Transcript respiratory system

RESPIRATORY SYSTEM
LABEL THE DIAGRAM
http://www.smm.org/heart/lungs/vascular.htm
http://www.smm.org/heart/lungs/in-out-lungs.htm
FUNCTION
Brings air from the atmosphere to the lungs
Transfers oxygen into the blood
Removes carbon dioxide from the blood
Expels heat and water vapour in air breathed out
Allows vocal cords to create speech as air is breathed out
Mechanics of Breathing
Inspiration – breathing in
The diaphragm, an involuntary muscle, contracts
downwards, making the chest cavity larger.
Deeper breathing occurs when muscles across the ribs,
intercostal muscles, contract further enlarging the chest
cavity.
As the chest cavity becomes larger, air pressure inside
becomes lower and air is sucked in.
Expiration – breathing out
Air is expelled partly by the upward movement of the
diaphragm as it relaxes and partly by the elastic recoil of the
chest wall.
Oxygen and Waste exchange
The exchange of oxygen and carbon dioxide from blood to
lungs occurs between the alveoli and the large number of
capillaries that surround the alveoli.
Alveoli are air sacs found at the end of the bronchioles in the
lungs.
Lung Volumes during Exercise
Respiration Rate: Breaths per minute. Average adult at rest
– 12 to 18 breaths.
Tidal Volume: Amount of air breathed in and out per breath.
Ventilation: Amount of air breathed out per minute.
(ventilation = tidal volume x respiratory rate)
Vital capacity: Maximum amount of air breathed out after
breathing in the maximum amount. Closely related to chest
size. Larger people generally have a higher vital capacity.
Immediate responses to exercise
Vital capacity does not significantly increase with exercise or
training, but it can be decreased by smoking and asthma.
Respiration rate, tidal volume and ventilation all increase
with exercise, but do not determine sporting performance.
How efficiently your body uses the oxygen is far more
important.
Training will improve your mechanics of breathing therefore
less breathing has to be done to maintain oxygen supply.
Maximum Oxygen Uptake (VO2 max)
Maximum amount of oxygen that can be transported
and used by the muscles during exercise.
VO2 max is used as a measure of aerobic capacity or
aerobic endurance.
Measured in ml/kg/min. ml of oxygen per kg of body
weight consumed by the body per minute.
Factors affecting VO2 max
Your V02 max increases with aerobic training
Age - VO2 max declines gradually from about 25 years on.
Sex - Males tend to have a 10% higher level for a given age.
Females have lower haemoglobin levels. Females have smaller
heart and lung volumes. Females have lower blood levels
Heredity - VO2 max is largely genetically determined. Genetic
factors set the limits on how much an athlete can improve VO2
max values through training.
Immediate Responses (during exercise.) Acute
responses
Blood flow to working muscles increases
Heart rate increases
Stroke volume increases
Cardiac output increases
AVO2differences increases
Systolic blood pressure increases
Respiratory rate increases
Tidal volume increases
Ventilation increases
Oxygen uptake increases
Training effects Long term or chronic
Size of left ventricle increase
Number of blood cells increases
Blood volume increases
Haemoglobin increases
Resting heart rate decreases
Recovery rate increases
Stroke Volume increases
Cardiac output increases
AVO2differences increases
Risk of high blood pressure decreases
RESPIRATORY SYSTEM – Definitions.
Pathway of air from environment to lungs
Nose/mouth > pharynx > larynx > trachea > bronchi >
bronchioles > alveloi
Pleura – membrane surrounding lungs
Epiglottis - flap of skin guarding larynx
prevents food entering lungs
Average adult breathing
- 15 breaths per minute
- 6 litres of blood per minute passes through lungs
Major muscles used for respiration – diaphragm & intercostals
Muscles contract during inspiration and relax during expiration
When relaxed diaphragm becomes domed shaped forcing air
out of lungs
Air movement into lungs – air moves from high to low pressure
area. During inspiration diaphragm and intercostals contract
expanding the chest cavity. This results in low pressure area in
the lungs. As a result air is sucked into this low pressure area.
Gas exchange between blood and lungs takes place between
alveloi and capillaries.
Vital Capacity - Maximum amount of air breathed out after
breathing in the maximum amount.
Tidal volume - Amount of air breathed in and out per breath.
Residual volume – Volume remaining after maximum
inspiration
Ventilation - amount of air breathed out per minute
tidal volume x respiratory volume
Haemoglobin – carries oxygen in red blood cells
Oxygen cost of breathing – amount of oxygen used by
diaphragm and intercostals during breathing
Breathing control rate – controlled either voluntarily or in
voluntarily by brain sensing level of CO2 in blood. Brain signals
lungs to breathe faster as CO2 levels rise.