air enters our nose or mouth and passes down the windpipe (trachea)
(singular = bronchus)
two tubes which split from the tranchea, one which leads to each lung
smaller tubes which have been divided from each bronchus
micrscopic air sacs where air eventually ends up
here gas exchange with blood takes place
covered in blood capillaries
a muscular sheet of tissue
helps air move in and out of lungs
thin moist membranes inside the thorax which surround the lungs
stop lungs sticking to ribs (they are moist)
How does amoeba take up oxygen?
(organism found in ponds)
oxygen diffuses through its cell membranes
How do lungs take up oxygen?
lungs have a very large SA
we breath so oxygen can diffuse into our blood
What is the function of the respiratory system?
uptake of O2 (for respiration)
release of CO2 (waste product)
Label this structure of a respiratory system
Label this structure of an alveloi
of the lungs
towards the heart
away from the heart
Label this gas exchange in the alveoli diagram
Label this gax echange in one alveolus diagram
How big is a blood cell?
approximately 8 µm
How big is a blood capillary?
approximately 10 µm
What is so special about the size of a blood capillary?
it is extremely small
blood cells have to travel single file and often on their sides because otheriwise they can't fit
this allows diffusion time
How is the respiratory system's surface area adapted for efficient gas exchange?
very large surface area (60 cm2)
lots of capillaries - high surface area between capillaries and alveoli
How is the respiratory system's concentration gradient adapted for efficient gas exchange?
the air in the aveolus has a higher concentration of oxygen than the blood entering the capillary network - oxygen diffuses from the air to the blood
there is more carbon dioxide in the blood than there is in the air in the lungs
the concentration gradient is maintained as blood in constantly moving on - breathing in high concentration of oxygen , moving on and breathing out a low concentration
diffusion gradient for carbon dioxide is in the opposite direction to that of oxygen
blood which leaves the capillaries and flows back to the heart has gained oxygen and lost carbon dioxide
How is the respiratory system's diffusion distance adapted for efficient gas exchange?
very small distance - blood is only seperated by the cells making up the wall of the alveolus and the capillary wall itself
diffusion occurs rapidly
How is the respiratory system adapted for efficient gas exchange? (other points)
surfactant and moisture (stops alveolus from sticking together when it contracts)
moisture in surfactant dissolves O2 so it can enter the blood
breathing in and breathing out
Complete this table
Label this diagram of ribs
Label this diagram of intercostal muscles
What happens when you inhale?
diaphragm contacts (flattens)
external intercostal muscles contract
ribcage moves out and upward
volume of chest cavity increases
pressure inside decreases
air rushes into lungs to equalise pressure
What happens when you exhale?
diaphragm relaxes (moves upwards)
internal intercostal muscles contracts
ribcage moves down and inward
volume of chest cavity decreases
lung volume increases
pressure inside lungs increases
air flows out of lungs due to high pressure