Animal Physio 2

Ways respratory gases are transmitted

simple diffusion

convection

Simple diffusion

high concentration → low concentration

Partial pressure

the individual pressure exerted by any particular gas in a gas mixture

independent of other gases

a fraction of total pressure

how to know the partial pressure of an aqueous solution

partial pressure of a gaseous solution

Gas solubility is affected by

temperature

salinity

diffusion of gases

high partial pressure → low partial pressure

convective gas transport (bulk flow)

gas mixture/aqueous solution flows and molecules in the gas or liquid are carried from place to place by the fluid flow

blood pumping

breathing

mechanical processes

Bulk flow costs _______ _____

metabolic energy

Pathway of oxygen

air → alveolar gas → arterial blood in lungs → capillary blood → mitochondria

Lungs

invaginated into the body and contain the environmental medium

external gils

evaginated from the body, project out

concurrent gas exchange

blood and medium flow in the same direction

gradually approach dquilibrium with each other

countercurrent gas exchange

blood flows in the direction opposite to the medium

achieves a more. complete transfer of O2 from the medium to the blood

Cross current gas exchange

buccal pressure

Systole

contraction

Diastole

relaxation

myocardium

muscular system of the heart

Myocardium in mammals

coronary arteries and veins

myocardium in fish

spongy, with no coronary vessels

only recieve blood which is returning to the system

Myogenic hearts

Innervated, but beat even if all nervous connections are gone

pacemaker cells

highest frequency of spontaneous depolarization of all cells in the heart

pacemaker cells

specialized muscle cells

sets the rythum of heart beating

conduction

depolarization spreading through a myogenic heart

adjacent muscle cells are electrically coupled via gap junctions

Neurogenic hearts

rhythmic depolarizaton responsible for initiating the heartbeats originates in nervous tissue

pressure in vascular systems

pressure produced by the beating of the heart

kinetic energy of blood’s motion

pressure of fluid column effects

Rate of blood flow

muscles in the walls of blood vessel change radius

laminar flow

internal friction exists within a moving liquid

effected by viscosity and dimensions of tube

kinetic energy is steadily degraded

arteries deliever blood to microcirculatory beds

smooth muscle allow for highly sensitive temporal and spatial control of blood distribution

percentage of the ventricular compact mycardium in relation to migration effort

more migration needs → higher percentage

Invertibrates with closed circulatory systems

respiratory pumps are anatomically separate from the systemic pump

oxygenated blood is separate from oxygenated blood

open circulatory system

blood exists discrete vessels and fills lacunae and sinuses that directly bathe the cells of nonvascular tissues

Rate of Gas diffusion

same as Fick’s Law

p1 and p2 = region of high partial pressure and region of low partial pressure

Diffusion is slower through ______ than ________

water than air

Internal gills

envaginated from the body and project into a superficial body cavity

O2 partial pressure in blood leaving a breathing organ

Good measure of breathing organ’s effectiveness

Tidally ventilated breathing organs

air in lungs is never “fully fresh,” has a lower partial pressure than the environment

unidirectional breathing organs

concurrent gas exchange

countercurrent gas exchange

Intracellular Responses to low oxygen

Hypoxia-inducible factors 1 and 2

transcription factors that increase when a cell experiences hypoxia

enhance the production of red blood cells

water flow in gills is controlled by

the buccal pressure pump

the opercular suction pump

Buccal pressure pump

mouth and buccal cavity

push water by compressing buccal cavity

Opercular suction pump

the gill chambers

pulls water by expanding the opercular cavity

ram ventilation

swimming fish holds its mouth open, elevates the buccal pressure to ventilate the gills to get more O2

countercurrent gas exchange

achieves a more complete transfer of O2 from the medium to the blood than concurrent/tidal exchange

Breathing system in amphibians

mix water breathing and air breathing

reptile lungs

multi-chambered lung w/vascularized folds

suction used for ventiliation instead of buccal pressure

tidal volume

volume of air inhaled and exhaled per breath

titally ventilated breathing organs

air in lungs is never fully fresh and therefore has lower partial pressure than the environment

