The lung is innervated by the parasympathetic nervous system via which nerve? Vagus
Fibers of the parasympathetic division of the autonomic nervous system... [Show More] (ANS) travel only in the vagus nerve to the lung.
What is the action of urodilatin? It inhibits salt and water reabsorption
Urodilatin (a natriuretic peptide) inhibits sodium and water reabsorption from the medullary part of collecting duct, thereby producing diuresis. It is not involved in the actions described by the other options.
What is the direct action of atrial natriuretic hormone? Sodium excretion
Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) inhibit the secretion of renin, inhibit angiotensin-induced secretion of aldosterone, vasodilate the afferent and constrict the efferent glomerular arterioles, and inhibit sodium and water absorption by kidney tubules. The other actions are not a result of the atrial natriuretic hormone.
Which statement best describes a Schilling test? Administration of radioactive cobalamin and the measurement of its excretion in the urine to test for vitamin B12 deficiency The Schilling test indirectly evaluates vitamin B12 absorption by administering radioactive B12 and measuring excretion in the urine. This selection is the only option that accurately describes a Schilling test.
Hemolytic disease of the newborn (HDN) can occur if the mother: Is Rh-negative and the fetus is Rh-positive
HDN can occur only if antigens on fetal erythrocytes differ from antigens on maternal erythrocytes. Maternal-fetal incompatibility exists only if the mother and fetus differ in ABO blood type or if the fetus is Rh-positive and the mother is Rh-negative. This erythrocyte incompatibility does not exist in any of the other options.
Which T-lymphocyte phenotype is the key determinant of childhood asthma? CD4 T-helper Th2 lymphocytes
Asthma develops because the Th2 response (in which CD4 T-helper cells produce specific cytokines, such as interleukin [IL]–4, IL-5, and IL-13) promotes an atopic and allergic response in the airways. This selection is the only option that accurately identifies the appropriate Tlymphocyte phenotype.
Perceived stress elicits an emotional, anticipatory response that begins where? Limbic system
Perceived stressors elicit an anticipatory response that begins in the limbic system of the brain, the only option responsible for emotions and cognition.
Hypersensitivity is best defined as a(an): Altered immunologic response to an antigen that results in disease
Hypersensitivity is an altered immunologic response to an antigen that results in disease or damage to the host. The other options are not accurate definitions of hypersensitivity.
It has been determined that a tumor is in stage 2. What is the meaning of this finding? Cancer is locally invasive.
Cancer confined to the organ of origin is stage 1; cancer that is locally invasive is stage 2; cancer that has spread to regional structures, such as the lymph nodes, is stage 3; and cancer that has spread to distant sites, such as a liver cancer spreading to the lung or a prostate cancer spreading to bone, is stage 4.
An infant has a loud, harsh, holosystolic murmur and systolic thrill that can be detected at the left lower sternal border that radiates to the neck. These clinical findings are consistent with which congenital heart defect? Ventricular septal defect (VSD)
On physical examination, a loud, harsh, holosystolic murmur and systolic thrill can be detected at the left lower sternal border. The intensity of the murmur reflects the pressure gradient across the VSD. An apical diastolic rumble may be present with a moderate-to-large defect, reflecting increased flow across the mitral valve. The presentations of the other congenital heart defects are not consistent with the described symptoms.
Which statement concerning exotoxins is true? Exotoxins are released during bacterial growth.
Exotoxins are proteins released during bacterial growth. The other options are not true of exotoxins.
The function of the foramen ovale in a fetus allows what to occur? Right-to-left blood shunting
The nonfused septum secundum and ostium secundum result in the formation of a flapped orifice known as the foramen ovale, which allows the right-to-left shunting necessary for fetal circulation. The foramen ovale is not involved in the blood flow described by the other options.
Which laboratory test is considered adequate for an accurate and reliable diagnosis of gonococcal urethritis in a symptomatic man? Gram-stain technique
Microscopic evaluation of Gram-stained slides of clinical specimens is deemed positive for Neisseria gonorrhoeae if gram-negative diplococci with the typical “kidney bean” morphologic appearance are found inside polymorphonuclear leukocytes. Such a finding is considered adequate for the diagnosis of gonococcal urethritis in a symptomatic man. The other options are not relevant to the diagnosis of this condition.
Which manifestations of vasoocclusive crisis are associated with sickle cell disease (SCD) in infants? Edema of the hands and feet
Symmetric, painful swelling of the hands and feet (hand-foot syndrome) caused by infarction in the small vessels of the extremities is often the initial manifestation of SCD in infants. This selection is the only option that accurately identifies the manifestations of a vasoocclusive crisis associated with SCD in infancy.
Which statement concerning benign tumors is true? The cells are well-differentiated.
A benign tumor is well-differentiated with its tissue appearing similar to the tissue from which it arose. The other options are characteristic of a malignant tumor.
Which primary characteristic is unique for the immune response? The immune response is specific to the antigen that initiates it.
Unlike inflammation, which is nonspecifically activated by cellular damage and pathogenic microorganisms, the immune response is primarily designed to afford long-term specific protection (i.e., immunity) against particular invading microorganisms; that is, it has a memory function. The other options are not unique characteristics of the immune response.
Which criterion is used to confirm a diagnosis of asthma in an 8-year-old child? Reduced expiratory flow rates confirmed by spirometry testing
Confirmation of the diagnosis of asthma relies on pulmonary function testing using spirometry, which can be accomplished only after the child is 5 to 6 years of age. Reduced expiratory flow rates that are reversible in response to an inhaled bronchodilator would be characteristic abnormalities. For younger children, an empiric trial of asthma medications is commonly initiated. The remaining options are major historical and physical factors that contribute but do not confirm the diagnosis of asthma in children.
Where are antibodies produced? Plasma cells
An antibody or immunoglobulin is a serum glycoprotein produced only by plasma cells in response to a challenge by an immunogen.
How much urine accumulates in the bladder before the mechanoreceptors sense bladder fullness?
250 to 300 ml
When the bladder accumulates 250 to 300 ml of urine, it contracts and the internal urethral sphincter relaxes through activation of the spinal reflex arc (known as the micturition reflex).
Which disorder results in decreased erythrocytes and platelets with changes in leukocytes and has clinical manifestations of pallor, fatigue, petechiae, purpura, bleeding, and fever? Acute lymphocytic leukemia (ALL)
Pallor, fatigue, petechiae, purpura, bleeding, and fever are generally present with the most common symptoms reflecting the consequence of bone marrow failure, which results in decreased red blood cells and platelets and changes in white blood cells. This selection is the only option that correctly identifies the disease with the symptoms described.
Carcinoma in situ is characterized by which changes? Cells remain localized in the glandular or squamous cells.
Carcinoma in situ (CIS) refers to preinvasive epithelial malignant tumors of glandular or squamous cell origin. These early stage cancers are localized to the epithelium and have not broken through the local basement membrane or invaded the surrounding tissue. Dysplasia refers to changes in mature cell structure.
What is the lifespan of platelets (in days)? 10
A platelet circulates for approximately 10 days and ages. Macrophages of the mononuclear phagocyte system, mostly in the spleen, remove platelets.
What is the primary cause of respiratory distress syndrome (RDS) of the newborn?
Surfactant deficiency
RDS is primarily caused by surfactant deficiency and secondarily by a deficiency in alveolar surface area for gas exchange. None of the other options are related to the cause of RDS.
What is the lifespan of an erythrocyte (in days)? 100 to 120
Because it cannot undergo mitotic division, the erythrocyte has a limited life span of approximately 120 days.
Low plasma albumin causes edema as a result of a reduction in which pressure? [Show Less]
