Download - Respiratory Sytem
-
7/23/2019 Respiratory Sytem
1/37
RESPIRATORY SYTEM
-
7/23/2019 Respiratory Sytem
2/37
Mammals breathe through an organ calledLungs. Air enters the lungs in a system of
passageways that arborize, branching like atrunk, branches and twigs of a decidous tree.At the end of the smallest passageways alveolilined by a respiratory epithelium are the sites
of gaseous exchange. Oxygen depleted andcarbon dioxide-enriched air, along withmetabolic water is exhaled via the same pathby which the air entered. [Video]
http://breathing%20respiration%20animation-part%202%203d-makemegenius.com%20series%20of%20education%20videos%20-%20youtube.flv/http://breathing%20respiration%20animation-part%202%203d-makemegenius.com%20series%20of%20education%20videos%20-%20youtube.flv/ -
7/23/2019 Respiratory Sytem
3/37
Usually exhibit
several lobes,asymmetrically,
with one more
on the right.
-
7/23/2019 Respiratory Sytem
4/37
However the lungs of a
number of aquatic and
terrestrial mammals are
not lobed.
Ex. Sirenians (sea cow/
dugong)
-
7/23/2019 Respiratory Sytem
5/37
And some are lobed on
the right side only
-are mammals that lay eggs.
Among the living mammals theyinclude the platypus and four
species of echidnas (or spiny
anteaters)
Ex. Monotremes
-
7/23/2019 Respiratory Sytem
6/37
Platypus
And some are lobed on
the right side only
Ex. Monotremes
-are mammals that lay eggs.
Among the living mammals theyinclude the platypus and four
species of echidnas (or spiny
anteaters)
-
7/23/2019 Respiratory Sytem
7/37
spiny anteaters
And some are lobed on
the right side only
Ex. Monotremes
-are mammals that lay eggs.
Among the living mammals theyinclude the platypus and four
species of echidnas (or spiny
anteaters)
-
7/23/2019 Respiratory Sytem
8/37
Left and right lung occupy separate pleural
cavities separated completely in the midline
by the mediastinum, a septum consisting of
loose (areolar) connective tissue that serves as
packing for all the organs of the thorax except
the lungs, and including principally the
esophagus, the heart within the pericardialsac, thymus, major descending and ascending
vessels, nerves and lymphatics, and the lower
end of the trachea.
-
7/23/2019 Respiratory Sytem
9/37
-
7/23/2019 Respiratory Sytem
10/37
Mediastinum
Anterior
Middle
Posterior
-
7/23/2019 Respiratory Sytem
11/37
The trachea divides into two primary bronchi,
each of which penetrates a lung at the hilus and
divides into one secondary bronchus for eachlobe, when lobe is present. These gives rise to
tertiary bronchi that branch and rebranch into
smaller and smaller passageway, the last of
which opens into several to a dozen thin walled
alveolar ducts.
-
7/23/2019 Respiratory Sytem
12/37*highlight the primary b.
-
7/23/2019 Respiratory Sytem
13/37
The walls of the bronchi and larger
bronchioles contain:
Smooth muscle fibers Connective tissue
Irregular cartilaginous plates
and lined with a ciliated pseudostratified
columnar epithelium cells
-
7/23/2019 Respiratory Sytem
14/37
As the branches becomes smaller, the cilia arelost, the epithelium becomes flatter, the
cartilage disappears, and then, in some
mammals atleast, the smooth muscle cells
disappear.
-
7/23/2019 Respiratory Sytem
15/37
The walls of the ducts are evaginated to form
clusters ofalveoli, or respiratory pockets,
estimated to number over 300 million eachhuman lung. It is these alveoli that gaseous
exchange takes place.
Alveoli are lined by a simple squamousepithelium(pavement cells) beneath which
is a rich plexus of capillaries held together by a
close network ofreticular connective tissue
fibers.
-
7/23/2019 Respiratory Sytem
16/37
Alveolar sacs consist of two or more alveoli
that share a common opening.
