NR283
NR283 Exam 1 Study Guide (Chapters 1, 2, 5, 6, 7, 20, & 21)
NR 283
NR283 Exam 1 Study Guide
(Chapters 1, 2, 5, 6, 7, 20, & 21)
*Make sure that
... [Show More] you understand all of the terms you are studying, if you don’t know what a term means, look it up before you continue studying. Take your thinking a step further by asking yourself “why” as you are reviewing material. This will lead to understanding of the material versus memorization which will better help you answer questions. Remember, this study guide does not mirror the exam and you are responsible for all course content; ensure that you have an understanding of concepts. That being said, if you complete and understand this study guide, you will be well prepared for the next exam.
*Ensure that you understand all highlighted terms in each chapter
* Answer the question and supplemental questions included with the original question
Chapter 1: Introduction to Pathophysiology
1. What are the 7 steps of health?
-Don’t smoke, avoid 2nd hand smoke
-Eat 5-10 servings of vegetables & Fruit daily. High fiber, lower-fat foods. Limit alcoholic drinks to 1 or 2 a day.
-Be active
-Protect yourself & family from the sun
-Follow cancer screening guidelines
-Visit doctor or dentist if any change in normal state of health
-Follow health & safety instructions at home and work when using, storing and disposing of hazardous materials.
2. What is the definition of disease?
Deviation from normal state or homeostasis: structure or function of any part, organ, system (or combination of these) or from a state of wellness.
3. Describe what homeostasis is: maintenance of stable internal environment of the body despite external changes.
a. Which factors indicate how well the body is maintaining homeostasis? (3 listed)
-Blood pressure
-Body Temp
-Fluid Balance
4. Describe the following & list examples:
a. Primary Prevention: Prevention of disease or experiencing an injury in the first place (doctors, vaccines)
Ex.) immunizations, screenings controlling potential hazards at home, education
i. When is this implemented? Before disease is present
b. Secondary Prevention: Baby aspirin-hypertension, frequent monitoring, modified work
i. When is this implemented? After illness or risk factors have been diagnosed to prevent complications. To slow progress of disease, limit long-term disability and prevent re-injury.
c. Tertiary Prevention: Pain management, support groups, rehab
i. When is this implemented? Diagnosed after complication to prevent & preserve quality of life. Helping people manage complicated, long term health problems
5. What are the 3 major health professional organizations who conduct research, publish findings, track certain diseases and are responsible for signaling warning about predisposing conditions or current treatments?
-United States Public Health Service
-Centers for Disease Control and Prevention (CDC)
-State & Local authorities
*Findings are gathered by World Health Organization (WHO)
6. Describe each characteristic of disease:
-Pathogenesis: development of the disease or events involved in tissue changes related to specific disease process
-Onset: sudden and obvious or acute
-insidious: gradual progression with vague or mild signs
-acute: short-term illnesss developing quickly with marked signs (fever, severe pain)
-Chronic: milder condition developing gradually. Persisting for a long time (rheumatoid arthritis)
-Subclinical state: pathologic changes occur, no obvious manifestations show by patient
-Latent stage: no clinical signs. Also referred to incubation period, time between exposure to microorganism and onset of signs or symptoms. Disease may be communicable or contagious.
-Prodromal period: early development of disease when aware of a change in the body, but signs aren’t specific. Ex.) fatigue, headache.
-Manifestations: clinical evidence or signs and symptoms. Ex.) redness, swelling. May also be systemic=general indicators of illness like a fever
-Signs: objective or observed by someone other than affected individual. Ex.) fever, rash
-Symptoms: subjective feelings felt and said by patient. Ex.) pain, lethargy etc.
-Lesion: specific local change in a tissue . Ex.) blister or pimple
-Syndrome: collection of signs and symptoms, affecting more than one organ and occur together due to certain condition
-Diagnostic Tests
-Remissions & exacerbations: course or progress of disease.
-Precipitating factor: condition that triggers an acute episode. Ex.) seizure in individual with a seizure disorder.
