Respiratory System Flashcards
What is the pathway of air?
Nasal cavity
Pharynx
Epiglottis
Larynx
Trachea
Bronchi
Bronchioles
Alveoli
Nose
• Air enters the respiratory system through the nose and mouth.
• It is here that the air is warmed, filtered by tiny hairs and moistened.
• From the nose, the air passes through the throat (the pharynx).
Pharynx
The pharynx lies behind the nose and mouth and both cavities open into it.
• Both food and air pass through the pharynx, the food is then directed to
the oesophagus.
Larynx (voice box)
• The cavity of the larynx is separated from the pharynx by a flap known as the epiglottis.
• This prevents food from entering the windpipe (trachea), into the lungs
Trachea
• The trachea is approximately 10-12cm long.
• It is kept open by a series of rings of cartilage.
• It contains cells which remove foreign particles from the air.
•Inside the trachea is covered in small hairs called cilia.
•The cilia filter the air and catch dust and other particles.
• It contains cells which
remove foreign particles from the air.
•Inside the trachea is covered in small hairs called cilia.
•The cilia filter the air and catch dust and other particles
Bronchi
• The trachea divides into two bronchi.
• One leading to each lung.
• Each bronchi then breaks up into smaller tubes known as bronchioles.
Bronchioles
• The bronchial tubes further divide into
smaller tubes called bronchioles.
• Bronchioles are very narrow tubes less than 1mm in diameter.
• They then terminate into clusters of air sacs known as alveoli.
Alveoli
• Alveoli ‘grape like’ clusters at the end of the bronchioles.
• There are millions of alveoli in each lung and it is here that gaseous exchange takes
place.
• Gaseous Exchange is the transfer of oxygen and carbon dioxide through the walls of the alveoli
• Alveoli have large surface areas and thin walls.
• Are surrounded by a network of pulmonary capillaries.
Mechanics of breathing
- Lungs
Two ‘Bags’ in the chest, behind the ribcage, that fill with air. Filled with Bronchi, Bronchioles and Alveoli. - Diaphragm
A muscular partition which contracts and relaxes to cause inspiration and expiration. - Rib cage and Sternum
A cage of bone surrounding the lungs and vital organs. It can move up and down during breathing. - Intercostal Muscles
Muscles that lie in-between the ribs and help lift the rib cage during breathing.
What is pulmonary ventilation?
Process by which air is transported into and out of the lungs.
What are the two stages of breathing?
Inspiration/inhilation
Expiration/ exhalation
Inspirations - breathing in
The breathing muscles contract
Contraction of the diaphragm causes it to flatten moving down.
Contraction of the intercostal muscles cause the rib cage to rise.
The size of the chest cavity increases.
The chest cavity increases in volume as it expands.
Volume increases = Pressure decreases
Air is passively drawn (sucked) into the lungs.
High pressure outside to Low pressure inside the lungs
Expiration - breathing out
The breathing muscles relax
Diaphragm relaxes and returns to it’s dome
shape, pushing up.
The weight of the ribs draws them
downwards as the intercostals muscles relax.
The size of the chest cavity decreases
The chest cavity decreases in volume.
Volume Decreases = Pressure Increases
Air is passively expelled from the lungs.
Lower pressure in the bronchi and trachea to High pressure inside the lungs
During inspiration
Sternocleidomastoid and Pectorals
now contract to allow for a greater
increase in chest cavity size.
•More air therefore enters the lungs.
During expiration
The abdominal muscles contract
to help force air out of the lungs.
•What is normally a passive
process is now assisted by the
abdominals.
•This speeds up expiration.
Gas exchange
• Gaseous Exchange is the process by which
one type of gas is exchanged with another.
• This occurs by diffusion between air in the
alveoli and blood in the capillaries
• It and
• It surrounding their walls.
delivers oxygen from the lungs to the
bloodstream removes carbon dioxide from the
bloodstream to the lungs.
What features assist the process of gaseous exchange?
- The alveoli are covered in tiny capillaries (blood vessels). Gases can pass through the
thin walls and travel into the blood stream. - A large blood supply.
An increased red blood cell content increases the amount of oxygen supplied to
muscles and other body tissues. - Capillaries very near to alveoli, so diffusion distance is very short.
- Large surface area of alveoli allows diffusion to take place.
- Moist thin walls (one cell thick) of the cells promotes quick diffusion.
- Gases will always move from areas of high concentration to areas of a low
concentration.
Haemoglobin
• Haemoglobin carries oxygen around the body.
• It is a red pigment found in red blood cells.
• When haemoglobin and oxygen combine they create
oxyhaemoglobin.
• Carbon dioxide is also carried in this way.
What is a spirometer?
• A spirometer captures
inspired and expired air,
measuring and recording
volumes.
