Pathophysiology Pathophysiology Bio 395 Bio 395
Dec 25, 2015
PathophysiologyPathophysiology
Bio 395Bio 395
TerminologyTerminology PathologyPathology – focus on physical – focus on physical
changes in diseased organs and changes in diseased organs and tissuestissues
PathophysiologyPathophysiology – abnormal – abnormal functioning of diseased organs and functioning of diseased organs and how it applies to medical treatment how it applies to medical treatment and patient careand patient care
DiseaseDisease – loss of homeostasis, or – loss of homeostasis, or when physical or mental capacities when physical or mental capacities cannot be fully utilized (interruption, cannot be fully utilized (interruption, cessation or disorder in the function cessation or disorder in the function of an organ or system).of an organ or system).
EtiologyEtiology = cause of the disease = cause of the disease
When the etiology is unknown, the When the etiology is unknown, the disease is said to bedisease is said to be idiopathic idiopathic..
Iatrogenic: disease and/or injury as a Iatrogenic: disease and/or injury as a result of medical interventionresult of medical intervention
Categories of etiologyCategories of etiology Genetic diseaseGenetic disease– genes are responsible – genes are responsible
for a structural or functional defectfor a structural or functional defect Congenital diseaseCongenital disease– genetic information – genetic information
is intact, but the intrauterine environment is intact, but the intrauterine environment interferes with normal developmentinterferes with normal development
Acquired diseaseAcquired disease – disease is caused by – disease is caused by factors encountered after birth (biological factors encountered after birth (biological agents, physical forces, and chemical agents, physical forces, and chemical agents)agents)
Nosocomial – diseases acquired as a result Nosocomial – diseases acquired as a result of being in the hospitalof being in the hospital
Clinical manifestations – Clinical manifestations – indications indications that the person is sickthat the person is sick
SymptomsSymptoms – unobservable effects of a – unobservable effects of a disease reported by the patientdisease reported by the patient
SignsSigns – observable or measurable – observable or measurable traits traits
SyndromeSyndrome - a characteristic - a characteristic combination of signs and symptoms combination of signs and symptoms associated with a particular disease.associated with a particular disease.
PathogenesisPathogenesis - sequence of events in the - sequence of events in the of development of a diseaseof development of a disease
SequelaeSequelae – lesions or impairments resulting – lesions or impairments resulting from a diseasefrom a disease
Acute conditionsAcute conditions – rapid onset, develop – rapid onset, develop quickly, usually of short durationquickly, usually of short duration
Chronic conditionsChronic conditions – longer duration – longer durationonset may be sudden or onset may be sudden or insidiousinsidious
Remission – periods when clinical Remission – periods when clinical manifestations disappear or diminish manifestations disappear or diminish significantlysignificantly
Exacerbation – periods when clinical Exacerbation – periods when clinical manifestations become worse or more manifestations become worse or more severesevere
Distribution of lesions may be:Distribution of lesions may be:
LocalLocal – confined to one area of the – confined to one area of the bodybody
SystemicSystemic – widely distributed – widely distributed throughout throughout the bodythe body
Within an organ damage can be:Within an organ damage can be:
FocalFocal if there are only one or more if there are only one or more distinct sites of damagedistinct sites of damage
DiffuseDiffuse if the damage is uniformly if the damage is uniformly distributeddistributed
DiagnosisDiagnosis – identification of the – identification of the specific diseasespecific disease
TherapyTherapy – the treatment of the – the treatment of the disease to either effect a cure or disease to either effect a cure or reduce the patient’s signs and reduce the patient’s signs and symptomssymptoms
PrognosisPrognosis – prediction of a disease’s – prediction of a disease’s outcomeoutcome
Normal Functioning Normal Functioning of Cellsof Cells
Boundary – Cell Boundary – Cell membranemembrane(plasma membrane)(plasma membrane)Composed of lipid molecules in bilayer
Phospholipids have hydrophobic tailPhospholipids have hydrophilic headsAlso contains embedded proteins
proteins are important for cell-cellcommunication:
receptors for hormonescell recognition
also important for metabolic processes inside the cell:
channelspumpsenzymes
CytoplasmCytoplasmCytosol – aqueous gel-like medium
Important metabolic processes occur here
Organelles – membrane bound structuresMembranes provide compartments forseparation of chemical reactions
NucleusNucleusDNA codes for proteinsDNA codes for proteins
Rough Endoplasmic Rough Endoplasmic ReticulumReticulumContains ribosomes – make Contains ribosomes – make proteinsproteins
Smooth ERSmooth ERsynthesizes phospholipidssynthesizes phospholipidsdetoxifiesdetoxifies
Golgi ApparatusGolgi ApparatusPackages protein for exportPackages protein for export
MitochondriaMitochondriaThe cell’s power plantThe cell’s power plant
Cellular respirationCellular respiration
VesiclesVesicles“sacs” that hold molecules within a cell
lysosomes –digestive enzymesmolecules to be exported
InclusionsInclusions
Temporary structuresTemporary structures ribosomesribosomes filaments – cytoskeleton – protein filaments – cytoskeleton – protein
strandsstrands other molecules without membranes:other molecules without membranes: melaninmelanin lipids, etc.lipids, etc.
