Pathopart3

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 3

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Part 3
Disease at the Cellular Level

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• The Cell
– Basic unit of all living organisms.
– Nucleus: central portion of cell.
– Organelles: structures within nucleus that carry out
biological processes.
– Prokaryotic cells: do not contain nucleus or organelles.
– Eukaryotic cells: contain nucleus and organelles.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Figure 12-32 Eukaryotic cells, such as the generalized animal cell shown here, have internal
membrane-bound organelles.
(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
• The Plasma Membrane and Cytoplasm
– Plasma membrane: consists of chemicals;
phospholipids.
– Cell membrane: lipid bilayer.
– Cytoplasm (cytosol): fills inside of cells; water, salts,
organic molecules, enzymes that catalyze biochemical
reactions.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• The Plasma Membrane and Cytoplasm
– Intracellular fluid: water component of cytoplasm.
– Membrane proteins:
 Linkers
 Enzymes
 Receptors
 Transporters

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Plasma Membrane Functions
– Cells adhere to each other or stick together; cell
adhesion molecules (CAMs).
– Cell-cell recognition; ability of cell to distinguish one
type of cell from another.
– Maintains structural integrity of cell.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Table 12-7 Mechanism of Transport across the Plasma Membrane
Mechanism Description
Simple diffusion Random movement from region of high to region of low
concentration
Facilitated diffusion Movement from region of high to region of low
concentration with the aid of a carrier or channel
protein
Osmosis Movement of water from a region of high water
concentration (low solute concentration) to a region of
low water concentration (high solute concentration)
Active transport Movement from region of high to region of low
concentration with the aid of a carrier or channel
protein and energy, usually from ATP
Endocytosis Materials engulfed by the plasma membrane and
drawn into the cell in a vesicle
Exocytosis Membrane-bound vesicle from inside the cell fuses
with the plasma membrane and spills contents outside
the cell

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Role in communications between cells.
– Regulates movement of substances into and out of
cell.
– Simple diffusion: random movement of molecules from
area of higher concentration to area of lower
concentration.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Figure 12-36 Simple diffusion is the random movement of molecules from a region of higher
concentration to a region of lower concentration. Solutes diffuse across the membrane until
equilibrium is reached on both sides.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Rate of diffusion proportional to concentration gradient
across membrane.
– Osmotic gradient: movement of water across
semipermeable membrane.
– Osmosis: movement of water molecules from area of
high water concentration to area of low water
concentration.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Free water: water free of solute.
– Water: universal solvent.
– Isotonic: concentrations of solutions on both sides of
semipermeable membrane are equal.
– Hypertonic: solution on one side of membrane more
concentrated than solution on other side.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Osmosis generates pressure: osmotic pressure.
– Osmolarity: concentration of solute particles in solution.
– Osmolality: measures concentration of particles in body
fluids.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Facilitated diffusion: no expenditure of metabolic
energy; transport assisted by integral proteins in
plasma membrane.
 Carrier proteins
 Ion channels

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Active transport: cell moves solute across plasma
membrane against concentration gradient.
 Carrier protein; energy in form of ATP.
– Sodium-potassium pump: transport of sodium ions out
of cell and potassium ions into cell, against
concentration gradient.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Endocytosis: plasma membrane encircles substance to
be ingested.
 When separated from cell membrane, vesicle released into
cell.
– Phagocytosis: cell engulfs large particles or bacteria.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Figure 12-43 Phagocytosis. The cell engulfs large particles or bacteria.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Pinocytosis: cell engulfs droplets of fluid carrying
dissolved substances.
– Endocytosis: large molecules leave cell by becoming
encircled in membrane vesicle.
– Exocytosis: membrane-bound vesicle containing
substance to be released from cell approaches cell
membrane.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Cellular Environment: Fluids and Electrolytes
– Severe derangements in fluid and electrolyte status
can result in death.
– Water: most abundant substance in body (60 percent);
total body water (TBW).
– Intracellular fluid (ICF): all fluid found inside body cells.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Table 12-8 Body Fluid Compartments
Compartment
Percentage of Total
Body Water
Volume in 70-kg Adult
(42 L total body water)
Intracellular fluid 70.0 percent 29.40 L
Extracellular fluid 30.0 percent 12.60 L
Interstitial fluid 25.0 percent 10.50 L
Intravascular fluid 5.0 percent 2.10 L

