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Chapter 05: Genes, Environment-Lifestyle, and Common Diseases
McCance/Huether: Pathophysiology: The Biologic Basis of Disease in Adults and Children, 8th Edition
MULTIPLE CHOICE
- The data reporting that sickle cell disease affects approximately 1 in 600 American blacks is an example of which concept?
| a. | Incidence |
| b. | Prevalence |
| c. | Ratio |
| d. | Risk |
ANS: B
Prevalence rate is the proportion of the population affected by a disease at a specific point in time. Thus both the incidence rate and the length of the survival period in affected individuals determine prevalence. The incidence rate is the number of new cases of a disease reported during a specific period (typically 1 year), divided by the number of individuals in the population. A numerical expression representing a part of a larger whole or proportion is considered a ratio. Any factor that increases the chance of disease or injury is considered a risk.
PTS: 1 DIF: Cognitive Level: Remembering
- The ratio of the disease among the exposed population to the disease rate in an unexposed population is referred to as what type of risk?
| a. | Attributable |
| b. | Contingency |
| c. | Causal |
| d. | Relative |
ANS: D
A common measure of the effect of a specific risk factor is the relative risk. Assuming a factor is the cause of a disease, attributable risk is the amount of risk that is due to that factor. A future event or circumstance that is possible but cannot be predicted with certainty is a contingency risk. The probability of the outcome is termed a causal risk factor.
PTS: 1 DIF: Cognitive Level: Remembering
- What are empirical risks for most multifactorial diseases based on?
| a. | Chromosomal testing |
| b. | Direct observation |
| c. | Liability thresholds |
| d. | Relative risks |
ANS: B
For most multifactorial diseases, empirical risks (i.e., risks based on direct observation of data) have been derived. Chromosomal testing, liability thresholds, and relative risks are not the basis for determining the empirical risk of most multifactorial diseases.
PTS: 1 DIF: Cognitive Level: Remembering
- What is the cause of familial hypercholesterolemia (FH)?
| a. | Diet high in saturated fats |
| b. | Increased production of cholesterol by the liver |
| c. | Reduction in the number of low-density lipoprotein (LDL) receptors on cell surfaces |
| d. | Abnormal function of lipoprotein receptors circulating in the blood |
ANS: C
A reduction in the number of functional LDL receptors on cell surfaces causes FH. Lacking the normal number of LDL receptors, cellular cholesterol uptake is reduced and circulating cholesterol levels increase. High dietary fat intake, increased cholesterol production, and abnormal circulating lipoprotein receptors are not the basis for developing familial FH.
PTS: 1 DIF: Cognitive Level: Remembering
- Which risk factor for hypertension is influenced by genetic factors and lifestyle?
| a. | Sodium intake |
| b. | Physical inactivity |
| c. | Psychosocial stress |
| d. | Obesity |
ANS: D
The most important environmental risk factors for hypertension are increased sodium intake, decreased physical activity, psychosocial stress, and obesity. However, obesity is, itself, influenced by genes and the environment.
PTS: 1 DIF: Cognitive Level: Remembering
- A student asks, “What is the percentage of all cases of breast cancer that are identified as an autosomal dominant form?” What response by the professor is best?
| a. | <1 |
| b. | 5 to 10 |
| c. | 15 to 20 |
| d. | 20 to 30 |
ANS: B
An autosomal dominant form of breast cancer accounts for approximately 5% to 10% of breast cancer cases in the United States.
PTS: 1 DIF: Cognitive Level: Understanding
- When a woman has one first-degree relative with breast cancer, her risk of developing breast cancer is how many times greater?
| a. | 2 |
| b. | 3 |
| c. | 6 |
| d. | 10 |
ANS: A
If a woman has one affected first-degree relative, her risk of developing breast cancer doubles.
PTS: 1 DIF: Cognitive Level: Remembering
- Adoption studies have shown that the offspring of an alcoholic parent have what amount of an increased risk of developing alcoholism when raised by a nonalcoholic parent?
| a. | Twofold |
| b. | Threefold |
| c. | Fourfold |
| d. | Tenfold |
ANS: C
Adoption studies have shown that the offspring of an alcoholic parent, even when raised by nonalcoholic parents, have a fourfold increased risk of developing the disorder.
PTS: 1 DIF: Cognitive Level: Remembering
- Studies have identified several genes that play a role in the prevention of obesity by affecting what?
| a. | Regulation of appetite |
| b. | Metabolizing of fat |
| c. | Absorption of fat |
| d. | Altering the sense of satiety |
ANS: A
Clinical trials using recombinant leptin have demonstrated moderate weight loss in a subset of obese individuals. In addition, leptin participates in important interactions with other components of appetite control, such as neuropeptide Y and a-melanocyte-stimulating hormone and its receptor, the melanocortin-4 receptor (MC4R). Currently, no research supports the other options as being genetically regulated.
PTS: 1 DIF: Cognitive Level: Remembering
- The BRCA1 and BRCA2 mutations increase the risk of which cancer in women?
| a. | Ovarian |
| b. | Lung |
| c. | Uterine |
| d. | Pancreatic |
ANS: A
BRCA1 mutations increase the risk of ovarian cancer among women (20% to 50% lifetime risk), and BRCA2 mutations also confer an increased risk of ovarian cancer (10% to 20% lifetime prevalence). BRCA1 and BRCA2 mutations are not currently believed to be linked with risks of lung, uterine, or pancreatic cancers.
PTS: 1 DIF: Cognitive Level: Remembering
- What are blood pressure variations associated with?
| a. | b1-Adrenergic receptors to increase heart rate |
| b. | The release of an antidiuretic hormone (ADH) |
| c. | The renin-angiotensin system’s effect on vasoconstriction |
| d. | Serum bradykinin, causing vasodilation |
ANS: C
Studies of blood pressure correlations within families indicate that about 20% to 40% of the variation in both systolic and diastolic blood pressure is caused by genetic factors. Significant research is now focused on specific components that may influence blood pressure variation, such as the renin-angiotensin system (involved in sodium reabsorption and vasoconstriction). b1-Adrenergic receptors, ADH, and bradykinin are not the subjects of such research.
PTS: 1 DIF: Cognitive Level: Remembering
- What are the two most important risk factors for type 2 diabetes?
| a. | Autoantibodies and human leukocyte antigen associations |
| b. | Autoantibodies and obesity |
| c. | Obesity and positive family history |
| d. | HLA associations and positive family history |
ANS: C
The two most important risk factors for type 2 diabetes are positive family history and obesity. Autoantibodies and human leukocyte antigen associations are not believed to be important risk factors for this form of diabetes.
PTS: 1 DIF: Cognitive Level: Remembering
- A parent wants to know how to prevent type 1 diabetes in the newborn. The healthcare professional explains that prevention is not possible, because which of these is a major characteristic of type 1 diabetes mellitus?
| a. | Partial insulin secretion |
| b. | An autoimmune cause factor |
| c. | Insulin resistance |
| d. | Obesity as a common risk factor |
ANS: B
A strong association between type 1 diabetes and the presence of several human leukocyte antigen (HLA) class II alleles indicate that type 1 diabetes mellitus is an autoimmune disease. The remaining options are associated with type 2 diabetes.
