Respiration Gas Exchange
Summary
TLDRThis video covers the process of gas exchange in the human body, focusing on how oxygen and carbon dioxide are transported. It explains the journey of deoxygenated blood returning to the heart, traveling through the lungs to release carbon dioxide, and becoming re-oxygenated. The video also explores the role of hemoglobin in oxygen transport, carbon dioxide transport methods, and the relationship between carbon dioxide levels and blood pH. Finally, it touches on oxygen saturation levels and the importance of maintaining them for proper body function.
Takeaways
- 🌬️ Gas exchange involves the transportation of oxygen and carbon dioxide throughout the body via the lungs, heart, and tissues.
- 🫁 Deoxygenated blood, which contains higher concentrations of carbon dioxide, returns to the heart through the vena cava and is pumped to the lungs through the pulmonary artery.
- 💨 In the lungs, deoxygenated blood offloads carbon dioxide and absorbs oxygen, becoming oxygenated blood, which then returns to the heart through the pulmonary vein.
- 🫀 The heart pumps oxygenated blood through the aorta, arteries, and arterioles, eventually reaching tissues where oxygen is offloaded, and carbon dioxide is taken up.
- 🌡️ Partial pressures of oxygen and carbon dioxide in tissues and blood dictate the movement of these gases during exchange processes.
- 🩸 Oxygen is primarily transported in the blood bound to hemoglobin in red blood cells, while a small portion is dissolved in plasma.
- ⚛️ Carbon dioxide is mainly transported as bicarbonate in plasma, with smaller amounts bound to hemoglobin and dissolved in plasma.
- 🔄 Carbon dioxide and pH levels are closely related, with increases in carbon dioxide causing a drop in pH, making blood more acidic.
- 🧪 In the lungs, carbon dioxide in the blood is released into the alveoli for exhalation, and oxygen is absorbed into the blood to form oxyhemoglobin.
- 📊 Oxygen saturation refers to the concentration of oxygen in the blood, with normal levels being 95-100%.
Q & A
What is the primary focus of the video?
-The primary focus of the video is explaining the process of gas exchange in the body, specifically how oxygen and carbon dioxide are transported between the lungs, heart, and tissues.
How does deoxygenated blood return to the heart?
-Deoxygenated blood returns to the heart via venules and veins, entering either through the inferior or superior vena cava.
What happens to deoxygenated blood in the lungs?
-In the lungs, deoxygenated blood offloads carbon dioxide and gets re-oxygenated as it takes in oxygen, becoming oxygenated blood.
How is most oxygen transported in the body?
-Most oxygen is transported in the body bound to hemoglobin in red blood cells, where it can disassociate and be used by tissues.
What are the three mechanisms by which carbon dioxide is transported in the blood?
-Carbon dioxide is transported in three ways: dissolved in plasma (10%), bound to hemoglobin as carboaminohemoglobin (20%), and as bicarbonate in plasma (70%).
What role does carbonic anhydrase play in carbon dioxide transport?
-Carbonic anhydrase is an enzyme in red blood cells that facilitates the fast conversion of carbon dioxide and water into bicarbonate and hydrogen ions.
How does carbon dioxide affect blood pH levels?
-An increase in carbon dioxide leads to a higher concentration of hydrogen ions, which decreases blood pH and makes the blood more acidic. Conversely, a decrease in carbon dioxide increases pH, making the blood more alkaline.
What happens during gas exchange in the alveoli?
-In the alveoli, carbon dioxide is transported from the blood to the alveolus to be exhaled, while oxygen is inhaled and enters the bloodstream, primarily binding to hemoglobin in red blood cells.
What is oxygen saturation and why is it important?
-Oxygen saturation refers to the concentration of oxygen in the blood. It is important because it indicates how well oxygen is being transported to tissues, with normal levels ranging from 95% to 100%.
What is the next topic the video will cover?
-The next video will cover the control of respiration, which likely involves the regulation of breathing and gas exchange.
