Exchange surface > SA, cells > vol
Small organism - large SA:V
Large organism - small SA:V so exchange surfaces w/ large ratio, thin d dis, seletively permeable, medium movement conc grad, transport system for medium

Insects - trachae network sup by rings, tracheoles in tissues directly deliver gas maintain conc grad
Abdominal pump push air in out of trachea
H20 in trachea moves in muscle when produce lactate low h20 pot so D occurs in gas phase
Spiracles on surface to allow gas movement, usually shut prevent h20 loss
Save water loss: small SA:V, chitin h20proof cuticle, spiracles can open/close
------------------------------------------
Fish - gills behind head of gill filaments, gill lamellae on each one large SA, H20 comes from mouth over gills and out
Counter current flow for max conc grad and more absorbance

Plants - D in gas phase, stomata and air spaces so short diffusion distance, large SA:V ratio, stomata open/close w/ guard cells via osmosis to prevent water loss
Xerophytes: thick cuticle, roll up leaves/hairs on leaves/sunken stomata > region of still air saturated w/ h20, reduced SA:V balance photosynthesis/water loss
------------------------------------------
Trachea - airway w/ cartilage ring, muscle, ciliated epithelial, mucus
Bronchi - trachea divisions
Bronchioles - bronchi divisions, muscle, epithelial, control air in/out alveoli
Alveoli - airsacs, collagen/muscle between, 1 layer epithelial, surrounded by thin capillaries, RBC slowed, RBC against wall

Inspiration (active) - external intercostal contract, internal relax
Ribs move up/out ^thorax vol
Diaphragm muscle contract ^thorax vol
Atmospheric pressure lower than pulmonary, air moves in

Expiration (passive recoil/active strenuous) - internal intercostal contract, external relax
Ribs move down/in thorax vol dec
Diaphragm muscle relax thorax vol dec
Pulmonary pressure higher than atmospheric, air moves out
------------------------------------------
Oesphagus, stomach, ileum, large intestine, rectum, salivary glands (amylase), pancreas (protease/lipase/amylase)

Carbohydrates - saliva amylase hydrolyse starch > maltose, stops in stomach since acidic
Pancreatic amylase starch > maltose in ileum
Food pushed against membrane, maltase (membrane-bound) hydrolyse maltose > a-glucose
Sucrase and lactase can also be present

Proteins - endopeptidase, hydrolyse middle peptide bond for shorter chains
Exopeptidase - hydrolyse bonds at end of short chains to di and AA
Dipeptidase (membrane bound) - hydrole di to AA
------------------------------------------
Ileum - microvilli/blood capillary network, thin walls, muscles to mix

AA/monosaccharides - diffusion/co-transport

Triglycerides - lipase hydrolyse ester bond > fatty acids/monoglycerides
Bile salts emulsify forming micelles
Non-polar micelles break down, diffuse into epithelial CSM
In ER reform to triglycerides
In golgi associate w/ chloresterol/lipoproteins > chylomicrons
Chylomicrons undergo exocytosis into lymphatic capillaries
Enter bloodstream and hydrolysed by enzyme in endothelial cells to diffuse into cells
------------------------------------------
Each polypeptide chain associated with a haem group w/ Fe2+
Dif haemoglobin AA sequence = dif affinity

O2 associates at lungs, diassociates at tissues
High affinity = associates easily
Low affinity = disassociates easily

Haemoglobin changes affinity under presence of CO2 due to more acidity
Exchange surface - CO2 conc low so high pH, high affinity to associate and not lose
Tissue - CO2 conc is high so low pH, low affinity to disassociate, higher rate of resp = lower pH so more easily disassociated
------------------------------------------
Relationship of haem saturation, partial pressure
Left curve = higher affinity
Right curve = lower affinity
When CO2 conc high = curve shifts left
When CO2 conc low = curve shifts right

First O2 difficult to bind, polyp subunits close together
After one, shape changes so easier for others called positive cooperation
Low resp tissue - lose 1 O2, return w/ 75%
High resp tissue - lose 3 O2, return w/ 25%

Low O2 conc conditions - left shifted curve to readily associate
Smaller animals - big SA:V lose heat quick, respire more so right shifted
Bigger animals - opposite ^
------------------------------------------Closed double circulatory system - blood passes heart twice to boost speed, necessary due to ^temp/metabolic rate

Heart - 2 pumps, left oxygenated/right deoxygenated, necessary to low blood p to lungs, high to rest of body
Atrium - thin walls, elastic
Ventricle - thick walls
Bicuspid in left side, tricuspid in right side

