Download Chapter 2- 27 Chemistry Fluids Electrolytes Acid Base Balances

Chapter 2 & 27: The Chemical Level
of Organization, Fluid, Electrolyte, and
Acid-Base Homeostasis
Copyright 2009, John Wiley & Sons, Inc.
Introduction

Since chemicals compose your body and all
body activities are chemical in nature, it is
important to become familiar with the
language and fundamental concepts of
chemistry.
Copyright 2009, John Wiley & Sons, Inc.
How Matter is Organized

Chemical Elements

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
All forms of matter are composed of chemical
elements which are substances that cannot be
split into simpler substances by ordinary chemical
means.
Elements are given letter abbreviations called
chemical symbols.
Trace elements are present in tiny amounts
Copyright 2009, John Wiley & Sons, Inc.
Ions, Molecules, & Compounds

Ions

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
an atom that gave up or gained an electron
written with its chemical symbol and (+) or (-)
Molecule

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atoms share electrons
written as molecular formula showing the
number of atoms of each element (H2O)
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Free Radicals


A free radical is an electrically charged atom or group
of atoms with an unpaired electron in its outermost
shell
Unstable and highly reactive; can become stable



by giving up an electron
taking an electron from another molecule
Antioxidants are substances that inactivate oxygen-derived
free radicals
Copyright 2009, John Wiley & Sons, Inc.
Chemical Bonds


The atoms of a molecule are held together by
forces of attraction called chemical bonds.
The likelihood that an atom will form a
chemical bond with another atom depends on
the number of electrons in its outermost shell,
also called the valence shell.
Copyright 2009, John Wiley & Sons, Inc.
Ionic Bonds

When an atom loses or gains a valence
electron, ions are formed (Figure 2.4a).

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Positively and negatively charged ions are
attracted to one another.
Cations are positively charged ions that have
given up one or more electrons (they are electron
donors).
Anions are negatively charged ions that have
picked up one or more electrons that another
atom has lost (they are electron acceptors).
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The Ionic Bond Formation
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Covalent Bonds


Covalent bonds are formed by the atoms of molecules
sharing one, two, or three pairs of their valence
electrons.
 Covalent bonds are common and are the strongest
chemical bonds in the body.
 Single, double, or triple covalent bonds are formed by
sharing one,two, or three pairs of electrons,
respectively.
Covalent bonds may be nonpolar or polar.
 In a nonpolar covalent bond, atoms share the
electrons equally; one atom does not attract the
shared electrons more strongly than the other atom
Copyright 2009, John Wiley & Sons, Inc.
Copyright 2009, John Wiley & Sons, Inc.
Polar Covalent Bonds

Unequal sharing of electrons between atoms. In
a water molecule, oxygen attracts the hydrogen
electrons more strongly

Oxygen has greater electronegativity as indicated by
the negative Greek delta sign.
Copyright 2009, John Wiley & Sons, Inc.
Hydrogen Bonds



Approximately 5% as strong as covalent
bonds
Useful in establishing links between
molecules or between distant parts of a
very large molecule
Large 3-D molecules are
often held together by a
large number of hydrogen
bonds.
Copyright 2009, John Wiley & Sons, Inc.
Hydrogen Bonds

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are weak
intermolecular bonds;
they serve as links
between molecules.
help determine threedimensional shape
give water
considerable cohesion
which creates a very
high surface tension
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Chemical Reactions



New bonds form and/or old bonds are broken.
Metabolism is “the sum of all the chemical
reactions in the body.”
Law of conservation of energy

The total mass of reactants equals the total mass of the
products.
Copyright 2009, John Wiley & Sons, Inc.
Forms of Energy and Chemical
Reactions

Energy is the capacity to do work.

Kinetic energy is the energy associated with
matter in motion.

Potential energy is energy stored by matter
due to its position.
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Energy Transfer in Chemical
Reactions

An exergonic reaction is one in which the bond being
broken has more energy than the one formed so that
extra energy is released, usually as heat (occurs during
catabolism of food molecules).

