Hi
Readers,
My
name is Franz Devantier, creator of this blog. I
am an Herbalist, who uses local and indigenous herbs when available, in
preference to imported herbs. Because
Herbalists deal with living human beings, it is important to have an
understanding of Anatomy and Physiology, as well as many other related subjects,
as well as many other related subjects.
Membranes
in the Ventral Body Cavity
All the walls of the ventral body cavity and the organs it
contains are covered by an extremely thin, double layered membrane. This membrane is generally called the “serous
membrane”. The part of the membrane
lining the cavity walls is called the “parietal serosa”, the part of the
membrane covering the organs is called the “visceral serosa”. Actually it is one membrane the “serous
membrane”, that folds double on itself, and covers both the walls of the
Ventral cavity “parietal serosa” and the organs of the ventral cavity the
“visceral serosa”. Visceral comes from
“Viscus”, which means an organ in a body cavity. Parietal comes from “parie”, which means
wall, and always refers or pertains to the walls of the cavity. So the serous membrane is divided into the
parietal serosa and the visceral serosa.
Think of the serous membrane like this. Imaging that the serous membrane was a
balloon that was only half inflated. Now
imaging that you can take you fist and push it right into the balloon. Imagine that the part touching your fist
corresponds to the visceral serosa, and the outer part that is separated by air
from your fist corresponds to the parietal serosa. However there are few differences, for
example: the part of the balloon that represents the parietal serosa, and lines
the walls of the cavity, is always fused to the cavity. The space between the parietal serosa and the
visceral serosa is not filled with air as in the balloon, but with a thin
lubricating fluid called; “Serous Fluid”.
This fluid is secreted by both sides of the membrane. There is a space between these two membranes,
but in reality they lie very close to each other.
The slippery serous fluid allows the organs to slide
without friction against the cavity walls, and one another, as the organs carry
out their routine activities. This
serous fluid between the two sides of the serous membrane is very important for
mobile organs like the heart and the churning stomach. Think about how painful it would be to breath
if this serous fluid were not between the two parts of the serous membrane to
allow the movement between the lungs and the wall of the chest.
Specific serous membranes are named after the cavity and
organs for which they are associated.
The parietal pericardium lines the pericardial cavity. The visceral pericardium covers the heart
within that cavity. So instead of
parietal serosa and visceral serosa, we have parietal pericardium and visceral
pericardium. The pericardium is the
cavity in which the heart is located.
Now let’s turn to the lungs. The parietal pleura lines the wall of the
thoracic cavity, and the visceral pleura covers the lungs. Remember that both of these are part of the
serous membrane, which is folded double, one part against the walls of the
cavity, and the other part covering the organ in the cavity.
Now let’s turn to the abdominopelvic cavity. The parietal peritoneum lines the walls of
the abdominopelvic cavity. The visceral
peritoneum covers most of the organs within that cavity.
When the serous membrane becomes inflamed, also usually has
a deficit of lubricating or serous fluid.
This condition can lead to excruciating pain, as the organs stick
together and drag across one another.
For example pleurisy, which is inflammation of the pleurae, means the
person will experience pain when breathing.
Peritonitis, which is an inflammation of the peritonea; in other words
the person will experience excruciating stomach pain.
Of course there are other body cavities as well, in
addition to the large closed body cavities.
There are also several smaller body cavities. These body cavities are mainly located in the
head, and open to the body exterior.
Oral and
digestive cavities:
Certainly the digestive cavity is like one long pipe that
starts at the mouth, and ends at the anus, where it opens to the exterior
again. The digestive cavity forms part
of and is continuous with the digestive organs.
The Oral cavity, called the mouth, contains the teeth and the tongue.
Nasal cavity:
The nasal cavity is located within and posterior (behind)
to the nose. The nasal cavity forms part
of the passages of the respiratory system.
Orbital cavities:
The orbital cavities or the orbits, house the eyes. The eyes are presented on the anterior
position of the head.
Middle ear
cavities:
The middle ear cavities are carved into the temporal bone
of the skull, and lie medial to the the eardrums. These middle ear cavities contain tiny bones
that transmit sound vibrations to the organ of hearing in the inner ears.
Synovial
cavities:
These are joint cavities that are enclosed within fibrous
capsules that surround the freely movable joints of the body, such as the elbow
and knee joints. Similar to the serous
membranes of the ventral body cavity, membranes lining the synovial cavities
secrete a lubricating fluid that reduces friction as the bones in the joint
move across each other. Try to imagine a
synovial cavity like this: imagine a soccer ball that has been deflated and
squashed flat. Now inside the ball we find
the membranes lining the synovial cavity, and between the two surfaces or
membranes we get the lubricating fluid.
Actually it is one continuous membrane, not two membranes. Also a Synovial cavity is a lot smaller than
a flattened soccer ball, and is not perfectly round. I think that I might need to draw pictures to
make these things easier to assimilate.
Franz Devantier.