PTS: 1 DIF: Cognitive Level: Comprehension
- A patient with several risk factors is concerned about developing type 2 diabetes. The healthcare professional advises the patient to lose weight, explaining that obesity is an important risk factor for type 2 diabetes mellitus because it causes what?
| a. | Reduced insulin production by the pancreas |
| b. | Increased resistance to insulin in the cells |
| c. | Obstructed outflow of insulin from the pancreas |
| d. | Stimulation of glucose production by the liver |
ANS: B
People with type 2 diabetes mellitus suffer from insulin resistance. Obesity causes this resistance so their cells have difficulty using insulin. Obesity does not lead to reduced insulin production, obstructed insulin outflow, or stimulation of glucose production.
PTS: 1 DIF: Cognitive Level: Remembering
- Traits caused by the combined effects of multiple genes are referred to by which term?
| a. | Polygenic |
| b. | Multifocal |
| c. | Modifiable |
| d. | Involuntary |
ANS: A
Traits in which variation is thought to be caused by the combined effects of multiple genes are polygenic, meaning many genes. Multifocal means relating to or arising from many points. Modifiable refers to the changeability of something. Involuntary suggests being out of the control of someone or something.
PTS: 1 DIF: Cognitive Level: Remembering
- Regarding type 2 diabetes, obesity is considered to be what type of risk?
| a. | Genetic |
| b. | Empirical |
| c. | Relative |
| d. | Modifiable |
ANS: D
A modifiable risk is one a person can change in order to reduce risk. Obesity is a modifiable risk factor for many diseases including heart disease, stroke, hypertension, and type 2 diabetes. Genetic, empirical, and relative risks are not changeable by individuals in order to reduce their chance of developing diseases.
PTS: 1 DIF: Cognitive Level: Remembering
- Which disease form is associated with identified empirical risks?
| a. | Polygenic |
| b. | Multifactorial |
| c. | Monozygotic |
| d. | Genetic |
ANS: B
For most multifactorial diseases, empirical risks (i.e., risks based on direct observation of data) have been derived. Traits in which variation is thought to be caused by the combined effects of multiple genes are polygenic. Monozygotic is a term that refers to identical twins. Genetic refers to issues related to genes and their influence on the body.
PTS: 1 DIF: Cognitive Level: Remembering
- The number of persons living with a specific disease at a specific point in time is referred to by which term?
| a. | Relativity |
| b. | Survivability |
| c. | Prevalence |
| d. | Incidence |
ANS: C
The prevalence rate is the proportion of the population affected by a disease at a specific point in time. Thus both the incidence rate and the length of the survival period in affected individuals determine prevalence. The term “relativity” is not related to disease statistics. Survivability would refer to the chances of a person being able to survive a specific disease and is also not related to the question. The incidence rate is the number of new cases of a disease reported during a specific period (typically 1 year) divided by the number of individuals in the population.
PTS: 1 DIF: Cognitive Level: Remembering
- Which type of cancer is said to aggregate among families?
| a. | Breast |
| b. | Lung |
| c. | Skin |
| d. | Brain |
ANS: A
Breast cancer appears to aggregate strongly in families. The other cancers are not believed to be familial in nature.
PTS: 1 DIF: Cognitive Level: Remembering
- Which dietary lifestyle choice has been associated with a decreased risk for developing colon cancer?
| a. | Increased consumption of dairy products |
| b. | Increased consumption of foods containing vitamin C |
| c. | Decreased consumption of foods high in fat |
| d. | Decreased consumption of artificial food coloring |
ANS: C
A low-fat, high-fiber diet is thought to decrease the risk of colon cancer. Consumption of dairy products, vitamin C, and artificial food coloring are not thought to be related to colon cancer.
PTS: 1 DIF: Cognitive Level: Remembering
- What is currently believed about the risk for developing Alzheimer disease?
| a. | It is not directly related to genetic predisposition. |
| b. | It is higher among men than it is among women. |
| c. | It occurs less among Hispanics than in Asians. |
| d. | It doubles among those with an affected first-degree relative. |
ANS: D
The risk of developing Alzheimer disease doubles in individuals who have an affected first-degree relative. There is a genetic link to the disease. It is not true that the risk is higher among men than it is among women. Hispanics have relatively low risk of developing this disease.
PTS: 1 DIF: Cognitive Level: Remembering
- The number of new cases of a disease reported during a specific period divided by the number of individuals in the population is defined as which characteristic of a disease?
| a. | Prevalence rate |
| b. | Incidence rate |
| c. | Relative risk |
| d. | Frequency |
ANS: B
The incidence rate is the number of new cases of a disease reported during a specific period (typically 1 year) divided by the number of individuals in the population. The prevalence rate is the proportion of the population affected by a disease at a specific point in time. The relative risk is a ratio of the increased rate of disease among a population exposed to a risk factor compared with the increased rate of the disease in an unexposed population. Frequency is a simple measure of how often something occurs.
PTS: 1 DIF: Cognitive Level: Remembering
MULTIPLE RESPONSE
- Which are cancers that cluster strongly in families? (Select all that apply.)
| a. | Breast |
| b. | Colon |
| c. | Ovarian |
| d. | Lung |
| e. | Brain |
ANS: A, B, C
Although breast, ovarian, and colon cancers have shown a strong familial tendency, lung and brain cancers have not.
PTS: 1 DIF: Cognitive Level: Remembering
- Which genes are responsible for an autosomal dominant form of breast cancer? (Select all that apply.)
| a. | LCAT |
| b. | CHK1 |
| c. | CHK2 |
| d. | BRCA1 |
| e. | BRCA2 |
ANS: D, E
Women who inherit a mutation in BRCA1 or BRCA2 experience a 50% to 80% lifetime risk of developing breast cancer. The other options do not carry this risk.
PTS: 1 DIF: Cognitive Level: Remembering
- Which lifestyle modifications affect health-related risk factors? (Select all that apply.)
| a. | Diet |
| b. | Exercise |
| c. | Education |
| d. | Finances |
| e. | Stress reduction |
ANS: A, B, E
Lifestyle modification (e.g., diet, exercise, stress reduction) can often reduce health risks significantly. Education and finances have not been shown to have an effect on health in a way that involves lifestyle modifications.
PTS: 1 DIF: Cognitive Level: Remembering
- What factors are typically considered when assessing an individual’s risk for developing such common diseases as hypertension? (Select all that apply.)
| a. | Age |
| b. | Diet |
| c. | Exercise habits |
| d. | Family history |
| e. | Spiritual beliefs |
ANS: A, B, C, D
Many factors influence the risk of acquiring a common disease, such as cancer, diabetes, or hypertension. These factors can include age, gender, diet, exercise, and family history of the disease. Current research does not support a connection between spiritual beliefs and the development of hypertension.
