b2 Flashcards
state one other function of the kidneys
osmoregulation
state the function of surfactant
reduces surface tensions of water and stops alveoli collapsing
explain why a person with emphysema produces less ATP than a healthy person
because there is a decreased surface area which means less alvelo therefore less diffusion of O2 in the blood which means no enough O2 for aerobic respiration
explain why it is important for the wallas of the alveoli to be moist
enables gaseous exchange
because stops alveoli collapsing
due to reduction in surface tension so gives large surface area
Explain why soda lime is used in the spirometer
to remove carbon dioxide because CO2 is toxic and it can alter breathing rate so oxygen consumption can be calculated
Explain how the movements of the rib cage and diaphragm enable a person to inhale
ribcage muscles contract
ribcage moves up and expands
diaphragm contracts
lowers moves down
which causes an increase in volume
lungs expand
so pressure in lungs reduces
Discuss how the structures in the lungs are adapted to enable them to carry out their function. You may include annotated diagrams to support your answer
bronchi/bronchioles
•distributes air to lungs/many alveoli
• no gaseous exchange from these tubes
• air pathway
• bronchi walls contain cartilage to keep them open
• bronchi and bronchiole walls contain smooth muscle (which can
relax/contract) so these airways can dilate/constrict
• bronchi lining contains goblet cells and cilia
• goblet cells produce mucus that traps pathogens/particles
cilia beat to move mucus up and out of airways
• lungs are protected by ribs/ribcage
. close proximity to heart enabling fast re-oxygenation of blood
Alveoli
• primary function is gaseous exchange
• many of them
• gives large surface area
• diffusion of gases
• short diffusion distance
faster rate of diffusion of gases
. reference to Fick’s law
5 Discuss how the structures in the lungs are adapted to enable them to carry out their function. You may include annotated diagrams to support your answer.
Bronchi/bronchioles/bronchial tubes/bronchial tree/airways/trachea:
• distributes air to lungs/many alveoli
• no gaseous exchange from these tubes
• air pathway
• bronchi walls contain cartilage to keep them open
• bronchi and bronchiole walls contain smooth muscle (which can
relax/contract) so these airways can dilate/constrict
• bronchi lining contains goblet cells and cilia
• goblet cells produce mucus that traps pathogens/particles
(6)
cilia beat to move mucus up and out of airways
• lungs are protected by ribs/ribcage
. close proximity to heart enabling fast re-oxygenation of blood .
pleural membranes secrete pleural fluid (into cavity) to reduce friction/make breathing easier
surfactant/moisture prevents alveoli collapsing (which would reduce SA
•
for gas exchange)
• {elastin/elasticity} for stretch and recoil
Capillaries/blood supply:
• maintain (steep) concentration gradient
. maintains diffusion (uf yases).
Increased air flow enables faster rate of diffusion of oxygen (from alveoli blood)/carbon dioxide (from blood to alveoli) /more efficient gaseous exchange.
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D e s c r i p t o r
No rewardable material.
Demonstrates adequate knowledge of scientific facts/concepts with generalised comments made.
Generic statements may be presented rather than linkages being made so that lines of reasoning are unsupported or partially supported.
The discussion shows some structure and coherence
Demonstrates good knowledge and understanding by selecting and applying some relevant scientific knowledge facts/concepts to provide the discussion being presented.
Lines of argument mostly supported through the application of relevant
e v i d e n c e .
The discussion shows a structure which is mostly clear, coherent and
logical.
Demonstrates comprehensive knowledge and understanding by selecting and applylng relevant knowledge of sclentific facts/concepts to provide the discussion being presented.
Line(s) of argument consistently supported throughout by sustained application of relevant evidence.
The discussion shows a well-developed structure which is clear, coherent and logical.
what is the structure of alveoli
large surface area = more space for gas molecules to pass theough
short diffusion pathway = walls are made of squamous epithelial cells and are only one cell thick this reduces the distance these molecules have to diffuse through
capillary network = each alveolus is close to a capillary which has a walla which is also one call thick to give SDP for molecules
diffusion gradients = O2 diffuses from a high conc inside alveoli dowb a conc gradient to an area of lower conc in blood and are maintained by ventillation
moisture = a layer of moisture lines the alveoli
describe inspiration
• external intercostal muscles contract pulling rib cage up and out
• thoraic vol increases
• pressure in lungs reduces lower than atmospheric pressure
• air moves into lungs down a pressure graduent
decribe expiration
• external intercostal muscles relax so rib cage moves down and in
• thoraic vol decreases pressure in lings greater than atmospheric pressure
• air moves out of lungs down a pressure gradient
a mechanical ventilator can be used to asist breathing these are used in cases where patients have
muscle weakness
severe lung infection
describe the pathway of oxygen from the atmosphere to the blood
squamous epithelial cell of alveoli > endothelial walla of capillary higher O2 to lower O2 >
CO2 moves from blood into alveoli
describe the peak flow meter
before each use make sure sliding point on peak flow meter is reset to the 0 mark
hold the PFM by the handle
stand up straight
remove chewing gum, candy or food from your mouth
take a deep breath and put the mouthpiece in your mouth. seal your lips and teeth tightly around the mouthpiece
blow our as hard and fast as you can. a fast blast better than slow blow
note the number where the sliding pointer has stopped on the scale
reset the pointer to zero
repeat 3 times the 3 readings should be close together if not adjust your technique
if you cough during a measurement repeat the measurement
describe the use of a spirometer
a spirometer consists of a chamber filled with oxygen that floats on a tank of water. a disposiable mouthpiece is connected to a tube.
this is connected to the tank and the patient breathes in and out
breathing in= removes oxygen from the chanber so it moved down
breathing out = pushes carbon dioxide in so the chamber moves up
the movement of the chamber up and down is recorded using a datalogger and produces a trace
soda lime is attached to the tube to absorb CO2 that is breathed out
this means the total volume of gas in the spirometer will gradually decrease
the volume of CO2 breathed out is the same as the volume of oxygen breathed in
this means that as the CO2 is removed the total decrease equals the vol of oxygen used by the person
the trace shows a slope and this can be used to measure the vol of oxygen used in a certain time