-
7/23/2019 Respiratory Sytem
17/37
Red blood cells in the capillaries take an
oxygen to form oxyhemoglobin, and carbondioxide and some metabolic water pass from
the blood plasma into the alveoli to be
exhaled
-
7/23/2019 Respiratory Sytem
18/37
The parietal peritoneum of each pleural
cavity lines the chest wall as the parietalpleura and covers the cephalic surface of
the diaphragm as the diaphragmatic
pleura.
-
7/23/2019 Respiratory Sytem
19/37
At the root of each lung, where the
primary bronchus and pulmonaryvessels enter and leave, the parietal
pleura is continuous with the
visceral pleura that lies on the
surface of the lung.
-
7/23/2019 Respiratory Sytem
20/37
The space between the parietal and visceral
pleurae is the actual pleural cavity. It
surrounds the lung except at the hilus. A
subatmospheric pressure exists in the pleuralcavity , and the higher normal atmospheric
pressure exerted via the passageway from
nares to alveoli keeps highly elastic wall of thelung in intimate contact with the thoracic wall
at all times, with only a thin layer of serous
lubricant intervening.
-
7/23/2019 Respiratory Sytem
21/37
The lubricant is a product of the pleural
mesothelium. The fluid minimizes friction
between lungs and chest walls as the latter
rises and falls with each inhalation andexhalation.
Inflammation of the pleura causes an increase
of fluid in the cavity, a condition known aspleurisy. Perforation of the thoracic wall and
the parietal pleura from a gunshot for
example allows atmospheric air to enter the
-
7/23/2019 Respiratory Sytem
22/37
The pleural cavity, resulting in deflation of the
lung on that side , a condition known as
pneumothorax.
-
7/23/2019 Respiratory Sytem
23/37
Lets listen to an explanation
-
7/23/2019 Respiratory Sytem
24/37
accomplished primarily by a
dome-shaped muscular
diaphragm (unique in
mammals) that functions as
a suction pump.
Anchored to the
xiphoid process of the
sternum ventrally
to a half dozen or so of thecaudalmost ribs and their
costal cartilages laterally
And to several of the more
anterior lumbar vertebrae
dorsally
The dome bulges
cephalad into the
thoracic cavity when
not under tension. Contraction of the
diaphragmatic muscles
flattens the diaphragm,
this further decreasesthe already
subatmospheric
pressure within the
pleural cavity.
-
7/23/2019 Respiratory Sytem
25/37
Consequently, normal
atmospheric pressure,
continually exerted via
the nares andrespiratory tract,
pushes more air into
the lungs to fill the
vacuum.
The diaphragm acts as a
suction pump because
it creates a vacuum that
causes air to be suckedinto the duct system.
-
7/23/2019 Respiratory Sytem
26/37
Is largely a passive phenomenon attributable
to the following:
1. Relaxation of the diaphragm, which returns it to
the domed position, decreasing the volume of thethorax and restoring (increasing) the pressure
around the lungs to the resting subatmospheric
level
2. the upward pressure exerted on the relaxing
diaphragm by the resuent abdominal viscera
which are under compression while the
diaphragm is flattened
-
7/23/2019 Respiratory Sytem
27/37
-
7/23/2019 Respiratory Sytem
28/37
3. resilience of the abdominal wall, which bulges
when the abdominal viscera are compressed
4. return of the ribs to a resting position as the
intercostal and supracostal muscles relax 5. elasticity of the lungs, which enables them to
conform to these changes.
-
7/23/2019 Respiratory Sytem
29/37
As a result, air is squeezed out of the lungs.
During forceful expiration, a in panting,
roaring, coughing, or when a trained singer is
performing, the abdominal wall participatesactively in the expulsion of air.
-
7/23/2019 Respiratory Sytem
30/37
-
7/23/2019 Respiratory Sytem
31/37
Marine mammals that seek their food in the
depths of the oceans have exceptionally
muscular diaphragms. The water spout of a
whale for instancethe sign that exhalation istaking place last 3-5 minutes.
