Pleural Space [HD]
Summary
TLDRDr. Ricardo Gonzalez Rafi and Jody Chapman explore the pleura and pleural space in this informative video. They explain the pleura's role in regulating lung pressure and the function of pleural fluid, which normally contains 8-10 mL per side in an adult, providing lubrication during breathing. The script delves into the mechanics of pleural fluid absorption and the consequences of pleural effusion, such as lung compression and shortness of breath, caused by disruptions in the pleural space. Clinical examples include effusions due to heart failure, tumors, and pneumonia, highlighting the impact of various diseases on pleural fluid dynamics.
Takeaways
- 📚 The pleura is a continuous membrane of cells that folds over itself at the apex and base of each lung.
- 🌐 The pleural space is a potential space between the parietal pleura (lining the chest wall) and the visceral pleura (lining the lungs).
- 🛠 The pleural space helps regulate pressure during breathing and provides lubrication for the lungs and chest wall as they move against each other.
- 💧 The pleural space typically contains 8-10 milliliters of fluid per side in an average-sized adult, serving as a lubricant for the pleural surfaces.
- 🧬 Pleural fluid is a clear plasma filtrate originating from small capillaries in the chest wall, containing solutes like sodium chloride, bicarbonate, glucose, and small amounts of protein.
- 🔬 Pleural fluid has equivalent glucose concentrations to serum but slightly higher concentrations of albumin and bicarbonate, resulting in an alkaline pH of about 7.6.
- 🔄 The pleural fluid provides mechanical coupling between the pleural surfaces, allowing for the transmission of forces and sliding during the breathing cycle.
- 💉 Pleural fluid is absorbed primarily through the mesothelial cells of the visceral pleura and exits via microscopic uni-directional valves known as lymphatic stoma in the parietal pleura.
- 🚫 A pleural effusion occurs when there is too much fluid in the pleural space, disrupting the mechanical coupling and causing the lung to pull away from the chest wall.
- 🏥 Clinical examples of pleural effusions include conditions that increase hydrostatic pressure (like heart failure), tumors obstructing lymphatic drainage, and inflammation from pneumonia.
- 🛑 A trapped lung occurs when the lung physically pulls away from the chest wall due to conditions like inflammatory, infectious, or neoplastic changes, leading to pleural effusion.
Q & A
What is the pleura and what is its function?
-The pleura is a continuous membrane of cells that folds over onto itself at the apex and base of each lung. It functions to help regulate the pressure inside and outside the lungs during breathing and provides lubrication for the pleural surfaces as they slide against each other during the breathing cycle.
What is the pleural space and where is it located?
-The pleural space is a potential space between the parietal pleura, which lines the inside of the chest wall, and the visceral pleura that lines the lungs. It is where the two pleural membranes fold upon themselves.
How much fluid is normally present in the pleural space?
-The pleural space is estimated to hold between eight and ten milliliters of fluid per side in an average-sized adult man.
What is pleural fluid and what substances does it normally contain?
-Pleural fluid is a clear plasma filtrate that originates from small capillaries in the chest wall and contains small solutes like sodium chloride, bicarbonate, glucose, and small amounts of protein including albumin. It also contains macrophages, lymphocytes, and mesothelial cells.
What is the normal pH of pleural fluid and why is it alkaline?
-The normal pH of pleural fluid is approximately 7.6, which is alkaline due to the increased bicarbonate concentration compared to serum.
How does the pleural space provide mechanical coupling during breathing?
-The fluid in the pleural space provides mechanical coupling between the two pleural surfaces, allowing instantaneous transmission of perpendicular forces between them, similar to how a damp glass coaster sticks to the bottom of a glass.
Where does pleural fluid come from and how is it absorbed?
-Pleural fluid originates from plasma filtrate drawn by a pressure gradient from the subpleural capillaries in the chest wall. It is primarily absorbed through the mesothelial cells of the visceral pleura and exits the space through microscopic unidirectional valves known as lymphatic stoma found in the parietal pleura.
