20. lungs are part of the respiratory
system, a group of organs and tissues
that work together to help breathing.
The respiratory system's main job is to
move fresh air into your body while
removing waste gases.
22. Through breathing, inhalation and exhalation, the respiratory system
facilitates the exchange of gases between the air and the blood and
between the blood and the body’s cells. The respiratory system also
helps us to smell and create sound.
. Inhalation and Exhalation Are Pulmonary Ventilation—That’s Breathing
External Respiration Exchanges Gases Between the Lungs and the
Bloodstream
Internal Respiration Exchanges Gases Between the Bloodstream and
Body Tissues
. Air Vibrating the Vocal Cords Creates Sound
Olfaction, or Smelling, Is a Chemical Sensation
23. External Respiration Exchanges Gases Between the Lungs and the Bloodstream
https://youtu.be/P_DdfXUK3xs
Inside the lungs, oxygen is exchanged
for carbon dioxide waste through the
process called external respiration. This
respiratory process takes place through
hundreds of millions of microscopic sacs
called alveoli. Oxygen from inhaled air
diffuses from the alveoli into pulmonary
capillaries surrounding them. It binds to
hemoglobin molecules in red blood cells,
and is pumped through the bloodstream
24. Internal Respiration Exchanges
Gases Between the Bloodstream
and Body Tissues
In this respiratory process, red
blood cells carry oxygen
absorbed from the lungs
around the body, through the
vasculature. When
oxygenated blood reaches
the narrow capillaries, the red
blood cells release the
oxygen. It diffuses through the
capillary walls into body tissues This Photo by Unknow n author is licensed under CC BY-SA.
25. . Air Vibrating the Vocal Cords
Creates Sound
Phonation is the creation of sound by
structures in the upper respiratory
tract of the respiratory system. During
exhalation, air passes from the lungs
through the larynx, or “voice box.”
When we speak, muscles in the
larynx move the arytenoid
cartilages. The arytenoid cartilages
push the vocal cords, or vocal folds,
together. When the cords are pushed
together, air passing between them
makes them vibrate, creating sound.
This Photo by Unknow n author is licensed under CC BY-SA.
26. Olfaction, or Smelling, Is a
Chemical Sensation
The process of olfaction
begins with olfactory fibers
that line the nasal cavities
inside the nose. As air
enters the cavities, some
chemicals in the air bind to
and activate nervous
system receptors on the
cilia. This stimulus sends a
signal to the brain
This Photo by Unknow n author is licensed under CC BY-SA.
28. ▪ The cardiac conduction system is a group of
specialized cardiac muscle cells in the walls of the
heart that send signals to the heart muscle causing
it to contract.
▪ The main components are :
▪ 1 .SA NODE
▪ 2 .AV NODE
▪ 3 .BUNDLE OF HIS
▪ 4 .PURKINJE FIBERS.
29. SA Node
SA NODE
▪ Is a collection of specialized Cells ( pacemaker
cells ) these pacemaker cells can spontaneously
generate electrical impulse ,resulting in atrial
contraction ,with blood moving from atria into the
ventricle.
30. Atrioventricular
node
A.V.NODE
▪ After the electrical impulse spread across the atria
,they converge at the atrioventricular node ,the
a.v.node acts to delay the impulses ,to ensure the
atria have enough time to fully eject blood into the
ventricle before ventricular systole.
31. Bundleofhis
▪ Is a continuation of the specialised tissue of the
a.v.node ,and serve to transmit the electrical
impulse from the a v.node to the purkinje fibers of
the ventricle.
32. Purkinjefibers
ARE A NETWORK OF SPECIALIZED CELLS ,THEY ARE
ABUNDANTWITH GLYCOGEN AND HAVE EXTENSIVE GAP
JUNCTION.
▪ These cells are able to rapidly transmit cardiac
action potential from bundle of his to the
myocardium of the ventricles.
33. ▪ The rapid conduction allows co- ordinated
ventricular contraction ( ventricular systole ) and
blood is moved from the right and left ventricles to
the pulmonary artery and aorta respectively.