PTS: 1 DIF: Cognitive Level: Remembering
- Which are examples of multifactorial diseases associated with adults? (Select all that apply.)
| a. | Breast cancer |
| b. | Coronary heart disease |
| c. | Emphysema |
| d. | Diabetes mellitus |
| e. | Schizophrenia |
ANS: A, B, D, E
Multifactorial diseases in adults include coronary heart disease, hypertension, breast cancer, colon cancer, diabetes mellitus, obesity, Alzheimer disease, alcoholism, schizophrenia, and bipolar affective disorder. Emphysema is not considered multifactorial.
PTS: 1 DIF: Cognitive Level: Remembering
Chapter 28: Structure and Function of the Hematologic System
McCance/Huether: Pathophysiology: The Biologic Basis of Disease in Adults and Children, 8th Edition
MULTIPLE CHOICE
- What is the most abundant class of plasma protein?
| a. | Globulin |
| b. | Albumin |
| c. | Clotting factors |
| d. | Complement proteins |
ANS: B
Albumin (approximately 60% of total plasma protein at a concentration of about 4 g/dL) is the most abundant plasma protein.
PTS: 1 DIF: Cognitive Level: Remembering
- What is the effect of low plasma albumin?
| a. | Clotting factors decrease, thus increasing the chance of prolonged bleeding. |
| b. | Fewer immunoglobulins are synthesized, thus impairing the immune function. |
| c. | Less iron is stored, thus increasing the incidence of iron deficiency anemia. |
| d. | Osmotic pressure decreases; thus water moves from the capillaries to the interstitium. |
ANS: D
In the case of decreased production (e.g., cirrhosis, other diffuse liver diseases, protein malnutrition) or excessive loss of albumin (e.g., certain kidney diseases, extensive burns), the reduced oncotic pressure leads to excessive movement of fluid and solutes into the tissues and decreased blood volume. Low plasma albumin does not affect clotting factors, immunoglobulins, or iron.
PTS: 1 DIF: Cognitive Level: Remembering
- What is the life span of an erythrocyte (in days)?
| a. | 20 to 30 |
| b. | 60 to 90 |
| c. | 100 to 120 |
| d. | 200 to 240 |
ANS: C
Because it cannot undergo mitotic division, the erythrocyte has a limited life span of up to approximately 120 days.
PTS: 1 DIF: Cognitive Level: Remembering
- What does the student learn about erythrocytes?
| a. | Erythrocytes contain a nucleus, mitochondria, and ribosomes. |
| b. | Erythrocytes synthesize proteins. |
| c. | Erythrocytes have the ability to change shape to squeeze through microcirculation. |
| d. | Erythrocytes are more abundant in women than men. |
ANS: C
Reversible deformity enables the erythrocyte to assume a more compact torpedo-like shape, squeeze through the microcirculation, and return to normal. The mature erythrocyte lacks a nucleus and cytoplasmic organelles so it cannot synthesize protein or carry out oxidative reactions. Men have more erythrocytes than women (48% to 42% respectively).
PTS: 1 DIF: Cognitive Level: Remembering
- What are granulocytes that contain granules of vasoactive amines, such as histamine, called?
| a. | Neutrophils |
| b. | Eosinophils |
| c. | Monocytes |
| d. | Basophils |
ANS: D
Basophils contain cytoplasmic granules that hold an abundant mixture of biochemical mediators, including histamine, chemotactic factors, proteolytic enzymes, and an anticoagulant (heparin). These substances are not found in neutrophils, monocytes, or eosinophils.
PTS: 1 DIF: Cognitive Level: Remembering
- Which of these are formed elements of the blood that are not cells but are disk-shaped cytoplasmic fragments essential for blood clotting?
| a. | Monocytes |
| b. | Platelets |
| c. | Macrophages |
| d. | Erythrocytes |
ANS: B
Platelets (thrombocytes) are not true cells but are disk-shaped cytoplasmic fragments that are essential for blood coagulation and control of bleeding. Monocytes, macrophages, and erythrocytes are cells.
PTS: 1 DIF: Cognitive Level: Remembering
- What are blood cells that differentiate into macrophages known as?
| a. | Monocytes |
| b. | Neutrophils |
| c. | Eosinophils |
| d. | Basophils |
ANS: A
Monocytes migrate into a variety of tissues and fully mature into tissue macrophages and myeloid dendritic cells. Neutrophils, eosinophils, and basophils do not undergo this transformation.
PTS: 1 DIF: Cognitive Level: Remembering
- Without prior exposure to an antigen, which cells are able to destroy some types of tumor cells and some virus-infected cells?
| a. | Lymphocytes |
| b. | Plasma cells |
| c. | Megakaryocytes |
| d. | Natural killer (NK) cells |
ANS: D
NK cells, which resemble large granular lymphocytes, kill some types of tumor cells (in vitro) and some virus-infected cells without being induced by previous exposure to these antigens. This capability is not true of lymphocytes, plasma cells, or megakaryocytes.
PTS: 1 DIF: Cognitive Level: Remembering
- What is the life span of platelets (in days)?
| a. | 10 |
| b. | 30 |
| c. | 90 |
| d. | 120 |
ANS: A
A platelet circulates for approximately 8 to 11 days and ages. Macrophages of the mononuclear phagocyte system, mostly in the spleen, remove platelets.
PTS: 1 DIF: Cognitive Level: Remembering
- Fetal hematopoiesis occurs primarily in which structure?
| a. | Gut |
| b. | Spleen |
| c. | Bone marrow |
| d. | Thymus |
ANS: B
The spleen is the largest of the secondary lymphoid organs and the primary site of fetal hematopoiesis. The bone marrow and thymus are other primary lymphoid organs. Peyer patches in the small intestine are considered secondary lymphoid organs.
PTS: 1 DIF: Cognitive Level: Remembering
- What is the consequence of a splenectomy?
| a. | The level of iron in circulation increases. |
| b. | Antibody production increases to improve immune function. |
| c. | The number of defective cells in circulation increases. |
| d. | The number of clotting factors increases. |
ANS: C
Splenic absence from any cause (e.g., atrophy, traumatic injury, removal because of disease) has several secondary effects on the body, among them an increase in morphologically defective blood cells in the circulation, confirming the spleen’s role in removing old or damaged cells. Loss of the spleen does not increase iron blood levels, increase antibody production, or increase the number of clotting factors.
PTS: 1 DIF: Cognitive Level: Remembering
- A professor explains to a class that the reason lymph nodes enlarge and become tender during infection is because of what reason?
| a. | B lymphocytes proliferate. |
| b. | The nodes are inflamed. |
| c. | The nodes fill with purulent exudate. |
| d. | The nodes are not properly functioning. |
ANS: A
The B lymphocyte proliferation in response to significant antigen (e.g., during infection) may result in lymph node enlargement and tenderness (reactive lymph node). The nodes are not specifically inflamed or filled with purulent exudate.
