Term
A. Explain why a cast placed around a fractured leg in which extensive tissue damage has occurred might be too tight after 24 hours
B. Explain why such a cast might become loose in 3 weeks |
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Definition
a. Inflammation related to tissue damage causes increasing edema for at least 48 hours under the rigid, non-expandable cast.
b. Inflammation has subsided and muscle atrophy has occurred because of immobility. |
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Term
| List specific reasons why the inflammatory response is considered a body defense mechanism |
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Definition
| Pain and visible redness provide warning of tissue injury. Increased fluid at the site dilutes any toxic material. Fibrin mesh and leukocytes localize (wall off) the causative agent. Migration of phagocytic cells, leukocytes, and antibodies (globulins) to the area combat or destroy the agent, and remove debris in preparation for healing. |
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Term
A. Explain the rationale for each of the following with acute inflammation: (i) warmth, (ii) fever.
B. State three systemic signs of inflammation |
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Definition
a. Warmth results from vasodilation and increased blood flow to the area; fever is caused by the release of pyrogens from WBCs.
b. Low-grade fever occurs with increased WBCs, malaise, anorexia, and headache. |
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Term
| Explain why leukocytosis, a differential count, and elevated erythrocyte sedimentation rate are usual data but are of limited value |
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Definition
| They confirm the presence of inflammation in the body but do not define the specific cause or location of the problem. In some cases, a differential count is helpful. |
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Term
A. Explain how acute inflammation predisposes to the development of infection
B. Classify each as inflammation or infection: (i) sunburn, (ii) skin rash under adhesive tape, (iii) common cold, (iv) red, swollen eye with purulent exudate |
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Definition
a. The increased permeability may permit leakage or penetration of toxins or bacteria (e.g., through the intestinal wall). Any necrosis breaks the barrier, allowing microbes to invade. The edema or increased interstitial fluid may impair arterial flow to an area, leading to ischemia and decreased access of leukocytes to the site. The exudate provides a nutritious medium for organisms to reproduce.
b. Inflammation accompanies i and ii; infection is associated with iii and iv. |
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Term
| How does the presence of thick, cloudy, yellowish fluid in the peritoneal cavity differ from the normal state |
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Definition
Normal fluid should be watery, clear, and colorless.
Thick yellowish fluid often indicates the presence of a bacterial infection (peritonitis). |
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Term
| If a large volume of fluid has shifted from the blood into the peritoneal cavity, how would this affect blood volume and hematocrit |
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Definition
| Blood volume would be low (hypovolemia), and the hematocrit level would be elevated. |
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Term
| Explain how acute inflammation impairs movement of a joint |
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Definition
| Excessive fluid in the joint cavity and surrounding tissues prevents further stretching of the tissues, such as ligaments, tendons, and skin, as required for movement. |
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Term
| Explain two mechanisms used to increase body temp. as a fever develops |
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Definition
| The body attempts to increase body temperature through shiver-increased skeletal muscle activity, peripheral vasoconstriction, and decreased blood flow and heat loss. |
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Term
| What might a client be advised to avoid taking acetylsalicylic acid a few days before extensive oral surgery (e.g., multiple tooth extractions)? |
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Definition
| Aspirin (acetylsalicylic acid [ASA]) interferes with blood clotting (prevents platelet adhesion). |
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Term
| Explain why a young child taking prednisone (glucocorticoid) for chronic kidney inflammation is at high risk for infection and might need prophylactic antibiotics |
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Definition
| Prednisone decreases the immune response, causes atrophy of lymphoid tissue, decreases the number of leukocytes, and suppresses the inflammatory response, thus decreasing resistance to infection. |
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Term
A. What part of the heart muscle dies, how does it heal?
B. How would the new tissue affect the strength of the heart contraction |
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Definition
a. Heart muscle heals through scar tissue. Cardiac muscle does not regenerate.
b. Scar tissue is nonfunctional and therefore cannot contract; thus, heart contractions would be weaker |
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Term
| Suggest several reasons why healing is slow in the elderly |
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Definition
| Circulation may be impaired, decreasing the supply of oxygen and nutrients to the site. The metabolic rate is decreased, slowing protein synthesis and cell mitosis. Other pathological conditions may interfere with the supply of nutrients or oxygen. The immune response is decreased, predisposing the person to infection and delaying healing. |
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Term
Explain how scar tissue could affect the function of the following:
a. small intestines
b. brain
c. cornea of the eye
d. mouth
e. lungs |
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Definition
a. Small intestine—scar tissue may cause obstruction by stenosis as it shrinks, or adhesions may twist or pull on a loop of intestine.
