Gas exchange Flashcards
(23 cards)
Counter-current flow
Blood flows in opp direction to water
-blood has little O2 and extracts from water
-If no gaseous exchange it will meet an equilibrium
How does the trachea control O2 uptake in insect
-Modifying SA for exchange
- low = tracheal fluid leaks into tracheoles
Diseases with breathing
Chronic Bronchitis
Asthma
Why is there always residual volume in the lungs
Lungs cannot be completely flattened
- trachea held open by cartilage
-Bronchioles/bronchi held open by elastic fibres
Vital Capacity/ Residual/ Tidal volume
- Maximum volume of air moved by the lungs in one breath (varies age/height/gender)
- Volume of air left in the lungs after forced exhalation
- Volume of air moved in and out of the lungs in one breath (0.5dm3)
Tissues in trachea and bronchi
-Thick several layers of cartilage
- Cartilage, C rings - inside glandular and connective tissue, elastic tissue, smooth muscle, blood vessels
- inner lining - ciliated epithelium, goblet cells
Bronchioles tissue
Smooth muscle
What is secreted to prevent friction between ribcage and lungs during ventilation
A lubricator
Inspiration
- External intercostal muscles contract
-Ribs move up and out
-Diaphragm contracts
-Volume of thorax increases
-Pulmonary greater than atmospheric
-Air pushed out
Expiration
- Internal intercostal muscles contract
-Ribs move down and in
-Diaphragm relax
-Volume of thorax decreased
-Pulmonary lower than atmospheric
-Air pushed in
Spirometer
Measures the volume and function of the lungs
-Inhalation/exhalation moves lid
-recorded by data logger
- CO2 Soda lime chamber
Physiological changes that occur when we exercise
- Volume of air breathed in/ out increases
-More O2 to alveoli - Conc maintained at a higher level and o2 transported via blood
Mechanism of ventilation that enables more air to enter/leave
-Diaphragm contracts more
- Internal intercostal muscles contract more
Why do insects have a tracheal system
-open circulatory
- flow affected by bodily movements
- Cannot easily direct blood flow
- Air diffuses into spiracoles so can be directed where needed
- O2 can diffuse more quickly than in a liquid
Cell below the llamle of a fish
the squamous epithelium
What is at the end of the tracheoles
Tracheal fluid, so gases can dissolve and diffuse into cells
- spiracoles open/close to prevent excessive water loss
Why does a fish need to be in water
-gill filaments and llamle will stick together and there will no longer be a SA for exchange
- gills will eventually dry out
Sharks don’t have an operculum and some have lost their ability to pump water through the buccal cavity, why will they drown if they stop moving
-Buccal pump and operculum pump water over the gills
-If unable to pump water, flow wills top if the fish stops moving
- all O2 in gills gets used up
What does the squamous epithelium provide
A short diffusion distance
Glandular tissue
Produces mucous
What do many small blood vessels give
A large SA which means quicker diffusion than a few big ones
Fish ventilation
-Open mouth
-Lowering floor of buccal cavity
- Water in
- Close mouth
- Buccal cavity raises, increasing pressure
- Water forced over the gill filaments by difference in pressure between mouth cavity and opercular cavity
Suggest mechanism by which irritant could cause constriction of the airways
- Irritant inhaled
- Irritant has shape that is complimentary to shape of receptor on the plasma membrane of the smooth muscle cells
- Smooth muscle responds by contracting