Bird respiratory systems

lungs and air sacs

2 primary bronchi off the trachea, similar to mammals

Gas exhange sites in avian lungs

parabronchi contains air capilaries

cross-current gas exhange

permits the o2 partial pressure of the mixed blood leaving the breathing organ to be higher than that of exhaled medium

Insect breathing system

tracheal system of gas-filled tubes that reach into all tissues from body surface

Respiratory pigments

(ex. blood)

undergo reversible combination with O2

strongly color

Metalloproteins

contain metal atoms

iron in hemoglobin

Hemoglobin ________ can vary from tissue to tissue within the same animal

structure

hemoglobins

increase blood’s oxygen-carrying capacity

acid-base buffers

blood CO2 transport

facilitate O2 diffusion into cells

Hemoglobin is similar to ________

ENZYMES

binds to O2 at binding site (specific, noncovalent)

allosteric ligands

Cooperativity

binding of O2 at 1 or 2 of the O2 binding sites on hemoglobin alters the molecule’s conformation in ways that enhance the affinity of the remaining sites for O2

Oxygen equilibrium curve

a graph that shows how hemoglobin binds and releases oxygen in the blood

This shape happens because of positive cooperativity—as each oxygen molecule binds to hemoglobin, it changes the shape of the protein and makes it easier for the next oxygen molecule to bind.

O2 affinity and Partial pressure are _________ _______

inversely related

The Bohr Effect

oxygen affinity depends on the partial pressure of CO2 and the PH

How does the Bohr effect work?

Protons (or CO2) exert their effects on O2 affinity by combining with respiratory-pigment molecules and behaving as allosteric modulators.

The Bohr effect typically ________ O2 delivery in an animal

enhances

The Root Effect

unusual cases

CO2 and PH dramatically affect the oxygen-carrying capacity of a respiratory pigment

Oxygen affinity depends on tissue ___________

temperature

Why? During exercise, thermal shifts in affinity will enhacne O2 delivery to the muscles

Other examples of modulators of oxygen affinity

organic modulators

Inorganic ions

Do octopuses have a venous reserve?

No

exhibit a bohr effect

have only a small venous O2 reserve at rest, increase unloading O2 when they excersize

must meet hightened O2 requirements

O2 affinity in the hemoglobin of primates is a regular function of what?

body size

The respiratory pigment physiology of individuals may undergo what kind of change?

Acclimation

Forms of CO2

carbonic acid → bicarbonate → carbonate

The Haldane Effect

the carbon dioxide equilibrium curve depends on blood oxygenation

Deoxygenation promotes CO2 uptake by the blood, whereas oxygenation promotes CO2 unloading

Is normal blood pH a temperature-dependent variable?

yes

pH varies with temperature

molting

body swells, breaks through swelling tissue and leave that behind, build a new exoskeleton

interstitial fluid

between cells and ordinary tissues

blood plasma

all the parts of blood other than blood cells

water flows toward ______ osmotic pressure

higher

Osmotic regulators - osmoregulation

as osmotic pressure goes up, blood osmotic pressure increases

Ionic regulators

regulate ion concentrations in blood plasma

When the freshwater fish takes on a quantity of H20 by osmosis, the following changes occur:

osmotic pressure decreases

ion concentration decreases

bolume of water in the blood plasma

cell volume regulation

dilute solution → cell swells, reduces dissolved entities

concentrated solution → loses water and shrinks, increases dissolved entities

modulation of organic solutes permits ______ and _____ regulation

volume and ionic

Gases diffuse from

high partial pressure → low partial pressure

follows fick’s law

Evaporation effects

osmotic presssure increases

ionic concentration increases

volume decreases

kidney function

regluate the composition of the blood plasma by removing blood and ion concentration

volume regulation

ionic regulation

Obligatory water loss

respiratory → lose water by evaporation

waste products