2.1 structure and function of ventilatory system Flashcards
principle structures of the airways
nose
mouth
pharynx - carries air, food and fluid from the nose to the mouth
larynx - job is to protect the lower respiratory tract from aspiring food into the trachea while breathing.
trachea
lungs
bronchi
bronchioles
alveoli
the conducting airways - nose
the nose is an external opening for the respiratory system, there is low resistance pathway for airflow.
it also warms, filters and moistens the air
the conducting airways - mouth
the mouth is an external opening for the respiratory system. there is low resistance in the pathways for airflow.
yet it just lets air in, there is no filtering or moistening or warming of the air.
what is pulmonary ventilation
the inflow and outflow of air between the atmosphere and lungs AKA BREATHING
what is inspiratory reserve volume IRV
the maximum amount of air forcibly inspired adding to the tidal volume
what is vital capacity VC
the max amount of air that can be exhaled after the max inhalation
what is total lung capacity TLC
the volume of air in the lungs after a maximal inhalation
FORMULA: TLC = VC + RV
what is tidal volume
the volume of air breathed in and out every breath
what is expiratory reserve volume
the maximum amount of air that is forcibly expired in addition to tidal volume
what is residual tidal volume
the volume of air still inside the lungs after maximal exhalation.
what is minute minute ventilation
the volume of air breathed in and out per minute
FORMULA: MV= TV x breathing rate
mechanics of ventilation: breathing in (inspiration)
1) intercostal muscles contract moving the chest walls up and out
2) the diaphragm contracts and flattens
3) this increases the volume of the thoracic cavity
4) there is a decrease in pressure inside the chest cavity which forces the air inside because the air moves from high to low pressure.
mechanics of ventilation: breathing out (expiration)
1) intercostal muscles relax moving the chest walls down and in
2) the diaphragm relaxes moving up and bulges upward (back to a dome shape)
3) the volume of the thoracic cavity decreases
4) pressure inside the thoraic cavity increases
5) air rushes out of the lungs because it moves from high to low
mechanics of ventilation: passive respiration
occurs at rest with no extra energy required
mechanics of ventilation: active respiration
occurs during exercise forming a higher depth and rate of breathing. additional accessory muscles are recruited to support.
1) inspiration - pecs and trapezius
2) expiration - abdominals and intercostal
muscles
lungs are then compressed more and faster
nervous and chemical control of respiration: stretch receptors
location: in the lungs
purpose: gives info abt the state of lungs
impacts: monitors the respiration rate (reducing it) to prevent the over expanding of the lungs
nervous and chemical control of respiration: baroreceptors
location: in the blood vessels
purpose: gives info abt the state of the blood vessels and pressure
impacts: can impact the cardiac output
nervous and chemical control of respiration: chemoreceptors
location: around the arteries of the heart and the brain
purpose: detects the CO2 lvls, monitor the concentration of H+ ions (which make the blood more acidic and decrease the pH)
impacts: if the pH is low (bcs of a the CO2 producing carbonic acid) then the chemoreceptors will send a message to increase the breathing rate.
nervous and chemical control of respiration: proprioceptors
location: in muscles and limbs
purpose: gives info abt joint angle, muscle length, tension and detects motion.
nervous and chemical control of respiration: nervous system
location: CNS and PNS
purpose: the autonomous NS sends signals to change the breathing rate
sympathetic: increase BR
parasympathetic: decrease BR
Outline the role of haemoglobin in oxygen transportation.
an iron containing compound that allows for oxygen to bind to red blood cells and be carried in the blood stream, it allows for oxygen to be transported from the lungs to working cells. the oxygen is released when the carbon dioxide is to be transported from the cells to the lungs during expiration.
each molecule of haemoglobin can carry four oxygen molecules. and 98.7% of haemoglobin becomes oxyhemoglobin (red blood cells that are carrying oxygen). trained athletes have a higher haemoglobin level because they can carry around more oxygen around their body and therefore have a higher respiration rate
Explain the process of gaseous exchange at the alveoli.
1) gas exchange occurs in the lungs between the capillaries and alveoli
2) gas moves from a region of high conc and partial pressure to low conc and partial pressure
3) the membrane the gases pass through is one cell thick meaninh diffusion distance is short.
4) oxygen moves out of thу lungs and into blood and CO2
