Q = D*A*∆P /L

• Q is the rate of diffusion • D is the diffusion coefficient ◦ it is chemical specific • A is the surface area • ∆P is the concentration gradient • L Distance over which diffusion happens

Ventilation regers to a gas exchange with the environment

- it matches needs. Jogging requires more oxygen than sitting. Sprinting needs more oxygen than jogging.

Oxygenated blood runs counter current to the deoxygenated blood. THis way there is always a gradient at every point. 

- Con current (parellel) flow would lower the gradient

-The respiratory surface has to be moist

-Alveoli have surfactants so that they don't remain squished

A protein found in the red blood cells of all vertebrates. It carries oxygen connected to an iron atom and gives blood its red colour. 

-Porifera draw water into their body unidirectionally

-Cnidarians- draw water through body walls and tentacles--Endoparasites such as the cestoda facilitate this by reducing volume and becoming small and pancake like

Gills are highly complex but relatively small. They manipulate the L and A components of Fick's Law. 

Single epithelial cell layers ensure that the distance diffusion occurs over (L) is relatively small

External Gill Slits: Kept open to the environment and have a constant gradient. Elasmobranchii species such as the great white shark have external gill slits 

Internal Gill Slits are safe from predators, but require an active gradient ex. the operculum in bony fishes

Systems which facilitate internal gas exchange

- The individual parts are relatively simple, but complex infolding allows for a greater surface area

-The trachea funstions like ducts and allow O2 to penetrate to the cells in Insecta

-Trachea terminate in the cells directly

-Tracheal systems can become more complex to accomodate needs

- ex mammalian repiratory systems have trachea then bronchioles have alveoli

Annelids usually use skin as their primary respiratory surface

-They are typically moist thin and long

-Large polycheats have specialized gills. These are outgrowths of the body surface. 

-Their gill tentacles are ventilated by cilia or via muscular contration

-These work to stimulate a gradient and decrease the occurance of still-water

Most mollusca have variations on bipectinate gills

-Cilia help water flow and work to clean of debris

-Incurrent and excurrent siphons help to ventilate the gill ex. clams

-Many molluscs have monopectinate gills

-These have filaments on only one side of the central axis

Cephaloods have closed circulatory systems

- Mantle contractions draw water into cavity

-No countercurrent exchange large gill surfaces instead

- Coupled ventilation and "jetting" motion

-Likely the case that more they make use of jet propulsion, the more ventilation that occurs- good for swift predators. 

Have pallial lungs and pneumostomes (breathing pores) a pneumostome is a hole in the side of its body cavity that facilitates gas exchange

-It allows oxygen inspiration but at the cost of a lot water

-It classifies organisms partly according to their evolutionary branching pattern and partly according to the overall morphological similarity

-The major limitation of evolutionary taxonomy is that it requires a highly arbitrary judgment about how much information to use for overall similarity and how much information about branching pattern to use. It relies on personal intution, some traits, similarity and descent. This judgment is always highly subjective, and makes evolutionary taxonomy a very poor method of classification, albeit one that survives in the hands of certain older taxonomists.

Synapomorphies- based on relationships/ descent. Robust statistics. Parsimony. First proposed by Willi Hennig. Various cladistical algorythms can make this method quite successful. \Relies upon the fact that all species evolve by descent with modification. Cladistic determines the evolutionary branching order on the basis of shared derived characteristics. It does not use shared primitive characteristics as a basis for classification, since these may be lost or modified through the course of evolution. To establish which characters are primitive and which are derived, cladistic classification generally relies upon one or more outgroups, species hypothesized to be primitive ancestors of all the organisms under study.

Vicariance is the process by which the geographical range of a population is split into parts by a physical or biotic barrier to gene fow or disperrsal. At the micro level it causes populations to drift independently. Adaptations must develop specific for the new local environment. Natural selection occurs in ways different than would in the old population area. 

On the macro level it leads to speciation. 

BTW chelicerata is one of the four divisions of arthropoda.

