respiration Flashcards
cells in the trachea
goblet cell and ciliated cell
func of goblet cell
secretes mucus which traps foreign pathogens and particles
func of cilia
sweep foreign particles trapped in mucus up and out of trachea
alveoli: one cell thick wall
decr distance for diffusion, incr rate of gaseous exchange
alveoli: thin film of moisture
allows gases to dissolve, incr rate of diffusion into alveolar capillary
alveoli: rich supply of blood capillaries
constant flow of blood in capillaries maintains a steep conc gradient btw alveolus and capillary, incr and constant rate of gaseous exchange
alveoli: bulbous shape and numerous
incr sa:v, incr rate of gaseous exchange
absorption of o2 into bloodstream
- alveolar air contains higher o2 conv than blood, o2 diffuses into alveolar cavity and binds reversibly with haemoglobin in rbc
- rbcs in capillary contain higher o2 conc than tissue fluid, o2 diffuses into tissue fluid to tissues
role of carbonic anhydrase
catalyses reversible conversion of co2 and h2o to h2co3
when inhaling, external intercostal muscles
contract
when inhaling, internal intercostal muscles
relax
when inhaling, diaphragm muscles
contract
when inhaling, diaphragm
flattens
when inhaling, thorax
volume incr, pressure decr
when inhaling, lungs
expand, volume incr, pressure decr to less than atmospheric pressure
when exhaling, external intercostal muscles
relax
when exhaling, internal intercostal muscles
contract
when exhaling, diaphragm muscles
relax
when exhaling, diaphragm
arches
when exhaling, thorax
volume decr, pressure incr
when exhaling, lungs
compress, volume decr, pressure incr to higher than atmospheric pressure
when inhaling, ribcage
swings up and out, sternum raised
when exhalation, ribcage
swings down and in, sternum lowered
nicotine (3)
- addictive, stimulates secretion of adrenaline, inccr heart rate and bp
- promotes blood clotting, incr rate of blood clots in vessels, incr risk of coronary heart disease
- suppresses insulin secretion, incr in blood glucose levels
carbon monoxide (3)
- binds irreversibly with haemoglobin to form oxyhaemoglobin, decr o2 transport efficiency of rbcs
- incr rate of fatty deposits on inner arterial walls, incr risk of atherosclerosis
- damages lining of blood vessels, incr risk of blood clotting in arteries
tar
- carcinogenic, cuases uncontrolled cell division in epithelium, incr risk of lung cancer
- paralyses cilia, failure to remove dust particles trapped lining airways, reduces gas efficiency if air sacs are blocked
- incr risk of chronic bronchitis and emphysema
irritants
paralyses cilia, failure to remove dust particles in trachea, incr risk of chronic bronchitis and emphysema
decr gas exchange efficiency
chronic bronchitis (3)
- chronic inflammation of bronchi
- cilia gets paralysed, mucus and dust particles cannot be removed from airway, breathing difficulties due to blocked airways
- persistent coughing to clear airways, lung infection
emphysema (4)
- breathing difficulties due to damage of alveoli and bronchioles
- persistent inflammation + violent coughing –> breakage in alveoli partition walls
- lung becomes inflated with air and loses elasticity
- sa:v ration decr, breathing difficulties (wheezing, breathlessness)
lung cancer
- uncontrolled division of cells in lungs that gives rise to tumours
