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