It contains horseshow crabs, sea spiders and arachnids

-Generally they have book lungs ( two organs in the abdomen, connected with a small opening or the purpose of respiration) they look like a folded book and also tracheae. The bok lungs are hemolymph filled lamella in an enclosed air space which may not be actively ventilated. This may have evolved to help the spider buid webs. The epipod (gill) became spinnerets . This is yet another example of structural continuity with functional shift. 

Echinoderms for the record are marine animals who are radially symmetrical, are diploblastic and have radial cleavage. 

- There is a network of fluid-filled canals, derived from the coelom (body cavity) that function in gas exchange.

-Generally use their fee for simple diffusion. In starfish there are invaginations between the spines which allow for countercurrent eschange.

- In sea cucumbers they respire through the cloace they push water out of the lungs all the way through their respiratory tree. It acts to transport oxygen through other parts of the body. This aids them in suspension breathing/ feeding. 

-Coelemic fluid transort oxygen (not blood)

They should 

1) Pull water through their little jawless mouths using simple pouches which gather oxygen

2) you will know you have a lamprey and not a hagfish, if instead it uses its nares to draw in water, pass it through its pharyngeal slits (which are only the beginnings of proper gills) . This allows it to breath while it is stuck to something, like the true D personality they have. 

Their gill arches have gill filaments which increase their surface area. Their spiracle draws in water, while their mouth in engaged. Water enters the mouth and passes out through the gills. While the shark is moving, water passes through the mouth and over the gills in a process known as "ram ventilation| while at rest most sharks pump water over their gills to ensure a constant supply of oxygenated water. 

-In ray fishes (teleosts) buccal pumping occurs which is a method of respiring by moving the floor of the mouth up and down in a rhythmic water to inflate the lungs. 

Amphibians breath through a bucal pump also which is made possible via their rib reduction.  This is again the moving of the floor of the mouth in a rhymthmic motion- filling the lungs. Most amphibians are able to exchange gases with the air or water via their skin. To enable sufficient cutaneous respirationm the surface area of their highly vascularized skin must retain moisture. 

FYI reptiles unlike amphibians do ot have an aquatic larval stage. 

-Some have a modified cloaca for gas exchange. 

-Unicameral lungs(consisting of a single chamber) and also multicameral lungs. Faveolar lungs(birds) are composed of millions of tiny passages flowing posterior to anterior

-Crocodiles are adapted for breathing while submerged. THey have a diaphragmatic setuo called a hepatic piston in which the pelvis pulls down the diaphragm. 

Turtles: Limited by their shels and use "viscera" to ventilate their lunggs. When it hides in its shell it cant breathe

Birds rely on super efficient crosscurrent exchange. They posses a series of air sacs which extend from the humerus, the femur even to the skull.

-They dont have a diaphragm, instead, air is moved in and out through the respiratory system through air pressure changes in the air sacs. They have parabronchial lungs with both posterior and anterior air sacs which can function with minimal pressure gradients. 

They possess alveolar lungs which are paired lungs ventilted va the diphragm and intercostal muscles.  Tidal ventilation occurs which is the negative pressure of breathing. The rib cage gets smaller sas the rib muscles relax and bigger as intercostal muscles contract the diaphragm down. 

Often ventilation matches gate patterns, and shape changes aid in the ventilation of the gait. 

During the carboniferous era, when the air was 35% oxygen, organisms were able to accomplish greater diffusion and penetration of xygen into tracheal systems leading much marger insects. 

The bar-headed goose who flies at high altitudeas has a much larger heart, lungs and blood oxygen affinity.

The sperm whale has large lungs which absorb and store oxygen and their large size prevents compression as they dive deeply. 

Waste= CO2 feces and urine. Urine contains the nitrogenos wastes from protein catabolism and excess solutes. 

Urine= the nitrogenous wastes from protein catabolism and excess solutes

The individual level consisting of a semipermeable membrane of a cells which effects osmosis, diffusion and active transport

The organismal level 

In biology, fission is the division of a cell (or body, population or species) into two or more parts and the regeneration of those parts into seperate cells. It is the primary mechanism by which prokaryotes reproduce and some cells within eukaryotes.  All cells reproduced are genetically identical, barring random gene mutations. 