What happens when there is too much fluid in the pleural space, causing a pleural effusion?
-When there is too much fluid, it disrupts the mechanical coupling between the chest wall and the lung, causing the lung to pull away from the chest wall. This can lead to shortness of breath and a feeling of fullness in the chest, as the lung tissue becomes compressed and alveoli are electively reduced.
What are some clinical examples of conditions that can cause a pleural effusion?
-Conditions such as heart failure, which increases hydrostatic pressure leading to fluid accumulation; tumors in the lung or chest wall obstructing lymphatic drainage; and pneumonia, which increases capillary permeability, can all cause pleural effusions.
What is a trapped lung and how does it relate to pleural effusion?
-A trapped lung occurs when certain conditions cause the lung to become unexpanded, physically pulling away from the chest wall and creating an imbalance of pressure that favors increased filtration of fluid into the pleural space, leading to pathologic pleural effusion.
Can pleural effusions occur even when pleural mechanics are normal?
-Yes, pleural effusions can occur when fluid formation within the thorax and absorption are intact, but excess fluid entry occurs via non-physiologic routes, such as peritoneal dialysis fluid entering the pleural space via diaphragmatic defects in liver disease.
Outlines
😀 Introduction to Pleura and Pleural Space
Dr. Jody Chapman and Dr. Ricardo Gonzalez Rafi introduce the pleura as a continuous membrane of cells that folds over itself, lining the chest wall and lungs. The pleural space, located between the parietal and visceral pleura, is a potential space that helps regulate lung pressure during breathing. It contains a small amount of fluid, estimated at 8-10 milliliters per side in an average-sized adult, which serves as a lubricant for the pleural surfaces as they slide against each other during the breathing cycle. Pleural fluid is normally a clear plasma filtrate, containing solutes like sodium chloride, bicarbonate, glucose, and small amounts of protein, including albumin. It also contains cells like macrophages, lymphocytes, and mesothelial cells in low numbers. The pleural space's mechanics involve the fluid providing mechanical coupling, allowing the transmission of forces between the pleural surfaces, similar to how a damp glass coaster sticks to a glass surface.
😨 Pleural Effusion and Its Causes
The second paragraph delves into pleural effusion, a condition where an excess of fluid accumulates in the pleural space, disrupting the mechanical coupling and causing the lung to pull away from the chest wall. This can lead to reduced lung expansion, shortness of breath, and a feeling of chest fullness. The paragraph discusses various mechanisms that can lead to pleural effusion, such as increased hydrostatic pressure in heart failure, tumor obstruction of lymphatic drainage, and increased capillary permeability due to inflammation or infection. Examples include transudative effusions in heart failure, exudative effusions due to tumors, and parapneumonic effusions in pneumonia. The concept of a 'trapped lung' is introduced, where conditions like inflammatory or neoplastic changes can encase the lung, leading to pleural effusion. Lastly, the paragraph touches on scenarios where pleural mechanics are intact, but pleural effusion occurs due to non-physiological fluid entry, such as peritoneal dialysis fluid entering the pleural space in liver disease.
Mindmap
Keywords
💡Pleura
💡Pleural Space
💡Pleural Fluid
💡Mechanical Coupling
💡Starling Forces
💡Lymphatic Stoma
💡Pleural Effusion
💡Transudate
💡Inflammation
💡Trapped Lung
💡Diaphragmatic Defects
Highlights
Introduction of the pleura as a continuous membrane of cells that folds over itself at the apex and base of each lung.
Definition of the pleural space as the potential space between the parietal and visceral pleura.
Explanation of the pleural space's role in regulating lung pressure during breathing.
Description of pleural fluid as a clear plasma filtrate providing lubrication for the pleural surfaces.
Estimation of pleural fluid volume, holding between 8-10 milliliters per side in an average-sized adult.
Composition of pleural fluid including small solutes, glucose, and proteins like albumin.
Mechanical coupling in the pleural space allowing transmission of forces between pleural surfaces.
Comparison of mechanical coupling to a damp glass coaster sticking to a glass surface.