Aorta - left ven, oxygenated blood to body (artery)
Vena carva - right at, deoxygenated blood from body (vein)
Pulm artery - right ven, deoxygenated blood to lungs (artery)
Pulm vein - left at, oxygenated blood from lungs (vein)
Coronary artery - provide heart w/ oxygenated blood
Renal artery - provide kidneys w/ oxygenated blood
------------------------------------------
Diastole - blood returns from pulm vein/vena carva, atrial blood p^
Once blood p^ enough, atrioventricular valves open, blood moves into ven
Ven walls are relaxed so p is lower than aorta/pulm artery, semilunar valve closed

Atriole systole - Atria contract, ven relaxed
Ventricular systole - after delay, both ventricles contract so p^
Atrioventricular valves close, pressure rises above aorta/pulm artery, semilunar valves open
Blood moves through

Cardiovascular valves - cusp shaped, flexible fiberous tissue, when p on convex side high, open pushing cusps apart
Atrioventricular - prevents backflow when ven contract
Semilunar - prevents ven backflow when elastic vessel walls recoil
Pocket - in veins

Cardiac output = heart rate x stroke vol
------------------------------------------
Fiberous outer layer - prevent p changes
Elastic - maintain p via recoil ac
Muscle - contract control blood flow
Endothilium - smooth/thin reduce friction
Lumen - central cavity

Arteries - high bp > tissues
Thick muscle, constrict/control blood vol
Thick elastic, maintain high bp by stretching at systole going back at diastole
Thick wall, stop bursting
No valves

Atrioles - slight lower p arteries > capillaries
Thicker muscle, constrict blood further
Thinner elastic, lower bp

Veins - low p capillaries > heart
Thin muscle, doesn't control flow into tissues
Thin elastic, too low bp for recoil/burst
Thin wall, allow flattening aid flow
Valves, prevent backflow when contract

Capillaries - exchange materials
V thin wall, short D dis
Branched, large SA
Narrow, travel through tissue, short D dis
Epithelium spaces, WBC escape
------------------------------------------
Liquid w/ useful materials, means of transporting between cells/blood

High HS p from heart at arterial end, everything except cells/proteins move out of capillaries via ultrafiltration
Forms tissue fluid on outside, waste materials exchange with useful materials in cells
Low HS p at vein end vs tissue fluid, tissue fluid moves back into capillaries
WP low in capillaries h20 moves in via osmosis and blood goes to the heart

Some TF becomes lymph enters lymphatic capillary, carries to heart via 2 ducts connected to veins
Possible by HS p of TF, contractions of muscles squeezing lymphatic capillaries
------------------------------------------
Transpiration causes h20 to be pulled up xylem: h20 moves out stomata from airspace in leaf to air w/ low humidity via diffusion
H20 in cell walls of sur mesophyll cell moves to airspaces via osmosis
Continues w/ neighbouring cells creating WP grad

Cohesion tension theory (passive/sun energy):
H20 molecules h bonded (cohesion), continuous unbroken column xylem > mesophyll
H20 drawn up as leaves from mesophyll (transpiration pull)
Trans puts xylem under tension due to -p
------------------------------------------Sieve tube elements - long tubes
Sieve plates - perforated end wall
Companion cells - associated w/ STE
Sources - sugars produced
Sinks - sugars required

Mass flow of sucrose down HS grad (active translocation):
Sucrose moves from photosynthesising cells via fac D/conc grad to companion cells from source
H+ ions AT into cell wall of companion cells
H+ ions fac D thru carrier protein into STE w/ sucrose via cotransport
Sucrose gives STE low WP so h20 moves in via osmosis from xylem (high HS p @ source)
Sucrose used up at sink so AT in companion cell
Low WP at sink h20 moves in via osmosis from STE (low HS p @ sink)
------------------------------------------
Evidence for xylem:
Tree trunks change diameter dif time of day
If xylem breaks, plant cannot draw up h20
If xylem breams, h20 doesn't leak since under tension

Evidence for phloem:
Pressure in STE
Sucrose conc ^ in leaves than roots
Sugar moves down in day, stops at night
Poison/lack of O2 inhibits
Companion cells have mitochondria
Evidence against phloem:
Solutes don't move at the same speed
Sugars delivered to all regions at same rate
Sieve plate function is unknown

Experiments:
Ringing - protective layer/phloem removed from plant, area above swells w/ sugar liquid, proves translocation
Tracer - C14 in CO2 goes in sugars, autoradiograph phloem only black area