b. Brain—scar tissue is nonfunctional and can block conduction pathways or interfere with the flow of blood or CSF.
c. Cornea—scar tissue is not transparent and therefore blocks the passage of light rays, impairing vision.
d. Mouth—contractures may develop, preventing normal opening and movement of the mouth, affecting eating, speech, and facial expression.
e. Lungs—the bronchi or bronchioles may be narrowed, reducing airflow, and adhesions may impede movement and expansion of the pleural membranes. Because scar tissue is nonelastic, large amounts of it impair expansion and recoil of the lungs. Scar tissue interferes with blood flow. |
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Term
A. Explain the reason for pain and redness accompanying a burn
B. Explain three reasons why protein levels in the body are low after a major burn |
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Definition
a. Pain—chemical mediators irritate nerves; edema results from increased capillary permeability; erythema occurs because of increased blood in the area.
b. Over the long term, lower protein levels occur, with protein shifts into tissue and loss in exudates. In addition, protein is in increased demand for repair, but anorexia results in decreased intake, further lowering protein levels. |
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Term
A. Explain why immediate neutralization or removal of a chemical spilled on the hand minimizes burn injury
B. Describes some of the factors that would promote rapid healing of this burn |
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Definition
a. It removes damaging chemicals and prevents penetration into the deeper layers of the skin.
b. Good nutrition (including protein and vitamins), promotion of circulation, warmth, and avoidance of secondary infection would promote rapid healing. |
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Term
| Describe three potential complications of a full-thickness burn covering 30% of the body, including the legs and back |
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Definition
| Scar tissue is not elastic and tends to contract over time, leading to reduced range of movement or contractures, decreased coordination of fine movements, and loss of sensory function (e.g., touch, heat). |
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Term
| If the face receives a full-thickness burn, describe three ways function could be impaired after healing |
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Definition
| Function could be impaired because of possible distortion of the mouth and eyelids, interfering with function (speaking, eating) and facial expressions, such as a smile. There may be restricted mobility related to contractures or loss of elasticity, reduced sensitivity to touch or other sensory stimuli, and less strength. |
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Term
Explain how each of the following contributes to the virulence of bacteria
a. production of endotoxin
b. spore formation
c. presence of capsule |
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Definition
a. Endotoxins are released from the cell walls of dead gram-negative organisms and cause fever and shock.
b. Microbes survive unseen for a long time under adverse conditions, can be destructive, and can reproduce after entering the body.
c. The capsule protects the microbe from phagocytosis. |
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Term
Predict how each of the following could reduce host resistance to infection:
a. bone marrow damage
b. circulatory impairment
c. puncture wound |
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Definition
a. A deficit of WBCs reduces phagocytosis and immune response; a deficit of RBCs decreases oxygen and mitosis.
b. Circulatory impairment reduces the number of cells—WBCs, RBCs, and antibodies—to the area, slowing tissue repair.
c. A puncture wound is characterized by reduced oxygen and a risk of anaerobes causing infection because it is difficult to remove foreign material. |
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Term
| Explain two benefits of resident flora |
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Definition
| Resident flora deter invasion by other microbes, aid digestion, produce vitamin K, and maintain local pH (skin, vagina). |
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Term
| Differentiate infection from inflammation |
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Definition
| Infection results from microbial action; inflammation has many causes, such as ischemia, allergy, irritants, and thermal injury. |
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Term
| Describe three ways of reducing transmission of a respiratory infection |
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Definition
| A respiratory infection's chances of being transmitted are reduced by covering the mouth and nose when coughing, handwashing, properly disposing of tissues, protecting food, dishes, and people from contact with respiratory secretions, cleaning any contaminated surfaces, and maintaining a well-ventilated room. |
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Term
Explain each of the following:
a. Why the clinical signs of infections are not present immediately after the microorganism enters the body
b. Why the infection can often be cured without drug treatment
c. Why antibacterial agents might be prescribed for an infection |
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Definition
a. Invaders must take time to colonize and reproduce; sufficient microbes are needed to produce signs.
b. Reproduction is decreased as nutrient supply is diminished and wastes build up, altering pH and other parameters. Defenses are activated.