An endergonic reaction is just the opposite and thus
requires that energy be added, usually from a molecule
called ATP, to form a bond, as in bonding amino acid
molecules together to form proteins.
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Activation Energy
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Factors that Cause a Collision and
Chemical Reaction

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Concentration
Temperature
Catalysts are chemical compounds that speed up chemical reactions
by lowering the activation energy needed for a reaction to occur.
A catalyst does not alter the difference in potential energy between
the reactants and products. It only lowers the amount of energy
needed to get the reaction started.
 A catalyst helps to properly orient the colliding particles of matter
so that a reaction can occur at a lower collision speed.
 The catalyst itself is unchanged at the end of the reaction; it is
often re-used many times.
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Catalysts and chemical reactions
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Types of Chemical Reactions
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Synthesis reactions -- Anabolism
Decomposition reactions-- Catabolism
Exchange reactions
Reversible reactions
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Inorganic Compounds and Solutes

Inorganic compounds usually lack carbon
and are simple molecules; whereas organic
compounds always contain carbon and
hydrogen, usually contain oxygen, and
always have covalent bonds.
Copyright 2009, John Wiley & Sons, Inc.
Water

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
Is the most important and abundant inorganic
compound in all living systems.
Water’s most important property is polarity, the
uneven sharing of valence electrons
Enables reactants to collide to form products
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Polar Water Molecules
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Water as a Solvent
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In a solution the solvent dissolves the solute.
Substances which contain polar covalent
bonds and dissolve in water are hydrophilic,
while substances which contain non polar
covalent bonds are hydrophobic.
The polarity of water and its bent shape allow
it to interact with several neighboring ions or
molecules.
Water’s role as a solvent makes it essential
for health and survival.
Copyright 2009, John Wiley & Sons, Inc.
High Heat Capacity of Water

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Water has a high heat capacity.
It can absorb or release a relatively large amount of heat
with only a modest change in its own temperature.
This property is due to the large number of hydrogen
ions in water.
Heat of vaporization is also high
 amount of heat needed to change from liquid to gas
 evaporation of water from the skin removes large
amount of heat
Copyright 2009, John Wiley & Sons, Inc.
3 Common Mixtures
A mixture is a combination of elements or compounds that are
physically blended together but are not bound by chemical bonds.

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Solution: a substance called the solvent dissolves
another substance called the solute. Usually there is
more solvent than solute in a solution.
A colloid differs from a solution mainly on the basis of
the size of its particles with the particles in the colloid
being large enough to scatter light.
Suspension: the suspended material may mix with the
liquid or suspending medium for some time, but it will
eventually settle out.
Copyright 2009, John Wiley & Sons, Inc.
Concentration

The concentration of a molecule is a way of stating the
amount of that molecule dissolved in solution.

Percent gives the relative mass of a solute found in a
given volume of solution.

A mole is the name for the number of atoms in an atomic
weight of that element, or the number of molecules in a
molecular weight of that type of molecule, with the
molecular weight being the sum of all the atomic weights
of the atoms that make up the molecule.
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Dissociation of Acids, Bases, and
Salts
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Concept of pH
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pH scale runs from 0 to 14 (concentration of H+
in moles/liter)
pH of 7 is neutral
(distilled water -- concentration of OH- and H+ are
equal)
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pH below 7 is acidic ([H+] > [OH-]).
pH above 7 is alkaline ([H+] < [OH-]).
pH is a logarithmic scale
Example: a change of two or three pH units
pH of 1 contains 10x10=100 more H+ than pH of 3
pH of 8 contains 10x10x10=1000 more H+ than pH of 11
Copyright 2009, John Wiley & Sons, Inc.
The pH Scale
Copyright 2009, John Wiley & Sons, Inc.
Maintaining pH: Buffer Systems

The pH values of different parts of the body
are maintained fairly constant by buffer
systems, which usually consist of a weak acid
and a weak base.

convert strong acids or bases into weak acids or
bases.
Copyright 2009, John Wiley & Sons, Inc.
Carbon and Its Functional Groups

Many functional groups can attach to carbon skeleton
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esters, amino, carboxyl, phosphate groups
Very large molecules are called macromolecules (or
“polymers” if all the monomer subunits are similar)
Isomers have the same molecular formulas but
different structures (glucose & fructose are both
C6H12O6)
Copyright 2009, John Wiley & Sons, Inc.
Carbohydrates
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Carbohydrates provide most of the energy needed for
life and include sugars, starches, glycogen, and
cellulose.
Some carbohydrates are converted to other substances
which are used to build structures and to generate ATP.
Other carbohydrates function as food reserves.
Carbohydrates are divided into three major groups
based on their size: monosaccharides, disaccharides,
and polysaccharides
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Monosaccharides
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Disaccharides

Combining 2 monosaccharides by dehydration
synthesis releases a water molecule.

