Pathopart2

Copyright © 2017, 2013, 2009 Pearson
Education, Inc. All Rights Reserved.
Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Paramedic Care: Principles & Practice
Volume 1, 5e
Pathophysiology
Part 2

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Part 2
Disease at the Chemical Level

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Big Bang theory: universe began with explosion of
a primeval atom.
• Chemical evolution: simple chemicals present in
primordial atmosphere and ocean combined to
form larger, more complex chemicals.
• Led to formation of complex chemicals able to
self-replicate.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Marked transition from chemical evolution to
biological evolution.
• Once biological evolution began, natural selection
began.
• Self-replicating chemical surrounded by
membrane; cellular life began.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• The Chemical Basis of Life
– Atom: fundamental chemical unit.
– Within atom are subatomic particles: electrons,
protons, neutrons.
– Protons and neutrons: exist within nucleus of atom.
– Electrons: smaller particles; orbit nucleus.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Element: substance that cannot be separated into
simpler substances.
– Atomic number: number of protons in nucleus of atom
defines element.
– Periodic table of elements: elements classified by their
atomic number.
– Isotopes: elements have same number of protons; vary
in number of neutrons.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Figure 12-6 A portion of the periodic table of elements. Each element has an atomic number (the
number of protons), a mass number (the total number of neutrons and protons), and a one- or
two-letter symbol.
(Freeman, Scott, Biological Science, 4th Edition, © 2011. Reprinted by permission of Pearson Education,
Inc., Upper Saddle River, NJ.)

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Mass number: total number of neutrons and protons in
atom.
– Radioactive isotopes: combinations of neutrons and
protons make nucleus unstable.
– Radioactive decay: nuclei break down and emit
radiation (alpha, beta, gamma rays) until atom regains
stability.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Half-life: time it takes for parent isotope to decrease by
one-half.
– Orbital: specific shape; can hold two or more electrons.
– Electron shells: levels numbered starting with closest
shell to nucleus.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Valence shell: outermost shell of atom.
– Valence electrons: in valence shell.
– Noble gases: helium, neon, argon, krypton, xenon,
radon.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Chemical Bonding
– Atoms become stable by bonding to other atoms.
– Covalent bond: equal sharing of electrons.
– Molecule: substance made up of atoms held together
by covalent bonds.
– Ion: atom or molecule that acquired electrical charge.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Cation: atom or molecule with missing electrons and
net positive charge.
– Anion: atom or molecule with extra electrons and net
negative charge.
– Ionic bond: opposite charges attract; bonds form
between atoms of opposite (positive/negative) charges.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Metallic elements: lose electrons.
– Nonmetallic elements: gain electrons.
– Polar bond: unequal covalent bond; molecule is polar
molecule.
– Hydrogen bond: attraction between slightly positively
charged hydrogen atom and slightly negatively charged
oxygen atom.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Inorganic and Organic Chemicals
– Inorganic: do not contain carbon.
– Organic: do contain carbon (90 percent of all known
chemicals).
– Major elements of living systems:
 Carbon (C)
 Hydrogen (H)
 Oxygen (O)
 Nitrogen (N)

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Inorganic and Organic Chemicals
– Compound: chemical union of two or more elements.
– Major compounds of living systems:
 Carbohydrates
 Proteins
 Nucleic acids
 Lipids

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Classes of Biological Chemicals
– Carbohydrates
 Provide majority of calories in diets.
 Divided into sugars; polysaccharides
 Monosaccharides: simple sugars
– Glucose, fructose, galactose
 Disaccharides: complex sugars.
– Sucrose, lactose, maltose

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Carbohydrates
 Polysaccharides: starches, cellulose, glycogen
 Starches: polymers of glucose
– Amylose, amylopectin
 Cellulose: most abundant organic molecule in the world; major
structural material of plants.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Carbohydrates
 Glycogen: important polysaccharide; stored in liver and
skeletal muscle.
 Glycogenolysis: controlled by hormones glucagon and
epinephrine.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Proteins
 Nitrogen-based complex compounds; basic building blocks of
cells.
 Growth and repair of living tissues.
 Amino acids: smaller building blocks.
 Peptide bonds: two amino acid molecules join and molecule of
water released.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Table 12-1 Protein Functions
Protein Type Function
Antibodies and complement protein Defense (destruction of
diseasecausing agents)
Contractile and motor proteins Movement
Enzymes Catalyze chemical reactions
Peptide hormones Signal and control the activities of cells
Receptor proteins Receive chemical signals from outside
of the cell and initiate cellular response
Structural proteins Support cells and tissues; major factor
in various body structures
Transport proteins Move substrates across cell
membranes and throughout the body

