comparative notes

8/8/2019 Comparative Notes

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OUTLINE FOR EXAM 2 THROUGH 2/18

ANYTHING BOLDED ARE KEYWOR/DS YOU SHOULD PROBABLY HAVE A GOOD UNDERSTANDING OF OR THEIR ROLE IN

OTHER PROCCESSES

Homeostasis-most habitats are detrimental to animals cells

-salt water + fresh water fish must regulate their internal salinity

-temperature can inhibit chemical pathways

-many enviornments are variable +physical + chemical properties of the enviornment fluctuate

-control systems maintain very highly regulated internal enviornment of animals

-Clayde Bernarde french pioneer of physiology in 1800s

>Recognized the importance of animals need to regulate

>the living organism does not really exist in the external enviornment but in the liquid interiorthat

bathes tissue element

Interstitial fluid- internal enviornment that regulates + maintains internal conditions

-Cells in the body experience a constant enviornment tightly regulated

>Glucose levels, pH, osmotic Pressure, O2 levels, salinity

-must have the ability to maintain internal enviornment against changing external ones

Walter Cannon- functions of cells+ tissues

-Coined homeostasis in 1929

-key concept + framework for physiological thinking

-Keep everything constant

-not just mammals, but almost every living thing has forms of homeostasis

-evolution of Homeostasis allowed animals to invade many different habitats including very hostile ones

-Homeostasis is usually the answer to why animals do things

How Does it work?

Feedback Mechanisms- allow animal to pay attention to whats going on inside + make adjustments as neccesary

-Sensory Information measures phsiological paraments + then signal mechanisms to correct any deviation that

is outside the strict regulations, using sensors

-continuous sampling + measuring of inside levels

-Negative feedback- when things that are going out of control in the wrong direction are brought back to


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Normalcy

>keeps things constant

-set point- programmed regulations within body

> if there is deviation an error signal is sent to the Comparator which measures the amount of error

occuring + then calls into action an effector which pushes the system back to normalcy + sends a signal

that the system has been brought back to normal homeostatic levels

>level at which normalcy is attained

-keeps variables w/in normal limits

-Shivering Thermogenesis- regulates body temperature when internal levels begin to dip out of and below the

nomal range

-Positive feedback- tends to send things out of control for while

>production of action potentials in neurons

>Parterition- expulsion of baby from uterus

-if O2 levels drop or salinity levels change

>cope by confirming what is going on in the enviornment

>use less O2 or allow salt to accumulate in the body fluids

>parallels or conforms to habitual changes

`CONFORMITY

.Animals can die if they get to far out of normal internal limits by not conforming

.Stenohaline- conformity to salinity

.Tube worms living in substrate below a liquid medium

-oxyconformer- animal reoxygenates fluids in system+surface by water passing through it

>able to decrease O2 consumption by allowing O2 levels to fluctuate w/in body

.Ability to conform depends on bodies tolerance to these changes in body tissues

Regulators

.Regulate the internal even when external enviornment is in flux

-salt water concentrations w/in crustaceans

-allow better ability to w/stand change in the enviornment


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-Euryhaline- animals that can live in many different salt water concentrations

-Osmoregulators- regulate osmotic pressure within

-almost all vertebrates are oxyregulators

>allows tissues to be active despite enviornmental decrease in O2

.Decapod crustaceans, mollusks, + insects are both regulators and conformers

Types of tranport

.Fluid mosaic membrane

-phospholipid bilayer w/hydrophobic + hydrophillic tails

>integral+glyco proteins help to regulate what passes through

.Diffusion- passive movement w/in a system across concentration gradient from high to low

.Osmosis- H2O molecules moving down the concentration gradient (CG from here on out)

-osmotic pressure= driving force behind osmosis

-only possible w/semi-permeable membranes

-hydrostatic pressure opposes osmotic pressure

-osmosis stops when oposing forces are equal

.Uncharged molecules can pass through lipid bi-layer with ease

.Charged ions must pass through channels in the membrane

-provided by proteins

-Ligand(Chemically) regulated channels

>opens when binding cite is activated

>ions pass from low to high along CG

-voltage regulated channels

>open and close when there are specific changes in voltage on the inside or outside of the membrane