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Extracellular fluid (ECF): all fluid found outside body
cells.
– Intravascular fluid: fluid found outside cells and within
circulatory system.
– Interstitial fluid: all fluid found outside cell membranes;
not within circulatory system.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Total body water and distribution vary with age and
physiologic condition.
– Infant's TBW is 75 to 80 percent of body weight; 65
percent TBW average adult.
– Elderly, like very young, high risk for dehydration and
disorders related to electrolyte imbalances.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Intake: water coming into body.
– Output: water excreted from body.
– To maintain homeostasis, intake must equal output.
– Thirst regulates fluid intake.
– Body maintains fluid balance by shifting water from one
body space to another.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Dehydration: abnormal decrease in total body water.
 Gastrointestinal losses
 Increased insensible loss
 Increased sweating
 Internal losses
 Plasma losses

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Fluid replacement based on fluid and electrolyte
deficits.
– Dehydrated patient: dry mucous membranes, poor skin
turgor, excessive thirst.
– Overhydration: edema; heart failure may be present.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Electrolytes: substances that dissociate into electrically
charged particles when placed into water.
– Ions: charged particles.
– Cations: ions with positive charge.
– Anions: ions with negative charge.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Cations
 Sodium (Na+)
 Potassium (K+)
 Calcium (Ca++)
 Magnesium (Mg++)

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Anions
 Chloride (Cl-)
 Bicarbonate
 Phosphate
– Electrolytes measured in milliequivalents per liter
(mEq/L).

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Body's fluid compartments separated by cell
membranes.
– Semipermeable; selectively permeable.
– Compounds with small molecules (H2O) pass readily
through membrane; larger compounds (proteins)
restricted.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Movement of fluids through membrane enabled by
pores in membrane.
– Electrolytes do not pass through membrane as readily
as water due to their electrical charge.
– Water moves across cell membrane to dilute area of
increased electrolyte concentration.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Movement of water more rapid than movement of
electrolytes.
– Within extracellular compartment, movement of water
between plasma in intravascular space and interstitial
space function of forces in capillary beds.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Blood plasma generates oncotic force.
– Hydrostatic pressure: blood pressure; force against
vessel walls by contractions of heart.
– Filtration: hydrostatic pressure forces water out of
plasma across capillary wall into interstitial space.
– Starling's hypothesis: Net filtration = (Forces favoring
filtration) - (Forces opposing filtration)

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Edema: accumulation of water in interstitial space.
 Decrease in plasma oncotic force
 Increase in hydrostatic pressure
 Increased capillary permeability
 Lymphatic channel obstruction

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Edema: localized or generalized.
– Sign of underlying disease or problem; edema itself
causes problems.
– Antidiuretic hormone (ADH) or vasopressin: chief
regulator of water retention and distribution.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Intravenous Therapy (IV)
– Introduction of fluids and other substances into venous
side of circulatory system.
 Replace blood lost through hemorrhage
 Electrolyte or fluid replacement
 Medications directly into vascular system

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Intravenous Therapy
– Blood: fluid of cardiovascular system.
– Transports nutrients, oxygen, hormones, heat.
– Plasma: liquid portion.
– Blood cells: formed elements.
 Red blood cells: erythrocytes
 White blood cells: leukocytes
 Platelets: thrombocytes

