To support ___, cells take in oxygen and give out carbon dioxide by a process called ___ .
aerobic respiration | cellular respiration
aerobic respiration | gaseous exchange
anaerobic respiration | gaseous exchange
Gaseous exchange -the exchange of gases between an organism and its environment- takes place by..
Highlight the factors that determine the rate of diffusion in living things.
the amount of oxygen available in the blood stream only
the amount of carbon dioxide in the body
the size of the surface area available for gaseous exchange
the difference in concentration
the length of an organism
the length of the diffusion path
the size of a living thing only
The shorter the diffusion path, the lower the rate of diffusion -so the respiratory surface must be as thin as possible.
Many multicellular animals have very many of their cells too far away from the body surface to receive enough oxygen by diffusion alone.
Active organisms have an ___ metabolic rate and so require more___ in their cells; mammals have specialised organs for gaseous exchange.
increased | oxygen
decreased | oxygen
increased | carbon dioxide
decreased | carbon dioxide
In mammals the respiratory surface consists of..
Since the lungs are in a protective position inside the ___, air must be brought to the respiratory surface and so the lungs must be ___ .
chest | freed
oesophagus | cushioned
trachea | ventilated
thorax | ventilated
A ventilation system is..
an enzyme-activated mechanism that moves air in and out of the lungs efficiently, maintaining the concentration gradient for diffusion.
a pumping mechanism that moves air in and out of the lungs efficiently, maintaining the concentration gradient for diffusion.
a pumping mechanism that moves air into the lungs efficiently, maintaining the concentration gradient for diffusion.
a pumping mechanism that moves air out of the lungs efficiently and maintains the concentration gradient for facilitated diffusion.
The lungs are housed in the thorax, an ___ formed by the ___ and its ___ with a domed floor, the ___ .
airtight | rib-cage | intercostal muscles | diaphragm
impervious | rib-cage | intercostal muscles | abdomen
upright | rib-cage | muscles | diaphragm
airtight | ribs | intercostal muscles | stomach
The internal surfaces of the thorax are lined by the..
finger-like projections, villi
This membrane secretes ___ which is a lubricating liquid derived from ___ and protects the lungs from friction during breathing movements.
serotonin | platelets
pleural fluid | blood plasma
pleural fluid | platelets
oxytocin | platelets
The ___ work together to prevent food from entering the __ which which connects the lungs to the ___ at the rear of the mouth and runs beside the ___ .
glottis and epiglottis | trachea | pharynx | oesophagus
glottis and cartilaginous flap | trachea | pharynx | oesophagus
glottis and epiglottis | oesophagus | pharynx | trachea
glottis and epiglottis | pharynx | trachea | oesophagus
Air is drawn into the alveoli when the air pressure is lower in the lungs than in the atmosphere; it is then forced out when the situation reverses.
The volume of the thorax is decreased when the ribs move up and out an the diaphragm dome is lowered.
The volume of the thorax is decreased by the diaphragm muscles relaxing and becoming more dome shaped by pressure from below; the ribs now move in and down as the intercostal muscles relax.
The lung tissue consists of the alveoli, arranged in clusters and served by a bronchiole. They have ____ and a ___ system wraps around the clusters of them and is connected to the ___ and is drained by a branch of the ___ .
integral walls | capillary | pulmonary artery | pulmonary vein
elastic connective tissue | capillary | pulmonary artery | pulmonary vein
elastic connective tissue | capillary | pulmonary vein | pulmonary artery
Highlight the advantageous features of alveoli.
thick walls -prevent pathogens from crossing into blood stream
Large surface area
only artery supply to alveoli
Thin walls -short diffusion path
compact small surface area
capillary supply to alveoli
surface film of moisture