Respiratory system Flashcards
(38 cards)
Inspiration:
Diaphragm contracts/ flattens/ moves downwards
Intercostal muscles contract to move ribs up/out
Increase volume of thorax
Reduce pressure of thorax below atm pressure/ pressure gradient (-ve)
Adaptation of lungs:
Many alveoli - more s.a. for CO2/ O2 to diffuse
Epithelium of alveoli is very thin - short diffusion distance
Capillaries running over surface of alveoli - delivers CO2 (to be removed from blood)/carries O2 away (from alveoli)
Lungs surrounded by diaphragm/ icm- ventilation/ supply of O2/ removal of CO2
1 volume, inside/ of, jar increases ;
2 pressure inside, jar/ balloons, decreases;
3 to below pressure in atmosphere; [idea of creating a pressure gradient (between balloon and exterior)// Note: ‘makes pressure in jar lower than atmosphere’ = 2 marks]
4 (therefore) air, moves/ pushed/ forced, into, balloons/
glass tube; [flows / enter / fills]
Define tidal volume: (2mks) [f211 june14 q2bi]
1) volume of air, inhaled/ exhaled; [breathed / moved, in (and / or out of lungs)]
2) in, one/ each, breath;
3) during, steady/ regular, breathing; [at rest / during steady exercise / normal / quiet breathing]
Suggest how the bell-jar model may be used to demonstrate tidal volume: [f211 june14 q2bii]
1) up/ down, movements (of rubber sheet / band); [pull / push on rubber sheet / band // pull / push and let go]
2) small/ steady/ regular, movements (of rubber sheet); [rhythmically / in time with breathing / repetitively // Note: pulled down slightly = 2 marks]
Define vital capacity: [f211 june14 q2biii]
1) the maximum volume of air; [tidal volume + inspiratory reserve + expiratory reserve = 2 // total lung capacity – residual volume = 1 mark]
2) inhaled/ exhaled, in one breath; [breathed, in / out, in one breath]
Suggest how the bell-jar model may be used to demonstrate vital capacity: [f211 june14 q2biv]
pull down on rubber, sheet/ band, as far as possible and pushed up as far as possible [pull / push in either order // pull and push as hard as possible]
Role of squamous epithelium in lungs: [f211 june13 q2c]
short(er) diffusion, distance / path ; [reduced / shorter diffusion distance// thin diffusion barrier]
Role of large no of alveoli in lungs: [f211 june13 q2c]
large(r) surface area ; [increases surface area// (do NOT ref to sa : vol ratio) ]
Role of good supply of blood in lungs: [f211 june13 q2c]
high / large / steep, concentration gradient
OR removes oxygen (from lung surface) / brings carbon
dioxide (to lung surface); [maintains / creates concentration gradient// do NOT ref to diffusion grad.) ]
Role of good ventilation in lungs: [f211 june13 q2c]
high/ large/ steep, concentration gradient OR supplies oxygen (to alveoli)/ removes carbon dioxide
(from alveoli) ; [maintains/ creates concentration gradient]
Explain what causes the change in the volume of air
between point B and C on Fig5.1 (during expiration):
(4mks) f211 jun12 q5b
1 (external) intercostal muscles / diaphragm, relax ; [ref to internal intercostal muscles contracting]
2 rib cage / ribs, move down OR diaphragm, moves /
pushed, up ;
3 volume of, thorax / chest cavity / lungs, drops /
decreases ; [‘space inside’ or ‘air in’ for volume]
4 pressure inside, thorax / chest cavity / lungs, increases ;
5 above, external / atmospheric, pressure ; [(pressure) higher than outside]
6 air leaves down pressure gradient ;
7 (elastic) recoil of alveoli ;
Suggest why it is not possible to expel all the air from the lungs (tidal volume): (2ks) f211 jun12 q5d
1 thorax / rib cage / lungs, cannot be completely, compressed/ flattened;
2 trachea/ bronchi, held open by cartilage;
3 bronchioles/ alveoli, held open by elastic fibres;
4 [absence of pressure gradient/ atmospheric and thoracic pressure equal// presence of surfactant in alveoli// upward movement of diaphragm limited collagen fibres]
Using the mammalian gaseous exchange system as an example, explain how the different cells and tissues enable the effective exchange of gases. (5mks) [f211 june11 1c]
C1 thin / squamous, epithelium;
C2 thin endothelium (of capillary);
F1 (provides) short diffusion distance; [diffusion barrier , thin / one cell thick]
F2 ref to surfactant (from epithelial cells), reducing surface tension/ preventing alveoli collapsing;
C3 blood/ red blood cells/ erythrocytes; [blood supply/ supply of blood]