PTS: 1 DIF: Cognitive Level: Understanding
- Which hemoglobin is made from oxidized ferric iron (Fe3+) and lacks the ability to bind oxygen?
| a. | Deoxyhemoglobin |
| b. | Oxyhemoglobin |
| c. | Methemoglobin |
| d. | Glycosylated hemoglobin |
ANS: C
Without reactivation by methemoglobin reductase, the Fe3+-containing hemoglobin (methemoglobin) cannot bind oxygen. Deoxyhemoglobin is hemoglobin available for oxygen binding. Oxyhemoglobin is bound with oxygen. Glycosylated hemoglobin is hemoglobin with which glucose is bound.
PTS: 1 DIF: Cognitive Level: Remembering
- A patient has pernicious anemia and asks the healthcare professional to explain the disease. Which statement by the professional is most accurate?
| a. | The lack of certain foods in your diet |
| b. | Your body cannot absorb vitamin B12. |
| c. | You are not getting enough vitamin C. |
| d. | Your bone marrow has stopped working. |
ANS: B
Dietary vitamin B12 is a large molecule that requires a protein secreted by parietal cells in the stomach (intrinsic factor [IF]) to transport across the ileum. Defects in IF production lead to decreased B12 absorption and pernicious anemia. A lack of certain foods (i.e., meat) might lead to iron-deficiency anemia. Vitamin C lack would not lead to anemia, but in a severe state could lead to scurvy. If the bone marrow had totally failed, that would be termed aplastic anemia.
PTS: 1 DIF: Cognitive Level: Understanding
- By which structure are mature erythrocytes removed from the bloodstream?
| a. | Liver |
| b. | Lymph nodes |
| c. | Thymus |
| d. | Spleen |
ANS: D
At the end of their life spans, old erythrocytes are removed by tissue macrophages, primarily in the spleen.
PTS: 1 DIF: Cognitive Level: Remembering
- A patient has chronic anemia associated with chronic renal failure. What substance does the healthcare professional tell the patient is needed to treat this anemia?
| a. | Iron |
| b. | Erythropoietin |
| c. | Cobalamin (vitamin B12) |
| d. | Folate |
ANS: B
One of the most significant advances in the study of hematopoietic growth factors has been the development of erythropoietin for individuals with chronic renal failure. The other options are not associated with the treatment of chronic anemia.
PTS: 1 DIF: Cognitive Level: Understanding
- What is the role of thromboxane A (TXA2) in the secretion stage of hemostasis?
| a. | Stimulates the synthesis of serotonin. |
| b. | Promotes vasodilation. |
| c. | Stimulates platelet aggregation. |
| d. | Promotes formation of cyclooxygenase. |
ANS: C
Platelet aggregation is primarily stimulated by TXA2 and adenosine diphosphate (ADP), which induce functional fibrinogen receptors on the platelet. Thromboxane A is not involved with serotonin synthesis, vasodilation, or production of cyclooxygenase.
PTS: 1 DIF: Cognitive Level: Remembering
- Which of these is the role of nitric oxide (NO) in hemostasis?
| a. | Stimulates the release of fibrinogen to maintain the platelet plug. |
| b. | Stimulates the release of clotting factors V and VII. |
| c. | Causes vasoconstriction and stimulates platelet aggregation. |
| d. | Controls platelet activation through in concert with prostacyclin. |
ANS: D
Endothelial cell NO synthase produces NO, which controls platelet activation in concert with prostacyclin. The other options do not present an accurate description of the role of NO in hemostasis.
PTS: 1 DIF: Cognitive Level: Remembering
- The drug heparin acts in hemostasis by which processes?
| a. | Inhibiting thrombin and antithrombin III (AT-III) |
| b. | Preventing the conversion of prothrombin to thrombin |
| c. | Shortening the fibrin strands to retract the blood clot |
| d. | Degrading the fibrin within blood clots |
ANS: A
Clinically administered heparin binds to AT-III and induces a conformational change that greatly enhances its activity. Under normal conditions, the presence of endothelial cell heparin sulfate and available AT-III in the circulation cooperate to protect the vessels from the effects of spontaneously activated thrombin. Heparin does not prevent the conversion of prothrombin to thrombin, shorten fibrin strands, or degrade the fibrin in blood clots.
PTS: 1 DIF: Cognitive Level: Remembering
- What is plasmin’s role in the clotting process?
| a. | Stimulates platelet aggregation. |
| b. | Inhibits platelet adhesion and aggregation. |
| c. | Prevents the conversion of prothrombin to degrade the fibrin within blood clots. |
| d. | Degrades the fibrin within blood clots. |
ANS: D
Plasmin (also called fibrinase or fibrinolysin) is a serine protease that degrades fibrin polymers in clots. It is not capable of stimulating platelet aggregation, inhibiting platelet adhesion, or preventing conversion of prothrombin.
PTS: 1 DIF: Cognitive Level: Remembering
- Soon after birth, a newborn has cord blood drawn which shows hemoglobin of 28.2 mg/dL. What does the healthcare professional understand about this finding?
| a. | The baby suffered from hypoxia in utero. |
| b. | This is a normal finding from cord blood. |
| c. | The newborn needs a blood transfusion. |
| d. | The infant’s bone marrow is immature. |
ANS: A
A normal cord blood hemoglobin mean is 16.8 mg/dL, so this is a high value. A hypoxic intrauterine environment stimulates erythropoietin production in the fetus and accelerates fetal erythropoiesis, producing polycythemia. This value does not indicate a need for transfusion nor does it demonstrate immature bone marrow.
PTS: 1 DIF: Cognitive Level: Understanding
- Where are Kupffer cells located?
| a. | Kidneys |
| b. | Liver |
| c. | Pancreas |
| d. | Spleen |
ANS: B
The liver macrophages are the only location for Kupffer cells.
PTS: 1 DIF: Cognitive Level: Remembering
- The student learns that Langerhans cells are only found in which organ?
| a. | Skin |
| b. | Intestinal lining |
| c. | Kidney |
| d. | Thyroid |
ANS: A
The skin is the only location for Langerhans cells.
PTS: 1 DIF: Cognitive Level: Remembering
- What does the student learn about the role of collagen in the clotting process?
| a. | Initiates the clotting cascade |
| b. | Activates platelets |
| c. | Stimulates fibrin |
| d. | Deactivates fibrinogen |
ANS: B
Collagen and thrombin are particularly strong stimuli for platelet aggregation. Collagen does not initiate the clotting cascade, stimulate fibrin, or deactivate fibrinogen.
PTS: 1 DIF: Cognitive Level: Remembering
- Which form of iron (Fe) can be used in the formation of normal hemoglobin?
| a. | Fe+ |
| b. | Fe2+ |
| c. | Fe3+ |
| d. | Fe4+ |
ANS: B
It is crucial that the iron be correctly charged; only reduced ferrous iron (Fe2+) can bind oxygen in the lungs and release it in the tissues. Fe+ is simple iron. Fe3+ is bound with oxygen. Fe4+ is ferryl iron.