.Facillitated diffusion- carrier mediated mechanism

-transporter protein allows molecule to bind to active cite which is followed by a confirmation change in the

membrane which allows the molecule to pass through

-allows for movement against the CG


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-Sodium Potassium ATPase Pump - NA/K pump

>function: activatwes enzyme that facilitates transport of high energy bond

>can move 3 NA out of cell and 2 K back in

> high amount of K in the cell and low amount of NA inside the cell

-endocytosis- brings things in that are to large to pass through the membrane or its channels

>engulf particle via vesicles made by the cell membrane engulfing the particle

~phagocytosis- cell eating (solids)

~pinocytosis- cell drinking (liquids)

-exocytosis- expells material from the cell typically by vesicles meshing with cell membrane and contents being

expelled when cell membrane ruptures

>Neurotransmitter realease from neurons across synapse

-Hypotonic, Hypertonic, Isotonic

> in CH.3 if you need a refresher

-hypo-osmotic

>solute concentration is lower outside the animal than it is inside

>fresh water has a lower solute concentration than the intracellular fluid in freshwater fish

>fresh water is hypotonic to fish

-hyperosmotic- more salt in water than in cells of animal

>marine water is hypertonic to cells of the animals that live in it

>water leaves cells via osmosis which causes a salt overload in cells

>but animals cannot have impermeable membranes due to the need for gas exchange

>Active transport of solutes + passive Transport of water

-Protozoans, Sponges, + Hydra

>contractile vacuole- actively move solutes across membrane + into lumen

>water follows CG

>vacuole fills + fuses w/surface membrane + ruptures expelling water+solutes


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WASTE MANAGEMENT

.Excretory organs-Annelids

-Tubular structures allow water levels to adjust

>tubule picks up coelomic fluid + is expelled to the outside

>tubule is open on both ends

>filtration of fluid from blood into coelom leads to fluid entering tubule

>as tubule passes blood vessels selective reabsorbtion recovers materials the animal cant afford to get

rid of ex.sugar, amino acids, iron

-material animal needs to get rid of is secreted into the tubule and excreted via urine

-if tube is blind on one end capillaries are associated with that blind end

>filtration of blood occurs in the glomerulus

>urine is excreted via

-nephridia-kidney tubule

>lead to the outside of body via nephridopore

-protonephridia[early kidney]-flatworms, rotifers, + some Annelids

>flame cells in planarian + rotifers

~flagella creates negative pressure to draw liquid in

>blind ending tubes

>blind end has cillia or flagella inside

>flame bulb- name due to flickering flagella

~Microvilli forming interdigitated siv-like arrangement

-sets up negative pressure through siv

-urine is eventually released

-negative pressure acts as vaccuum pulling water into tube

-metanephridia- in more advanced animals

>tube open on both ends

>nephridiostome picks up coelomic fluid


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>clams and snails have 1 or 2

>annelids have 1 or 2 per segment due to there metamerism

>cillia draw fluid into tubule

>Selective reabsorbtion occurs in tubule near capillaries

>wastes are secreted into tube

>coelomiic fluid is hypertonic to blood in annelids

>long+highly convoluted for enough roomto make adjustments in fluid

>short + undifferentiated tubules in animals that are very iso-osmotic

>nitrogenous wastes

~Ammonia[NH3} + uria

>more advanced type in decapod crustaceans

~located in the head by antennae

~filtration=>selective reabsorbtion=>secretion=>excretion

-Solenocytes

-Green gland/antennal gland-sacuole is a remnant of the coelom

>coelom is reduced

>blind end goes through cells that are interdigitated called podocytes

-open circulatory system- blood leaves the heart to mix w/interstitial fluid forming hemolymph

>blood in the hemocoel bathes the end sac of a podocyte

>urine goes through labyrinth- area of increased complexity

>selective reabsorbtion and filtration take place

>nephridium exits via nephridiopore

-Ultrafiltrate-a process by which urine is formed by forcing fluid out of the blood

>water, sugars, ions, amino acids

-ammonia NH3- nitrogenous waste crustaceans produce and excrete through the gills