F3 transports (named) gas(es), to/ from, exchange surface/ alveoli;
C4 diaphragm/ intercostals, muscles;
F4 (maintains/ creates) diffusion/ concentration, gradient;
C5 ciliated epithelium/ goblet cells/ ciliated cells;
F5 idea of: protection from/ removal of, dust/ bacteria/ pollen/ spores; [trap, dust/ bacteria/ pollen/ spores]
C6 cartilage;
F6 hold airway open;
C7 smooth muscle;
F7 constrict/ control diameter of, airway/ blood vessel; [narrows lumen]
C8 elastic, fibres/ tissue;
F8 for recoil/ aiding ventilation; [prevent alveoli bursting]
C9 macrophage/ neutrophil;
F9 engulf/ destroy pathogens or protect from infection;
{{different q: many alveoli to produce large SA; barrier, thin/ only 2 cells thick; good blood supply/ many capillaries; to carry dissolved gases to and from the alveoli; ventilation to refresh the air in alveoli; contains elastic tissue to stretch and recoil to help expel air}}
Describe how the spirometer would be used to measure tidal volume. (3mks) [june11 5ai]
1 idea of not breathing through nose ; [e.g. subject wears nose clip / plug or holds nose]
2 subject breathes , evenly / normally / regularly ;
3 idea of (measure) height / amplitude , of waves
(from trace) ; [(measure) difference between peak
and trough]
4 measure at least three waves and calculate mean ;
5 detail of how spirometer works ; [e.g. as breathe in lid goes down / as breathe out lid goes up; e.g. movement of lid recorded , on trace / by data logger
e.g. pen attached to lid moves up/down as breathe;
DO NOT CREDIT description of water level
changing IGNORE ref to using mouthpiece, soda lime,
oxygen]
Using the axes below, complete the spirometer trace that you expect to see recorded from a healthy sixteen year old over ten further breaths, while at rest.
Describe how you could use a spirometer trace to measure the rate of oxygen uptake. [june11 5aiii]
10 further waves drawn with similar heights ;
trace falls ;
[Look for 10 extra peaks and 10 extra troughs
Note ‘similar’ means no wave drawn for vital capacity
– all waves should be approximately same
height]
Suggest two factors that should be considered when carrying out a risk assessment for an experiment using a spirometer. [june11 5b]
1 measure , volume of oxygen used/ decrease in volume in chamber; [‘measure how much the trace has
gone down’ or ‘measure decrease in trace’]
2 one detail of how to measure volume change; [e.g. draw line along tips of , peaks / troughs
e.g. find difference in height from one ,
peak / trough , to another]
3 measure time taken (to use this oxygen); [(measure volume of oxygen used) in a
given time]
4 divide (volume) by time taken; [unit stated to indicate rate has been
calculated e.g. dm3s-1 / dm3min-1]
NOTE ‘draw line along tips of, peaks / troughs and
calculate gradient of line’ = 3 marks
(mark points 1, 3 & 4)
Function of elastic tissue: [june10 1c]
function in the lungs: recoil/ OR return to original, size/ shape OR to help expel air OR prevents alveoli bursting [IGNORE stretch / expand ACCEPT ref to lungs, alveoli, airways recoiling etc DO NOT CREDIT ref trachea / bronchi recoiling]
Function of ciliated epithelium: [june10 1c]
waft/ wave/ move, mucus [transport / remove, mucus DO NOT CREDIT dirt particles without ref to mucus]
Function of goblet cells: [june10 1c]
secrete / release / produce, mucus
Function of smooth muscle: [june10 1c] [june09 1aiii]
constrict the airway [narrows lumen OR controls, airflow / diameter, of airways];
to constrict the bronchus [june09 1aiii]
Describe how goblet cells and ciliated cells work together to keep the lung surface clear of dust and other particles. [june09 1aii]
(goblet cells) secrete mucus;
(mucus) traps, dust / particles / named particle; [bacteria / microorganisms / pathogens]
ciliated cell/ cilia, wave / waft / move, mucus;
to, top of trachea / back of mouth;
Explain why blood capillaries and alveoli are very close together. [june09 1bi]
short, distance / path;
(so that) diffusion / concentration, gradient is, high/ steep; high rate of, (gas) exchange/ diffusion
[high rate of movement of named gas in correct direction ‘rapid’/ fast/ quick; ref to efficient, gas exchange/ diffusion]
The walls of the alveoli contain elastic fibres.
State the function of these elastic fibres: [june09 bii]
recoil / expel air / prevent bursting; [exhale more completely / force air out ]