Predisposed factor: at higher risk for disease because of life style habits/genetics. Ex.) coronary artery disease b/c high cholesterol diet
Sequelae: potential unwanted outcomes of primary condition. Ex.) paralysis following a stroke
Convalescence or Rehab: period of recovery, returning to normal state
7. What is prophylaxis and why is it important? What are some examples of prophylactic measures in health care? Measures designed to preserve health and prevent the incidence or spread of disease. Provides information that benefit patients’ needs and allows them to make better decisions about their health. Ex.) Treatment for myocardial infarction for high risk patient= 1 baby aspirin daily.
8. Describe the difference between acute and chronic disease:
Acute is the sudden onset of short term illness with marked signs such as fever, severe pain etc. Chronic is more mild gradually developing that persists for a long time.
9. Describe the difference between morbidity and mortality:
Morbidity is the disease rates within a group such as stroke cause within a population. Mortality is the number of deaths resulting from a particular disease.
10. Describe each term of cellular adaptation and list examples:
a. Atrophy: “shrink” decrease in size of cells=reduced tissue mass
i. Ex: limb in cast for several weeks
b. Hypertrophy: “grow in size” increase in size of cells=enlarged tissue mass
i. Ex: exercise on skeletal muscle or weight lifting
c. Hyperplasia: “grow in numbers” increased number of cells=enlarged tissue mass
i. Ex: Uterine enlargement during pregnancy
d. Metaplasia: “replace w/ diff. mature cell” mature cell type is replaced by diff mature cell type.
i. Ex: In smokers lining of lungs (ciliated columnar epithelium) gets replaced with more resistant tissue (stratified squamous epithelium). Decreases defense for lungs.
e. Dysplasia: “dysfunctional” cells vary in size and shape w/in a tissue
i. Ex: Pap smear
f. Anaplasia: “undifferentiated cells” un.diff. cells with variable nuclear and cell structures
i. Ex: Characteristic of cancer, basis for grading aggressiveness of tumors
g. Neoplasia: “new growth” new growth of a tumor, these are differentiated cells
i. Ex: malignant or benign tumors
11. Describe each term related to cell damage and list examples:
a. Apoptosis: Programmed cell death
b. Ischemia/Hypoxia
Ischemia: reduced blood flow to tissue or organ due to circulatory obstruction blocked artery, resp. impairment (chest pain) (Oxygen, nutrients, WBC/RBC)
Hypoxia: reduced oxygen in the tissue. Interferes with ATP production. Sodium pump stops as well as other cell functions.
i. What is the difference between ischemia and hypoxia?
Ischemia reduced blood flow & hypoxia reduced oxygen
c. Physical injury: related to heat or mechanical pressures. Impair blood supply to cells or metabolic processes.
Ex.) Radiation damages cells by altering chem. Constituents, changing DNA, toxic materials inside cell
12. What is necrosis? When a group of cells die
a. Describe each type of necrosis and give examples:
i. Liquefaction necrosis: dead cells liquefy due to certain cell enzymes Ex.) brain issue dies, cavities, ulcers
ii. Coagulative necrosis (scar tissue): cell proteins are altered or denatured, cell keeps form for a little bit after death. Ex.) Heart attack due to lack of oxygen causing cell death.
iii. Fat necrosis: fatty tissue broke down into fatty acids due to infection or certain enzymes. Ex.) gangrene
iv. Caseous necrosis: coagulation, with thick, yellowish cheesy substance forming. Ex.) TB (development of granuloma, small solid mass of macrophages&lymphocytes)
13. What is infarction? Area of dead cells remaining from lack of oxygen
a. What happens to the tissue after it experiences infarction? It is replaced with scar tissue
b. Is that tissue functional like the previous tissue that died off? No, b/c it is replaced by scar tissue. Scar tissue isn’t flexible.
c. What is a common classic example of infarction? Heart attack
14. What is gangrene? Necrotic tissue invaded by bacteria
a. Why is it so dangerous? Buildup of gases w/in a tissue reducing blood supply
b. How is it treated? Surgically removed (amputation) sometimes antibiotics
Chapter 2: Fluid Electrolyte and Acid-Base Imbalances
15. What is the difference between intracellular compartment (ICF) and extracellular compartment (ECF)?
-ICF: fluid inside the cells. 40% in males 33% in females 40% in infants
-ECF: fluid outside the cells. 20% in males 17% in females 30% in infants
a. Where is the ECF found?