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sucrose = glucose & fructose
maltose = glucose & glucose
lactose = glucose & galactose (lactose intolerance)
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Polysaccharides
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Polysaccharides are the
largest carbohydrates and
may contain hundreds of
monosaccharides.
The principal
polysaccharide in the
human body is glycogen,
which is stored in the liver
or skeletal muscles.
When blood sugar level
drops, the liver hydrolyzes
glycogen to yield glucose
which is released from the
liver into the blood
Copyright 2009, John Wiley & Sons, Inc.
Lipids
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Lipids, like carbohydrates, contain carbon,
hydrogen, and oxygen; but unlike carbohydrates,
they do not have a 2:1 ratio of hydrogen to oxygen.
They have few polar covalent bonds
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

hydrophobic
mostly insoluble in polar solvents such as water
combines with proteins (lipoproteins) for transport in blood
Copyright 2009, John Wiley & Sons, Inc.
Triglycerides

Triglycerides are the most plentiful lipids in
the body and provide protection, insulation,
and energy (both immediate and stored).
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At room temperature, triglycerides may be either
solid (fats) or liquid (oils).
Triglycerides provide more than twice as much
energy per gram as either carbohydrates or
proteins.
Triglyceride storage is virtually unlimited.
Excess dietary carbohydrates, proteins, fats, and
oils will be deposited in adipose tissue as
triglycerides.
Copyright 2009, John Wiley & Sons, Inc.
Triglycerides
Copyright 2009, John Wiley & Sons, Inc.
Phospholipids
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
Phospholipids are important membrane
components.
They are amphipathic, with both polar and
nonpolar regions

a polar head
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
a phosphate group (PO4-3) & glycerol molecule
forms hydrogen bonds with water
2 nonpolar fatty acid tails

interact only with lipids
Copyright 2009, John Wiley & Sons, Inc.
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Steroids

Steroids have four rings of carbon atoms
Steroids include
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sex hormone
bile salts
some vitamins
cholesterol, with cholesterol serving as an
important component of cell membranes and as
starting material for synthesizing other steroids.
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Four Ring Structure of Steroids
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Proteins

Constructed from combinations of 20 amino acids.
 dipeptides formed from 2 amino acids joined by a
covalent bond called a peptide bond
 polypeptides chains formed from 10 to 2000 amino
acids.
Copyright 2009, John Wiley & Sons, Inc.
Formation of a Dipeptide Bond


Dipeptides formed from 2 amino acids joined by a
covalent bond called a peptide bond
 dehydration synthesis
Polypeptides chains contain 10 to 2000 amino acids.
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Levels of Structural Organization

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Levels of structural organization include
 primary
 secondary
 tertiary
 quaternary
The resulting shape of the protein greatly influences its
ability to recognize and bind to other molecules.
Denaturation of a protein by a hostile environment
causes loss of its characteristic shape and function.
Copyright 2009, John Wiley & Sons, Inc.
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Enzymes
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
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Catalysts in living cells are called enzymes.
Enzymes are highly specific in terms of the
“substrate” with which they react.
Enzymes are subject to variety of cellular
controls.
Enzymes speed up chemical reactions by
increasing frequency of collisions, lowering
the activation energy and properly orienting
the colliding molecules.
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How and Enzyme Works
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DNA and RNA
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Nucleic acids are huge organic molecules that contain
carbon, hydrogen, oxygen, nitrogen, and phosphorus.
Deoxyribonucleic acid (DNA) forms the genetic code
inside each cell and thereby regulates most of the
activities that take place in our cells throughout a
lifetime.
Ribonucleic acid (RNA) relays instructions from the
genes in the cell’s nucleus to guide each cell’s assembly
of amino acids into proteins by the ribosomes.
The basic units of nucleic acids are nucleotides,
composed of a nitrogenous base, a pentose, sugar, and
a phosphate group.
Copyright 2009, John Wiley & Sons, Inc.
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RNA Structure

Differs from DNA
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single stranded
ribose sugar not deoxyribose sugar
uracil nitrogenous base replaces thymine
Types of RNA within the cell, each with
a specific function
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
messenger RNA
ribosomal RNA
transfer RNA
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Adenosine Triphosphate (ATP)
Temporary
molecular storage of
energy as it is being
transferred from
exergonic catabolic
reactions to cellular
activities
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Formation & Usage of ATP

Hydrolysis of ATP (removal of terminal
phosphate group by enzyme -- ATPase)
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releases energy
leaves ADP (adenosine diphosphate)
Synthesis of ATP


enzyme ATP synthase catalyzes the addition
of the terminal phosphate group to ADP
energy from 1 glucose molecule is used during
both anaerobic and aerobic respiration to
create 36 to 38 molecules of ATP
Copyright 2009, John Wiley & Sons, Inc.
Body Fluid Compartments