Outlines
🔬 Introduction to Gas Exchange in the Body
This paragraph introduces the video topic of gas exchange, focusing on how oxygen and carbon dioxide are transported throughout the body. It begins with the function of the lungs and heart, describing how deoxygenated blood travels to the lungs to release carbon dioxide and gain oxygen. The blood's journey continues as oxygenated blood is pumped back to the heart and then delivered to tissues through arteries, arterioles, and capillaries. The focus is on how oxygen is used by tissues and carbon dioxide is produced as a byproduct, which reenters the bloodstream for removal.
🌬 Transport of Carbon Dioxide in the Blood
This section explains how carbon dioxide, produced as a byproduct in tissues, enters the bloodstream for transport. It describes three main ways CO2 is carried: dissolved in plasma, converted into bicarbonate, and attached to hemoglobin. The majority of CO2 is converted into bicarbonate via a fast reaction catalyzed by carbonic anhydrase in red blood cells. The paragraph also covers the chloride shift mechanism that balances the exchange of bicarbonate and chloride ions in the blood. Lastly, it discusses the relationship between carbon dioxide and blood pH, where increased CO2 lowers pH, making the blood more acidic.
🫁 Gas Exchange at the Alveoli
This paragraph dives into the process of carbon dioxide offloading from the blood into the alveoli of the lungs, where it can be exhaled. CO2 is carried in several forms, such as bicarbonate, which reacts with hydrogen ions to form CO2 again. This process occurs quickly in red blood cells due to the enzyme carbonic anhydrase. Additionally, some CO2 is released directly from hemoglobin. After CO2 is removed, oxygen is inhaled and enters the bloodstream, where it binds to hemoglobin or dissolves in plasma. Oxygen transportation is primarily handled by hemoglobin, with only a small fraction dissolved in plasma.
Mindmap
Keywords
💡Gas exchange
💡Deoxygenated blood
💡Pulmonary circulation
💡Hemoglobin
💡Bicarbonate
💡Partial pressure
💡Alveoli
💡Oxygen saturation
💡Carbonic anhydrase
💡Respiration
Highlights
Introduction to gas exchange in the body, focusing on oxygen and carbon dioxide transportation.
Deoxygenated blood returns to the heart after tissues use oxygen, entering through the inferior or superior vena cava.
The heart pumps deoxygenated blood through the pulmonary artery to the lungs, where it offloads carbon dioxide.
Oxygenated blood returns to the heart via the pulmonary vein, ready to be distributed to the tissues.
Red blood cells play a major role in oxygen transport by binding oxygen to hemoglobin.
Oxygen dissociates from hemoglobin, enters tissues through plasma or interstitial fluid, and is used as energy.
Carbon dioxide, a byproduct of metabolism, is transported back to the lungs in various ways, including plasma and as bicarbonate.
The enzyme carbonic anhydrase in red blood cells speeds up the conversion of carbon dioxide and water into bicarbonate.
Carbon dioxide is transported as bicarbonate in plasma (70%), bound to hemoglobin (20%), and dissolved in plasma (10%).
Carbon dioxide and pH levels are closely linked; an increase in carbon dioxide lowers pH, making the blood more acidic.
In the lungs, carbon dioxide is exhaled and oxygen is inhaled, leading to gas exchange at the alveolar level.
Oxygen is primarily transported bound to hemoglobin in red blood cells (98%); a small amount is dissolved in plasma (2%).
The majority of carbon dioxide in the blood is transported in the form of bicarbonate via fast processes inside red blood cells.
Oxygen saturation refers to the concentration of oxygen in the blood, with normal levels being 95-100%.
The next video will focus on the control of respiration, expanding on the mechanisms discussed in gas exchange.