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Erythrocytes: hemoglobin; transports oxygen; 99
percent of blood cells.
– Hemoglobin: iron-based compound that binds with
oxygen.
– Leukocytes: responsible for immunity and fighting
infection.
– Thrombocytes: major role in blood clotting.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Figure 12-49 Blood components.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Plasma can be separated from formed elements by
centrifugation.
– Hematocrit: percentage of blood occupied by
erythrocytes.
– Most desirable fluid for blood loss replacement is whole
blood.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Table 12-9 Resuscitation Fluids
Resuscitation Fluid Used
Diagnosis 1st Choice 2nd Choice 3rd Choice 4th Choice
Hemorrhagic
shock
Whole blood Packed RBCs Plasma or
plasma
substitute
Lactated
Ringer's or
normal
saline
Shock due to
plasma loss
(burns)
Plasma Plasma
substitute
Lactated
Ringer's or
normal saline
—
Dehydration Lactated
Ringer's or
normal saline
— — —

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Blood often fractionated (separated into parts); packed
red blood cells used.
– Typed and cross-matched to prevent severe allergic
reaction.
– Transfusion reactions: discrepancy between blood type
of patient and blood type of blood being transfused.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Intravenous fluids: colloids and crystalloids.
– Colloid: proteins; remain in intravascular space for
extended period.
 Plasma protein fraction (Plasmanate)
 Salt-poor albumin
 Dextran
 Hetastarch (Hespan)

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Crystalloids: primary compounds used in prehospital
intravenous fluid therapy.
 Isotonic solutions
 Hypertonic solutions
 Hypotonic solutions
– Intravenous replacement fluids: needs of patient;
underlying problem.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Most commonly used solutions in prehospital care:
 Lactated Ringer's solution
 0.9 percent sodium chloride (normal saline)
 5 percent dextrose in water (D5W)
– Lactated Ringer's solution and normal saline used for
fluid replacement.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Organelles and Their Functions
– Nucleus: largest organelle; contains cell's genetic
information.
– Genetic information encoded by base sequences on
DNA molecule.
– DNA controls cell functions and production of specific
proteins.
– Genetic information on threadlike structures called
chromosomes.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Figure 12-52 Diagram of the nucleus.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Humans: 46 chromosomes (23 pairs).
– Nuclear envelope: double membrane encases nucleus.
– Nucleoplasm: chromatin and materials inside nucleus.
– Nuclear pores: openings in nuclear envelope.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Nucleolus: region of DNA active in production of
ribosomal RNA (rRNA).
– Ribosomes: synthesis of polypeptides and proteins.
– Endoplasmic reticulum: network of tubules, vesicles,
sacs; interconnect with plasma membrane, nuclear
envelope, other organelles in cell.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Rough endoplasmic reticulum (RER): contains
ribosomes during protein synthesis.
– Smooth endoplasmic reticulum (SER): without
ribosomes.
– Endoplasmic reticulum: role in replenishment and
maintenance of plasma membrane.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Figure 12-55 The endoplasmic reticulum has rough and smooth portions. Rough endoplasmic
reticulum (RER) has ribosomes attached during protein synthesis. Smooth endoplasmic
reticulum (SER) has no attached ribosomes and serves various functions, depending on the cell
type.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Golgi apparatus (Golgi complex): processes proteins
for cell membrane and other cell organelles.
– Lysosomes: "garbage disposal system" of cells.
 Break down foreign substances and invaders; degrade worn
out parts of cell.
 Process macromolecule products.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Vacuoles: membrane-bound organelles used for
temporary storage or transport of substances.
– Peroxisomes: generate and degrade hydrogen
peroxide (H2O2); highly toxic to cells.
 Detoxify harmful substances; regulation of oxygen tension
within cell.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Mitochondria: "powerhouses" of cells; provide energy
needed for all of cell's biochemical processes.
– Cellular respiration.
– Cristae: inner membrane folds form shelves within
mitochondria.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Cytoskeleton and Internal Cell Structures
– Microtubules: long, hollow rods made of protein tubulin.
– Microfilaments: made from protein actin.
– Centrioles: cylindrical structures composed of groups
of microtubules.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Figure 12-58 Mitochondria are sites of energy conversion in the cell.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Cytoskeleton and Internal Cell Structures
– Cytoskeleton: three-dimensional structure; serves as
skeleton for cell stability.
– Cilia: hairlike structures that move in back-and-forth
motion.
– Flagella: much longer than cilia; move in undulating,
wavelike manner.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Cellular Respiration and Energy Production
– Digestive system breaks down nutrients:
carbohydrates, proteins, lipids.
– Cellular respiration: aerobic; requires oxygen.
– Fermentation: anaerobic; does not require oxygen.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Oxidation: loss of electrons from one atom to another.
– Reduction: gain of electrons by one atom from another.
– Three biochemical processes glucose molecule must
pass to produce energy through cellular respiration:
glycolysis, citric acid cycle, electron transport.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Glycolysis
 Occurs in cytoplasm; breakdown of six-carbon sugar glucose.
 Energy-using and energy-yielding phases.
– Citric acid cycle (Kreb's cycle or tricarboxylic acid
[TCA] cycle):
 Completely oxidizes remainder of glucose molecule.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Electron Transport Chain
 Five types of carriers.
 Electrons transferred from one molecule to next; energy
released.
 Passed to oxygen; ultimate electron acceptor.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Fermentation
 Breakdown of glucose without oxygen
 Final electron acceptor is pyruvate, not oxygen
 Very inefficient
 Lactic acid fermentation
 Alcohol fermentation