In lean adults, body fluids constitute 55% of
female and 60% of male total body mass

Intracellular fluid (ICF) inside cells
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About 2/3 of body fluid
Extracellular fluid (ECF) outside cells
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Interstitial fluid between cell is 80% of ECF
Plasma in blood is 20% of ECF
Also includes lymph, cerebrospinal fluid, synovial fluid,
aqueous humor, vitreous body, endolymph, perilymph,
and pleural, pericardial, and peritoneal fluids
Copyright 2009, John Wiley & Sons, Inc.
Body Fluid Compartments
Copyright 2009, John Wiley & Sons, Inc.
Fluid Balance

2 barriers separate ICF, interstitial fluid and plasma
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Plasma membrane separates ICF from surrounding
interstitial fluid
Blood vessel wall divide interstitial fluid from plasma
Body is in fluid balance when required amounts of
water and solutes are present and correctly
proportioned among compartments
Water is by far the largest single component of the
body making up 45-75% of total body mass
Process of filtration, reabsorption, diffusion, and
osmosis all continual exchange of water and solutes
among compartments
Copyright 2009, John Wiley & Sons, Inc.
Sources of Body Water Gain and Loss

Fluid balance related to electrolyte balance
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Body can gain water by
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Intake of water and electrolytes rarely proportional
Kidneys excrete excess water through dilute urine or
excess electrolytes through concentrated urine
Ingestion of liquids and moist foods (2300mL/day)
Metabolic synthesis of water during cellular respiration and
dehydration synthesis (200mL/day)
Body loses water through
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Kidneys (1500mL/day)
Evaporation from skin (600mL/day)
Exhalation from lungs (300mL/day)
Feces (100mL/day)
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Daily Water Gain and Loss
Copyright 2009, John Wiley & Sons, Inc.
Regulation of body water gain


Mainly by volume of
water intake/ how much
you drink
Dehydration – when
water loss is greater than
gain


Decrease in volume,
increase in osmolarity of
body fluids
Stimulates thirst center
in hypothalamus
Copyright 2009, John Wiley & Sons, Inc.
Regulation of water and solute loss

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Elimination of excess body water through urine
Extent of urinary salt (NaCl) loss is the main factor that
determines body fluid volume
Main factor that determines body fluid osmolarity is extent
of urinary water loss
3 hormones regulate renal Na+ and Cl- reabsorption (or not)


Angiotensin II and aldosterone promote urinary Na+ and Clreabsorption of (and water by osmosis) when dehydrated
Atrial natriuretic peptide (ANP) promotes excretion of Na+ and
Cl- followed by water excretion to decrease blood volume
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Hormonal Regulation of
+
Na
Copyright 2009, John Wiley & Sons, Inc.
and
Cl
Major hormone regulating water loss is
antidiuretic hormone (ADH)
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Also known as vasopressin
Produced by hypothalamus, released from
posterior pituitary
Promotes insertion of aquaporin-2 into principal
cells of collecting duct
Permeability to water increases
Produces concentrated urine
Copyright 2009, John Wiley & Sons, Inc.
Movement of water between compartments

Normally, cells neither shrink or swell because
intracellular and interstitial fluids have the same
osmolarity
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Increasing osmolarity of interstitial fluid draws water out of
cells and cells shrink
Decreasing osmolarity of interstitial fluid causes cells to swell
Changes in osmolarity most often result from changes
in Na+ concentration
Water intoxication – drinking water faster than the
kidneys can excrete it

Can lead to convulsions, coma or death
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Series of Events in Water Intoxication
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Electrolytes in body fluids


Ions form when electrolytes dissolve ad
dissociate
4 general functions
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
Control osmosis of water between body fluid
compartments
Help maintain the acid-base balance
Carry electrical current
Serve as cofactors
Copyright 2009, John Wiley & Sons, Inc.
Concentrations in body fluids

Concentration of ions typically expressed in
milliequivalents per liter (mEq/liter)
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Na+ or Cl- number of mEq/liter = mmol/liter
Ca2+ or HPO42- number of mEq/liter = 2 x mmol/liter
Chief difference between 2 ECF compartments
(plasma and interstitial fluid) is plasma contains many
more protein anions

Largely responsible for blood colloid osmotic pressure
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ICF differs considerably from ECF