-Intravascular Fluid (IVF) or blood
-Interstitial fluid (ISF) or intercellular fluid “around” 15% in males 9% in females 25% in infants
-Cerebrospinal Fluid (CSF)
-Transcellular Fluids: In secretions of Pericardial cavity (heart), Synovial cavities (joints). Serves as lubrication.
*60% of adults body weight is water
*70% of infants body weight is water
*Females-higher percentage of fatty tissue=lower water content than males
16. Where is the thirst mechanism controlled in the brain? In the Hypothalamus by the osmoreceptor cells that sense the internal environment (goes down w/ age)
17. Which hormone controls the amount of fluid leaving the body in urine? ADH (antidiuretic hormone) promotes reabsorption of water into the blood from the kidney tubules
a. Where does the reabsorption of water take place?
Kidney tubules into the blood
18. Describe the term, causes, and examples of the following:
a. Edema: excessive amount of fluid in the interstitial compartment
i. What are local effects (symptoms/clinical manifestations) of edema?
-Swelling
-Pitting edema: depression or “pit” on affected area when pressure is applied
-Increased body weight
-Functional Impairment: restricts movement, reduced vital capacity, impaired diastole
-Impaired arterial circulation: ischemia leading to tissue break down. Blood isn’t moving & too much pressure in area
-Dental Practice
-Tearing of Skin
ii. Why does edema cause pain? Puts pressure on surrounding nerves, headache in cerebral edema (brain swelling), stretching of capsule in organs (liver, kidney)
iii. What is the consequences of edema causing arterial circulation impairment? ischemia leading to tissue break down. Blood isn’t moving & too much pressure in area
b. Dehydration: insufficient body fluids from inadequate intake or excessive loss of fluids
i. Which is hematocrit increased during dehydration?% of RBCs in a volume of blood. Higher proportion of RBCs compared with water in the blood. Due to the fluid imbalance by the protein shift
ii. How does the body attempt to compensate for the fluid loss?
-increase thirst
-increase heart rate
-constricting cutaneous blood vessels=pale & cold skin
-producing less urine & concentrating urine
-renal vasoconstriction & increased secretion of aldosterone and ADH
c. Compare and contrast the clinical manifestations of edema (fluid volume overload) and dehydration (fluid volume deficit) [Table 2-3]: Edema: localized swelling, pale or red skin, weight gain, slow pulse, high BP, decreased hematocrit, decreased serum sodium, high urine volume.
Dehydration: sunken eyes, thirst, weight loss, rapid, weak pulse, low BP, and orthostatic hypotension, fatigue, weakness, dizziness, increased body temp, increased hematocrit, increased electrolytes, low urine volume.
19. Describe each electrolytes function, causes for imbalance and clinical manifestations of hyper/hypo imbalance:
a. Sodium: cation, ECF, Diffusion between vascular & interstitial fluids. Controlled by Sodium-potassium pump or active transport=high Na levels in ECF, low inside cell. Secreted in mucus & other secretions (urine, sweat, feces). Form of sodium chloride & sodium bicarbonate. Controlled by kidneys through action of Aldosterone.
-Hyponatremia:” Decreased Sodium” Sodium concen. Below 3.8 to 5mmol per liter or 135-145 milliequivalent.
Causes: Losses from excessive sweating, vomiting, diarrhea or excess of water in the ECF=dilution of sodium.