Transcripts
Armondo hustling on biology and medicine
videos please make sure to subscribe
join the forum and group for the latest
videos please visit Facebook Armando her
pseudonym
in this video we're going to look at gas
exchange so essentially we're looking at
how gases are transported around our
body the oxygen and carbon dioxide and
how our tissues receive this oxygen in
our lungs receive the carbon dioxide so
we can exhale it so let's just begin
this journey with the lungs here and
here I'm drawing the heart as well and
also tissues
so here is our tissue our heart and our
lungs after the tissue has utilized or
used oxygen the blood return will then
return to the heart the blood returning
to the heart is deoxygenated blood
because it contains you can say low
oxygen the oxygen has been used by the
tissue now the blood leaving the tissues
in order will be venules veins and then
as it enters the heart it can either
enter through the inferior or superior
vena cava so will enter the heart and
then from the heart the heart will pump
this deoxygenated blood through the
pulmonary artery so why is it called
deoxygenated blood well it's because we
have more concentration you can say of
carbon dioxide compared to oxygen or
it's properly said we have a higher
partial pressure of carbon dioxide
compared to oxygen that is why they are
deoxygenated as a deoxygenated blood
enters the lungs it will the blood will
offload the carbon dioxide and then the
lungs will re oxygenate the blood
essentially putting in more oxygen into
the blood forming oxygenated blood and
this oxygenated blood supply will then
go back to the heart through the
pulmonary vein so if we look at the
partial pressure of oxygen and carbon
dioxide again we can see that we have
higher amounts of oxygen compared to
carbon dioxide
so as this pulmonary vein brings this
oxygenated blood back to the heart
the heart can then pump this oxygenated
blood to tissues or around our body
first of all through the aorta then the
arteries then the arterioles where the
arterioles will then form capillaries
and then in and then into tissues and if
we look at the partial pressure of gases
in this oxygenated blood supply we can
see that we have
higher amounts of oxygen compared to
carbon dioxide and so within the tissues
again we have oxygen being offloaded
into the tissues so the tissue can use
it as energy and then carbon dioxide
release back into the blood as a
by-product and within the tissues if we
look at the partial pressure of the
gases we have slightly higher amounts of
carbon dioxide compared to oxygen carbon
dioxide and oxygen are transported
mostly within red blood cells now let's
zoom into this area here and see how the
red blood cells
offloads the oxygen to the tissues and
how the tissues will then offload the
carbon dioxide back to the blood and how
carbon dioxide is transported so zooming
into this area here we have the tissues
are the cells of the tissue and here I'm
drawing the lining of the blood vessel
so in red here this means that this is
here is the blood and here is the
interstitial fluid
let us firstly look at how oxygen enters
the tissue some oxygen can be dissolved
in plasma and can enter the interstitial
fluid and then can enter the tissue
where the tissue can utilize it as
energy
however most oxygen in our body is
transported in red blood cells
such as this one I am drawing here
oxygen is transported bound to a
molecule known as hemoglobin HB so here
is hemoglobin oxygen bound to hemoglobin
the hemoglobin and oxygen can
disassociate forming hemoglobin and
oxygen gas this oxygen can then enter
the interstitial fluid and then oxygen
can be used by the tissue okay
so that was the two ways oxygen enters a
tissue from the blood now let's look at
carbon dioxide because the tissues form
carbon dioxide as a by-product after
using oxygen
some of the carbon dioxide a little very
little amount can actually just enter
the blood and just be transported
through plasma some of it can re-enter
the blood react with water and through a
slow process form bicarbonate and
hydrogen ions and so carbon dioxide in
this case is being transported as
bicarbonate
however most of the carbon dioxide will
actually enter the red blood cells and
then here it will react with water
within red blood cells you have these
membrane bound enzymes called carbonic
anhydrase which will through a fast
process convert carbon dioxide and water
to form bicarbonate and hydrogen ion
exactly the same as the process that
occurred outside which was slow and then
bicarbonate can then be trying to pumped
out by the red blood cell into the
actual plasma and so be transported as
bicarbonate the transporter will take
bring in a chloride ion in exchange the
hydrogen ion here can react with the
hemoglobin molecule within the red blood
cell to form on the hydrogen hemoglobin
and then you have another mechanism
where the carbon dioxide can enter the
red blood cell and actually attach with
hemoglobin to form carbo amino
hemoglobin
so now if we will look if we're going to
look at the waste carbon dioxide is