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Proteins
 Peptide: protein chain of less than 10 amino acids.
 Polypeptide: chain of greater than 10 amino acids.
 Levels of structure: primary, secondary, tertiary, quaternary.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Table 12-2 Protein Structure
Level Description Stabilized by Example: Hemoglobin
Primary The sequence of
amino acids in a
polypeptide
Peptide bonds
Secondary Formation of alpha
helices and beta-
pleated sheets in a
Polypeptide
Hydrogen bonding between
groups along the
peptidebonded backbone;
thus, depends on primary
structure
Tertiary Overall three-
dimensional shape
of a polypeptide
(includes
contribution from
secondary
structures)
Bonds and other
interactions between side
chains or between side
chains and the peptide-
bonded backbone; thus,
depends on primary
structure
Quaternary Shape produced
by combinations of
polypeptides (thus,
combinations of
tertiary structures)
Bonds and other
interactions between side
chains, and between
peptide backbones of
different polypeptides; thus,
depends on primary
structure

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Proteins
 Enzymes: proteins; speed up chemical reactions.
 Substrate binds to enzyme, forming enzyme-substrate
complex.
 Cofactors: nonprotein substances; aid in conversion of
substrate to end product.
 Coenzymes: organic cofactors.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Nucleic Acids
 Deoxyribonucleic acid (DNA): contains genetic instructions for
life.
 Two long polymers (nucleotides) joined by paired substances
(nucleobases).
 Genetic code: four nucleobases and sequence of these
encodes information.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Figure 12-20 DNA is a nucleic acid in which two chains of nucleotides twist around one another
to form a double helix (spiral). The two chains are held together by hydrogen bonds between the
nitrogen-containing bases. Each nucleotide of DNA contains the five-carbon sugar doxyribose, a
phosphate group, and one of four nitrogen-containing nucleobases: adenine (A), thymine (T),
cystosine (C), and guanine (G).
(Goodenough, Judith and Betty A. McGuire, Biology of Humans: Concepts, Applications, and Issues, 3rd
Edition, © 2010. Reprinted by permission of Pearson Education, Inc., Upper Saddle River, NJ.)

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Nucleic Acids
 Genes: code specific amino acid sequence; make up specific
protein.
 Number of chromosomes in cell nucleus varies with type of
organism.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Nucleic Acids
 Ribonucleic acid (RNA): chemical similar to DNA; major role in
protein synthesis.
 Nucleotides: five-carbon sugar molecules.
 Nitrogen bases: adenine, cytosine, guanine, thymine uracil.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Table 12-3 RNA and DNA Structural Differences
Characteristic RNA DNA
Sugar Ribose Deoxyribose
Bases Adenine, guanine,
cytosine, uracil
Adenine, guanine,
cytosine, thymine
Number of strands One Two, twisted to form a
double helix

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Figure 12-21 RNA is a single-stranded nucleic acid formed by the linking together of nucleotides
composed of the five-carbon sugar ribose, a phosphate group, and one of four nitrogen-
containing nucleobases: cystosine (C), adenine (A), guanine (G), and uracil (U).
(Goodenough, Judith and Betty A. McGuire, Biology of Humans: Concepts, Applications, and Issues, 3rd
Edition, © 2010. Reprinted by permission of Pearson Education, Inc., Upper Saddle River, NJ.)

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Nucleic Acids
 Adenosine triphosphate (ATP): nucleotide; one of monomers of
RNA.
 Principal source of energy for most energy-using activities of
cells.
 Phosphate bonds in ATP highly unstable.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Lipids
 Chemicals that do not dissolve in water; nonpolar.
 Function in long-term storage of biochemical energy,
insulation, structure, control.
 Triglycerides: rich sources of energy for body.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Lipids
 Triglycerides: saturated or unsaturated.
 Phospholipids: form membrane that surrounds cells.
 Steroids: basic unit is cholesterol.
 Anabolism: synthesis of steroid compounds by the body.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Water
 Universal solvent; polar molecule.
 Transports substances throughout body.
 Helps to maintain constant body temperature.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Figure 12-30 Water is polar and participates in hydrogen bonds.
(Freeman, Scott, Biological Science, 4th Edition, © 2011. Reprinted by permission of Pearson Education,
Inc., Upper Saddle River, NJ.)