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ECF most abundant cation is Na+, anion is
ClICF most abundant cation is K+, anion are
proteins and phosphates (HPO42-)
Na+ /K+ pumps play major role in keeping K+
high inside cells and Na+ high outside cell
Copyright 2009, John Wiley & Sons, Inc.
Electrolyte and protein anion
concentrations
Copyright 2009, John Wiley & Sons, Inc.
Sodium Na+
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Most abundant ion in ECF
90% of extracellular cations
Plays pivotal role in fluid and electrolyte balance
because it account for almost half of the
osmolarity of ECF
Level in blood controlled by



Aldosternone – increases renal reabsorption
ADH – if sodium too low, ADH release stops
Atrial natriuretic peptide – increases renal excretion
Copyright 2009, John Wiley & Sons, Inc.
Chloride Cl


Most prevalent anions in ECF
Moves relatively easily between ECF and ICF
because most plasma membranes contain Clleakage channels and antiporters
Can help balance levels of anions in different fluids

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Chloride shift in RBCs
Regulated by


ADH – governs extent of water loss in urine
Processes that increase or decrease renal
reabsorption of Na+ also affect reabsorption of Cl-
Copyright 2009, John Wiley & Sons, Inc.
Potassium K+

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Most abundant cations in ICF
Key role in establishing resting membrane
potential in neurons and muscle fibers
Also helps maintain normal ICF fluid volume
Helps regulate pH of body fluids when exchanged
for H+
Controlled by aldosterone – stimulates principal
cells in renal collecting ducts to secrete excess K+
Copyright 2009, John Wiley & Sons, Inc.
Bicarbonate HCO3

Second most prevalent extracellular anion
Concentration increases in blood passing through systemic
capillaries picking up carbon dioxide




Carbon dioxide combines with water to form carbonic acid
which dissociates
Drops in pulmonary capillaries when carbon dioxide exhaled
Chloride shift helps maintain correct balance of anions in
ECF and ICF
Kidneys are main regulators of blood HCO3
Can form and release HCO3- when low or excrete excess
Copyright 2009, John Wiley & Sons, Inc.
Calcium Ca2+
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Most abundant mineral in body
98% of calcium in adults in skeleton and teeth
In body fluids mainly an extracellular cation
Contributes to hardness of teeth and bones
Plays important roles in blood clotting, neurotransmitter
release, muscle tone, and excitability of nervous and
muscle tissue
Regulated by parathyroid hormone

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

Stimulates osteoclasts to release calcium from bone – resorption
Also enhances reabsorption from glomerular filtrate
Increases production of calcitrol to increase absorption for GI tract
Calcitonin lowers blood calcium levels
Copyright 2009, John Wiley & Sons, Inc.
Phosphate




About 85% in adults present as calcium phosphate salts in
bone and teeth
Remaining 15% ionized – H2PO4-, HPO42-, and PO43- are
important intracellular anions
HPO42- important buffer of H+ in body fluids and urine
Same hormones governing calcium homeostasis also
regulate HPO42- in blood
 Parathyroid hormone – stimulates resorption of bone by
osteoclasts releasing calcium and phosphate but inhibits
reabsorption of phosphate ions in kidneys
 Calcitrol promotes absorption of phosphates and calcium
from GI tract
Copyright 2009, John Wiley & Sons, Inc.
Magnesium
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In adults, about 54% of total body magnesium is part of
bone as magnesium salts
Remaining 46% as Mg2+ in ICF (45%) or ECF (1%)
Second most common intracellular cation
Cofactor for certain enzymes and sodium-potassium
pump
Essential for normal neuromuscular activity, synaptic
transmission, and myocardial function
Secretion of parathyroid hormone depends on Mg2+
Regulated in blood plasma by varying rate excreted in
urine
Copyright 2009, John Wiley & Sons, Inc.
Acid-base balance

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
Major homeostatic challenge is keeping H+
concentration (pH) of body fluids at
appropriate level
3D shape of proteins sensitive to pH
Diets with large amounts of proteins produce
more acids than bases which acidifies blood
Several mechanisms help maintain pH of
arterial blood between 7.35 and 7.45

Buffer systems, exhalation of CO2, and kidney
excretion of H+
Copyright 2009, John Wiley & Sons, Inc.
Buffer systems

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
Act to quickly temporarily bind H+
Raise pH but do not remove H+
Most consist of weak acid and salt of that acid functioning
as weak base
Protein buffer system