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Cellular Response to Stress
– Cellular adaptation: physiologic and structural changes
to cell, in response to change or stress.
 Hyperplasia
 Hypertrophy
 Atrophy
 Metaplasia

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Hyperplasia: increase in number of cells in tissue or
organ.
 Hormonal hyperplasia: stimulation by hormones.
 Compensatory hyperplasia: increase in tissue mass following
tissue injury or loss.
 Can be pathological.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Hypertrophy: increase in size of cells in tissue or organ.
 Due to creation of more structural components within cell
 Physiologic hypertrophy: increased physical demand
 Pathological hypertrophy: abnormal stress

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Atrophy: decrease in size of cell.
 May be physiologic (effect of hormones) or pathological (result
of disease or injury).
– Metaplasia: cell can change from one adult cell type to
another adult cell type; reversible.
 Protects organism from stress.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
Figure 12-67 Abnormal cell responses to stress include hypertrophy, hyperplasia, atrophy,
metaplasia, and dysplasia.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
• Cell Injury and Cell Death
– Cells stressed to point they can no longer adapt, or
exposed to toxic agents, cell injury results.
– Cell injury persistent or severe, cell death occurs.
– Irreversibly damaged cells undergo necrosis or
apoptosis; normal process of keeping body healthy.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Ischemia: diminished blood flow.
– Hypoxia: decreased availability of oxygen.
– Cellular respiration impaired; energy production limited
to glycolysis.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Oxygen free radicals steal electrons from other
compounds and generate new species of free radicals.
 Process can continue until components of cell used up.
– Various chemicals, including drugs, can cause injury to
a cell.

Bryan E. Bledsoe
Richard A. Cherry
Robert S. Porter
– Apoptosis: cellular program activated; causes release
of enzymes that destroy genetic material within nucleus
of cell and selected proteins in cytoplasm.
 Can be physiologic or pathological.
– Dysplasia: abnormal or disordered growth in a cell.
 Precursor to development of cancer.

Pathopart3

Recommended

Recommended

More Related Content

Viewers also liked

Viewers also liked (13)

Similar to Pathopart3

Similar to Pathopart3 (20)

More from djorgenmorris

More from djorgenmorris (20)

Recently uploaded

Recently uploaded (20)

Pathopart3

Editor's Notes