• A Spirometry trace is then
produced which can be
used to interpret the
various volumes
Total lung capacity
• The total amount of air that can be
inhaled after one long, deep breath.
Normally around,
• 6000cm3 for adult males
• 4200cm3 for adult females.
Vital capacity
amount of air forced from lungs by maximal respiration
Residual volume
• The amount of air that is left in the lungs after maximal expiration.
• There is no change during exercise.
• There is always some air left in the lungs.
What does total capacity equal?
Vital capacity + residual volume
Expiratory reserve volume
• The amount of air that
can be forced out of
the lungs after a
normal
breath/expiration
(above Tidal Volume).
• Expiratory Reserve
Volume decreases
during exercise as tidal
volume increases.
Inspiration reserve volume
• The amount of air that can be forced into the lungs after a deep breath (above
Tidal Volume).
• Inspiratory Reserve Volume decreases during exercise as tidal volume increases.
Tidal volume
•The normal amount/volume of air inhaled or exhaled per breath. Tidal Volume
•Tidal volume increases with exercise as we breath harder.
•Average Tidal Volume is 500 cm3 of air.
Minute volume
volume of air passing through the lungs each minute
What does vital capacity equal?
Tidal volume + inspirations reserve volume + expiratory reserve volume
What are the two ways we control our breathing?
Neural control
Chemical control
What is neural control?
Breathing is largely involuntary (controlled by the respiratory centres of the brain).
Inspiration is an active process, diaphragm actively contracts which causes air to enter the lungs.
Expiration is a passive process, as the diaphragm relaxes, this causes air to exit the lungs.
The process is controlled by neurones in the medulla (section in the middle of the brain). Responsible for involuntary functions such as breathing, heartbeat and sneezing.
What is chemical control?
We control our breathing rate by detecting changes (levels of oxygen and carbon dioxide in the blood.
The sensors that respond to these changes are called Chemoreceptors They are found in the medulla, aortic arch, and carotid arteries and medulla.
The sensors are detecting changes in carbon dioxide and also the acidity of the blood. Signals are then sent to the brain that will make changes to
breathing rates.
What are responses of a single exercise session on the respiratory system
Increased breathing rate
(• Deeper, faster breathing
• Muscles demand more oxygen
• Increased C02 production
• Capillary network expands
• Increasing blood flow to lungs
• Increasing diffusion)
Increased total volume
(• TV increases to allow more air to pass through the lungs.
• Oxygen diffusion increases)
Adaptations of regular exercise session on the respiratory system
Increased vital capacity
(• To provide an increased and more efficient supply of oxygen to working muscles.)
Increase in oxygen/Co2 diffusion rate
(• Allows these to diffuse more quickly, allowing you to train longer and harder as your muscles will be supplied with more oxygen and the increased CO2 removed
more quickly.)
Increased strength of respiratory muscles
(• The diaphragm and intercostal muscles increase in strengthallowing great expansion of the chest cavity, making
breathing easier and the chest cavity to expand further.)
What is asthma?
Airways become restricted making it harder for the air to enter the body, resulting in coughing, wheezing or shortness of breath.
During normal breathing, the bands of muscle that surround the airways are relaxed and air moves freely.
Asthma makes breathing difficult. Asthma makes the bands of muscle contract and tighten so the air cannot move freely in or
out of the body.
Whats the impact of asthma on performance?
Asthma can have a negative effect on sports performance as people with the condition will not be able to get enough oxygen
into their lungs to supply their muscles, especially with the increased amounts required during exercise.
Can exercise help asthma?
Regular exercise will strengthen your respiratory system and help prevent asthma. Regular aerobic training can help improve breathing and muscular strength, and endurance training will also improve oxygen uptake.
Altitude and partial pressure on respiratory
Athletes like to train at altitude as the air
pressure is lower. This means that the density of the oxygen in the air is lower, and it is harder to breath due to lower partial pressure. Over time the athlete’s respiratory system will adapt to this lower pressure and become more efficient.
Altitude short term effects
Short term effects of altitude on the body are that the lung must work harder this can cause shortness of breath, dizziness,
headaches and difficulty in concentrating.
Hypoxia occurs when the body has insufficient access to oxygen.
To cope with the decrease in available oxygen you must breathe faster and deeper.
Altitude long term effects
Over a long period of time of training at altitude the respiratory system adapts so you can cope with the decrease in available
oxygen.
Lungs will acclimatise by becoming larger which enables them to take in more oxygen.
The body will also produce more red blood cells and capillaries, enabling the lungs to oxygenate the blood more efficiently.
Altitude training for athletes
Athletes who train at altitude feel the benefits of a more efficient respiratory system when they return to compete at lower altitudes.
Athletes born at high altitudes benefit even more, having grown up and developed in that environment.