PTS: 1 DIF: Cognitive Level: Remembering
- What change to the hematologic system is related to age?
| a. | Platelet adhesiveness decreases. |
| b. | Lymphocyte function decreases. |
| c. | Cellular immunity increases. |
| d. | Erythrocyte reproduction accelerates. |
ANS: B
Blood composition changes little with age. A delay in erythrocyte replenishment may occur after bleeding, presumably because of iron deficiency. Lymphocyte function appears to decrease with age. Particularly affected is a decrease in cellular immunity. Platelet adhesiveness probably increases with age.
PTS: 1 DIF: Cognitive Level: Remembering
- What is the function of erythrocytes?
| a. | Tissue oxygenation |
| b. | Hemostasis |
| c. | Infection control |
| d. | Allergy response |
ANS: A
Erythrocytes are solely responsible for tissue oxygenation. Hemostasis occurs due to the actions of multiple substances such as fibrin, collagen, and clotting factors. Infection control and allergic responses are mediated by white blood cells.
PTS: 1 DIF: Cognitive Level: Remembering
MULTIPLE RESPONSE
- Which characteristics allow erythrocytes to function as gas carriers? (Select all that apply.)
| a. | Permanent shape |
| b. | Compactness |
| c. | Reversible deformability |
| d. | Presence of hyperactive mitochondria |
| e. | Biconcavity |
ANS: C, E
A red blood cell (RBC) is a small disk with two unique properties: (1) a biconcave shape and (2) the capacity to be reversibly deformed. Compactness is not a feature that promotes gas exchange. Erythrocytes do not contain mitochondria.
PTS: 1 DIF: Cognitive Level: Remembering
- Which statements about plasma proteins are correct? (Select all that apply.)
| a. | Provide clotting factors. |
| b. | Transport triglycerides. |
| c. | Synthesize complement proteins. |
| d. | Create hydrostatic pressure. |
| e. | Transport cholesterol. |
ANS: A, B, C, E
Plasma proteins do not create hydrostatic pressure. The other options are all accurate statements regarding plasma proteins.
PTS: 1 DIF: Cognitive Level: Remembering
- What are the primary anticoagulant mechanisms? (Select all that apply.)
| a. | Antithrombin III |
| b. | Tissue factor pathway inhibitor |
| c. | Hematopoiesis |
| d. | Protein C |
| e. | Phagocytosis |
ANS: A, B, D
The major regulatory factors that control hemostasis reside where the greatest probability of clotting would occur—on the endothelial cell surface. The primary anticoagulant mechanisms include thrombin inhibitors (e.g., antithrombin III), tissue factor inhibitors (e.g., tissue factor pathway inhibitor), and mechanisms for degrading activated clotting factors (e.g., protein C). Hematopoiesis and phagocytosis are processes that are not related to anticoagulation.
PTS: 1 DIF: Cognitive Level: Remembering
- What does the student learn regarding the role of the endothelium in clot formation? (Select all that apply.)
| a. | The surface of the endothelium produces plasma protease inhibitors. |
| b. | Plasma protease inhibitors assist in preventing clot formation. |
| c. | Thrombomodulin is a protein that is converted on the surface of endothelial cells. |
| d. | Protein A binds to thrombomodulin. |
| e. | Activated protein C enhances the adhesion ability of neutrophils. |
ANS: A, B, C
The surface of the endothelium produces plasma protease inhibitors to resist clot formation. Thrombomodulin is a membrane thrombin-binding protein matter and is converted to activated protein C on the surface of endothelial cells. Protein C in the circulation binds to thrombomodulin. Activated protein C inhibits the adhesion of neutrophils to the endothelium.
PTS: 1 DIF: Cognitive Level: Remembering
- Which statements characterize albumin? (Select all that apply.)
| a. | It retains sodium to maintain water balance. |
| b. | It provides colloid osmotic pressure. |
| c. | It is synthesized in the liver. |
| d. | It is a carrier for drugs that have low water solubility. |
| e. | It is a small molecule. |
ANS: B, C, D
Albumin is a plasma protein produced by the liver. It serves as a carrier molecule for the normal components of blood, as well as for drugs that have low solubility in water (e.g., free fatty acids, lipid-soluble hormones, thyroid hormones, bile salts). Albumin molecules are large and do not diffuse freely through the vascular endothelium; thus they maintain the critical colloidal osmotic pressure (or oncotic pressure) that regulates the passage of water and solutes into the surrounding tissues.
PTS: 1 DIF: Cognitive Level: Remembering
- Which nutrients are necessary for the synthesis of DNA and the maturation of erythrocytes? (Select all that apply.)
| a. | Protein |
| b. | Iron |
| c. | Cobalamin (vitamin B12) |
| d. | Folate |
| e. | Pantothenic acid |
ANS: C, D
Cobalamin and folate are necessary for the synthesis of DNA and for the maturation of erythrocytes. The remaining options are not necessary for these processes to occur.
PTS: 1 DIF: Cognitive Level: Remembering
- Which nutrients are necessary for hemoglobin synthesis? (Select all that apply.)
| a. | Protein |
| b. | Iron |
| c. | B6 (pyridoxine) |
| d. | Vitamin C |
| e. | Cobalamin (vitamin B12) |
| f. | Pantothenic acid |
ANS: B, C
Iron and B6 (pyridoxine) are necessary for hemoglobin synthesis. The remaining options are not necessary for hemoglobin synthesis.
PTS: 1 DIF: Cognitive Level: Remembering
Chapter 41: Structure and Function of the Digestive System
McCance/Huether: Pathophysiology: The Biologic Basis of Disease in Adults and Children, 8th Edition
MULTIPLE CHOICE
- In the mouth and stomach, salivary a-amylase initiates the digestion of which nutrients?
| a. | Proteins |
| b. | Carbohydrates |
| c. | Fats |
| d. | Fiber |
ANS: B
Salivary a-amylase is an enzyme that initiates carbohydrate digestion in the mouth and stomach. Pepsin breaks down protein-forming chains in the stomach. Thirty percent of fats are broken down by gastric lipase. Fiber is not broken down and contributes to stool volume.
PTS: 1 DIF: Cognitive Level: Remembering
- Saliva contains which immunoglobulin (Ig)?
| a. | IgA |
| b. | IgE |
| c. | IgG |
| d. | IgM |
ANS: A
Saliva contains only IgA, which helps prevent infection.
PTS: 1 DIF: Cognitive Level: Remembering
- What effect is a result of inhibiting the parasympathetic nervous system with a drug such as atropine?
| a. | Salivation becomes thinner. |
| b. | Salivation decreases. |
| c. | The pH of saliva changes. |
| d. | Digestive enzymes are inhibited. |
ANS: B
The sympathetic and parasympathetic divisions of the autonomic nervous system control salivation. Because cholinergic parasympathetic fibers stimulate the salivary glands, atropine (an anticholinergic agent) inhibits salivation and makes the mouth dry. Atropine (and similar drugs) does not cause saliva to become thinner, change the pH of saliva, or inhibit digestive enzymes.