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Most abundant buffer in ICF and blood plasma
Hemoglobin in RBCs
Albumin in blood plasma
Free carboxyl group acts like an acid by releasing H+
Free amino group acts as a base to combine with H+
Side chain groups on 7 of 20 amino acids also can buffer H+
Copyright 2009, John Wiley & Sons, Inc.
Buffer Systems

Carbonic acid- bicarbonate buffer system

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

Based on bicarbonate ion (HCO3-) acting as weak base and
carbonic acid (H2CO3) acting as weak acid
HCO3- is a significant anion in both ICF and ECF
Because CO2 and H2O combine to form this buffer system
cannot protect against pH changes due to respiratory
problems in which there is an excess or shortage of CO2
Phosphate buffer system



Dihydrogen phosphate (H2PO4-) and monohydrogen
phosphate (HPO42-)
Phosphates are major anions in ICF and minor ones in ECF
Important regulator of pH in cytosol
Copyright 2009, John Wiley & Sons, Inc.
Exhalation of carbon dioxide



Increase in carbon dioxide in body fluids lowers
pH of body fluids
Because H2CO3 can be eliminated by exhaling
CO2 it is called a volatile acid
Changes in the rate and depth of breathing can
alter pH of body fluids within minutes

Negative feedback loop
Copyright 2009, John Wiley & Sons, Inc.
Regulation of blood pH by the respiratory
system
Copyright 2009, John Wiley & Sons, Inc.
Kidney excretion of H+

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
Metabolic reactions produce nonvolatile acids
One way to eliminate this huge load is to excrete
H+ in urine
In the proximal convoluted tubule, Na+ /H+
antiporters secrete H+ as they reabsorb Na+
Intercalated cells of collecting duct include proton
pumps that secrete H+ into tubule fluid
Urine can be up to 1000 times more acidic than
blood
2 other buffers can combine with H+ in collecting
duct

HPO42- and NH3
Copyright 2009, John Wiley & Sons, Inc.
Secretion of H+ by intercalated cells in the
collecting duct
Copyright 2009, John Wiley & Sons, Inc.
Acid-base imbalances

Normal pH range of arterial blood 7.35-7.45



Acidosis – blood pH below 7.35
Alkalosis – blood pH above 7.45
Major physiological effect of


Acidosis – depression of synaptic transmission in CNS
Alkalosis – overexcitability of CNS and peripheral nerves
Copyright 2009, John Wiley & Sons, Inc.
Physiological responses to normalize
arterial blood pH

Changes in blood pH may be countered by
compensation




Complete – brought within normal range
Partial – still too low or high
Respiratory – hyperventilation or hypoventilation
Renal – secretion of H+ and reabsorption of HCO3-
Copyright 2009, John Wiley & Sons, Inc.
Respiratory acidosis/ alkalosis results from
changes in partial pressure of CO2 in systemic
arterial blood

Respiratory acidosis – abnormally high PCO2 in
systemic arterial blood




Inadequate exhalation of CO2
Any condition that decreases movement of CO2 out –
emphysema, pulmonary edema, airway obstruction
Kidneys can help raise blood pH
Goal to increase exhalation of CO2 – ventilation therapy
Copyright 2009, John Wiley & Sons, Inc.
Respiratory alkalosis

Abnormally low PCO2 in systemic arterial blood



Cause is hyperventilation due to oxygen deficiency from
high altitude or pulmonary disease, stroke or severe
anxiety
Renal compensation can help
One simple treatment to breather into paper bag for
short time
Copyright 2009, John Wiley & Sons, Inc.
Metabolic acidosis/alkalosis

Results from changes in HCO3- concentration

Metabolic acidosis – abnormally low HCO3- in
systemic arterial blood





Loss of HCO3- from severe diarrhea or renal dysfunction
Accumulation of an acid other than carbonic acid –
ketosis
Failure of kidneys to excrete H+ from metabolism of
dietary proteins
Hyperventilation can help
Administer IV sodium bicarbonate and correct cause of
acidosis
Copyright 2009, John Wiley & Sons, Inc.
Metabolic alkalosis

Abnormally high HCO3- in systemic arterial blood






Nonrespiratory loss of acid - vomiting of acidic stomach
contents, gastric suctioning
Excessive intake of alkaline drugs (antacids)
Use of certain diuretics
Severe dehydration
Hypoventilation can help
Give fluid solutions to correct Cl-, K+ and other
electrolyte deficiencies and correct cause of alkalosis
Copyright 2009, John Wiley & Sons, Inc.