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Acids and Bases
– Dissociation reaction: compound or molecule breaks
apart into separate components.
– Acids: substances that give up protons during chemical
reactions.
– Bases: substances that acquire protons during
chemical reactions.
– Acid-base reaction: transfer of protons.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Acids and Bases
– Water: ability to act as acid or base.
– Mole: molecular weight.
– Logarithm: base number raised to certain power.
– pH scale: degree of acidity or basicity (alkalinity) of a
substance.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Table 12-4 The pH Scale and Hydrogen Ion Concentrations
Characteristic Example Hydrogen Ion Concentration
Acidic 0
1
2
3
4
5
6
Hydrochloric acid
Stomach secretions
Lemon juice
Cola drinks
White wine
Tomato juice
Coffee, urine, saliva
10-0
10-1
10-2
10-3
10-4
10-5
10-6
(1.0)
(0.1)
(0.01)
(0.001)
(0.0001)
(0.00001)
(0.000001)
Neutral 7 Distilled water 10-7 (0.0000001)
Basic 8
9
Blood, semen
Bile
10-8
10-9
(0.00000001)
(0.000000001)

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Acids and Bases
– Buffer Systems
 Counter body's normal production of acids; prevent variations
in body's pH.
 Buffer: substance dissolved in water that counteracts changes
in pH.
– Carbonic acid-bicarbonate buffer system
– Protein buffer system
– Phosphate buffer system

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Acids and Bases
– Buffer Systems
 Carbonic acid-bicarbonate buffer system: regulates pH of
blood.
 Buffer changes in pH caused by organic acids and fixed acids
in extracellular fluid (ECF).
 Can function only when respiratory system and control centers
functioning normally.
 Limited by amount of available bicarbonate ions.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Acids and Bases
– Buffer Systems
 Protein buffers depend on ability of amino acids in protein
chain to react to changes in pH.
 Hemoglobin buffer system helps to prevent changes in ECF
pH when PaCO2 is rising or falling.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Acids and Bases
– Buffer Systems
 Phosphate buffer system limited in ECF; major role in
stabilizing pH of urine.
– Acid-base balance tightly controlled.
 Excess hydrogen ions bind to water molecules; removed
through exhalation of carbon dioxide from lungs or removed
via kidneys.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Acids and Bases
– Change in pH occurs, buffer systems react fastest.
– Respiratory and renal systems help correct problem.
– Potassium levels and hydrogen ion levels major aspect
of pH.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Table 12-5 Maintenance of Acid–Base Balance
System Mechanism Rate of Action
Buffer pairs
• Carbonic acid–
bicarbonate
• Proteins/
hemoglobin
• Phosphate
Releases or absorbs
hydrogen ions
Immediate
Respiratory system Retain or remove
CO2 (H2CO3)
Minutes to hours
Electrolyte shifts Exchange Na+ and/or K+ for
H+ in ECF
Minutes to hours
Renal system Secretion or absorption of H+
and/or HCO-
3, phosphate,
and ammonia buffering
Hours to days

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Acid-Base Disorders
– Any significant deviation of pH outside normal
operating parameters (7.35–7.45).
– Two body systems: respiratory system and renal
system.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Table 12-6 pH as a Function of Metabolism and Respiration

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Acidosis: excess of acids in body.
– Alkalosis: excess of base in body.
– Respiratory acid-base disorders: inequality in carbon
dioxide generation in peripheral tissues and carbon
dioxide elimination in respiratory system.
 Respiratory acidosis
 Respiratory alkalosis

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Metabolic acid-base disorders: production of organic or
fixed acids or conditions that affect levels of
bicarbonate in ECF.
 Metabolic acidosis
 Metabolic alkalosis

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Respiratory acidosis: respiratory system cannot
eliminate all carbon dioxide generated through
metabolic activities in peripheral tissues.
 Increase in PCO2; decrease in pH.
 Hypercapnia: elevation in plasma CO2 level.
 Decrease in respiratory rate, tidal volume, or combination of
the two.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Respiratory alkalosis: respiratory system eliminates too
much carbon dioxide through hyperventilation resulting
in hypocapnia.
– Hyperventilation: emotional situations, metabolic
disorders, medical conditions, environmental factors, or
combination.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Metabolic acidosis: deficiency of bicarbonate (HCO3
-)
in body.
– Kidney: major role in maintaining stable pH levels.
– Metabolic alkalosis: uncommon; due to increase in
HCO3
- levels or decrease in circulating acids.

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