PTS: 1 DIF: Cognitive Level: Remembering
- Food enters the stomach via which orifice or sphincter?
| a. | Cardiac |
| b. | Upper esophageal |
| c. | Gastric |
| d. | Fundal |
ANS: A
Each end of the esophagus is opened and closed by a sphincter. The upper esophageal sphincter (cricopharyngeal muscle) prevents entry of air into the esophagus during respiration. The lower esophageal sphincter (cardiac orifice) prevents regurgitation from the stomach. The lower esophageal sphincter is located near the esophageal hiatus—the opening in the diaphragm where the esophagus ends at the stomach. The gastric sphincter controls the release of food from the stomach to the small intestine and is also known as the pyloric sphincter. The fundal sphincter is not a structure in the GI system.
PTS: 1 DIF: Cognitive Level: Remembering
- Which gastric cells secrete hydrochloric acid and intrinsic factor?
| a. | Parietal |
| b. | Chief |
| c. | G |
| d. | D |
ANS: A
The parietal cells (oxyntic cells) secrete hydrochloric acid and intrinsic factor. The chief cells secrete pepsinogen. The pyloric gland mucosa in the antrum synthesizes and releases the hormone gastrin from G cells. D cells secrete somatostatin.
PTS: 1 DIF: Cognitive Level: Remembering
- Which cells in the stomach secrete histamine?
| a. | Oxyntic |
| b. | Chief |
| c. | D |
| d. | Enterochromaffin-like |
ANS: D
Enterochromaffin-like cells secrete histamine. The parietal cells (oxyntic cells) within the glands secrete hydrochloric acid, intrinsic factor, and gastroferrin. The chief cells secrete pepsinogen. D cells secrete somatostatin.
PTS: 1 DIF: Cognitive Level: Remembering
- Which gastric hormone inhibits acid and pepsinogen secretion, as well as decreases the release of gastrin?
| a. | Motalin |
| b. | Histamine |
| c. | Somatostatin |
| d. | Acetylcholine |
ANS: C
Somatostatin inhibits the secretion of acid and pepsinogen and decreases gastrin release. The hormones gastrin and motilin stimulate gastric emptying. Histamine stimulates acid secretion by activating histamine receptors (H2 receptors) on acid-secreting parietal cells. Acetylcholine stimulates pepsin secretion.
PTS: 1 DIF: Cognitive Level: Remembering
- Which enzyme breaks down protein-forming polypeptides in the stomach?
| a. | Acetylcholine |
| b. | Pepsin |
| c. | Gastrin |
| d. | Secretin |
ANS: B
Pepsin, a proteolytic enzyme, breaks down protein-forming polypeptides in the stomach. Acetylcholine stimulates pepsin secretion. The hormones gastrin and motilin stimulate gastric emptying. Secretin stimulates pancreas to secrete alkaline pancreatic juice and liver to secrete bile; decreases gastrointestinal motility; inhibits gastrin and gastric acid secretion.
PTS: 1 DIF: Cognitive Level: Remembering
- Exposure to which substance protects the mucosal barrier of the stomach?
| a. | Prostaglandins |
| b. | Acetylcholine |
| c. | Helicobacter pylori |
| d. | Regurgitated bile |
ANS: A
Prostaglandins and nitric oxide protect the mucosal barrier by stimulating the secretion of mucus and bicarbonate and by inhibiting the secretion of acid. Acetylcholine stimulates pepsin secretion. Helicobacter pylori are bacteria found in the stomach. Bile is secreted by the liver.
PTS: 1 DIF: Cognitive Level: Remembering
- The ileum and jejunum are suspended by folds of the peritoneum that contain an extensive vascular and nervous network. What are these folds called?
| a. | Ligament of Treitz |
| b. | Mesentery |
| c. | Auerbach folds |
| d. | Lamina propria |
ANS: B
The ileum and jejunum are suspended in loose folds from the posterior abdominal wall by a peritoneal membrane called the mesentery. The mesentery facilitates intestinal motility and supports blood vessels, nerves, and lymphatics. The duodenum begins at the pylorus and ends where it joins the jejunum at a suspensory ligament called the Treitz ligament. Intrinsic reflexive activity is mediated by the myenteric plexus (Auerbach plexus) and the submucosal plexus (Meissner plexus) of the enteric nervous system. The lamina propria (a connective tissue layer of the mucous membrane) lies beneath the epithelial cells of the villi and contains lymphocytes and plasma cells, which produce immunoglobulins and macrophages.
PTS: 1 DIF: Cognitive Level: Remembering
- Where in the small intestines are lymphocytes, plasma cells, and macrophages produced?
| a. | Brush border |
| b. | Microvilli |
| c. | Lamina propria |
| d. | Crypts of Lieberkühn |
ANS: C
The lamina propria, which is a connective tissue layer of the mucous membrane, lies beneath the epithelial cells of the villi and contains lymphocytes, plasma cells, which produce immunoglobulins and macrophages. Together the microvilli create a mucosal surface known as the brush border. The villi and microvilli greatly increase the surface area available for absorption. Between the bases of the villi are the crypts of Lieberkühn (intestinal glands), which extend to the submucosal layer. Undifferentiated cells arise from stem cells at the base of the crypt and move toward the tip of the villus, maturing to become columnar epithelial secretory cells (water, electrolytes, and enzymes) and goblet cells (mucus).
PTS: 1 DIF: Cognitive Level: Remembering
- The student asks the professor why water and electrolytes are transported in both directions through tight junctions and intercellular spaces rather than across cell membranes. What response by the professor is best?
| a. | The intercellular hydrostatic pressure is inadequate to push the water and electrolytes across the cell membranes. |
| b. | A balance of cations and ions among the electrolytes on each side of the cell membranes cannot be maintained. |
| c. | The epithelial cell membranes are formed of lipids that are hydrophobic and therefore repel water. |
| d. | Receptors on those cell membranes are occupied with a diffusion of amino acids and monosaccharides. |
ANS: C
The epithelial cell membranes of the small intestine are formed of lipids and are hydrophobic or tend to repel water. Therefore, water and electrolytes are transported in both directions—toward the capillary blood or toward the intestinal lumen—through the tight junctions and intercellular spaces rather than across cell membranes.
PTS: 1 DIF: Cognitive Level: Remembering
- Which statement best describes the gastrointestinal tract?
| a. | The gastrointestinal tract is a muscular tube that transports food from the mouth to the stomach. |
| b. | The gastrointestinal tract is a hollow tube that extends from the mouth to the anus. |
| c. | The gastrointestinal tract is a baglike structure that propels partially digested food (chyme). |
| d. | The gastrointestinal tract is 5 m long and consists of three segments. |
ANS: B
The gastrointestinal tract is a hollow tube that extends from the mouth to the anus. The esophagus is a muscular tube that transports food from the mouth to the stomach. The stomach is a baglike structure that secretes digestive juices, mixes and stores food, and propels partially digested food (chyme) into the duodenum. The small intestine is 5 m long and has three segments.
