Medical Surgical A

1. Medical Surgical A

3. Study Tips • Frequent quizzes • Understand the material • Read the text • Study frequently for short periods • Find a study buddy

4. Classroom Etiquette and rules: Turn off cell phones ! No chewing gums Be considerate of others: Take out what you bring in. Be ontime, No late more than 5-10m Talk to me, NOT your neighbor! No absence from exams without prior excuse Do not ask for grades over the phone or internet.

5. Academic Integrity • Use Professional ethics • NO: • Plagiarism • Cheating • Allowing others to copy from you • Penalties can be severe !!

6. Terminology Disease – loss of homeostasis, or when physical or mental capacities cannot be fully utilized (interuption, 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.

7. 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)

8. 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.

9. 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

10. Understanding the cell

11. Structural Levels

12. Cell The cell is the building block of each living organism. Each cell is a self-contained system that undergoes the functions of energy production and usage, respiration, reproduction, and excretion

13. CellularFunctions • Organization • Metabolism • Catabolism • Anabolism • Responsiveness • Conductivity • Movement • Reproduction • Growth • Differentiation • Respiration • Secretion • Excretion

14. Pathophysiologic concepts The cell faces a number of challenges through its life. Stressors, changes in the body’s health, disease, and other extrinsic and intrinsic factors can alter the cells’ normal functioning. • Adaptation • Cells generally continue functioning despite challenging conditions or stressors. However, severe or prolonged stress or changes may injure or destroy cells. When cell integrity is threatened, the cell reacts by drawing in its reserves to keep functioning, by adaptive changes or by cellular dysfunction.

15. If cellular reserve is insufficient, the cell dies. If enough reserve is available and the body doesn’t detect abnormalities> • The cell adapts by: • atrophy, • hypertrophy, • hyperplasia, • metaplasia, or • dysplasia.

17. Cells change to adapt to their environment • Atrophy = shrinkage = decrease in cell size. • Reversible • Due to : • decreased use (disuse) • decreased blood supply • decreased nutrition • denervation, • or reduced endocrine stimulation • of tissues or organs .

18.  Size of organelles  Size of organelles Energy Usage Atrophy  Workload (or disease state)  Efficiency -OR-  Functionality in disease state

19. Hypertrophy an increase in the size of a cell due to an increased workload. It may be normal or abnormal. Hypertrophy is primarily seen in cells that cannot adapt to increased work by increasing their numbers through mitosis (cardiac and skeletal muscle cells).

20. There are three main types of hypertrophy: -Physiologic hypertrophy (i.e., increased muscle bulk through exercise). -Pathologic hypertrophy( hypertrophy of the left ventricle in response to longstanding hypertension) . -Compensatory hypertrophy (the loss of one kidney causes the cells of the remaining kidney to undergo hypertrophy).

21.  Size  # of organelles  contractility Hypertrophy  Size  # of organelles  Workload (or disease state)  ability to meet demands! -OR-  Functionality in disease state

22. HyperplasiaHyperplasia, an increase in the number of cells, caused by increased workload/ hormonal stimulation. It can only occur in cells that undergo mitosis ( liver, kidney, and connective tissue cells). Hyperplasia may be: *Physiologic (monthly in uterine endometrial cells) . *Pathophysiologic (with excessive hormonal stimulation, which is seen in acromegaly) *Compensatory (cells of a tissue reproduce to make up for a previous decrease in cells ; liver cells after surgical removal of sections of liver tissue).

23.  rate of cell division  functionality Hyperplasia  Workload Physiological state  tissue size by  # of cells 2 types: Compensatory & Hormonal  ability to meet demands! ...

24. Hyperplastic endometrium

25. Metaplasia • is the replacement of one adult cell with another adult cell that can better endure the change or stress. • It’s usually a response to chronic inflammation or irritation; the change in the cells of the respiratory passages from ciliated columnar epithelial cells to stratified squamous epithelial cells in response to years of cigarette smoking. • Stratified epithelial cells are better able to survive smoke damage. Unfortunately, they do not assume the vital protective role of ciliated cells.

26. Normal Cells Abnormal Cells Replacement Metaplasia Ex: Cigarette Smoking Pathological

27. Dysplasia In dysplasia, deranged cell growth of specific tissue results in abnormal size, shape, and appearance.;adaptive and potentially reversible, they can precede cancerous changes. The most common sites of dysplasia are the RT (especially the squamous cells present as a result of metaplasia)and the cervix. Cervical dysplasia usually results from infection of the cells with the human papilloma virus (HPV). Dysplasia is usually rated on a scale to reflect its degree, from minor to severe.

28. Mutation Normal Cells Abnormal Shape & Size Dysplasia Epithelial Tissue Pathological

29. Cerical Dysplasia Normal Tissue Abnormal Tissue

30. Cell injury A person’s state of wellness and disease is reflected in the cells. • Injury to any of the cell’s components can lead to illness. • One of the first indications of cell injury is a biochemical lesion that forms on the cell at the point of injury. • This lesion changes the chemistry of metabolic reactions within the cell. Consider, for example, a patient with HIV. The cells of the immune system may be altered, making the patient susceptible to infection.

