respiratory system Flashcards
Pathway of air
- Passes through the mouth
- To the pharynx onto the larynx
- Trachea
- Right and left bronchus
- Bronchioles
- Alveoli
Structure to function of the alveoli
- walls are very thin = short diffusion distance
- large number of alveoli = large surface = higher O2 uptake
- good blood supply = step concentration gradient
Muscles used during inspiration at rest
- diaphragm
- external intercostal muscles
Muscles used in inspiration during exercise
- diaphragm
- external intercostal muscles
- sternocleidomastoid
- scalenes
- pectoralis minor
Muscles used during experation at rest
diaphragm
external intercostal muscles
Muscles used in experation during exercise
internal intercostal muscles
abdominals
Definition of minute ventilation
the volume of air inspired and expired per minute
Definition of tidal volume
volume of air breathed in and out per breath
Definition of inspiratory reserve volume
volume of air that can be forcibly inspired after a normal breath
Definition of expiratory reserve volume
volume of air that be forcibly expired after a normal breath
Definition of residual volume
volume of air that remains in the lungs after maximum expiration
Definition of spirometer
a device that is used to measure the volume of air inspired and expired by the lungs
Definition of the partial pressure
the pressure exerted by an individual gas when it exists
Why does the pressure in the muscles need to be lower than the blood
so oxygen can diffuse in from high to low
Diffusion pathway of oxygen in the alveoli to the blood vessels
100mmHg - 40mmHg
Diffusion pathway of carbon dioxide from the blood to the alveoli
45mmHg to 40mmHg
Definition of pulmonary ventilation
breathing
What does the respiratory centre control
the rate and depth of the breaths
Definition of expiratory centre
stimulates the expiratory muscles during exercise
Definition of inspiratory centre
responsible for controlling inspiration and expiration
How does the inspiratory centre work
- sends impulses via the phrenic nerves to the inspiratory muscles(diaphragm and external intercostal muscles)
- causes them to contract
- this stimulation lasts for approx. 2 seconds and the impulse stops
Control for the inspiratory centre
- receptors
- medulla
- phrenic nerve
- diaphragm and external intercostal muscels
Control for expiratory centre
- receptors
- medulla
- intercostal nerve
- abdominals and internal intercostal muscles
What do stretch receptors do
prevent over-inflation of the lungs by sending impulses to the expiratory centre, down the intercostal muscles, to the expiratory muscles
What do the proprioreceptors do
provides feedback to the respiratory centre to increase breathing rate during exercise
What do the barioreceptors do
detect decreased blood pressure in aorta and carotid artery to increase breathing rate
Definition of respiration
taking in of oxygen and removal of carbon dioxide
Definition of internal respiration
exchange of gases between the blood and capillaries and body cells
Definition of external respiration
gaseous exchange between the blood and the lungs
Definition of cellular respiration
metabolic reactions and processes that take place in a cell to obtain energy from fuels such as glucose
What does smoking do to the lungs
- irritates the trachae and bronchi
- reduces lung function and increased breathlessness due to increased narrowing of the airway
What happens if the cilia in the lungs is damaged
- excess mucus can build up in the lung passages which leads to smokers cough
- damage the alveoli as their walls break down and join together to form a large air space (reduce efficiency of gaseous exchange - leads to COPD)
Definition of COPD (chronic obsrtuctive pulmonary disease)
long term progressive disease that causes shortness of breath
main cause is smoking
Why do people that smoke become breathless
carbon monoxide binds to the haemoglobin more readily than oxygen
reduces oxygen carrying capacity of the blood which increases breathlessness
