the exchange of CO2 and O2 between air and the blood
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where do..
a) CO2
b) O2
move from and to
a) blood to lungs
b) air inhaled into the lungs to blood
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between which two structures does gas exchange occur?
(the air in) the alveoli and (the blood in) pulmonary capillaries
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1. is oxygen concentration high or low in:
a) air in the alveoli
b) blood in the pulmonary capillaries
2. what does this tell us?
1. \
a) high
b) low
2. that oxygen diffuses from the alveoli to the pulmonary capillaries
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1. is CO2 concentration high or low in:
a) air in the alveoli
b) blood in the pulmonary capillaries
2. what does this tell us?
1. \
a) low
b) high
2. that CO2 diffuses from the pulmomary capillaries to the alveoli
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define breathing
the process of moving air in and out of the lungs
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what happens if a person stops breathing?
concentration of O2 in the alveoli drops as the oxygen moves to the pulmonary capillaries. when the O2 levels are equal between the two, O2 stops diffusing
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what are the 2 phases of breathing?
inhalation and exhalation
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do the lungs contain muscle?
no
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what is the diaphragm and what does it do?
a skeletal muscle separating the chest and abdominal cavities. when it contracts, we inhale
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which organs are in the thoracic cavity? (2)
which organs are in the abdominal cavity? (3)
thoracic- heart and lungs
abdominal- stomach, liver, intestines (+)
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what are the steps of inhalation (4)
1. diaphragm contracts and moves down 2. the thoracic cavity increases in volume 3. air pressure in the alveoli decreases 4. air from outside the body rushes into the lungs
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does the diaphragm move up or down when contracting?
down
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what are the steps of exhalation (4)
1. the diaphragm relaxes and moves up 2. the thoracic cavity decreases in volume 3. air pressure in the alveoli increases 4. air is squeezed out of the lungs
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how does the respiratory system clean itself? (2)
1) sticky mucus traps tiny particles
2) cilia lining the trachea beat, moving the mucus containing trapped particles up and out of the trachea
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where in the respiratory system are mucus-secreting goblet cells found? (3)
lining the trachea, bronchi and bronchioles
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what is internal respiration?
the process by which gases are exchanged between the blood and cells in the body
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what is external respiration?
the process by which gases are exchanged between the air in the alveoli and the blood in pulmonary cap.
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during internal respiration…
1. O2 diffuses from __ to __ 2. CO2 diffuses from __ to __
1. blood, body cells 2. body cells, blood
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during external respiration…
1. O2 diffuses from __ to __ 2. CO2 diffuses from __ to __
1. air in alveoli, blood 2. blood, air in alveoli
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what is the pleura?
a two layer membrane covering each lung and lining the thoracic cavity
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what is the pathway of air in the respiratory system? (8)
nose, pharynx, larynx, trachea, bronci, bronchial tubes, bronchioles and alveoli
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what are hollow spaces in the nose?
nasal passages
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what are 3 functions of the nasal passages?
to warm, moisten and filter air before it reaches the lungs
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how do humans make sounds?
by controlling vibrations of the vocal cords
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what is the larynx? what are the vocal cords?
larynx- voice box
vocal cords- two pairs of membranes stretched across the inside of the larynx
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what keeps the trachea open?
rings of cartilage in its walls
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how does smoking affect cilia?
smoking stops the motion of cilia for a short period of time
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name the…
a) number of cell layers in alveoli
b) number of alveoli in the lungs
c) total surface area of the alveoli
\
a) 1
b) 300 million
c) 70 square meters
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what is emphysema
scarlike tissue forms in the alveoli, reducing surface area and the elasticity of the lungs and causes shortness of breath
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what are the four stages of gas exchange?
breathing, external respiration, internal respiration, oxygen and carbon dioxide transport
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how many times does one breathe per minute?
12-25 times per minute
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which structure controls breathing?
the respiratory center
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what are chemoreceptors?
\-structures found in large arteries that sense the amount of O2 and CO2 in the blood
\-stimulates the respiratory center to increase breathing rate when CO2 increases
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what is oxyhemoglobin?
oxygen and hemoglobin that combine in the lungs
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which three ways is CO2 carried to the lungs?
1) combines with water and forms carbonic acid, then breaks down into hydrogen and bicarbonate ions -70%
2) combines with hemoglobin to make carboxyhemoglobin -20%
3) dissolves in plasma -10%
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what is…
a) asthma
b) bronchitis
a) allergic reaction causing a range of difficulty breathing. bronchioles spasm, squeezing air passages
b) bronchial tube lining becomes irritated/swollen, causing alveoli to swell and clog with mucus and coughing
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what is…?
a) pneumonia
b) lung cancer
a) alveoli fill with fluid, preventing gas exchange
b) tumours form in the lungs as a result of uncontrollable cell growth