c. Antimicrobial agents may be prescribed to prevent secondary infections and, in cases involving virulent microbes, to dangerous sites such as the brain, and to immunosuppressed individuals or those with chronic disease. |
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Term
| Explain why it is important to take the complete course of antimicrobial medication prescribed |
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Definition
| The complete course of medication should be taken because if all microbes are not eradicated, infection may recur. In addition, microbes mutate after drug exposure and become drug-resistant. |
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Term
| Explain why viral infections are difficult to treat |
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Definition
| Viral infections are difficult to treat because they are more difficult to culture and identify, and viruses exist inside host cells. Moreover, antiviral drugs can reduce replication, but they do not destroy the virus. |
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Term
| State two local and two systemic signs of influenza |
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Definition
| Local signs of influenza are sore throat and a nonproductive cough. Systemic signs of influenza are fever, aching, and headache. |
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Term
| Explain why a new influenza vaccine is prepared each year and consists of several components |
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Definition
| Viral strains mutate and change antigens, resulting in loss of immunity; strains from three groups of the virus, A, B, and C, may cause infection. |
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Term
| Describe the role of the macrophage in the immune response |
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Definition
| Following phagocytosis of foreign material, macrophages process the antigen for use by the lymphocytes, thus initiating an immune response. Macrophages also stimulate proliferation of lymphocytes. |
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Term
| State the origin and purpose of lymphocytes |
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Definition
| Lymphocytes originate from the stem cells in bone marrow, mature in the thymus or bone marrow, and then migrate to lymphoid tissue, where they are responsible for the immune response. |
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Term
| Compare active natural immunity and passive artificial immunity, describing the causative mechanism and giving an example |
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Definition
| Active natural immunity results when a person naturally experiences an infection such as chickenpox (varicella) and develops permanent immunity (memory cells) to the invading virus. Passive artificial immunity is a temporary protection against an infection, such as rabies, gained through forced introduction of antibodies into the body from an external source. |
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Term
| What is the purpose of a booster vaccination |
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Definition
| A booster is an additional injection of antigen that serves as a reminder to the memory cells in the immune system and stimulates additional production of antibodies. |
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Term
| Describe the purpose of gamma globulins |
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Definition
| Gamma globulin is given as an injection of antibodies from an external source immediately following exposure to a microbe to minimize the effects of an impending infection (e.g., measles, rubella). |
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Term
| Where is IgA found in the body? |
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Definition
| IgA is found in saliva, the secretions and mucous membranes of the respiratory and digestive tracts, and colostrum. |
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Term
| Describe how type III sensitivity develops |
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Definition
| Immune deficits may result from dysfunction of the cellular component or antibody production. One or both types of lymphocytes may be deficient because of bone marrow problems or damage to mature lymphocytes (e.g., from human immunodeficiency virus [HIV] infection). Phagocytic cells also may be defective. The second group of immunodeficiencies arises from an abnormality of the immunoglobulins, which may result from a protein deficit, genetic abnormalities, or B cell dysfunction. Immune deficits for both these groups may be classified as primary or secondary disorders. |
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Term
| Explain the process by which an attack of hay fever follows exposure to pollen |
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Definition
| On first exposure to the pollen, IgE antibodies form and attach to mast cells in the nasal mucosa. On subsequent exposure to the same pollen, the allergen reacts with the antibodies on the mast cell, causing release of histamine and other chemical mediators from the mast cells and resulting in inflammation of the nasal mucosa. Inflammation causes swelling of the nasal mucosa, sneezing, and increased watery secretions (hay fever). |
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Term
| Explain why anaphylaxis is considered life threatening |
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Definition
| Anaphylaxis results in severe hypoxia very quickly because of combined respiratory (airway obstructions) and cardiovascular (shock) impairment, leading to loss of consciousness and potential cardiac or respiratory arrest. Immediate treatment is essential. |
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Term
| Describe the pathophysiology of a type III hypersensitivity reaction |
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Definition
| An antigen-antibody complex forms and is deposited in tissue, activating complement and causing inflammation. |
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Term
| Define an autoimmune disease and explain how the causative mechanism differs from a normal defense |
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Definition
| In an autoimmune disorder, the immune system identifies a component of the individual’s tissues as foreign (self antigens) and develops autoantibodies to it. The ensuing antigen-antibody reaction causes inflammation and, eventually, necrosis in various organs and tissues. In a normal immune response, the body does not identify its own tissues as foreign, and antibodies are formed as a defense against external foreign material. |
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Term
| Describe two factors that promote a successful organ transplant |
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Definition
| A successful organ transplantation is promoted by a close tissue match, using blood type and HLA antigens on the lymphocytes, good circulation, and maintenance of antirejection drugs. |
