respiration

Question 1

cells in the trachea

Answer 1

goblet cell and ciliated cell

Question 2

func of goblet cell

Answer 2

secretes mucus which traps foreign pathogens and particles

Question 3

func of cilia

Answer 3

sweep foreign particles trapped in mucus up and out of trachea

Question 4

alveoli: one cell thick wall

Answer 4

decr distance for diffusion, incr rate of gaseous exchange

Question 5

alveoli: thin film of moisture

Answer 5

allows gases to dissolve, incr rate of diffusion into alveolar capillary

Question 6

alveoli: rich supply of blood capillaries

Answer 6

constant flow of blood in capillaries maintains a steep conc gradient btw alveolus and capillary, incr and constant rate of gaseous exchange

Question 7

alveoli: bulbous shape and numerous

Answer 7

incr sa:v, incr rate of gaseous exchange

Question 8

absorption of o2 into bloodstream

Answer 8

1. alveolar air contains higher o2 conv than blood, o2 diffuses into alveolar cavity and binds reversibly with haemoglobin in rbc
2. rbcs in capillary contain higher o2 conc than tissue fluid, o2 diffuses into tissue fluid to tissues

Question 9

role of carbonic anhydrase

Answer 9

catalyses reversible conversion of co2 and h2o to h2co3

Question 10

when inhaling, external intercostal muscles

Answer 10

contract

Question 11

when inhaling, internal intercostal muscles

Answer 11

relax

Question 12

when inhaling, diaphragm muscles

Answer 12

contract

Question 13

when inhaling, diaphragm

Answer 13

flattens

Question 14

when inhaling, thorax

Answer 14

volume incr, pressure decr

Question 15

when inhaling, lungs

Answer 15

expand, volume incr, pressure decr to less than atmospheric pressure

Question 16

when exhaling, external intercostal muscles

Answer 16

relax

Question 17

when exhaling, internal intercostal muscles

Answer 17

contract

Question 18

when exhaling, diaphragm muscles

Answer 18

relax

Question 19

when exhaling, diaphragm

Answer 19

arches

Question 20

when exhaling, thorax

Answer 20

volume decr, pressure incr

Question 21

when exhaling, lungs

Answer 21

compress, volume decr, pressure incr to higher than atmospheric pressure

Question 22

when inhaling, ribcage

Answer 22

swings up and out, sternum raised

Question 23

when exhalation, ribcage

Answer 23

swings down and in, sternum lowered

Question 24

nicotine (3)

Answer 24

1. addictive, stimulates secretion of adrenaline, inccr heart rate and bp
2. promotes blood clotting, incr rate of blood clots in vessels, incr risk of coronary heart disease
3. suppresses insulin secretion, incr in blood glucose levels

Question 25

carbon monoxide (3)

Answer 25

1. binds irreversibly with haemoglobin to form oxyhaemoglobin, decr o2 transport efficiency of rbcs
2. incr rate of fatty deposits on inner arterial walls, incr risk of atherosclerosis
3. damages lining of blood vessels, incr risk of blood clotting in arteries

Question 26

tar

Answer 26

1. carcinogenic, cuases uncontrolled cell division in epithelium, incr risk of lung cancer
2. paralyses cilia, failure to remove dust particles trapped lining airways, reduces gas efficiency if air sacs are blocked
3. incr risk of chronic bronchitis and emphysema

Question 27

irritants

Answer 27

paralyses cilia, failure to remove dust particles in trachea, incr risk of chronic bronchitis and emphysema

decr gas exchange efficiency

Question 28

chronic bronchitis (3)

Answer 28

1. chronic inflammation of bronchi
2. cilia gets paralysed, mucus and dust particles cannot be removed from airway, breathing difficulties due to blocked airways
3. persistent coughing to clear airways, lung infection

Question 29

emphysema (4)

Answer 29

1. breathing difficulties due to damage of alveoli and bronchioles
2. persistent inflammation + violent coughing –> breakage in alveoli partition walls
3. lung becomes inflated with air and loses elasticity
4. sa:v ration decr, breathing difficulties (wheezing, breathlessness)

Question 30

lung cancer

Answer 30

1. uncontrolled division of cells in lungs that gives rise to tumours