Topic on a page - Structure and functions of the cardio-respiratory system Flashcards
what happens at the nose and mouth
air enters the body through the nose and mouth
what happens at the trachea
air from the nose and mouth enters the wind pipe called the trachea. the trachea is surrounded by rings of cartilage to keep its shape and prevent it collapsing
what happens at the bronchi
air travels from the trachea and to each lung via a bronchus . bronchi is the term for both the left and right bronchus. the passage of air gets smaller and smaller
what happens at the bronchioles
the smaller airways that branch off the bronchi are called bronchioles. bronchioles branch out throughout the lungs and carry the air from the bronchi to the alveoli
what happens at the alveoli
the bronchioles carry the air to the alveoli which are tiny air sacs. they are attached to the bronchioles. the exchange of oxygen and carbon dioxide occurs at the alveoli
what is the trachea surrounded by
rings of cartilage
why is the trachea surrounded by rings of cartilage
to keep its shape and prevent it from collapsing
where does the exchange of oxygen and carbon dioxide occur
at the alveoli
what features assist gas exchange
- alveoli have very tiny air sacs with moist thin walls that are only one cell thick
- alveoli have a very large surface area
- alveoli are surrounded by a network of capillaries which provides a large blood supply
explain the process of gas exchange
- gases move from areas of high concentration to areas of low concentration. if there is more oxygen in the alveoli than the capillaries oxygen will move into the capillaries
- oxygen is diffused into the blood. it binds with the haemoglobin in the blood to form oxyhaemoglobin
- oxyhaemoglobin is transported to the working muscles where it is used for aerobic activity
- during aerobic activity carbon dioxide is produced this is removed from the muscles by haemoglobin
- gaseous exchange occurs at the alveoli (- cappillaries and capillaries - muscle tissue)
what is gas exchange
the spreading out of particles from areas of high concentration to areas of low concentration
what are the three blood vessels
artery
vein
capillary
features of the artery
thick muscular walls
thick elastic walls
small lumen
carry blood at high pressure
carry blood away from the heart
usually carry oxygenated blood (except pulmonary artery)
what pressure does the artery carry blood at
high pressure
does the artery carry blood to or away from the heart
away
features of the vein
thin walls
large lumen
carry blood at low pressure
contain valves
mainly carry deoxygenated blood (except pulmonary vein)
what pressure does the vein carry blood at
low pressure
does the vein carry blood to or away from the heart
to
features of the capillary
very thin walls - one cell thick
small lumen
link smaller arteries with small veins
allow gaseous exchange
carry blood at low pressure
what pressure does the capillary carry blood at
low
what is blood redistribution
when we exercise,blood is redistributed. the working muscles need more oxygen than other inactive areas of the body (such as the stomach). blood is diverted away from inactive areas to the working muscles
why does blood get redistributed
the working muscles need more oxygen than other inactive areas of the body (such as the stomach).
what is vasoconstriction
the blood vessels constrict to make them smaller. chemical changes signal the nervous system to constrict blood vessels to inactive areas
what is vasodilation
the blood vessels dilate to make them bigger. chemical changes signal the nervous system to dilate blood vessels that supply active areas
the cardiac cycle - the pathway of blood
- the right atrium contracts (systole) ejecting deoxygenated blood through a valve and into the right ventricle
- the right ventricle is relaxed (diastole) and fills with deoxygenated blood
- the right ventricle contracts (systole) pushing the deoxygentated blood through valves to the pulmonary artery
- the pulmonary artery carries deoxygenated blood away from the heart to the lungs. the blood becomes oxygenated
- the pulmonary vein transports the oxygenated blood back to the heart and into the left atrium, which fills with oxygenated blood
- the left atrium contracts (systole) ejecting oxygenated blood through a valve and into the left ventricle
- the left ventricle is relaxed(diastole) and fills with oxygenated blood
- the left ventricle contracts (systole) pushing the oxygenated blood through valves to the aorta
- the aorta carries oxygenated blood away from the left ventricle to the working muscles the blood then become deoxygenated
- the vena cava is the main vein bringing the deoxygenated blood back to the heart and into the right atrium
what happens in inspiration
the diaphragm and external intercoastal muscles contract. the external intercoastal muscles raise the ribs upwards and outwards. this increases the volume of the chest cavity and causes air to rush into the lungs
what do the diaphragm and external intercoastal muscles do during inhalation
contract
what do the external intercoastal muscles do to the ribs during inhalation
move them upwards and outwards
what happens to the volume of the chest cavity during inhalation
it increases which causes air to rush into the lungs
what happens in expiration
the diaphragm and external intercoastal muscles relax, the internal intercoastals contract. this lowers the ribs downwards and inwards. this decreases the volume pf the chest cavity and causes the air to be forced out the lungs
what do the diaphragm and intercoastal muscles do during exhalation
diaphragm and external intercoastal muscles relax
internal intercoastals contract
what happens to the ribs during exhalation
they lower downwards and inwards
what happens to the volume of the chest cavity during exhalation
it decreases the volume of the chest cavity and causes the air to be forced out of the lungs
what happens during inspiration in exercise
the pectorals and sternocleidomastoid muscles raise the sternum allowing the lungs to expland further
what happens during expiration in exercise
the rib cage is pulled down quicker due to the contraction of the abdominal muscles
what is the equation for cardiac output
cardiac output = stroke volume x heart rate
what is cardiac output
amount of blood leaving the heart per minute
what is stroke volume
amount of blood being ejected from the heart per beat
what is heart rate
the number of times the heart beats per minute
explaining heart rate graph that rises then stays similar then falls
A = heart rate is at its lowest at rest
B = immediately before exercise resting heart rate will increase. this is called an anticipatory rise; this is due to the release of the hormone adrenaline
C = when you start to exercise the heart rate increases sharply. this is due to the demand of oxygen. cardiac output increases
D = during continuous exercise heart rate levels because the heart rate is sustaining the amount of oxygen needed
E = immediately after exercise heart rate decreases sharply, this is because exercise has stopped and the demand for oxygen has reduced
F = heart rate slowly returns to its resting rate
what is tidal volume
the amount of air inspired (inhaled) or expired (exhaled) in a normal breath
what is vital capacity
the maximum amount of air the lungs can expire (breathe out) after the maximum inspiration (breathe in)
what is expiratory reserve volume
the maximum volume of air that can be exhaled. in addition to tidal volume
what is inspiratory reserve volume
the maximum volume of air that can be inhaled. in addition to tidal volume
what is residual volume
the amount of air that remains in the lungs even after a forced maximal exhalation
what happens to breathing during exercise
tidal volume during exercise increases. breathing rate and depth increase due to meet the demand of oxygen, carbon dioxide is also removed