-
7/23/2019 Respiratory Sytem
32/37
Also deep-sea foraging marine mammals do
not store oxygen in their lungs in anticipation
of a dive. While animal is breathing at the
surface, oxygen entering the lungs istransferred immidiately to rete mirabilia of the
blood stream. The animal then exhales before
comencing a dive and breathing may not takeplace again for as long as 2 hours. The lungs
collpase totally shortly after the dive gets
underway.
-
7/23/2019 Respiratory Sytem
33/37
END
-
7/23/2019 Respiratory Sytem
34/37
Some comparison
Lungs are like the gill of fishes, which extracts
oxygen. They have the same end product and
function, its just that the gill works on water
and the lungs does not.
Lungs differ from those of birds in that the
incoming air enters a system of passageways
that arborize, branching like a tree
-
7/23/2019 Respiratory Sytem
35/37
Mammalian lungs usually exhibit several
lobes, asymmetrically, with one more on the
right.
The
-
7/23/2019 Respiratory Sytem
36/37
why we couldn't breathe liquid unaided, as in
the film The Abyss; our lungs lack the power
needed to pump a dense fluid in and out
quickly enough by themselves.)
If you live in the sea, it makes sense to have
gills, right? Wrong. No. 1 on a recent list of
evolutionary mistakes was the fact thatwhales have blowholes, not gills.
http://www.newscientist.com/article/mg18925331.300-breathing-in-oceans-full-of-air.htmlhttp://www.imdb.com/title/tt0096754/http://www.wired.com/science/discoveries/magazine/17-08/st_besthttp://www.wired.com/science/discoveries/magazine/17-08/st_besthttp://www.wired.com/science/discoveries/magazine/17-08/st_besthttp://www.wired.com/science/discoveries/magazine/17-08/st_besthttp://www.imdb.com/title/tt0096754/http://www.newscientist.com/article/mg18925331.300-breathing-in-oceans-full-of-air.html -
7/23/2019 Respiratory Sytem
37/37
How about mammals under water
Adaptations of the Respiratory SystemThe BlowholeUnlike other mammals who breathethrough their nostrils and mouth, dolphins breathe through the blowhole, which is situated on
the top on its head. A reason for this difference is that the blowhole will facilitate the breathing
at the surface of the water. Since the blowhole is at the top of the head, only a small region of
the head is required to break the surface of the water to inhale air.
The dolphin starts to exhale before reaching the surface and this helps to reduce the amount of
time spent breathing at the surface. Dolphins can catch a breath about five times in a minute
before diving again, without hindering the progress of their swim. Usually, a dolphin breathes
two to four times each minute when it is swimming near the surface. It can hold its breath for
seven minutes or more when it is diving.
The LungsThe lungs of dolphins are not significantly larger or smaller than the land mammals.
Obviously, the size of the lungs does not determine the amount of oxygen that can be stored
and utilized.
However, the dolphin lungs contain a lot more alveoli (air cells) than human lungs do. Dolphin
lungs are made up of two layers of capillaries, and this arrangement increases the efficiency of
gas exchange since most mammals have only one layer of capillary. Therefore, this means that
the surface area of the lungs have been greatly increased and gas exchange can occur more
quickly.
The pleurae of dolphins are thick and elastic. The pulmonary tissue proper contains a generous
supply of myoelastic fibers for better elasticity. The bronchial tubes are lined with muscular
tissue. Tiny bronchioles are found together with sphincters that cut off the alveoli from the rest
of the lung.
These anatomical mechanisms attribute to a more efficient exchange of gas. In dolphins,
residual air - the fixed volume of air that always remain inside the lungs - never exceeds 15
percent of total capacity, and their vital capacity - the volume of air that is exchanged
frequently - is over 85 percent. In some cases, the vital capacity can even reach 92 percent.Normally in human, only 10 to 20 percent of the air in the lungs are exchanged. But in dolphins,
about 80 to 90 percent is renewed, so that their body can get as much oxygen as possible.
The respiratory system of whales certainly has some unusual features, but they are adaptations
to prevent water entering the airways: the nasal passages are complex and convoluted, and the
larynx (the upper end of the respiratory tube) extends up into the nasal cavity rather than
opening into the throat. Powerful muscles form a special plug within the blowhole, preventing
water from entering the lungs when the dolphin is underwater.