-malpighian tubule-up to hundreds in certain arthropods

>dump urine into gut=>rectum=>hindgut

>use nephridium to produce urine + use digestive tract to selectively reabsorb important material


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>secretion- active movement of solutes across membrane + passive movement of water

>material excreted may be so dehydrated it is crystalline in form

>very dehydrated uric acid

>water put into tubule is reabsorbed at very efficient rates

>urine is hyperosmotic to blood of the animal

~insects, birds, + mammals

VERTEBRATE WASTE STRUCTURES

.Archinephrose- beginning of kidney evolution

-open tubules in every segment of metamerated animals

-kidneys are dorsal to coelom-retroperitoneal

~outside main internal cavity of animals

.Pronephrose- drains into duct

-retroperitoneal

-anterior kidney material becomes present

-posterior kidney material becomes present

.Mesenephrose- nephrons are blind ending

-retroperitoneal

-have a glomerulus- closed end of tube

-drains through duct

-tubules are used to conduct(lead) the material the gonads produce outsidwe the body

.Opistonephrose- fish kidney

-retroperitoneal

-opistoduct shares function w/kidney + gonads

.Metanephrose- new drainage

-ureter is separate

-testes still share tubules

-urinary bladder forms offcloaca- common sewer along the stretch of systems in the body


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HUMAN KIDNEY

.Nephrons- tubule of kidney~ humans have 1million per kidney

-structure allows it to function+produce hyperosmotic urineif water needs to be conserved

-2 kidneys both retroperiteneal

-cortex- outer portion

-medula- inner portion

-capillary networks surround nephrons

-renal corpuscle(RC)- made of glomerulus/knot of capillaries + ofbowmans capsule

>blind end of nephron

>where filtration occurs

-cuboidal epithelium makes up the tubule

>lots of absorbtion and secretion can occur due to structure

-Urines journey - RC=>proximal tubule=>loop of henle- descending+ascending limbs with some going from the

cortex to medula and back, the deeper they go the more concentrated the urine can get=>distal tubule-dump

into=>collecting duct=>Medula=>ureter

-during processchanges are made tothe urine

>filtration, selective reabsorbtion, secretion, osmotic concentration

-urea- main nitrogenous waste in humans

>NA, K, ions, RBC pigments are what give it color

-produce primary filtrate urine into bowmans capsule

-selective reabsorbtion puts material back into the blood stream

-secretion of material into lumen of tubule from capillaries

.Glomerular filtration- filtration barrier btw blood + lumen

-lining of blood vessels is called endothelium- very porous or fenestrated epithelium

-basolamina located btw bowmans capsule + vessels

-podocytes have pedicells- interdigitated extensions

>sets up a porous siv-like arrangement

>allows small molecules to get out


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-result ofhydrostatic pressure/blood pressure

>drives fluids out of blood and into lumen of tubule

-colloid osmotic pressure-material left behind draws things back in

-blood pressure is stronger

>keeps urine flowing

-Glomerular filtration rate[GFR]- 125mL/min + 180 L/day

>rest of nephron spends a lot of time decreasing urinary output to 1% of GFR by selective reabsorbtion

>blood is brought to glomerulus through afferent arterioles

>after filtration whatever is left leaves through efferent arterioles

>resistance in the blood vessels can change and influnce GFR

.Tubular reabsorbtion- interchangeable with selective reabsorbtion

-secretion also occurs along the length of the tubule

-endothelium breaks up into network od capillaries to selectively reabsorb materials

-proximal tubule- 1st location where reabsorbtion occurs

>actively transported- sugars, ions, NA

>2/3 of water is reabsorbed passive

-NA is actively transported into blood via NA/K pumps

>3 ions of NA+ bind to interior

>complex binds ATP and cleaves it

>3 NA+ are released to exterior and 2 K+ ions bind to transporter

>phosphate released and 2K+ are moved into the ccell

>use cotransporters to assist w/movement across the gated channels

~aka 2ndary active transporters

>water passively passes through aquaporins

-saturation kinetics- since a carrier is involved the glucose is limited to however many carriers are available

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