respiratory system Flashcards
What parts is the respiratory system part of ?
- nose
- airways
- lungs
- respiratory muscles
What journey does the passage of the airway go through ?
- atmosphere
- nasal cavity (cilli filter waste)
- pharynx (throat)
- larynx (voice-box)
- trachea (windpipe)
- bronchus (separates)
- bronchioles
- alveoli
What are the functions of the respiratory system ?
- pulmonary ventilation
- Gaseous exchange
- external respiration
- internal respiration
What is pulmonary ventilation ?
the inspiration and expiration of air
What is external respiration ?
The movement of o2 into blood (capillaries) and co2 into lungs
What is internal respiration ?
The release of o2 to respiring cells for energy production and removing waste products
How is o2 transported in the blood ?
- carried by red blood cells
- attaches itself to the haemoglobin
What is carbon dioxide used for in the respiratory system ?
Carbon dioxide is the waste product of aerobic respiration must be removed from respiring tissues and transported to the alveloi
How is co2 transported in the blood ?
- 70% - dissolved in water
- 23% - carried with haemoglobin
- 7% - dissolved in blood pressure
What is breathing rate ?
The amount of times you inspire or expire per minute
What is the average breathing rate ?
12-15 breaths per minute
What happens to breathing rate as a response to exercise ?
Br increase in proportion to exercise intensity until we approach our maximum of 50-60 breaths per minute
What happens to breathing rate during sub-maximal exercise ?
Br can plateau as o2 supply matches o2 demand from muscles
What is tidal volume ?
Volume of air inspired or expired in one breath
What does tidal volume depend on ?
- lung size
- age
- gender
- fitness
What is an average tidal volume ?
5000ml per breath
What effect does exercise have on tidal volume ?
- This increases initially in proportion to exercise intensity up to aprox. 3 litres
What effect does sub-maximal exercise have on tidal volume ?
During sub-maximal exercise it can reach a plateau when o2 supply meets o2 demand
What is minute ventilation ?
The volume of air inspired or expired per minute
How can minute ventilation be calculated ?
Breathing rate x tidal volume
What is minute ventilation measured in ?
litres/min
How is minute ventillation calculated ?
- initial increase due to adrenaline release before exercise
- rapid increase at the start of exercise due to Tv and Br increase
- steady mv as o2 supply meets o2 demands
- initially rapid and then more gradual decrease to resting levels
Why does oxygen move into the nasal cavities ?
Because the pressure outside of the body than the pressure inside the body
Why does carbon dioxide need to move out of the body ?
Because the air pressure is higher in the lungs than the atmosphere
What reduces the pressure in the lungs ?
Inreasing the volume of the thoraic cavity (chest cavity) which menas inspiration can happen.
What muscles are used in inspiration at rest ?
- diaphragm
- external intercostals
What muscles are used during expiration at rest ?
- the diaphragm relaxes
- the intercostals relax
What muscles are used during inspiration when exercise
- diaphragm
- external intercostals
- sternocleidomastoid
- scalenes
- pectoralis minor
What muscles are used during exhalation in exercise ?
- internal intercostals
- abdominals
What is the leftover air in the lungs after maximum expiration called ?
- residual volume
What is the inspiratory reserve volume ?
- volume of air that can be forcibly inspired after a normal breath
What is expiratory reserve volume ?
- volume of air that can forcibly expired after a normal breath
What happens to inspiratory reserve volume during exercise ?
decreases
What do you use to measure the air we inspire and expire ?
Spirometer
How does a spirometer work ?
- an individual breathes in and out of a sealed chamber through a mouth piece
- The chamber then inflates and deflates as this happens
- a pen recorder traces the breathing movements onto a chart
- the machine is calibrated so breathing volume can be calculated
What is gaseous exchange ?
- getting oxygen from the air into the lungs so it can diffuse into the blood and then the cells.
- the removal of carbon dioxide form the blood
What two key terms are used when talking about gaseous exchange ?
- partial pressure
- diffusion
What do all gases do ?
- exert a pressure
How much of the air does oxygen take up ?
- 21%
What is partial pressure ?
- the pressure exerted by an individual gas when it exists in a mixture of gases
What is diffusion ?
- the movement of gas molecules from an of high concentration or partial pressure to an area of low concentration or partial pressure
What happens to partial pressure of the oxygen in the respiratory system ?
- as the air moves from the alveoli to the blood to the muscle, the partial pressure of oxygen get’s lower
- this is because gases flow from an area of high pressure to low pressure
Where is partial pressure of oxygen bigger when oxygen goes to the alveoli ?
- partial pressure of oxygen is higher in the alveoli than the capillary beds
Why is the partial pressure of oxygen lower in the capillaries than in the alveoli ?
Because the oxygen has been removed by the working muscles so its concentration in the blood is lower and therefore so is partial pressure
What is the difference in partial pressure called ?
- concentration/ diffusion gradient
What is a concentration/diffusion gradient ?
- Often referred to as the concentration gradient
- explains how gases flow from an area of high concentration to low concentration
- the steeper the gradient, the quicker the diffusion is
What happens during internal respiration at rest ?
- the exchanges of gas at the muscle cells between the oxygenated blood in the capillaries and the muscle cells which produce co2
- haemoglobin’s disassociate with o2 in the capillary which allow oxygen to diffuse into the muscle cells down a pressure gradient
- co2 diffuses from muscle cells into the capillary down a pressure gradient. This removes all the co2
What happens during external respiration during exercise ?
- due to o2 demand, blood returning to the lungs has less oxygen
- o2 diffusion gradient is steeper and more o2 diffuses from alveoli to the capillaries
- co2 diffusion gradient steepens and more co2 diffuses from the capillaries to the alveoli
How many oxygen molecules are haemoglobin’s able to carry?
4
When will oxygen’s associate with haemoglobin ?
when there is a high concentration of oxygen
What is the partial pressure of o2 at rest in the blood ?
40 mm/Hg
How much oxygen has disassociated when the pO2 of the muscle tissue is 40mmHg ?
25%
What is the pO2 during exercise ?
15 mmHg
How much oxygen has disassociated when the pO2 of the muscle tissue is 15mmHg ?
75%
What are the 3 factors which affect the disassociation of oxygen with haemoglobin ?
- increase in temperature
- increase co2 production
- increase in the prodcution of lactic acid (pH change)
What is the Bohr shift ?
The 3 factors that lead to the oxyhemoglobin disassociation curve shifting to the right
How does the sympathetic nervous system effect the respiratory system ?
Increases breathing rate
How does the parasympathetic nervous system effect the respiratory system ?
Decreases breathing rate
What does RCC stand for ?
Respiratory control centre
What are the two parts of the RCC ?
- ICC = inspiratory control centre
- ECC = expiratory control centre
How does an increase in carbon dioxide in the blood increase breathing rate ?
- the carbon dioxide makes the blood more acidic
- change is detected by chemoreceptors
- sends the information to the VCC/medulla
- Impulses tell the respiratory muscles to contract faster