-Use of certain diuretic (make you urinate a lot) drugs combined w/ low salt diet
-Hormonal imbalances: insufficient aldosterone, adrenal insufficiency, excess ADH secretion
-Early chronic renal failure
Effects: Low Na levels: Impair nerve conduction=fluid imbalance in compartments=fatigue, muscle cramps, abdominal discomfort, nausea, vomiting
-Decreased osmotic pressure in ECF=Fluid shift into cells leads to Hypovolemia & decreased BP
-Cerebral edema: brain swelling
Hypernatremia: Excessive Na level in blood an ECF “To much Sodium” more than 145mEq per liter
Causes: Excess Na from ingestion of large amounts of Na w/out enough water intake or faster loss of water from the body than loss of Na. Imbalance in Na & water
-Insufficient ADH (diabetes insipidus) = large vol. of dilute urine
-Loss of thirst mechanism
-Watery diarrhea
-Prolonged periods of rapid respiration
Effects: *fluid shift out of cells=increased osmotic press. Of interstitial/extracellular fluid
-Weakness/agitation
-Dry, rough mucous membranes
-Increased BP
-Decreased urine output b/c ADH is secreted
manifestations can change depending on cause of problem/ If caused by fluid loss due to lack of ADH urine output is high
b. Potassium: intracellular cation, serum levels are low 3.5-5mEq. Intracellular concen level are 160mEq. Ingested in foods, excreted primarily in urine under influence of ADH, insulin promotes movement of potassium into cells. Potassium levels influenced by acid-base balance in body. Acidosis tends to shift potassium ions out of the cells into the extracellular fluids (hydrogen ions diffuse from blood-interstitial fluid b/c of high H concen in the blood, K+ is sent out of cell, excessive K+ in ICF diffuse into the blood leading to hyperkalemia) Acidosis promotes H+ excretion by kidneys & retention of K+ in the body and alkalosis tends to move more potassium into the cells. abnormal levels of K cause changes in cardiac conduction can be life threatening
Hypokalemia: “To low Potassium” serum level less than 3.5mEq/L
Causes: Excessive losses due to diarrhea
-Diuresis assoc. w/ some diuretic drug. Pts may have to increase K+ intake
-Excessive aldosterone or glucocorticoids-retaining sodium & excreting potassium
Effects: Cardiac dysrhythmias-prolonged repolarization lead to cardiac arrest
-Interferes with neuromuscular function-muscles less responsive to stimuli
-Paresthesias: “pins and needles”
-Decreased digestive tract motility: decreased appetite & nausea
-Shallow Respirations
-Impaired renal function: failure to concentrate urine with increased urine output (polyuria=to much water in urine)
Hyperkalemia: “To much Potassium” serum level is greater than 5mEq/L
Causes: Renal Failure
-Deficit of aldosterone
-“Potassium-sparing” diuretic drugs”: prevent K+ from being excreted in adequate amounts (get rid of water in urine & keep K+)
-Leaking of ICF k+ into ECF (pts w/ extensive tissue damage)
-Prolonged or severe acidosis
Effects: Cardiac dysrhythmias, may lead to cardiac arrest
-muscle weakness, may lead to paralysis
-Neuromuscular impairment
-Fatigue, nausea, paresthesias
c. Calcium: Extracellular cation, ingested in food, stored in bone, excreted in urine & feces, balance controlled by parathyroid hormone (PTH) & calcitonin, vitamin D promotes absorption from intestine, activated in kidneys
Functions: structural strength for bones & teeth, stability of nerve membranes, muscle contractions, metabolic processes & enzyme reactions, blood clotting
calcium increases, phosphate decreased. Calcium decreases phosphate increases
Hypocalcemia: “To low calcium” serum level less than 4mEg/L
Causes: Hypoparathyroidism: decreased parathyroid hormone=decreased intestinal calcium absorption
-Malabsorption syndrome: decreased intestinal absorption of vitamin D or calcium
-Deficient serum albumin
-Increased pH level (alkalotic or basic)
-Renal Failure: retention of phosphate causes loss of calcium; vitamin D is not activated=decrease intestinal absorption of calcium
