Transcript The Respiratory System

The Respiratory System
Respiration
• Respiration is the interchange of gases
between an organism and the medium in
which it lives.
• Internal respiration is the exchange of
gases between the bloodstream and
nearby cells.
• External respiration is the exchange of
gases
between
the
lungs
and
bloodstream.
Purpose of the Respiratory
System
• To provide a constant supply of oxygen to
keep your body cells functioning
• To remove carbon dioxide from the body
cells
Internal Respiration
Exchange of O2 and CO2 between the Capillary and the Body Cell
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Organs of the Respiratory
System
Nose / mouth
Nasal cavity
Pharynx
Epiglottis
Larynx
Trachea
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Trachea
Bronchus (bronchi)
Bronchioles
Lungs
Alveoli
Pleura
Diaphragm
Organs of Respiration
• Mouth & Nose
– Brings air into the body
– Nasal hairs in nostrils trap dust
• Nasal Cavity
– Warms & moistens air
– Glands that produce sticky mucus line the
nasal cavity
– traps dust, pollen, and other materials that
were not trapped by nasal hairs .
Cont…
• Pharynx
– Tube-like passageway used by food, liquid, and air
.
– At the lower end of the pharynx is a flap of tissue
called the epiglottis(a thin piece of tissue behind the
tongue that prevents food or drink form entering the
lungs) .
• Larynx
– “Voice box”
– The airway to which two pairs of horizontal folds of
tissue, called vocal cords, are attached .
Cont…
• Trachea
– Air-conducting tube
– Connects the larynx with the bronchi
– Lined with mucous membranes and cilia
– Contains strong cartilage rings
– cartilage the strong white tissue that is
important in support and especially in joints
prevent the bones rubbing each other
Cont…
• Bronchi
– Two short tubes that branch off the lower end
of the trachea
– Carry air into the lungs.
– Singular – bronchus
• Bronchioles
– Tiny branches of air tubes in the lungs
– Connect bronchi to alveoli.
Cont…
• Alveoli
– Tiny, thin-walled, grapelike clusters at the end of
each bronchiole
– Surrounded by capillaries
– Where carbon dioxide and oxygen exchange take
place
– Singular – alveolus
• Pleura
– Membrane lining the lungs and chest cavity
Cont….
• Diaphragm
– Muscle wall between the chest and the
abdomen that the body uses for breathing
Block Diagram of Air Pathway
Lung Volumes and Capacities
Lung Volumes and Capacities
•
Important volumes to consider are shown in Figure. They are for a standard
70-kg male breathing at rest.
•
Tidal Volume (TV) 500 mL, is the depth of breathing or the volume of gas
inspired or expired during each respiratory cycle.
•
Inspiratory Reserve Volume (IRV) 3600 m L, is the maximal amount of
gas that can be inspired from the end-inspiratory position (extra inspiration
from the high peak tidal volume).
•
Expirarory Reserve Volume (ERV) 1200 mL, is the maximal amount of
gas chat can be expired from end-expiratory level (extra expiration from the
low peak tidal volume).
•
Residual Volume (RV) 1200 mL, is the amount of gas remaining in the
lungs at the end of maximal expiration (amount that cannot be squeezed out
of the lung). Even a collapsed lung contains 500 to 600 mL.
Lung Volumes and Capacities
Important capacities (addition of various lungs volumes) to consider are also
shown in the figure.
Total Lung Capacity (TLC) 600 mL, is the amount of gas contained in the
lungs at the end of maximal inspiration and is the sum of inspiratory capacity
(IC) and functional residual capacity (FRC).
Vital Capacity (VC) 4800 mL, is the maximal amount of gas that can be
expelled from the lungs by forceful effort from maximal inspiration.
Inspiratory Capacity (IC) 3600 mL, is the maximal amount of gas that can be
inspired from the resting expiratory level and is the sum of TV and IRV.
Functional Residual Capacity (FRC) 2400 mL, is the amount of gas
remaining in the lungs at the resting expiratory level (end-expiratory position is
used as a base because it varies less than the end-inspiratory state). It is the
sum of ERV and RV.
Relationship to digestive system
• Cellular respiration requires
glucose and oxygen to release
energy to the body
• Oxygen is provided by the respiratory
system
• Glucose is provided by the digestive
system
• (glucose is made during photosynthesis)