefficient as it
takes too long for the oxygen to diffuse through the body. The gap between our
epidermis and our cells is too large, hence we need a ventilation system to efficiently
supply our body with the oxygen it requires.
Task 1
1.1) Outline the structure and functions of the respiratory system in humans. Use
a labelled annotated diagram for this and write an account.
The respiratory system is responsible for supplying the body with the oxygen that it
needs to function and respire. The biological system is made up of specific organs
which carry out gas exchange when animals or plants breathe. The speed that this
process happens is very dependent on the size of the organism and their environment.
Some animals and plants have specific adaptations to increase the speed that this
process can be carried out.
The lungs also work with the circulatory system to pump oxygenated rich blood around
the body, which makes its way back around with waste such as carbon dioxide for us to
exhale out.
The respiratory system consists of; Nasal cavity/oral cavity, Pharynx, trachea, carina of
trachea, left and right main bronchus, Bronchi, lungs and diaphragm. Air is taken in from
either one of the cavities into the Pharynx which allows movement of air from the
nose/mouth to the larynx. The trachea or windpipe allows the air to move down into the
bronchi through the main bronchus and the air is taken into the bronchioles which allow
gas exchange with blood: they have several branches which branch out into the alveoli
and alveolar infundibulum.
The alveoli act as the bridge between the lungs and the bloodstream, the oxygen in the
air that was inhaled is absorbed from here and carbon dioxide that is a waste product is
removed from here.. Although these are tiny microscopic air sacs, they are also known
as the workhouses of the respiratory system.
The air is taken in by the shift in pressure and volume in the ribcage. The diaphragm
aids in the main processes of inspiration and expiration.
, Unit 11 assignment 5
1.2) Explain what is meant by respiration and breathing.
Respiration is a chemical reaction that takes place in plants cells and animal cells, for
energy to be released from glucose so that all the other processes needed can happen.
This is the opposite to photosynthesis. On the other hand, breathing is a physical
process involving the movement of air in and out of the lungs to facilitate gas exchange.
1.3) Outline how inspiration and expiration are brought about.
Ventilation is the movement of air into and out of the lungs. This process includes both
inspiration and expiration.
Inspiration is when lung pressure is decreased below atmospheric pressure, causing air
to move into the lungs
Expiration is when lung pressure is increased above the atmospheric pressure which
causes air to be pushed out of the lungs.
This all works by a scientific law known as Boyle’s law, which states that as the volume
of the container (lungs) increases the pressure of the container decreases. They have
an inverse relationship.
1.4) Explain in detail why a multicellular organism like man/woman needs a
ventilation system.
The ventilation system in human beings is highly important as it is needed for us to
obtain oxygen for our body, and get rid of the waste product like carbon dioxide
Humans especially need this as they have a small surface area to volume ratio and a
large diffusion distance. Smaller organisms such as insects can breath through their
skin, however because we are much larger organisms diffusion is very inefficient as it
takes too long for the oxygen to diffuse through the body. The gap between our
epidermis and our cells is too large, hence we need a ventilation system to efficiently
supply our body with the oxygen it requires.