Effects: Increased permeability & excitability of nerve membranes-spontaneous stimulation of skeletal muscle; muscle twitching, Trousseau;s sign carpopedal spasm: when BP cuff blocks circ. To hand
-Cheosteks: spasm of lip or face when face is tapped in front of the ear
-tetany (skeletal muscle spasms)
-Laryngospasm: obstructs airway
-Weak heart contractions from insufficient calcium needed for muscle action: delayed conduction, may lead to dysrhythmias & decreased BP
Skeletal muscle spasms result from the increased irritability of the nerves associated with the muscle fibers, whereas the weaker contraction of cardiac muscle (which lacks nerves). adequate calcium is stored in the skeletal muscle cells to provide for contractions, whereas contraction of cardiac muscle relies on available extracellular calcium ions passing through the calcium channels
Hypercalcemia: “To much calcium” serum greater than 5mEq/L
Causes: uncontrolled release of calcium ions from bones due to neoplasms (directly destroy bones releasing excess calcium also may secrete excess PTH)
-Hyperparathyroidism
-Immobility (demineralization): decrease stress on bone
-Increased Calcium intake: excessive vitamin D or excess dietary calcium
-Milk-alkali syndrome: increased milk & antacid intake elevating calcium serum levels
Effects: Depressed neuromuscular activity=muscular weakness, lethargy, personality changes, anorexia, nausea
-Interference with the function of ADH in kidneys=less absorption of water & polyuria, decrease in renal function
-increased strength in cardiac contractions, dysrhythmias may occur
d. Magnesium: Intracellular ion, serum level 0.7-1.1mol/L. Serum levels are linked to potassium & calcium levels
-Important in enzyme reactions, protein & DNA synthesis
Hypomagnesemia: from malabsorption or malnutrition assoc. w/ alcoholism
Causes: diuretics, diabetic ketoacidosis, hyperthyroidism, hyperaldosteronism
Effects: neuromuscular irritability, tremors, insomnia, personality changes, increased heart rate w/ arrhythmias
Hypermagnesemia: occurs with renal failure, depresses neuromuscular function, decreased reflexes, lethargy, cardiac arrhythmias
e. Phosphate: Serum level 0.85 to 1.45mol/L
-Important in: bone & tooth mineralization
-Metabolic processes, involving cellular energy source (ATP)
-Phosphate buffer system (acid-base balance) Removes H+ from the body through kidneys
-Reciprocal relationship with serum calcium
Hypophosphatemia: low serum phosphate levels
Causes: mal absorption, diarrhea, excessive use of antacids, alkalosis, hyperparathyroidism
Effects: Neurological function impairment
-Tremors
-weak reflexes
-paresthesias
-confusion, anorexia, difficulty swallowing(dysphagia)
Hyperphosphatemia: High serum levels of phosphate
Causes: Renal failure
f. Chloride: extracellular anion normal serum level 98-106mol/L
-Chloride levels are related to sodium levels (High Na=High Cl) (Low Na=Low Cl)
-Assists with bicarbonate ions to maintain acid-base balance by exchanging places as the blood circulates through the body
Hypochloremia: Low serum chloride
Causes: Alkalosis, vomiting when hydrochloric acid is lost from the stomach
-Excessive perspiration assoc. w/ fever or hard labor on hot a day may lead to loss of sodium chloride=hyponatremia & hypochloremia also dehydration
Hyperchloremia: Excessive chloride
Causes: excessive intake of sodium chloride taken orally or intravenously, hypernatremia from other causes, leading to edema & weight gain
Chapter 21: Congenital and Genetic Disorders
20. Describe the difference between karyotype, genotype, and phenotype:
Karyotype is the visual representation of chromosomes that are arranged in order of size, used to diagnosis chromosomal disorders. Genotype is the genetic info carried by the individual all cells except gametes. Phenotype is the physical appearance of individual’s characteristics this is the expression of genes.