31. Draw on your reserves, adapt, or die • When cell integrity is threatened (toxins, infection, physical injury, or deficit injury), the cell reacts in one of two ways: • • by drawing on its reserves to keep functioning • • by adapting through changes or cellular dysfunction. • If enough cellular reserve is available and the body doesn’t detect abnormalities, the cell adapts. • If there isn’t enough cellular reserve, cell death (necrosis) occurs. Necrosis is usually localized and easily identifiable.

32. Hypoxic Chemical Structural (trauma) Infectious Immunologic / Inflammatory Mechanismsof Injury

34. 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

35. Deficiencies: Deficiency in oxygen most important

36. HypoxicInjury  Atmospheric Oxygen  Respiratory Function Loss of Hb  Cardiovascular Function  Hb function (CO)  erythropoiesis Most Common Cause of Cellular Injury!

37. Ischemia is inadequate blood supply to a cell or tissue. Ischemia can cause hypoxia.

38. Trauma -- physical disruption of cells • Ex: abrasion, cutting, burns, microorganisms etc.

39. Intoxication (or introduction of toxins into the cell) Effect on cell depends on toxin and on cell Some examples: Lead -- injures nervous system CO -- deprives body of oxygen Ethanol -- effects central nervous system

40. Apoptosis • “fallen apart” • Regulated cell death • During development • Worn out cells • Diseased cells (tumor suppressor gene, natural killer or Tc cells)

41. Necrosis • Messy cell death • Initiates inflammation • Gangrene – large mass of tissue undergoes necrosis

42. Infections agents • Microorganisms can invade and harm cells • Cell injury can have effects on the entire body • Examples: fever, pain, increased heart rate

43. Conditions of Disease or Injury • 1-Hypoxia: decreased concentration of oxygen in the tissues. Oxygen is required by the mitochondria for production of ATP. • Consequences of Hypoxia • cell begins to swell and burst, because NA diffuses into the cell and withdraw water. • production of lactic acid, decreased ph causes damage to the nuclear structures. • The effects of hypoxia are reversible if oxygen is returned within a certain period of time, the amount of which varies and depends on the tissue.

44. Hypoxia • Signs & Symptoms: • Tachycardia, tachypnea, muscle weakness, and decreased level of consciousness. • Complications • - Altered consciousness progressing to coma and death • -Organ failure, including adult respiratory distress syndrome ARDS, heart failure, RF, may occur if hypoxia is prolonged. • Treatment: Increase oxygen in inspired air through a mask or mechanical ventilation.

45. 2-Temperature Extremes • - Exposure to very high temperatures can cause burn injuries, which directly kill cells or indirectly by causing coagulation of blood vessels or the breakdown of cell membranes . • - Exposure to very cold temperatures injures cells in two ways: vasoconstriction which decreases deliver nutrients and oxygen to the extremities and the formation of ice crystals in the cells. These crystals directly damage the cells and can lead to cell lysis (bursting). Prolonged exposure to the cold can lead to hypothermia.

46. Extreme temperature • Signs & symptoms: • - Numbness or tingling of the skin or extremities. • - Pale or blue skin that is cool to the touch. • - Shivering early on, then lack of shivering • - Decreased LOC, drowsiness, and confusion. • Complications • - Blood clotting, characterized by pain and a decrease in pulse downstream from the clot. If blood flow is inadequate for an extended time, gangrene may result. • - Frostbite. • - Ventricular dysrhythmia.

47. 3-Radiation Injury • Higher or low energy. • High-energy radiation ( ionizing radiation). • Low-energy radiation (non-ionizing radiation). • Ionizing radiation may injure or kill cells directly by destroying the cell membrane and causing intracellular swelling and cell lysis, interstitial edema, white blood cell accumulation, and tissue scarring. It may alter DNA leading to cell death or subsequent cancer .

48. Radiation • Cells most susceptible to damage by ionizing radiation are cells that undergo frequent divisions, (GI, skin and hair, and the blood-forming cells of the bone marrow) • Ionizing radiation is emitted by the sun, in x-rays, and in nuclear weapons. • Non-ionizing radiation includes microwave and ultrasound radiation. The energy of this radiation is too low to break DNA bonds or damage the cell membrane

49. Radiations • Clinical Manifestations of Ionizing Radiation • - Skin redness or breakdown. • - With high doses, vomiting and nausea caused by GI damage. • - Cancer may develop years after the exposure . • - anemia if the bone marrow is destroyed.

50. Radiation • Pediatric Consideration • Fetal cells rapidly undergo cellular division and are highly susceptible to the damaging effects of ionizing radiation. Infants and young children also experience periods of rapid cellular growth and are at risk of genetic damage from ionizing radiation. Studies suggest that there are no apparent health risks to fetuses exposed to non-ionizing radiation .