2. Exercise is the most influential
physiological stress on breathing
Exercise increases the
breaths/minute
Exercise increases the
amount of air in each breath
(tidal volume)
How is increased ventilation accomplished?
3. respiratory and cardiovascular systems make
adjustments in response to
the intensity of exercise
duration of exercise
same amount of blood pumped by the heart to the lungs
as to all the rest of the body
4. • As cardiac output rises, the pulmonary perfusion, increases
as well.
O2 diffusing capacity may increase threefold during
maximal exercise because more pulmonary
capillaries become maximally perfused.
Greater surface area available for diffusion of O2 into
pulmonary blood capillaries
5. When muscles contract during exercise,
they consume large amounts of O2
produce large amounts of CO2
During vigorous exercise,
O2 consumption and breathing both increase.
At the onset of exercise, an abrupt increase in breathing
is followed by a more gradual increase.
moderate exercise, the increase is due mostly to an
increase in the depth of breathing rather than to increased
breathing rate.
When exercise is more strenuous, the frequency of
breathing also increases
6. During light exercise
Ventilation increases linearly with
oxygen uptake and carbon dioxide
production
This increase in ventilation is
accomplished more by increased tidal
volume (breathing deeper in and out)
7. During higher exercise levels
Ventilation is increased more by increased
breathing frequency
This will keep the blood saturated with oxygen
because the blood is in the alveoli capillaries
long enough for the complete diffusion of
gases
8. Steady rate (moderate) exercise
sufficient oxygen is supplied to muscles
due to increased oxygen up take, there is little, or
no, build up of lactic acid in the muscles
some lactate will be produced and removed by
the blood stream
lactic acid is neutralized in the blood (this
reaction produces carbon dioxide as a by-
product)
increased carbon dioxide in the blood will
stimulate increased ventilation
Increased ventilation is accomplished by both
increased tidal volume and frequency
9. How does pulmonary ventilation
(breathing) increase during exercise?
1. During light exercise (walking)?
By increasing the tidal volume (breathing deeper)
2. During intense exercise (sprinting)?
By increasing the frequency of breathing
3. During steady state exercise (jogging)?
By increasing both the tidal volume and the
frequency of breathing
10. • The more gradual increase in breathing during
moderate exercise is due to chemical and
physical changes in the bloodstream, including
(1) slightly decreased PO2 , due to increased
O2 consumption;
(2) slightly increased PCO2 , due to increased
CO2 production by contracting muscle fibers;
(3) increased temperature due to the
liberation of more heat as more O2 is utilized.
11. During strenuous exercise, HCO3 buffers react
with H+ released by lactic acid in a reaction that
liberates CO2, which further increases PCO2 .
At the end of exercise
The initial decrease is due to changes in neural
factors when movement stops or slows;
the more gradual phase reflects the slower
return of blood chemistry levels and
temperature to the resting state.
14. EFFECT OF SMOKING ON RESPIRATION
(1) Nicotine constricts terminal bronchioles, which
decreases airflow into and out of the lungs.
(2) Carbon monoxide in smoke binds to hemoglobin
and reduces its oxygen-carrying capability.
(3) Irritants in smoke cause increased mucus
secretion by the mucosa of the bronchial tree and
swelling of the mucosal lining, both of which impede
airflow into and out of the lungs.
(4) Irritants in smoke also inhibit the movement of
cilia and destroy cilia in the lining of the respiratory
system.
(5) With time, smoking leads to destruction of elastic
fibers in the lungs and is the prime cause of
emphysema
15. Chronic obstructive pulmonary disease (COPD) is a
collective term for chronic bronchitis and
emphysema.
It is among the leading causes of disability and death
in the United States and is majorly caused by
cigarette smoking
Chronic obstructive
pulmonary disease
(COPD)
16. Hypoxia
A deficiency of O2 at the tissue level.
Based on the cause, can classify hypoxia into four
types,
Hypoxic hypoxia
a low PO2 in arterial blood as a result of high altitude, airway
obstruction, or fluid in the lungs.
Anemic hypoxia
Too little functioning hemoglobin is present in the
blood, which reduces O2 transport to tissue cells.
Causes are hemorrhage, anemia, and failure of
hemoglobin to carry its normal complement of O2, as
in carbon monoxide poisoning.
17. Ischemic hypoxia
blood flow to a tissue is so reduced that too little
O2 is delivered to it, even though PO2 and
oxyhemoglobin levels are normal.
Histotoxic hypoxia
The blood delivers adequate O2 to tissues, but
the tissues are unable to use it properly because
of the action of some toxic agent.
Cyanide poisoning, in which cyanide blocks an
enzyme required for the use of O2 during ATP
synthesis
18. Asphyxia
Condition of severely deficient supply of oxygen to
the body that arises from abnormal breathing.
An example of asphyxia is choking.
Asphyxia causes generalized hypoxia, which
affects primarily the tissues and organs.
Many circumstances that can induce asphyxia, all
of which are characterized by an inability of an
individual to acquire sufficient oxygen through
breathing for an extended period of time.
Asphyxia can cause coma or death.
19. Asthma
A disorder characterized by chronic airway
inflammation, airway hypersensitivity to a
variety of stimuli, and airway obstruction.
20. Emphysema
Blown up or full of air
A disorder characterized by destruction of the
walls of the alveoli, producing abnormally large
air spaces that remain filled with air during
exhalation.
With less surface area for gas exchange, O2
diffusion across the damaged respiratory
membrane is reduced.
Blood O2 level is somewhat lowered, and any
mild exercise that raises the O2 requirements
of the cells leaves the patient breathless.
21.
22. Pneumonia
An acute infection or inflammation of the
alveoli.
Certain microbes enter the lungs, they release
damaging toxins, stimulating inflammation and
immune responses that have damaging side
effects.
The toxins and immune response damage
alveoli and bronchial mucous membranes;
inflammation and edema cause the alveoli to
fill with fluid, interfering with ventilation and
gas exchange