21. Describe the difference between meiosis & mitosis:
Meiosis (sexual repro) sperm & ovum receive 23 chromosomes, 1 chromosome from each pair, ovum is fertilized by sperm=zygote that has 46 chromosomes, or 23 pairs, of genetic info inherited from each parent. During mitosis (cell division) chromosome replicate and each daughter cell get a copy of DNA that is identical to the parent cell, same genetic info is carried on.
22. List examples of the following:
a. Single-Gene Disorders: Trait controlled by one set of alleles, classified by inheritance patterns, single gene may control a limited function
i. Autosomal dominant disorders: inheritance of one alleles causes disorder, only one parent needs to carry allele. Ex.) Huntington’s disease
ii. Autosomal recessive disorders: Both parents must pass on the allele for disorder. Heterozygous Cc & Cc parents are not affected of disease but possibility of passing recessive trait “c” onto children, they are a carrier OR Homozygous: cc & cc parents are affected & child has the disorder. Ex.) Cystic Fibrosis
iii. X-linked dominant disorders (can happen in male & female): Inherited as a dominant allele on the X chromosome, mutation causes affected X chromosome to appear constricted or broken. Ex.) Fragile X chromosome
iv. X-linked recessive disorders: Allele carried on X chromosome not Y chromosome. Heterozygous males lacking matching unaffected gene on the Y chromosome XA Y=normal, Xa Y=affected male. Heterozygous females Xa XA=carriers. Homozygous recessive female may be affected Xa Xa. Ex.) Hemophilia A
b. Multifactorial Disorders: Genes/ genetic influences combined with environmental factors. Ex.) cleft palate
c. Chromosomal Disorders: Extra or missing chromosomes on a pair of chromosomes. Ex.) Down syndrome
23. Explain the probability of a child being affected by the following:
a. Autosomal recessive disorders
b. Autosomal dominant disorders
c. X-linked recessive disorders
24. Describe each disorder:
a. Fragile X Syndrome: Mental retardation, cognitive deficit. Inherited as a dominant allele carried on X chromosome-mutation causes affected X to appear constricted or broken.
b. Down Syndrome (Trisomy 21): Can be caused by nondisjunction/ translocation. 3 chromosomes rather than two on the 21st pair of chromosome. Individual has 47 chromosomes instead of the normal 46. Delayed development & delayed/incomplete sexual development, loose joints.
c. Turner Syndrome (Monosomy X) XO: When only one sex chromosome, X chromosome is present. Person only has 45 chromosomes. Affects females, short stature, infertility.
d. Klinefelter Syndrome XXY: Extra X chromosome is present. 47 chromosomes.
25. What needs to be present in order for a multifactorial disorder to occur?
Number of genes/genetic influences combined with environmental factors
26. Describe an amniocentesis procedure: extraction of amniotic fluid from the uterus & extraction of a sample of the chorionic villus of the fetus. To examine sample of fetal tissue
a. Why is it done?
To detect chromosomal abnormalities
b. What are the risks? (2)
1. Physical risk to mother and baby
2. Some tests may not show conclusive results
Chapter 6: Infection
27. Does bacteria need living tissue to survive? No
28. What are exotoxins secreted by bacteria, how are they harmful? Produced by gram-pos. bacteria, they diffuse through body fluids affecting nerve conduction (tetanus). Stimulate antibody/antitoxin production which are than used as toxoids to induce immune response.
29. What are endotoxins secreted by bacteria, how are they harmful? Present in cell wall of gram-neg. bacteria that are released when bacterium dies. They cause fever, weakness, effected circulatory system=increased capillary permeability, loss of vascular fluid & endotoxic shock.
30. How do we try to limit bacterial growth? Besides antibiotics.
Locate/remove or isolate reservoir of infection
-Identify & restrict access to contamination
-Reduce contact between infected persons & non-infected persons
-block portals of exit/entry
-Remove or block modes of transmission
-Reduce susceptibility by immunizations, adequate nutrition & access to health care
31. Do viruses require a living host? Why? Yes, uses the host’s cell to synthesize viral proteins & nucleic acids (replication).