Origin of pleural fluid from plasma filtrate drawn by pressure gradient in the pleural space.
Absorption of pleural fluid through the mesothelial cells of the visceral pleura and lymphatic stoma.
Discovery of fluid absorption via electrolyte coupling through mesothelial surfaces of both pleural layers.
Impact of pleural effusion on mechanical coupling and lung function, leading to shortness of breath.
Examples of conditions causing pleural effusion, such as heart failure and increased hydrostatic pressure.
Role of tumors in obstructing lymphatic drainage and causing pleural fluid accumulation.
Inflammation and infection increasing capillary permeability, leading to pleural effusion in pneumonia.
Concept of trapped lung and its relation to inflammatory, infectious, or neoplastic changes causing pleural effusion.
Existence of pleural effusion with intact pleural mechanics due to non-physiological fluid entry routes.
Example of peritoneal acidic fluid entering the pleural space in liver disease as a cause of pleural effusion.
Transcripts
hi my name is Jody Chapman and I'm here
with dr. Ricardo Gonzalez Rafi to give
you an inside look into the pleura and
the pleural space
what is the pleura exactly the pleura is
a continuous membrane of cells that
folds over onto itself at the apex at
the base of each lung
what is the pleural space well the
pleural space is a potential space
that's between the parietal pleura that
lines the inside of the chest wall and
the visceral pleura that lines the lungs
as the two pleural membranes fold upon
themselves what are the functions of the
pleura in the pleural space the pleural
space it helps regulate the pressure
inside and outside the lungs during
breathing it is thought that the fluid
in the space that provides lubrication
for the pleural surface is on the lungs
and the chest wall as they slide against
each other during the breathing cycle
how much fluid is in the pleural space
this virtual space is estimated to hold
between eight and ten milliliters of
fluid per side and an average-sized
adult man so it's not very much fluid
and under normal circumstances that
amount is held at a pretty fairly
constant volume what is plural fluid
what kind of substances would you find
in it normally pore fluid is a very
clear plasma filtrate if you will which
originates from small capillaries in
chest wall and it contains small solutes
like sodium chloride bicarbonate also
contains glucose as well as the small
amounts of protein including albumin and
when compared with serum pleural fluid
actually has their equivalent
concentrations of glucose but it has
slightly higher concentrations of
albumin and by car
in fact the increased bicarbonate
concentration results in an alkyl otic
pH of about seven point six under normal
conditions plural fluid also contains
macrophages lymphocytes and mesothelial
cells that are exfoliated from the
pleura and these are also found in
pleural fluid in low numbers under
normal circumstances generally under
1700 cells per cubic millimeter one of
the mechanics of the pleural space how
does it work the fluid in the pleural
space provides mechanical coupling
between the two pleural surfaces and it
actually allows instantaneous
transmission of perpendicular forces
between them what exactly do you mean by
mechanical coupling the mechanism of
mechanical coupling is similar to that
which occurs say when a glass coaster
sticks to the bottom of a slightly damp
glass you have a thin film of fluid
between the two smooth surfaces and and
this creates a partial vacuum that
forces the two surfaces to cling to one
another yet allows the two surfaces to
slide against each other
a similar situation occurs between the
two chloral surfaces during breathing as
the lungs expand and contract woman's
chest cavity
where does pleural fluid come from you
know for a very long time we weren't
exactly certain how this came about the
during breathing the recoil of the lungs
creates a negative pressure in the
pleural space especially towards the
apex of the lung and plasma filtrate is
drawn by a pressure gradient from the
sub pleural capillaries in the chest
wall and this fluid passes through the
mesothelial cells of the parietal pleura
into the pleural space by what are
called Starling or pressure related
forces so the volume of fluid in the
pleural space is maintained in
equilibrium under normal circumstances
so such that fluid inflow is proximate
to fluid absorption from the pleural
space how it's plural fluid absorbed
pleural fluid is primarily absorbs
through the mesothelial selling of the
visceral pleura fluid also exits the
space to these microscopic uni
