Respiration is the process of supplying the body
with O2 and removing CO2.
* It has three basic steps:
1. Pulmonary ventilation or breathing
2. X (pulmonary) respiration
3. Internal (tissue) respiration
External
Pulmonary ventilation or breathing: is the
inhalation (inflow) and exhalation (outflow) of air
and involves the exchange of air between the
atmosphere and the X. Inhalation
permits O2 to enter the lungs and exhalation
permits CO2 to leave the lungs.
alveoli of the lungs
the alveoli of the lungs and the blood in pulmonary capillaries
pulmonary capillary blood
blood in systemic capillaries and tissue cells
The respiratory system consists of the nose, …. (throat), ….. (voice
box), trachea (windpipe), bronchi, and lungs.
pharynx
larynx
Structurally, the respiratory system consists of two parts:
upper and lower
The upper respiratory system includes the nose, nasal cavity, pharynx, and
associated structures;
(2) The lower respiratory system includes the larynx, trachea, bronchi, and lungs.
Functionally, the respiratory system also consists of two parts (or ‘zones’):
(1) The X zone: interconnecting cavities and tubes (outside and within the
lungs) that filter, warm, and moisten air and conduct it into the lungs. These include
the nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and terminal
bronchioles.
(2) The X zone: tubes and tissues within the lungs where gas exchange occurs.
These include the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli.
conducting
respiratory
Functions of the respiratory system:
blood pH
In pulmonary ventilation, air flows between the atmosphere and the alveoli of the
lungs because of X differences created by contraction and
relaxation of respiratory muscles.
alternating pressure
The air flows from HIGHER to LOWER pressure.
The rate of airflow and the
amount of effort needed
for breathing are also
influenced by:
airway resistance
Boyle’s law: the pressure of a gas in a closed container is inversely proportional to
the X of the container
volume
For air to flow into the lungs, the pressure inside the alveoli must become higher/lower than the atmospheric pressure.
lower
And, according to Boyle’s law, for the pressure of the gas (air inside the lungs)
to decrease, the volume of the container (lungs) must increase. how?
diaphragm and external intercostals (=muscles)
Because both, normal quiet inhalation
and inhalation during exercise or
forced breathing, involve muscular
contraction, the process of inhalation
is said to be active.
true/false
true
Normal exhalation during quiet breathing, unlike inhalation, is a passive process
because no muscular contractions are involved.
true/false
true
are combinations of different lung volumes
The apparatus used to measure volumes
and capacities is called a spirometer or
respirometer.
* The record is called a spiroX
gram.
Tidal volume (VT): the volume of X
one breath
Respiratory dead space (DS): portion of the tidal volume that X
remains in the conducting
airways does not take part in gas exchange
reaching the alveoli in each
inspiration:
Respiratory Rate (RR): x
Number of breaths per minute
Minute Ventilation (MV): x
the total volume of air inhaled and exhaled each minute
The alveolar ventilation (AV): the volume of air per minute that actually reaches x
the
respiratory zone
Inspiratory Reserve Volume (IRV): Maximum volume of air taken in a forceful
inhalation (except the tidal volume).
a maximal
inhalation.
SEE P 28