32. Why is it difficult to become immune or get the right vaccine for certain viruses? What do they do to prevent this immunity? What are some examples? Viruses are constantly changing during replication. They also lack their own metabolic processes/structures that would normally be attacked by drugs.
33. What is the candida fungi? Yeast
a. What infections can it cause? Thrush (oral infection), vaginal infections (yeast infection)
34. What is the purpose of resident (normal) flora? Help in preventing other or foreign organisms from growing or forming a colony
35. What 3 areas of the body do not have normal flora and should be sterile?
Blood, cerebrospinal fluid, lungs
36. Describe the different modes of transmission for infection:
a. Direct contact: Touching infectious lesion, sexual activity, contact w/ infected blood or bodily secretions.
b. Indirect contact: Intermediary object or organism, contaminated by hand or food, or fomite-inanimate object (toys, phones, stethoscope etc.)
c. Droplet transmission: Resp. or salivary secretions are expelled from infected individual (coughing, sneezing etc.)
d. Aerosol transmission: “airborne” small particles from the resp. tract, suspended in the air and can travel farther than droplets. (TB)
e. Vector-borne: Insect or animal is an intermediate host
37. What is the major body part for transmitting infection?! HANDS
a. That being said, HAND WASHING is one of the most important interventions anyone can do to prevent the spread of infection – remember this for the rest of your life.
38. What are nosocomial infections? Infections that occur in health care facilities Ex.) UTI from Foley
39. What are two main nosocomial infections that are extremely dangerous and often deadly?
C. diff (Clostridium difficile) & MRSA (Methicillin-resistant Staphylococcus aureus)
40. Describe ways that a host can be resistant to infection?
41. What is an interferon and why are they important?? Interferons are the bodies 2nd line of defense that help fight against viruses, they also protect uninfected cells against viruses.
42. What are factors that decrease host resistance? Age, pregnancy, malnutrition, chronic disease, severe physical/emotional distress.
43. What is the difference between virulence and pathogenicity?
Pathogenicity is the capability of a microbe to cause disease & virulence is the degree of pathogenicity. Virulence is based on invasive qualities, toxic qualities, adherence & ability to avoid host defenses (how bad is it?)
44. Describe each stage of the chain of infection & how to break it at each stage if applicable (Figure 6-12):
a. Reservoir: Source of infection. Environmental source such as contaminated soil. Infected person or animals
b. Portal of exit: mouth, skin, intestine (minimize coughing & sneezing, disposal of contaminated items)
c. Transmission:
i. Direct: saliva, blood, feces, semen, exudates from skin (gloves, glasses, gowns, safe waste disposal)
ii. Indirect: resp. droplet on hands, surfaces, insect bites (vectors), contaminated food or water (hand-washing, disinfect, sterilize, food handling & cooking, water treatment)
d. Entry: mouth, nose, vagina (covering nose & mouth w/ mask, covering open wounds or mucous membranes
e. Susceptible host: Health status, point of entry, # of microbes
f. Incubation period: Time between entry of organism into the body and the appearance of clinical signs of the disease. asymptomatic
g. Infectious disease: Infectious disease fully develops, clinical manifestations reach a peak
i. Carrier: Person with subclinical signs of the disease (no signs or symptoms)
45. Describe each technique to reduce transmission of infection:
a. Sterilization: exposure to heat such as autoclaving & incineration
b. Disinfectants: Chemical solutions that destroy microorganisms or their toxins on inanimate objects (bleach, alcohol wipes)
c. Antiseptics: Chemicals applied to the body (skin) that do not cause damage (before surgery or iodine, isopropyl alcohol-70% or hand sanitizer)
46. Describe the following periods of infection and give signs and symptoms:
a. Incubation period: Time between entry of organism into the body and the appearance of clinical signs of the disease
b. Prodromal period: Time when infected person may feel fatigued, lose appetite. Typical “I’m not feeling well.” [Show Less]