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Pathophysiology
BIO230
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Tuesday 11 - 2 p.m. Thursday 1 – 2:30 p.m. Friday 11:30 – 1:00 p.m. And by appointment (please email
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Lecture Text: Essentials of Pathophysiology Concepts of Altered Health States,2nd ed., by Carol Mattson Porth.Lippincott Williams & Wilkins, pub.
Study Tips
Don’t cram Use the powerpoint slides and your
notes Understand the material Read the textbook Study frequently for short periods Find a study parnter (or group) Practice your presentations in
advance
Terminology• Pathology – focus on physical changes in
diseased organs and tissues
• Pathophysiology – abnormal functioning of diseased organs and how it applies to medical treatment and patient care
Disease – loss of homeostasis, or when physical or mental capacities cannot be fully utilized (interruption, cessation or disorder in the function of an organ or system).
Etiology = cause of the disease
When the etiology is unknown, the disease is said to be idiopathic.
Categories of etiology• Genetic disease– genes are responsible
for a structural or functional defect
• Congenital disease– genetic information is intact, but the intrauterine environment interferes with normal development
• Acquired disease – disease is caused by factors encountered after birth (biological agents, physical forces, and chemical agents)
Clinical manifestations – indications that the person is sick
Symptoms – unobservable effects of a disease reported by the patient
Signs – observable or measurable traits
Syndrome - a characteristic combination of signs and symptoms associated with a particular disease.
Pathogenesis - sequence of events in the of development of a disease
Sequelae – lesions or impairments resulting from a disease
Acute conditions – rapid onset, develop quickly, usually of short duration
Chronic conditions – longer duration
onset may be sudden or insidious
Distribution of lesions may be:
Local – confined to one area of the body
Systemic – widely distributed throughout the body
Within an organ damage can be:
Focal if there are only one or more distinct sites of damage
Diffuse if the damage is uniformly distributed
Diagnosis – identification of the specific disease
Therapy – the treatment of the disease to either effect a cure or reduce the patient’s signs and symptoms
Prognosis – prediction of a disease’s outcome
Normal Functioning of Eukaryotic Cells
Boundary – Cell membrane(plasma membrane)
Composed of lipid molecules in bilayerPhospholipids 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
CytoplasmCytosol – aqueous gel-like medium
Important metabolic processes occur here
Organelles – membrane bound structuresMembranes provide compartments forseparation of chemical reactions
NucleusDNA codes for proteins
Rough Endoplasmic ReticulumContains ribosomes – make proteins
Smooth ERsynthesizes phospholipids
detoxifies
Golgi ApparatusPackages protein for export
MitochondriaThe cell’s power plant
Cellular respiration
Vesicles“sacs” that hold molecules within a cell
lysosomes –digestive enzymesmolecules to be exported
InclusionsTemporary structures
• ribosomes
• filaments – cytoskeleton – protein strands
• other molecules without membranes:– melanin– lipids, etc.
TissuesMade up of cells with common function
Four major tissue types:
1. Epithelial covering and lining
interacts with the body’s environmentglandular tissue
2. 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.
Muscle
• Important to movement
• Three types– Skeletal– Smooth– Cardiac
Cells change to adapt to 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 sizeWe'll see this in heart, kidney (and others) w/ pathologyNOT due to increased cell volume or fluidRather, due to increased protein synthesis within the cell, or decreased protein breakdownResult is increased protein in organelles
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 anotherReversible
An example: ciliated columnar epithelium replaced by
stratified squamous epithelium
Dysplasia = change in cell resulting in abnormal cell size, shape or organizationWe'll see this in respiratory tract, cervix w/ pathologyIn mature cells only
Immature cells would be expected to change in size, shape as they grow and mature
Considered a reversible change
Neoplasia = associated with a malignant tumor
Intracellular accumulations
• Buildup of substances the cell can’t use or dispose of.– Normal body substances– Abnormal products from inside the body
(inborn errors of metabolism)– Substances from outside the body (transient
or permanent)
Cellular injury – cell unable to maintain homeostasis
• Causes of cell injury:
• Deficiency – lack of a substance necessary to the cell
• Intoxication or poisoning – presence of a toxin or substance that interferes with cell functioning
• Trauma – physical injury and loss of 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
Ischemia is inadequate blood supply to a cell or tissue.
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.
Free radicals :uncharged atom or group of atoms with an
unpaired electronFormed by radiation, redox reactions, chemicals
Atom is unstable needs to gain or lose an electroncan alter chemical bonds in proteins, lipids, carbohydrates and nucleic acidscan cause chain reaction in cell
Apoptosis
• “fallen apart”
• Regulated cell death
• During development
• Worn out cells
• Diseased cells (tumor suppressor p53 gene, natural killer or Tc cells)
Necrosis
• Messy cell death
• Initiates inflammation
• Gangrene – large mass of tissue undergoes necrosis
Infections agentsMicroorganisms can invade and harm cells
Cell injury can have effects on the entire bodyExamples: fever, pain, increased heart rate
Cell aging
• Programmed change theories
• Error theories
• Telomerase