transported in the blood we can we know
that there are at least three mechanisms
the first is that carbon dioxide can
dissolve in plasma about 10 percent of
it which is this one or carbon dioxide
can react with a hemoglobin within red
blood cells to form carbon Carboni amino
hemoglobin and this is about 20% of the
carbon dioxide being transported this
way and the last which is the majority
which is the major mode of
transportation for carbon dioxide is as
bicarbonate in plasma and this is about
70% of the carbon dioxide but again
forming bicarbonate there are two ways
one is that it can be formed in red
blood cells which is a fast process or
it can be formed in the plasma itself
which is much slower now it's also
important to understand that carbon
dioxide and pH is also very much related
if we have an increase in carbon dioxide
this will actually cause a decrease in
pH which means that it will make the
blood acidic if we have a decrease in
carbon dioxide this will make the blood
much more alkaline so an increase in pH
why is this well first of all let's just
pretend that we have more carbon dioxide
if we have more carbon dioxide this will
shift the reaction to form more
bicarbonate and hydrogen ions if we have
more hydrogen ions this just means that
it will be more acidic so that was
looking at how carbon dioxide gets
transported now let's look at how carbon
dioxide gets offloaded and then how
oxygen is transported in a bit more
detail so let's buy to look at this
let's let's go back to the lungs here
and zoom in the lungs are made up of
branches of bronchioles
and the ends of them called alveoli or
alveolar sac so the L vo this is cluster
of lvl alveoli they have blood supply
essentially the pulmonary artery coming
in and then the pulmonary vein leaving
so let us zoom into this area here where
gas exchange takes place within the
alveoli so here I'm drawing the cell
lining of one alveoli which is known as
an LV olace and then here I'm drawing
the boundary of the blood vessel and
here we can find the red blood cell so
here is the alveolus here is the blood
with the red blood cell and here's just
a fused membrane which is a thin gap
before we continue we have to understand
that the alveolus is the lung so it is
what it is a structure that receives the
carbon dioxide and that offloads oxygen
into the blood so let's first begin by
looking at how carbon dioxide is
transported from the blood back into the
alveolus into the lungs so that we can
exhale the carbon dioxide so if you
remember the previous diagram some of
the carbon dioxide is transported
through plasma so this carbon dioxide
can just enter the alveolus a majority
of the carbon dioxide is actually
transported if you remember in the blood
as bicarbonate and so this bicarbonate
can react with hydrogen ions in the
blood and through a slow process form as
an end product carbon dioxide and water
the carbon dioxide can then just enter
the alveolus of course some of this
actually a lot of it or however much of
this bicarbonate in plasma can actually
enter the red blood cells through a
transporter which will bring out
chloride ion an exchange within the red
blood cell bicarbonate can
react with hydrogen ion and through a
fast process and with the help of the
enzyme carbonic anhydrase the
bicarbonate hydrogen reaction can form
the carbon dioxide and water and it's
fast compared to the outside because of
an enzyme present and then this carbon
dioxide can then just exit the red blood
cell and enter the alveolus finally you
remember that some of the carbon dioxide
is transported in the blood bound to
hemoglobin as carbo amino hemoglobin and
so this will disassociate and then the
carbon dioxide after it's disassociated
with hemoglobin can then enter the
alveolus ok so now we have a lot of the
carbon dioxide in the alveolus our body
will our lungs will exhale this carbon
dioxide and then we'll inhale oxygen so
oxygen enters the alveolus and then
oxygen can be transported via two ways
small amount of oxygen will be
transported in plasma just enters the
plasma however most of the oxygen will
actually enter the red blood cell and
then bind to hemoglobin well hydrogen
bound hemoglobin and then this will form
essentially your oxyhemoglobin and so
this hydrogen ion will is the hydrogen
ion that supplies the bicarbonate
reaction here so again just to stress
what I'm trying to say oxygen transport
occurs through two ways it can be
dissolved in plasma which this is less
than 2% of oxygen is transported this
way most of the oxygen is bound to
hemoglobin which is 98% plus and this
brings us to the last concept which is
called oxygen saturation now oxygen
saturation is a kind of an important
term to know because it's essentially
referring to the concentration of oxygen
in the blood and normal blood oxygen
levels normal blood
oxygen saturation levels should be at
least 95 to 100 percent thank you for
watching hope you enjoyed this video on
gas exchange the next video we will look
at is control of respiration
you
تصفح المزيد من مقاطع الفيديو ذات الصلة
5.0 / 5 (0 votes)