Hemaphroditic- having bot the male and female reproductive organs in the same individual. 

An advantage is that less energy needs to be expended on mate selection and competition. As well, both parents are pproducing offpring- leading to twice as many offspring. 

All else being equal- an asexually reproducing population will grow at twice the rate of a sexually reproducing population. THe reason for this is that members of a sexually reproducing population must produce both sexes, but can only effectively have half of them give birth to offspiring. In contrast all offspring of an individual from an asexually reproducing population can potentially give birth.

Despite the costs, sexual reproduction is the primary mode of reproduction so it must be more advantageous. The strongest advantage is variation.

In a sensory system a sensory receptor is a sensory nerve ending that responds to a stimulus in the internal or external environment of any organism. The sensory receptor initiates sensory tranduction by creating graded potentials or action potentials in the same cell or an adjacent one. 

It is the capture, conversion and transmission to the CNS of the sensation

Phototransduction in simple eyes detects light levels to avoid and move toward certain stimuli, for example the hydra and Cnidaria senses see light and dark and then decipher whether to move towards or away certain stimuli. 

Rod= light, cone=colour. 

Jewel beattles can detect heat and smoke. Mechanoreceptors in fish (lateral line) helps them feel the pressure of water and sense objects around them via pressure. The fish swim bladder vibrates to sense proximities

-In the cochlea the orans of Cortie feel the hairs vibrate and tranlate into sound

THe neuron deals with body communications and information processing. There are three typer of neurons- the sensory, inter and motor neurons. 

They are highly specialized cells that generate and transmit bioelectric impulses. The direction of conduction is always denrite to axon. They conduct the signal away from the body. THe synapse is the area between the neurons. Each neuron has a nucleus.

They differ depending on where they are in the body. The motor neurons contain mylented sheaths which speed up cell signal transmission  by forming an electrically insulating layer. Their terminals end up in muscles. 

inter neurons connect various neurons within the brain or the spinal chord.  Sensory neurons collect information by responding to tactile stimuli and acivating motor neurons to achieve muscle contraction

Hindbrain- breathing and balance

Midbrain-optical processing

Forebrain- Cerebrum and olfaction. As we move from reptiles to amphibians it becomes larger and larger. Allometric scaling laws relate body weight to brain weight. 

Includes mechanoreceptors called neuromasts- lateral line organs, arranged in an interconnected network along the head and the body. In sharks and rays some neuromasts have evolved into the electrreceptors called ampullae of lorenzini. These receptors are concentrated on the heads of sharks and can detect the minute electrical potentials generated by the muscle contractions of prey. THey also may be used for migration and navigation. 

=Statocyst is a small organ of balance found in many invertebrates consistin gof a fluid filled sac which stimulates sensory cells and helps indicate the position of the animal as it moves. 

It coordinates by functioning between different organs through hormones released into the blood stream from specific cells within endocrine glands. Works in conjunction with the nervous system to respond to stimuli. Once in ciculation, the hormones effect the function of the target tissue. Hormones bind to receptors located inside the cells that regulate gene function including corticosteroids, vitamin d and thyroid hormones. 

Structures: Hypothalamus and the thyroid/ anterior pituitaty gland and the like. 

- maintaining an internal environment even though the outside environment changes dramatically. 

- Two ways to maintain homeostasis: Negative and Positive Feedback

Ectotherms- derive heat from their environment

Endotherms- animals use metabolic processes to produce body heat. THe hypothalamuse senses heat outside and acts to bring the body to homeostais. It will dilate blood vessels to reduce heat or bring up goose bumps and hair to trap warmth in the blood vessels. 

Water soluble hormones aredissolved in water and cannot pass through target cell membranes. THey effect the cells by binding to receptors on the surface of the cell. This triggers a chemical response without activating the inside of the cell

Faat soluble hormones dissove in fats and usually formed from cholesterol. They pass through all cell  membranes. It can move around inside the cell. 

Trophic hormones are hormones that have other endocrine glands as their targets. Most are produced and secreted by the anterior pituitary. 

