Respiratory system Flashcards
Fick’s law of diffusion
depends on thickness of tissue
concentration of gases on either and the SA of the tissue
birds’ method of breathing
breath in once to posterior air sac, expire to internal
mid air sac, inspire to anterior air sac, expire out of body
mammals method of breathing
tidal breathing
- Fresh air not moving during half breathing cycle
- No countercurrent exchange
- Incoming air mixes with stale
- Dead space
amphibians method of breathing
positive pressure breathing
- nostrils open, drop pressure by dropping floor of mouth
- force air inside lungs by raising floor of mouth & closing nostrils
- bring air to mouth by dropping floor of mouth again
- forcing air out of mouth by reopening nostrils and raising floor of mouth
myoglobin vs haemoglobin, which is better?
myoglobin
control of breathing where (brain)
- Pons/medulla (brain stem) contract diaphragm
- PCO2 sensed by medulla: sensitive
- PO2 sensed by nodes in aorta and pulmonary artery: relatively insensitive
adaptations of diving mammals
Small lung volume, exhale before dive 2 x [Hb] Higher myoglobin Neuroglobin, cytoglobin Spleen storage Skeletal muscle buffer Gravity dives (less energy)
other respiratory pigments and location
Neuroglobin – nerve cells, cytoglobin - fibroblasts
what are fibroblasts?
Fibroblasts are the most common cells in connective tissue. Their main function is to maintain the structural integrity of the connective tissue
key part of fish respiration
counter-current flow mechanism
key functions of gills
- gas exchange organ
- osmoregulation and ion balance
- pH regulation
- immune function
what does the hormone Endothelin do?
can control blood to gill (fish)
where are pavement cells found and what do they do?
found in gills of fish
increase SA as have lots of ridges/microvilli
Insect method of breathing
Spiracles
Tracheae & tracheaoles
Air capillaries
Passive & body movements
Diving insects
Grab bubble of air