TissuesTissuesMade up of cells with common function
Four major tissue types:
1. Epithelial covering and lining
interacts with the body’s environmentglandular tissue
2. Connective tissue2. Connective tissue
Important to structure , support and protection
3. Nervous tissueMade up of neurons and supporting (glial) cells
receives info from outside (or inside) the bodyprocesses informationacts on the information through muscles, glands,
etc.
MuscleMuscle Important to movementImportant to movement Three typesThree types
– SkeletalSkeletal– SmoothSmooth– CardiacCardiac
Cells change to adapt Cells change to adapt to their environmentto their environment
Atrophy = shrinkage = decrease in cell size. Due to :
decreased use decreased blood supplydecreased nutrition
Of tissues or organs may be due to cell shrinkage or due to cell death.
Hypertrophy = increase in cell sizeResult is increased protein in
organelles, but number of cells staty the same
Hyperplasia = increase in cell numberDue to increased cell division
Uterus and breast tissueParathyroid gland in kidney failureLiver (compensatory hyperplasia)
Metaplasia = replacement of one cell type with another, still normal cellsReversible
An example: ciliated columnar epithelium replaced by stratified squamous epithelium
Dysplasia = change in cell resulting in abnormal cell size, shape or organization
in respiratory tract, cervix w/ pathology
Considered a reversible change
Neoplasia = associated with a malignant tumor
Normal Tissue
AbnormalTissue
Intracellular Intracellular accumulationsaccumulations Buildup of substances the cell Buildup of substances the cell
can’t use or dispose of.can’t use or dispose of.– Normal body substancesNormal body substances– Abnormal products from inside the Abnormal products from inside the
body (inborn errors of metabolism)body (inborn errors of metabolism)– Substances from outside the body Substances from outside the body
(transient or permanent)(transient or permanent)
Cellular injury – cell Cellular injury – cell unable to maintain unable to maintain homeostasishomeostasis Causes of cell injury:Causes of cell injury: DeficiencyDeficiency – lack of a substance – lack of a substance
necessary to the cellnecessary to the cell Intoxication or poisoningIntoxication or poisoning – –
presence of a toxin or substance presence of a toxin or substance that interferes with cell functioningthat interferes with cell functioning
TraumaTrauma – physical injury and loss – physical injury and loss of cell’s structural integrityof cell’s structural integrity
Deficiencies:
Deficiency in oxygen most important
Hypoxia = deficiency in oxygen at cellDue to :
Decreased oxygen in airDecreased hemoglobin or decreased oxygen transported to cellsDiseases of the respiratory and/or
cardiovascular system
Important to cell because of oxidative phosphorylation, which results
in the production of ATP
Oxidative: need oxygen to produce ATP
ATP: needed by cell for metabolism, cell life
Cellular response to hypoxiaDecreased mitochondrial reactions
decreased ATP produced decreased energy
Ion pumps cease, so can't regulate ions into/out of cell (ATP needed for this)
Can't pump Na+ and water out of cell, so get cell swelling organelle swelling
cell death
IschemiaIschemia is inadequate blood supply to a is inadequate blood supply to a cell or tissue.cell or tissue.
Ischemia can cause hypoxia.Ischemia can cause hypoxia.
Intoxication (or introduction of toxins into the cell)
Effect on cell depends on toxin and on cell
Some examples:Lead -- injures nervous systemCO -- deprives body of oxygenEthanol -- effects central nervous
system
Trauma -- physical disruption of cells
Ex: abrasion, cutting, burns, microorganisms etc.
ApoptosisApoptosis
““fallen apart”fallen apart” Regulated cell deathRegulated cell death During developmentDuring development Worn out cellsWorn out cells Diseased cells (tumor suppressor Diseased cells (tumor suppressor
p53 gene, natural killer or Tc p53 gene, natural killer or Tc cells)cells)
NecrosisNecrosis
Messy cell deathMessy cell death Initiates inflammationInitiates inflammation Gangrene – large mass of tissue Gangrene – large mass of tissue
undergoes necrosisundergoes necrosis
Coagulative Necrosis - Coagulative Necrosis - KidneyKidneyCoagulative Necrosis - Coagulative Necrosis - KidneyKidney
Necrosis
Fatty Necrosis - Fatty Necrosis - pancreaspancreasFatty Necrosis - Fatty Necrosis - pancreaspancreas
Necrosis
Dry GangreneDry GangreneDry GangreneDry Gangrene
Wet Gangrene 2Wet Gangrene 2º to diabetesº to diabetesWet Gangrene 2Wet Gangrene 2º to diabetesº to diabetes
Necrosis w/ liquefactive
component
Infections agentsMicroorganisms can invade and harm
cells
Cell injury can have effects on the entire body
Examples: fever, pain, increased heart rate
Cell agingCell aging
Programmed change theoriesProgrammed change theories Error theoriesError theories TelomeraseTelomerase