The respiratory system Flashcards
State and define the 2 types of respiration
- External respiration - exchange of O2 and CO2 between the lungs and blood
- Internal respiration - exchange of O2 and CO2 between the blood and the muscle tissues
Define the term breathing rate (f)
The number of inspirations or expirations per minute
Define the term tidal volume (TV)
The volume of air inspired or expired per breath
Define the term minute ventilation (VE)
The volume of air inspired of expired per minute TV X f = VE
Describe inspiration at rest
- active process
- external intercostal muscles between the ribs contract pulling the chest walls up and out
- the diaphragm muscles below the lungs contracts and flatten, increasing the size of the chest
Describe inspiration during exercise and state the effect
- the sternocleidomastiods lifts the sternum
- the scalene and pectoral minor contract and lifts the ribs more
Effect - the volume of the thoracic cavity increases, creating a larger concentration gradient between inside the lungs and outside the body. Air enters the lungs more quickly
Describe expiration at rest
- passive process
- external intercostal muscles between the ribs relax so that the chest walls move in and down
- the diaphragm muscle relaxes moving upwards reducing the volume within the lungs
Describe expiration during exercise and state the effect
- active process
- internal interc
ostal muscles contract and pull the ribs down and in - the recuts abdominus contracts and pushes the diaphragm up
Effect - a decrease in volume in the thoracic cavity increases pressure within the lungs, therefore creating a larger concentration gradient
What system is responsible for adjusting breathing rate and depth
The respiratory control centre (RCC) located in the medulla oblongata
What 2 centres can be found within the RCC and what are they responsible for
- The inspiratory centre (IC) - stimulates inspiratory muscles to contract at rest and during exercise
- The expiratory centre (EC) - inactive at rest due to it being a passive process but stimulate additional expiratory muscles to contract during exercise
Explain some key info about respiratory regulation at rest
- The IC (inspiratory centre) is responsible for the rhythmic cycle of breathing
- nerve impulses are generated and stimulate the inspiratory muscles causing them to contract
- this is via the intercostal nerve to the external intercostal and phrenic nerve to the diaphragm
Explain key info about respiratory regulation during exercise
- sensory nerves relay info to the RCC where a response is initiated by the IC and the EC
- the RCC receives info from chemoreceptors, thermoreceptors, proprioceptors and baroreceptors
Define the term gaseous change
Gaseous change is the exchange of oxygen and carbon dioxide by the process of diffusion
Define the term diffusion
The movement of gas from an area of high pressure to an area of low pressure
Define the term diffusion gradient
The difference between the high and low pressure (found between the lungs and alveoli + the capillaries and muscles)
Explain key info about partial pressure
Partial pressure is the pressure a gas exerts within a mixture of gases
Gas always move from an area of high partial pressure to an area of low partial pressure
Summarise gaseous exchange at rest - external respiration
- external respiration = the exchange of gases at the lungs
- oxygen moves from high pp in the alveoli to low pp in capillary blood down the diffusion gradient
- carbon dioxide moves from high pp in capillary blood to low pp in the alveoli down the diffusion gradient
Summarise gaseous exchange at rest - internal respiration
- internal respiration = the exchange of gases at the muscle cells
- oxygen moves from high pp in capillary blood to low pp of the muscle cells down the diffusion gradient
- carbon dioxide moves from high pp in the muscle cell to low pp in capillary blood down the diffusion gradient
Summarise gaseous exchange during exercise
- muscle tissues use a greater volume of O2 and produce a greater volume of CO2
- diffusion gradient steepens
- gaseous exchange occurs at a faster rate
Define the oxyhemoglobin dissociation curve
A graph showing the relationship between the p02 and percentage saturation of haemoglobin
Define the term dissociation and saturation
- The process of oxygen unloading from haemoglobin
- Haemoglobin fully loaded with oxygen
Summarise the Bohr shift (key info)
- the movement of the oxyhaemoglobin dissociation curve to the right
The effects are -
-increase in blood and muscle temperature
- increase in pp of carbon dioxide
-increase in production of lactic acids and carbonic acid
Describe the impact of the Bohr shift on performance
- the dissociation of 02 to respiring tissues is greater
- this enhances the volume of 02 available for diffusion and therefore aerobic energy production for exercise