directional valves that are in the
parietal pleura and they're known as a
lymphatic stoma and these lymphatic
stoma are really only found on the
parietal pleura the stoma stretch during
inspiration and allow cells and cell
debris and other particulate products
through it's been recently discovered
that fluid absorption from the pleural
space also occurs as a result of what's
called electrolyte coupling through the
mesothelial surfaces of both the
parietal pleura and the visceral pleura
we've gone over normal pleural fluid
mechanics when you have too much fluid
it's called a pleural effusion what
mechanics are broken when there's a
pleural effusion the sent film of fluid
between the parietal and visceral
pleural surface is it creates a partial
vacuum of negative pressure which forces
the surfaces of the pleura to cling to
one another if you have too much fluid
under pathologic circumstances this
disrupts the mechanical coupling between
the chest wall and the lung and the
pleural surface is no longer cling
together so the lung actually pulls away
from the chest wall
and this increased fluid into thoracic
cavity reduces the vital capacity of the
lung to fully expand during expiration
and this can lead to shortness of breath
and on occasion a feeling of fullness in
the chest the lung tissue in turn
becomes compressed by the effusion
causing an elective of the alveoli and
reduce ventilation to to the areas of
the lung that are being compressed could
you give me some examples of where you
would clinically see a pleural effusion
one mechanism of pleural effusion
formation is that it's caused by
conditions that increase hydrostatic
pressure in the case of heart failure
you have increased left ventricular
natural pressures which caused a back
pressure on the capillaries in the lung
and therefore you get interstitial
pulmonary flooding and this causes fluid
movement and accumulation by
transmutation into the pleural space the
nature of this fluid is that it's a very
low protein content and as such it's
usually referred to as a transudate
another example is when there's a tumor
in the lung or chest wall that's another
mechanism of pathologic formation of
pleural effusions and pleural effusion
can form as a result of impairment of
the lymphatic drainage a tumor in the
lung or in the chest wall can can
mechanically obstruct the thoracic
lymphatics causing a pleural fluid
accumulation by decreasing the rate of
absorption of pleural fluid that
normally occurs in cases of pneumonia
you commonly see pleural effusions what
causes an effusion in that case
inflammation can increase the
permeability or the leakiness of the
lung and the chest wall capillaries as a
result of inflammation and/or infection
so you write a classic example of this
mechanism of pleural fluid information
is Parana Monica fusion in the setting
of an infectious pneumonia you can have
an effusion when there's an unexplored
lung what is a trapped lung certain
conditions can cause the lung to become
unexpanded ballif you will in which case
the lung physically pulls away from the
chest wall causing an imbalance of
pressure which favours increased
filtration of fluid into the pleural
space and formation of pathologic
pleural effusion you can have
inflammatory infectious or neoplastic
changes which can encase the lung
surface leading to a trap lung with
subsequent formation of plural effusion
there are cases when there's a pleural
effusion and the pleural mechanics are
fine nothing's wrong with them where is
that fluid coming from that's correct
there are certain circumstances in which
the fluid formation within the thorax
and the absorption are intact there's
nothing wrong but the mechanism of
pleural effusion formation can occur as
a result of excess fluid entry via what
I would say are non physiologic routes
and the typical example of this can be
seen when peritoneal acidic fluid enters
the pleural space via defects in the
diaphragm in the setting of liver
disease such as cirrhosis I think
looking at these mechanisms from the
different perspectives that we've talked
about really helps conceptualize how
different disease processes can affect
plural flu information and I think it
helps the clinician conceptualize the
whole process better
you
浏览更多相关视频
Chest Tube Physiology Review
Pneumothorax - causes, symptoms, diagnosis, treatment, pathology
Development of the Respiratory System | Stages of Lung Development | Embryology
Pneumothorax Nursing, Pathophysiology, Interventions | Open vs Closed vs Tension Pneumothorax
Respiratory System of the Human Body - How the Lungs Work! (Animation)
Radiology of Thorax (Chest)
5.0 / 5 (0 votes)