Respiratory System :) Flashcards
lung volumes - spirometer
tidal volume
the volume of air inspired or expired per breath
+ during exercise
minute ventilation
the volume of air inspired or expired per minute
tidal volume x number of breaths per min =
big + during exercise
inspiratory reserve volume
the volume of air that can be forcibly inspired after a normal breath
- during exercise
expiratory reserve volume
the volume of air that can be forcibly expired after a normal breath
- during exercise
residual volume
the amount of air that remains in the lungs after maximal expiration
= during exercise
gaseous exchange
- getting oxygen from the air into the lungs so it can diffuse into the blood and be carried around the body
- removal of carbon dioxide from the blood so it can be breathed out and diffused into the air via the lungs
diffusion
the movement of gas molecules from and area of high partial pressure to an area of low partial pressure
partial pressure
pressure exerted by an individual gas when it exists within a mixture of gases
-oxygen only makes up 215 of air
characteristics of alveoli
responsible for gaseous exchange between lungs and blood via diffusion
- one cell thick walls- shorter diffusion pathway
- extensive capillary network - good blood supply
- large surface area- allows for greater oxygen uptake
gaseous exchange at alveoli
- partial pressure of oxygen (100mmHg) in alveoli is higher than partial pressure of oxygen in capillary (40mmHg) as working muscles take oxygen
- carbon dioxide moves in the opposite direction as the partial pressure of co2 in the blood (46mmHg) is higher than in the alveoli (40mmHg)
concentration/pressure gradient
the bigger the gradient- the faster the rate of diffusion
gases will continue to diffuse until the pressure/concentration is equal in both
gaseous exchange in muscles
-capillary membranes surrounding muscles have a lower partial pressure of oxygen (5mmHg) than in the blood (100mmHg), oxygen diffuses into muscles
gaseous exchange in muscles
- capillary membranes surrounding muscles have a lower partial pressure of oxygen (5mmHg) than in the blood (100mmHg), oxygen diffuses into muscles
- partial pressure of carbon dioxide in the blood (40mmHg) is lower then at the tissues (46mmHg) so diffusion occurs the other way to the blood
pulmonary ventilation
breathing- controlled automatically by parasympathetic and sympathetic systems
sympathetic nervous system: prepares body for exercise so increases breathing rate
parasympathetic nervous system: relaxes after exercise and reduces breathing rate
respiratory centre
located in medulla oblongata with two main areas:
inspiratory centre responsible for inspiration and expiration
- sends out nerve impulses via phrenic nerve to inspiratory muscles (diaphragm + external intercostals)
expiratory centre stimulates expiratory muscles during exercise
- sends out signal via intercostal nerve to the expiratory muscles (abdominals and internal intercostals)
chemoreceptors
detects increase in concentration of co2 so stimulates respiratory centre to increase breathing rate/ventilation
proprioceptors
detect increase in muscle movement and sends signal to respiratory centre to increase breathing rate
baroreceptors
detect decrease in blood pressure due to exercise so send signals to increase breathing rate
adrenaline
hormone that increases breathing rate in preparation for exercise
impact of poor lifestyle choices
smoking causes:
- carbon monoxide to combine with haemoglobin which reduces oxygen carrying capacity and causes breathlessness
- irritation of trachea and bronchi
- reduced lung function + swelling and narrowing of airways
- damage to cell lining leading to build up of excess mucus - cough
- reduction in efficiency of gaseous exchange leading to increased risk of COPD (chronic obstructive pulmonary disease)