PTS: 1 DIF: Cognitive Level: Remembering
- Glucose transport enhances the absorption of which electrolyte?
| a. | Sodium |
| b. | Phosphate |
| c. | Potassium |
| d. | Chloride |
ANS: A
Sodium passes through the tight junctions and is actively transported across cell membranes. Sodium and glucose share a common active transport carrier (sodium–glucose ligand transporter 1 [SGLT1]) so that sodium absorption is enhanced by glucose transport.
PTS: 1 DIF: Cognitive Level: Remembering
- What process is capable of increasing both intrathoracic and intraabdominal pressure, thereby facilitating defecation?
| a. | Relaxation of the internal anal sphincter |
| b. | Intestinal peristalsis |
| c. | Valsalva maneuver |
| d. | Ileogastric reflex |
ANS: C
The Valsalva maneuver consists of inhaling and forcing the diaphragm and chest muscles against the closed glottis and increases both intrathoracic and intraabdominal pressure. This pressure is transmitted to the rectum thereby facilitating defecation. Relaxation of the internal anal sphincter creates the urge to defecate. Peristalsis moves the products of digestion along in the gastrointestinal tract. The ileogastric reflex inhibits gastric motility when the ileum becomes distended.
PTS: 1 DIF: Cognitive Level: Remembering
- Which pancreatic enzyme is responsible for the breakdown of carbohydrates?
| a. | Trypsin |
| b. | Amylase |
| c. | Lipase |
| d. | Chymotrypsin |
ANS: B
Salivary and pancreatic amylases breakdown starches to oligosaccharides by splitting a-1,4-glucosidic linkages of long-chain molecules. Trypsin is involved in protein hydrolysis. Gastric lipase aids in the digestion of fat. Chymotrypsin works with trypsin.
PTS: 1 DIF: Cognitive Level: Remembering
- What is the formation of water-soluble molecules to facilitate the absorption of the byproducts of lipid hydrolysis accomplished by?
| a. | Micelles |
| b. | Phospholipase |
| c. | Chylomicrons |
| d. | Colipase |
ANS: A
The products of lipid hydrolysis must be made water soluble if they are to be efficiently absorbed from the intestinal lumen. The formation of water-soluble molecules known as micelles accomplishes this process. Phospholipase cleaves fatty acids from phospholipids. Triglycerides are covered with phospholipids, lipoproteins, and cholesterol to become particles called chylomicrons. Colipase is a coenzyme needed for optimal functioning of lipase.
PTS: 1 DIF: Cognitive Level: Remembering
- What is the primary source of physiologic iron?
| a. | Transferrin from plasma |
| b. | Pepsin form pepsinogen |
| c. | Bile from bilirubin |
| d. | Heme from animal protein |
ANS: D
The primary source of iron is heme from animal protein. A small portion of iron comes from recycling of old red blood cells.
PTS: 1 DIF: Cognitive Level: Remembering
- A professor has taught a class of students about the characteristics of vitamin B12. Which statement by a student demonstrates a need for more education?
| a. | Vitamin B12 is absorbed in the terminal ileum. |
| b. | Vitamin B12 is absorbed in its free (unbound) form in small amounts. |
| c. | Vitamin B12 is necessary for platelet maturation. |
| d. | Vitamin B12 binds to intrinsic factor. |
ANS: C
Most vitamin B12 (cobalamin) is bound to intrinsic factor (making it resistant to digestion) and is absorbed in the terminal ileum, although a small amount of the vitamin is absorbed in its free (unbound) form. Vitamin B12 is not necessary for platelet maturation. When a student makes this statement, the professor knows the student needs more education.
PTS: 1 DIF: Cognitive Level: Evaluating
- Which water-soluble vitamin is absorbed by passive diffusion?
| a. | Vitamin B6 |
| b. | Vitamin B1 |
| c. | Vitamin K |
| d. | Folic acid |
ANS: A
Of the options available, only Vitamin B6 is the water-soluble vitamin absorbed by passive diffusion. B1 and folic acid are absorbed by active transport. Vitamin K requires micelle formation with bile salts and lipid diffusion.
PTS: 1 DIF: Cognitive Level: Remembering
- Which vitamin facilitates the absorption of iron by the epithelial cells of the duodenum and jejunum?
| a. | B6 |
| b. | C |
| c. | E |
| d. | B12 |
ANS: B
Vitamin C reduces ferric iron to ferrous iron, which is the form more easily absorbed by the epithelial cells of the duodenum and jejunum. Vitamin B6 is important to many functions including synthesis of neurotransmitters. Vitamin E is an antioxidant. Atrophic gastritis and failure to absorb vitamin B12 result in pernicious anemia.
PTS: 1 DIF: Cognitive Level: Remembering
- What is the role of the normal intestinal bacterial flora?
| a. | Metabolizing bile salts, estrogens, and lipids |
| b. | Breaking down proteins into amino acids |
| c. | Facilitating the motility of the colon |
| d. | Metabolizing aldosterone and insulin |
ANS: A
The intestinal bacteria play a role in the metabolism of bile salts, contributing to the intestinal reabsorption of bile and the elimination of toxic bile metabolites. These bacteria also play a role in the metabolism of estrogens, androgens, and lipids, as well as in the conversion of unabsorbed carbohydrates to absorbable organic acids, the synthesis of vitamin K2, and the metabolism of various nitrogenous substances and drugs. Although they serve many functions, they do not break protein down into amino acids, facilitate colonic motility, or metabolize hormones such as aldosterone and insulin.
PTS: 1 DIF: Cognitive Level: Remembering
- How are Kupffer cells best described?
| a. | Natural killer cells that produce interferon-gamma (IFN-g) |
| b. | Contractile and therefore capable of regulating the sinusoid blood flow |
| c. | Bactericidal and therefore central to innate immunity |
| d. | Able to metabolize estrogen, progesterone, and androgens |
ANS: C
The sinusoids in the liver are lined with phagocytic cells, known as Kupffer cells, which are part of the mononuclear phagocyte system and are the largest population of tissue macrophages in the body. They are bactericidal and central to innate immunity. None of the other options accurately describe Kupffer cells.
PTS: 1 DIF: Cognitive Level: Remembering
- Bilirubin is a byproduct of the destruction of which aged cells?
| a. | Platelets |
| b. | Protein |
| c. | Leukocytes |
| d. | Erythrocytes |
ANS: D
Bilirubin is a byproduct of only the destruction of aged red blood cells or erythrocytes.
PTS: 1 DIF: Cognitive Level: Remembering
- The process of conjugation of bilirubin in the liver is best described as which transformation?
| a. | Unconjugated (fat-soluble) bilirubin into urobilinogen |
| b. | Unconjugated (fat-soluble) bilirubin into conjugated (water-soluble) bilirubin |
| c. | Conjugated (water-soluble) bilirubin into unconjugated (fat-soluble) bilirubin |
| d. | Conjugated (water-soluble) bilirubin into urobilinogen |
ANS: B
In the liver, unconjugated bilirubin moves from plasma in the sinusoids into the hepatocytes. Within hepatocytes it joins with glucuronic acid to form conjugated bilirubin, which is water-soluble.
