exchnage systems
gas exchange in different organisms
insects
tracheal system
trachea- inner tubulues
tracheoles- are smaller opening which span across the insects body and have tracheal fluid at the end where gas exchnage occurs
spiracles- pores in the insects body
process
from muscle contraction this squeezes the trachea allowing mass transport of air in and out
the anaerobic respiration occurs and water potential lowered as tracheal fluid goes into the cells which means that there is lower water potential in the tracheoles so more air goes into tracheoles from atmosphere
through a concentration gradient as oxygen goes into the cells from the tracheoles and is used up and this decreases the amount of oxygen so more goes in down the concentration gradient through the atmosphere to the trachea to the tracholes to the body
why they are small: to provide a short diffusion pathway
have a complex gas exchnage system as there is a chitin exoskeleton so air cant diffuse and also due to activity
fish
need a good gas exchnage system as oxygen saturation of water is 1%
there gas exchnage system is the gills
there is 2 bony arches made up of gill filaments
they have lamella which is a capillary network covered by a layer of epithelial cells
they have an operculum which creates one directional flow
counter current flow in fish when two liquids (Blood and water flow in opposite directions due to the orientation of the gill and lamellae which is important as it means that blood is always goig past water with highoxyen so concentration gradient formed all along the gill so gas exchnage is 80% not 50%
plants
adapatations of plants for gas exchnage
there is air spaces in the mesophyll layer so that diffusion can occur in the gaseous phase
abundance of stomata so that no cell is far from a stomata
Large Surface area of mesophyll cells for fast diffusion
how plants conserve water
waxy cuticle
by closing stomata
stomata situated in groove/ hair on leaf/ leaf rolled up to create a layer of still air which has mositure to have no water potential gradient so it doesnt leave tje plant
smaller SA of leaves
how insects conserve water
small SA
chitin exoskeleton
spiracles close at rest
gas exchange for humans
need an elaborate gas exhcnage system as each cell has its own matabolism and own temeprate which is maintained due to respiration
structure
nasal cavity- in the sinuses there is good blood supply to warm and thus moisten air. also has cells which prouce mucus that stops infection through trapping dirt and bacteria
trachea- tube that passes air to the bronchi . They have rings of hard cartilage which allow it to withstand pressure changes and between elastic and muscle fibres to allow flexibility
bronchioles that have muscle and elastic tissue which allow them to contracr and relax easily for ventilation
bronchi carry air to the bronchioles. Thyey have cartilage which allows them to withstand pressure changes
ventilation air moving in and out
mini air sacs lined with epithelium and alveoli are where gas exchnage occur s and covered with a capillary network
adaptations
muscle involvment
external and internal intercostal muscles both sets situated between the ribs
diaphragm muscle- a thin layer of muscle beneath the lungs
inspiration : 1) internal intercostal muscles relax and external intercostal muscles contract 2) ribs move up and out 3) diaphragm contracts 4) this increases thorax volume 5) pressure in the atmosphere more than pressur ein lungs so inspiration occurs
expiration 1) external intercostal muscles relax and internal intercostal relax 2) the ribs move down and in 3) the diaphragm relaxes and this pushes the abdomen up 4) this decreases the thorax volume 5) pressur ein lungs greater than pressure in atmosphere 6) air moves out
pulmonary ventilation rate: the total air breathed in by lungs in one minute: tidal volume ( the amount of air taken in by each breath) x ventilation rate ( amount of breaths in one minute)
digestion - to break down large insoluble molecules into smaller soluble ones
chemcial digestion- hydrolysis into small soluble molecules
mechanical digestion- physical breakdown of food particles
ailementary canal- route that food passes down
mouth- teeth mechanically digest food
salivary glands- prodcue amylase which hydrolyses starch into maltose
the oesophagus- moves food from mouth to stomach and has smooth muscle for peristalsis
stomach- churns up food (mechanical digestion) amylase doesnt work due to the HCL. HCL aids in avoiding infection due to killing microorganisms. And HCL helps in breakdown. The lining of the stomach protects rest of body from acidic environment
Liver- produces bile which neutralises stomach acid and helps emulsification of fats
gall baldder- stores bile :
pancreas- prodcue pancreatic juice which includes enzymes such as carbohydrases lipases and proteases
the small intestine: peristalisis ccurs to keep them close to villi. There is villi and micro villi to allow a ;large surface area for absorption. Enzymes are also produced for chemical breakdown
lipids: emulisification of fats from globules into droplets from bile which provides a bigger SA making the lipase better at hydrolysis. Lipases hydrolyse triglycerides into fatty acids and monoglycerides
proteins: peptidases. 1) endopeptidases hydrolyses amino acid bonds and leads to many smaller polypeptide chains 2) exopeptidases: hydrolyse terminal amino acids so that there are dipeptides and AA dipeptidases: hydrolyses between dipeptides for single amino acids
starch: the salivary ducts produce amylase which hydrolyses starch to maltose and then in the small intestine mixes with pancreatic juice and maltose hydrolsysed into glucose by maltase and small intestine gives alkaline salts to make optimum pH
absorption
absorption : co transport
absorption: co transport
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