Animal Physiology: Transport of Oxygen and Carbon Dioxide in Body Fluids Ch. 24

Venous Reserve

-Amount of O2 mixed in venous blood -During exercise, more O2 is drawn from each unit of blood and the reserve gets smaller

Blood respiratory pigment release rates at rest vs exercise?

-At rest, respiratory pigments release only a modest fraction of their O2 to the systematic tissues -During exercise, O2 delivery is enhanced by increases in both pigment unloading and rate of blood flow

Hemocyanins

-Contain Copper (Cu) -arthropods and molluscs -2nd most common respiratory pigments -contain copper and turn blue when oxygenated -always dissolved in the blood plasma

Hemerythrins

-Contain iron -marine worms (limited scattered distribution) -Colorless -Do not contain heme

Hemoglobins

-Contain iron (Fe) -Vertebrates and some invertebrates -most common and widespread respiratory pigments -virtually all vertebrates have hemoglobin -Usually in all red blood cells, sometimes hemoglobin is dissolved into blood plasma -Each molecule of hemoglobin can bind with 4 molecules of O2

Myoglobins

-Hemoglobins located inside muscles -In high concentrations, myoglobins make muscles red

Sigmoidal Curve

-Multiple O2 binding sites -Normal for blood pigments

Bohr effect

-a reduction in O2 affinity caused by a decrease in pH and/ or an increase in CO2 pp -typically enhances O2 delivery because it promotes O2 unloading in systematic tissues and promotes loading in breathing organs

Root Effect

-a substantial reduction of the O2 carrying capacity of a respiratory pigment -caused by a decrease in pH and/or an increase in O2 pp

What affect do elevated blood temperatures have on O2 affinity?

-decrease the O2 affinity of respiratory pigments -O2 affinity is inversely related to tempurature

Haladane Effect

-deoxygenated blood carries more CO2 than oxygenated blood -an increase in the total CO2 concentration of the blood caused by deoxegenation of the respiratory pigment -promotes CO2 uptake by the blood in systematic tissues and CO2 loss from breathing organs -** the necessary converse of the Bohr effect

CO2 Equilibrium Curve

-shows the relation between the total CO2 concentration of blood and the CO2 pp -water breathers: CO2 pp levels are low -Air breathers: CO2 pp levels are substantially higher

Chlorocruorins

-similar to hemoglobins and only occur in 4 families of annelid worms

Hyperbolic curve

-single O2 binding site -normal for myoglobins

what 2 features do all hemoglobin structures share?

1. All contain "heme", a particular metallotrophyrin containing iron 2. heme is noncovalently bonded to a protein known as globin

4 chemical categories of respiratory pigments

1. Hemoglobins 2. Hemocyanins 3. Hemerythrins 4. Chloccruoins

8 Functions of respiratory pigments in animals

1. transport O2 2. Store O2 in blood 3.Buffer blood pH 4. Transport CO2 5. Increase rate of diffusion and store O2 in tissues 6. Act as enzymes 7. Nonrespiratory transport 8. Tissue functions other than O2 supply

systematic tissues

All other tissues aside from the tissues of breathing organs

Why does O2 partial pressure decrease with increased exercise?

Blood passes through the pulmonary circulation faster as the intensity increases, thus decreasing the time available for equilibriation between the alveolar gas and the blood

How do buffers (H+ acceptors) affect the amount of HCO3-?

Buffers increase the ammount of HCO3-

Oxegenation (loading)

Deoxygenation (unloading)

Respiratory gases move from place to place by?

Diffusion and Convection

Respiratory Pigments

Increase the oxygen carrying capacity of blood

In all vertebrates, the central pattern generators for breathing are located in the...

Medulla

Heme

Metal containing molecule

Low affinity for O2

Pigments require high pp of O2 for full loading and unlaod substantial amounts of O2 at high pp

High affinity for O2

Pigments require low pp of O2 for full loading and unlaod substantial amounts of O2 at low pp

Characteristic of a tissues O2 partial pressure

The O2 partial pressure of a tissue is dynamic and has changing properties

Most carbon dioxide (CO2) carried in the blood is typically in the for of bicarbonate (HCO3-)

The extent of HCO3- formation depends on the buffer and determines the shape of the CO2 curve

Oxygen carrying capacity

The total amount of O2 that can be carried by the blood per unit of volume

Comparing related species based on O2 affinities...

Those with long evolutionary histories in O2 poor environments have evolved to have a higher O2 affinities

Chloride Shift

Transports HCO3- from RBC to plasma

mixed venous blood

blood drawnfrom the great veins leading back to the heart. "mixed" becauseit represents a mixture of venous blood coming from all parts of the body.

do organic phosphates increase or decrease affinity?

decrease

Carbonic Anhydrase

enzyme catalyzes CO2 => HCO3- reaction

Metabolic Acidosis

excess loss of HCO3 or increase in H+

Respiratory (oxygen transport) pigments

function isincrease the the amount of O2 that can be carried by a unit of volume in the blood

Metabolic Alkalosis

increase of HCO3 of decrease in H+

Respiratory Acidosis

not enough CO2 blown off, inspiration impaired

Alkalosis

pH of body fluids higher than normal--- too basic

Acidosis

pH of body fluids lower than normal---- too acidic

Percent Saturation

percentage of binding sites that are oxegenated

Globin

protein portion of hemoglobin

Erythrocytes

red blood cells

Blood Oxygen Utilization Coefficient

release of weighted average of O2 partial pressure of blood leaving the various tissues... defined to be the % of arterial O2 that is released to the systematic tissues

Oxygen Equilibrium (dissasosciation) Curve

shows relationship between O2 binding and the O2 partial pressure

Affinity for O2 is an inverse function of the partial pressure required for laoding

the higher the O2 pp required to load a pigment , the lower the affinity for O2

p50

the partial pressure of O2 at which a pigment is 50% saturated

Respiratory Alkalosis

too much CO2 blown off