Exam Feedback 2 Flashcards
(16 cards)
What is the function of the layer of cartilage and why is it not in a complete ring?
to prevent the trachea from closing and to allow room for the oesophagi to expand when swallowing food
How does movement of rib cage cause the changes in the pleural and alveolar pressures (in inspiration)?
intercostal muscles contract, outer pleural membrane is pulled outwards, reducing pressure in pleural cavity and pleural membrane pulls on lungs so alveoli expands and air moves in when a;violation pressure is lover then atmospheric pressure
One medical use of surfactant + why is it used?
Lung transplants - lowers the surface tension of the fluid in the alveoli to prevent alveoli from collapsing
Describe change in fluid level in the tracheoles during flight
fluid moves into muscle fibres so there is more area for gaseous exchange
What is a chemoautotroph?
An organism that uses chemical reactions to form complex organic matter
What is an autotroph?
Uses simple inorganic molecules to synthesis complex organic compounds
What is the function of mucus in digestion process?
- prevents autolysis of enzymes on the gut wall
- lubricate the food
Where are carbohydrates digested?
in the small intestine
Why is is better combining endo and exopeptidases together?
The combination gives more ends for the exopeptidases to work on so more free amino acids are released
How does a large blood loss affect the filtration rate?
Blood pressure is decreased so there is less filtrate formed
What product requires least volume of water for excretion?
Uric acid (by birds) - good because it’s light for flying and little mass for storage of eggs
How is the nephron adapted for ultrafiltration?
- capillaries have fenestrations so small molecules can squeezethrough
- high hydrostatic pressure due to lumen of afferent and efferent arteriole
- filtration slits within podocytes
Why do patients with kidney disease need a protein controlled diet and low sodium chloride intake?
- high protein means more urea which cannot be removed
- excess salts don’t need to be removed as high salt causes high blood pressure
Why is there a hole between right and left atrium in foetal development?
- lungs are not functional
- hole allows blood to pass from right to left atrium
What one disadvantage of a dissociation curve shifted to the left?
It is difficult for oxygen to dissociate/only dissociates and very low PPO2
