respiratory system Flashcards
the pathway of air
-nasal cavity/ mouth
-pharynx
-larynx
-trachea
-bronchi
-bronchioles
-alveoli
functions of the respiratory system
- Pulmonary ventilation
- Gaseous exchange
regulation of the respiratory system at rest
- the brain acts- at rest the inspiratory centre is responsible for rhythmic cycle of breathing. nerve impulses are generated and stimulate the inspiratory muscles
- inspiration-the external intercostal muscles and diaphragm contract
- expiration - stimulation to the external intercostal muscles and diaphragm stops, they relax and recoil.
regulation of the respiratory system during exercise
-receptors detect a change
-information sent to respiratory control centre which stimulates the inspiratory centre
Inspiration:
-increased stimulation of diaphragm and external intercostals
-recruitment of additional muscles (sternocleidomastoid & pectoralis minor)
Expiration:
-expiratory centre stimulated
-expiration becomes active
-recruitment expiratory muscles (internal intercostals & abdominals)
Overall increases minute ventilation
Breathing frequency (f)
The number of breaths per minute
Rest = 12 breaths
Max exercise = 40-50
Endurance athlete = 10
Endurance athlete at max exercise = 50-60
Tidal volume (TV)
The volume of air inspired or experienced per breath (litres)
Rest = 0.5
Max exercise =2.5-3
Endurance athlete = 0.5
Endurance athlete at max exercise = 3.2-3.5
Minute ventilation (VE) and values
The volume of air inspired or expired per minute (l/min)
Rest = 7
Max exercise =100-150
Endurance athlete = 5
Endurance athlete at max exercise = 160-210
External pressure
- happens at the lungs.
- between alveoli and capillaries
- o2 and co2 diffuse from a high to low partial pressure.
- moves down the diffusion gradient.
Internal pressure
- happens at the muscles.
- between capillaries and muscles
- o2 and co2 move from a high to low partial pressure.
- moves down the diffusion gradient.
Oxyhemoglobin dissociation curve at rest
haemoglobin associates with o2 to become oxyhemoglobin at the lungs.
The oxyhaemoglobin then carries 4 o2 particles and is fully saturated. when reaching the muscles one particle is lost and dissociates with the haemoglobin, making it only 75% saturaled.
oxyhemoglobin dissociation curve at exercise
At exercise theres more demand for oxygen at the muscles this means that the rate of dissociation increases from the oxyhemoglobin to muscles, resulting in it in it being only 20 - 40% saturated and it losing 3 particles.
4 factors that increase dissociation of oxyhemoglobin
- oxygen
- carbon dioxide
- body temperature
- acidity
Pulmonary ventilation
The inspiration and expiration of air
Gaseous exchange
The movement if oxygen and carbon dioxide at the lungs and at the muscles by the process of diffusion
- external respiration- movement of O2 into the blood(capillaries) and CO2 into the lungs
- internal respiration-Release of O2 to respiring cells for energy production &removing waste products
Inspiration at rest
- active
-diaphragm contracts and flattens - external intercostals contract
- rib cage moves up and out
- volume of thoracic cavity increases
- pressure of air in lungs decreases
- air rushes in
Expiration at rest
- passive
- diaphragm relaxes into dome shape
- external intercostals relax
- rib cage moves down and in
- volume of thoratic cavity decreases
- pressure of air in lungs increases
- air rushes out
Inspiration during exercise
- active
- diaphragm contract with more force and flattens further
- external intercostals contracts with more force
- rib cage moves up and out more
- volume of thoratic cavity increases more
- pressure of air inside lungs decreases more
-larger volume of air moves in
Expiration during exercise
- active
- diaphragm relaxes more and is pushed further up rib cage
- external intercostals relax more
- rib cage moves down and in more
- volume of thoratic cavity decreases more
- pressure of air inside lungs increases more
- larger volume of air moves out
Additional muscles used for inspiration during exercise
Sternocleidomastoid & pectoralis major
Additional muscles for expiration during exercise
Rectus Abdominals & internal intercostals
Minute ventilation equation
Breathing frequency x tidal volume = minute ventilation
F x TV = VE
Diffusion
Moment of a gas down a diffusion gradient from an area of high partial pressure to an area of low partial pressure
Diffusion gradient
The difference between the ares of high partial pressure and low partial pressure. The diffusion gradient is like a slide and the gases travel from the top of the slide to the bottom
Partial pressure
The pressure a gas exerts within a mixture of gases, and be written as ppO2/ppCO2
How does oxygen increase dissociation
the muscles are using more o2, so decreased ppo2 inside the muscle so a steeper diffusion garment between blood and muscle
How does carbon dioxide increase dissociation
the muscle is producing more co2, so increased ppco2 inside the muscle so a steeper diffusion gradient between the muscle and blood
How does body temperature increase dissociation
body temperature increases so o2 more likely to dissociate
How does acidity increase dissociation
lactic acid makes o2 more likely to dissociate from haemoglobin
Factors increasing dissociation
- oxygen
- carbon dioxide
- body temperature
- acidity
respiratory control centre
received information from the sensory nerve and sends it direct through motor nerves to change the type of respiratory muscle contraction
inspiratory centre
stimulates inspiratory muscles to contract during rest and exercise
expiratory centre
is inactive during rest but will stimulate additional expiratory muscles to contract during exercise
