Cardio repiratory system and cardiovascular system Flashcards
What is the function of the respiratory system
Inspiration and expiration of air, breathign so gaseous exchange can take place. Intake of oxygen and removal of carbon dioxide
Structure of respiratory system
Pharynx: Wind and food pipe Larynx: Voice box Trachea Bronchus Bronchiole Alveoli
Function of teh bronchus
our bronchi carry air to and from your lungs. The bronchi also help moisturize the air you breathe and screen out foreign particles. Your airways are lined with cells that create mucus.
Function of the bronchiole
As oyu inhale, oxygtenated blood is pumped into the bronchioles int o teh lungs where it then goes into the alveoli
It also removes carbon dioxide form the lungs as welll
Function of the alveoli
The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out.
How is the alveoli adapted to carry out gaseous exchnage
Large surface area
Thin walls: Providing short diffusion distance
Moist walls: Gases dissolve in the moisture helping them to pass across the gas exhcnage surface
Permemable walls: Allows gases through
Large blood supply: ensuring oxygen rich blood is taken away fromt he lungs and carbon dixoide rich blood is take to teh lungs
Large diffusion gradeint: Breathign ensures that the oxygen concetration in the alveoli is higher than in the cappilaries so oxygen moves from the alveoli to the blood.
Function of teh trachea
To carry air in and out of the lungs
How is teh cappirlaies adapted ot carry out their function
Walls that are one cell thick
They contain a large supply of blood
Have thin permebale walls
Their walls do not contain collagen or elastic fibers allowing rapid diffusion of substances between the blood and the cells
Define diffusion
The exchange of gases between the lungs and the blood and their movement at tissue level takes place passively by diffusion
What will a diffusion gradient cause
A diffusion gradeint will cause moleucles to move across a space by random molecular collision with membrane walls
What do steep diffusion gradients help with
Move substances froma high concetrniation to a low concetraiton where they take part in the repiration process
How do gases diffuse
From a high to a low pressuree
What does the rate of exchange depend on
Partial pressure of each gas, gas solubility and tempurature
Define partial pressure
The pressure a gas exerts within a mixture of other gases
The pathway of air
Nsal cavity, trachea, pharynx, larynx, trachea, bronchi, bronchiles, repiratry bronchioles, alveolar ducts adn to alveoli
Function of teh pharynx, larynx, trachea and bronchi
Contains mucous glands whch provides a cleaning and filtering mechanism for incoming air
Inspiration at rest
external Intercostal muscles contract
Diaphragm contracts
Internal intercostal muscles relax
Ribs and sternum moves upwards
Increase in chest cavity volume
Pressure between lpeural membrnaes is reduced
Allows elastic pulmonary tissue to expand
Lung volume increases
Pulmonary air pressuresfalls below atmospheric pressure
hece atopheric air is forcced into the lungs
Until lung pressure quals the pressure outside agin
Expiration at rest
External intercostal muslcles relax
Diaphragm relaxes
Ribs and sternum moves downwards
Decreas in chest cavity volume
Pressure bwteen pleurl memrbanes is increased
COmpresses elastic pulmonary tisse
Lung volume decreases
Pulmonary air pressure is driven about atmospheric pressure
Hence atmospheric air is forced out of lungs via the respirtory passages
Until lung ressure equal the pressure outside again
Inspiration during exercise
Additional muscles in the hest adn torso conracts such as teh ectroalis major
Chest cavity volue further increased
More air forced into lungs
Expiration during exericse
Internal intercostal muscles adn abdominal muscles contract powerfully, acting on ribs nd body cavity
Chest cavity vlume is further reduced
More pulmonary air is forced out of the lungs
What factors affect the effectvieness of gaseous exhcange
Po2 and pCO2
Gas solubility
Tempurature
What maximises diffusion gradient
Good lung venitalaiton Vast surface area of alveoli Short distanes between teh alveolar lining and blood Lrge amoutn of red corpuscles Large aounto fmuscle myoglobin Moist alveolar lining
Explain the process of gasoues exhcange
Oxygen from th air in the lungs is transferred by diffusion ot teh blood flwoing through the alveoli.Carbon dioxide is trasnferre fromt he blood to teh lungs, where it is breathed out
The gases travel through the cappilary walls and alveolar walls
Gaseous exchange at the tissue site
xygen is carried by teh blood and into teh tissues and there it diffuses into tissue cells.
Carbon dioide diffuses out of tissue cells into teh blood where it flows back through the venous system and the heart adn back to teh lungs
How gaseous exhcange is achiveed in the alveoli
The first step in oxygen trasnport is he diffsion of oxygen fromt eh alveoli into teh blood.
In the venous lood, the partial pressure of oxygen is 5.3kpa and in the alveolar air it is 13.3kpa, so oxygen travels through teh alveolar and cappilary walls fromt eh lungs int othe blod where it comines with haemoglobin to form oxyheamoglobin
What is the oxyhaemoglobin curve
The percentage of haemoglobin staurated with oxyegn at a given po2
Function of myoglobin
A substances which attracts and binds ot oxygen. Has a greater affintiy for oxygen than haemoglobin. Enables oxyegn to be carried across a cell to teh mitochondria where the oxygen is consumed and energy transfer takes place.
What is the advanatge of myoglobin having a higher affinity for xygen than haemoglobin
Arriving arterial blood has an oxygen partial pressure f 13.3kpa. Thsi is greater than tissue po2 sine the oxygen is beig used up in the cells durig the nergy creating prcoess. Becuase myoglobin in th etissue cells have a greater affintiy for oxygen than haemoglobin, oxyten diffuses through teh cappilray and cell walls from the blood into teh tissue cells. Myoglobin then facilliattes oxygen trasnfer to teh mitochodnria, notably at teh satrt of exercise and durign icrease in tintensity when p2 decreases
Affect of tempurature and ph on exercise
The higher the tempurature the more oxygen released
Exericse increases tempurature therfor when you exercise ph increases, lactic acid therfore oxygen release increased
Define boyles law
Boyles law- the volume of a gas at constant temperature varies inversely with the pressure exerted on it.