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Term
| Differentiate between a diagnonsis of being HIV-positive and a diagnosis of having AIDS |
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Definition
| When someone is HIV-positive, the virus and antibodies are present in body fluids, but there are no obvious signs, and the T lymphocyte count is normal. With AIDS, active infection is present, the T lymphocyte count is reduced, and acute opportunistic infections and cancers occur. |
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Term
| Why are opportunistic infections common with AIDS? |
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Definition
| Opportunistic infections are common with AIDS because of reduced resistance, surveillance, and immune response. |
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Term
| State three methods of transmitting HIV and three methods by which the virus is not transmitted |
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Definition
| HIV may be transmitted by blood or contaminated needles, through sexual intercourse, and/or transplacentally or through breastfeeding; it is not transmitted by casual contact, kissing, fomites, oral secretions, or toilets. |
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Term
| Describe two common complications associated with AIDS |
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Definition
| Common complications associated with AIDS are pneumonia Pneumocystis carinii pneumonia (PCP), severe lung congestion, wasting syndrome (severe diarrhea, malnutrition), and cancer (Kaposi’s sarcoma—purple tumors on the skin and organs or lymphomas in the brain). |
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Term
| Describe the structure of a hair follicle, including any gland associated with it |
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Definition
| The structure of a hair follicle is an indentation in the skin, lined with epithelial cells from the base of which a hair grows. A sebaceous gland opens into the hair follicle, and a smooth muscle is attached. |
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Term
| Describe the location of resident or normal flora related to the skin and its appendages |
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Definition
| Resident flora are present on the skin in all areas but are more numerous in hairy areas. They may vary in constituents in different areas and are found deep in hair follicles and glands, as well as on the surface. |
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Term
| State the location of nerves and blood vessels in the skin |
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Definition
| Nerves and blood vessels of the skin are found in the dermis. |
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Term
| List the functions of the skin |
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Definition
| The skin acts as a mechanical barrier to passage of foreign material, maintains body temperature, prevents fluid loss from the body, responds to many sensory stimuli, and synthesizes vitamin D. |
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Term
| Define the terms papule, ulcer, and fissure |
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Definition
| A papule is a small, firm, raised red lesion; an ulcer is a cavity into the dermis, resulting from necrosis; a fissure is a deep crack or tear in the skin. |
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Term
| Explain how the glucocorticoids may reduce pruritus and give examples of conditions for which these drugs may be helpful |
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Definition
| They reduce the immune response, response to allergens, and inflammatory response (e.g., contact dermatitis, eczema). |
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Term
| Compare the mechanisms and possible causes of allergic and irritant contact dermatitis |
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Definition
| Allergic dermatitis results from a type IV hypersensitivity response to an allergen at the site of contact. Irritant dermatitis is a direct inflammatory response to a chemical. |
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Term
Describe the manifestations of each of the following and state the causative agents for each:
a. shingles
b. boils
c. scabies
d. scleroderma |
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Definition
a. Shingles is the recurrence of varicella virus, which causes a painful vesicular rash unilaterally along the path of a spinal or cranial nerve.
b. With a boil, Staphylococcus aureus causes infection in a hair follicle and surrounding dermis, resulting in a hard, red, painful raised lesion filled with purulent exudate.
c. Scabies is caused by a mite, Sarcoptes scabiei, that burrows into the epidermis to lay eggs, causing a tiny brownish line, perhaps with vesicles, that is highly pruritic.
d. Scleroderma has an unknown cause, but the skin becomes tight, hard, and shiny and is immovable over the face or body. |
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Term
| Prepare a list of contagious skin disorders |
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Definition
| Contagious skin disorders include scabies, impetigo, herpes simplex, shingles, tinea, and pediculosis |
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Term
| Suggest a preventive measure that could reduce the risk of skin cancer |
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Definition
| Avoid exposure to the sun or ultraviolet light. |
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Term
| Explain why allergic responses tend to recur |
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Definition
| The antibodies remain on the mast cells, waiting for the next exposure to the antigen. |
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Term
| Compare the characteristics of the exudate found in a furuncle and in herpes simplex |
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Definition
| A furuncle has a thick yellowish purulent exudate; herpes simplex produces a clear, watery exudate. |
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Term
| Explain why Kaposi sarcoma is more common in immunocompromised patients |
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Definition
| Surveillance and destruction of abnormal cells (neoplastic changes) by the immune system are reduced; therefore, cancer such as Kaposi’s sarcoma develops more easily. |
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Term
Explain the specific cause of pruritus with the following:
a. scabies
b. pediculosis
c. contact dermatitis |
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Definition
a. In scabies, the burrows contain waste from mites, in addition to tissue damage, causing irritation.
b. In pediculosis, the bites release irritating saliva into the skin.
c. With contact dermatitis, an allergen causes an inflammatory reaction and the release of histamine. |
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