PTS: 1 DIF: Cognitive Level: Remembering
- A professor has been teaching a class on gastrointestinal function. Which statement by a student indicates the need for more education?
| a. | Within 30 min of eating, the gallbladder forces bile into the stomach. |
| b. | Cholinergic branches of the vagus nerve mediate gallbladder contraction. |
| c. | Cholecystokinin provides hormonal regulation of gallbladder contraction. |
| d. | The sphincter of Oddi controls the flow of bile from the gallbladder. |
ANS: A
Within 30 min after eating, the gallbladder begins to contract and the sphincter of Oddi relaxes, forcing bile into the duodenum through the major duodenal papilla. The other statements regarding the functioning of the gallbladder are accurate.
PTS: 1 DIF: Cognitive Level: Remembering
- Which structure synthesizes clotting factors and the vitamin K necessary for hemostasis?
| a. | Colon |
| b. | Spleen |
| c. | Gallbladder |
| d. | Liver |
ANS: D
The liver performs many hemostatic functions, including synthesis of clotting factors and vitamin K. These are not synthesized in the colon, spleen, or gallbladder.
PTS: 1 DIF: Cognitive Level: Remembering
- How many days does it take for the entire epithelial population of the small intestines to be replaced?
| a. | 30 to 45 |
| b. | 15 to 25 |
| c. | 7 to 15 |
| d. | 4 to 7 |
ANS: D
The entire epithelial population is replaced approximately every 4 to 7 days.
PTS: 1 DIF: Cognitive Level: Remembering
- Which statement, made by a student, is correct regarding the state of the intestinal tract at birth?
| a. | The intestinal tract is colonized by Escherichia coli. |
| b. | The intestinal tract is sterile. |
| c. | Clostridium welchii is present in but in very small numbers. |
| d. | Streptococcus colonization in the intestinal tract has begun. |
ANS: B
The intestinal tract is sterile at birth but becomes colonized with Escherichia coli, Clostridium welchii, and Streptococcus within a few hours.
PTS: 1 DIF: Cognitive Level: Remembering
MULTIPLE RESPONSE
- Gastric emptying is delayed by the presence of which substances? (Select all that apply.)
| a. | Solids |
| b. | Carbohydrates |
| c. | Nonisotonic solutions |
| d. | Bacteria |
| e. | Fats |
ANS: A, C, E
Solids, fats, and nonisotonic solutions delay gastric emptying.
PTS: 1 DIF: Cognitive Level: Remembering
- Which hormones are involved in the relaxation of the stomach’s fundus during swallowing? (Select all that apply.)
| a. | Progesterone |
| b. | Glucagon |
| c. | Motilin |
| d. | Gastrin |
| e. | Cholecystokinin |
ANS: D, E
Swallowing causes the fundus to relax (receptive relaxation) to receive a bolus of food from the esophagus. Relaxation is coordinated by efferent, nonadrenergic, noncholinergic vagal fibers and is facilitated by gastrin and cholecystokinin, two polypeptide hormones secreted by the gastrointestinal mucosa. Progesterone is a sex hormone not involved in gastrointestinal function. Glucagon is released by the pancreas when blood sugar gets too low. Motilin stimulates gastric emptying.
PTS: 1 DIF: Cognitive Level: Remembering
- Which hormones are involved in regulating gastric motility by lowering the threshold potential of muscle fibers? (Select all that apply.)
| a. | Estrogen |
| b. | Secretin |
| c. | Somatostatin |
| d. | Gastrin |
| e. | Motilin |
ANS: D, E
Gastrin and motilin (small intestine hormones) and the vagus nerve increase contraction by lowering the threshold potential of muscle fibers. Sympathetic activity and secretin (another small intestine hormone) are inhibitory and raise the threshold potential. The rate of peristalsis is mediated by pacemaker cells that initiate a wave of depolarization (basic electrical rhythm), which moves from the upper part of the stomach to the pylorus. Neither estrogen nor somatostatin inhibits gastric motility as described in the question.
PTS: 1 DIF: Cognitive Level: Remembering
- What requirements are necessary for calcium to be absorbed through the ileum at concentrations of less than 5 mmol/L? (Select all that apply.)
| a. | Receptor site on the ileum |
| b. | Vitamin D3 |
| c. | Vitamin K |
| d. | Carboxypeptidase |
| e. | A carrier protein |
ANS: B, E
At concentrations less than 5 mmol/L, calcium is transported actively across cell membranes, bound to a carrier protein. The carrier formation requires the presence of the active form of vitamin D3 (1,25-dihydroxyvitamin D). Receptors on the ileum, vitamin K, and carboxypeptidase are not involved in calcium absorption.
PTS: 1 DIF: Cognitive Level: Remembering
- Which water-soluble vitamins are dependent on sodium for absorption? (Select all that apply.)
| a. | Pantothenic acid |
| b. | Vitamin B1 |
| c. | Niacin |
| d. | Vitamin B12 |
| e. | Folic acid |
ANS: B, E
Vitamins B1 and folic acid depend on sodium facilitated active transport. Pantothenic acid and niacin rely on passive diffusion. Vitamin B12 relies on intrinsic factor for absorption.
PTS: 1 DIF: Cognitive Level: Remembering
- What information does the student learn regarding the functions of the pancreas? (Select all that apply.)
| a. | Cholecystokinin stimulates the release of pancreatic enzymes. |
| b. | Bilirubin and S cells inhibit the secretion of pancreatic enzymes. |
| c. | Pancreatic polypeptide is released after eating. |
| d. | Acetylcholine (ACh) is liberated from the pancreatic branches of the vagus nerve. |
| e. | ACh stimulates the release of pancreatic enzymes. |
ANS: A, C, D
The release of secretin and cholecystokinin stimulate pancreatic secretions and inhibit gastric secretions. Pancreatic polypeptide is released after eating and inhibits postprandial pancreatic exocrine secretion. Acid secretion is stimulated by the vagus nerve, which releases acetylcholine. As chyme enters the duodenum, its acidity (pH of 4.5 or less) stimulates the S cells of the duodenum to release secretin. Bilirubin is the product of the destruction of senescent red blood cells. ACh stimulates pepsin release.
PTS: 1 DIF: Cognitive Level: Remembering
- Which elements in saliva protect against tooth decay? (Select all that apply.)
| a. | Salivary a-amylase |
| b. | Ptyalin |
| c. | Mucin |
| d. | Exogenous fluoride |
| e. | A pH of 7.4 |
ANS: D, E
The bicarbonate concentration of saliva sustains a pH of approximately 7.4, which neutralizes bacterial acids and prevents tooth decay. Exogenous fluoride (e.g., fluoride in drinking water) is absorbed and then secreted in the saliva, providing additional protection against tooth decay. Salivary a-amylase, also known as ptyalin, initiates carbohydrate digestion in the mouth and stomach. Mucin provides lubrication in the saliva.
PTS: 1 DIF: Cognitive Level: Remembering
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