Non-trophic hormones directly stimulate target ccells to unduce effects. THey act directly on targeteed tissues or clells.They usually act in the end of the chain reaction g. estgen, testosterone, oxytosin. 

Cirripedia is of the subphylum crustacea. THey attatch themselves permanently to hard substrate such as whales. Thy have two larval stages- the nauplius and the cyprid which are morpholigically designed to find a place to settle and morph into their adult form. 

-It can castrate its male and female host as well as alter its behaviour so that it acts in the barnacle's best interest. For example it may force it to to stop moulting so all the energy can go to the parasite

Vs. Monogeneans= internal parasites. Digenea are a subclass within the platyhelminthes consisting of parasitic flatwrms. Vastly hermaphoditic. They have a musular pharynx for injesting food and caeca for digesting it. They often feed on the contents of the lumen including, food, bile and mucous. Some feed across the mucosal wall on host blood. 

They can also castrate their fish hosts and cause cysts in the brain making them swim through the shadows with their bellies up- very visible to prey. Herrons then eat the fish and the digenea can have a better host. 

Various factors effect the temporary bind of oygen to the iron rich red blood cells. One of these factors in pH. Is it is lower than normal in a body, the oxygen does not bind well.

The important physiological significance to this is the equation of water reacting with carbon dioide laeads to increads proton concentration.  Thus, as the amount of carbon dioxide increases, more H+ ion are formed and the pH decreases. Accrding to Bohr the lower pH causes hemoglobin to deliver more oxygen. Lends itself to homeostasis.

Arteries- arterioles- capilleries- venules-veins. Capilleries are only a single layer of cells thick allowing for small molecules- water, nutrients, ions and gases to permeate the cell wall in and out of the vessels.

Damaged capilleries become more leaky increasing permeability and allowing more fluid to enter the tissues. plasma can therefore enter damaged tissues in the inflammatory process to instigate blood clotting, stop the spread of infection, give nutrients to eed the tissues and proteins that effect phagocytes. 

Glomerular filtration --body fluid is filtered via selectively permeable membranes and hydrostatic pressure. Filtrate is then converted to waste material by selective transport tubular reabsorption conserve valuable nutrients and ions. Tubular secretion transports waste products real tubule (collecting duct)

-Active transport make the filter more dilute. We must be selectively able to pull out water.

membrane=Impermeable to water

We have movemtn of water, salts and selective permeability. to conserve h2o and produce highly concentrated wast 

Aquatic organisms can pass ammonia out over well ventilated gills. Most nitrogenous wastes in fish are produced and excreted as ammonia or urea. Ammonia is highly toxic because it can lower pH of animals.4 + . NH4 + cannot diffuse across epithelia.  It turns out the ammonia is moved through the lipid membranes with RH proteins. RH proteins tell us what th blood type is

Malpigian tubules of Instectae

 insects,myriapods, arachnids, and tardigrades. the system consists of branching tubules extending from thealimentary canal that absorbs solutes, water, and wastes from the surrounding hemolymph. The wastes then are released from the organism in the form of solid nitrogenous compounds. -          open into the mid to hid-gut junction

-          No initial filtration step. Active transport within the tubules. Waste moves into the hidgut where we have selective reapsorbtion and the passive transport of the waste.

store ammonia as glutamate until water s around. necounter freshwater and it draws salts out of you

-rprocess the urine by passing it over their gills again

Freshwater fish= hypertonic. Excretion??

Uric acid is a heterocyclic compound of carbon,nitrogen, oxygen, andhydrogen with the formulaC₅H₄N₄O₃. It forms ions and salts known as urates andacid urates, such as ammonium acid urate. Uric acid is a product of the metabolic breakdown ofpurine nucleotides. High blood concentrations of uric acid can lead to gout and are associated with other medical conditions including diabetesand the formation of ammonium acid urate kidney stones.

Guanine /ˈɡwɑːnᵻn/ (G, Gua) is one of the four mainnucleo

Spiders and scorpions convert ammonia, as a product of protein metabolism in the cells, to guanine, as it can be excreted with minimal water loss.bases found in thenucleic acids DNA and RNA,