membrane potential

What causes the rapid change in the resting membrane potential to initiate an action potential?
Question 1 options:
Potassium gates open and potassium rushes into the cell, changing the membrane potential from negative to positive
Sodium gates open and sodium rushes into the cell, changing the membrane potential from negative to positive.
Sodium gates close, allowing potassium into the cell to change the membrane potential from positive to negative.
Potassium gates close, allowing sodium into the cell to change the membrane potential from positive to negative.
Question 2
What is a consequence of leakage of lysosomal enzymes during chemical injury?
Question 2 options:
Enzymatic digestion of the nucleus and nucleolus occurs, halting deoxyribonucleic acid (DNA) synthesis.
Influx of potassium ions into the mitochondria occurs, halting the adenosine triphosphate (ATP) production.
Edema of the Golgi body occurs, preventing the transport of proteins out of the cell.
Shift of calcium out of the plasma membrane occurs, destroying the cytoskeleton.
Question 3
In hypoxic injury, sodium enters the cell and causes swelling because:
Question 3 options:
The cell membrane permeability increases for sodium during periods of hypoxia.
Adenosine triphosphate (ATP) is insufficient to maintain the pump that keeps sodium out of the cell.
The lactic acid produced by the hypoxia binds with sodium in the cell.
Sodium cannot be transported to the cell membrane during hypoxia.
Question 4
What mechanisms occur in the liver cells as a result of lipid accumulation?
Question 4 options:
Obstruction of the common bile duct, preventing the flow of bile from the liver to the gallbladder
Increased synthesis of triglycerides from fatty acids and decreased synthesis of apoproteins
Increased binding of lipids with apoproteins to form lipoproteins
Increased conversion of fatty acids to phospholipids
Question 5
Which solution is best to use when cleaning a wound that is healing by 101. During an Immunoglobulin E (IgE)-mediated hypersensitivity reaction, the degranulation of mast cells is a result of which receptor action?
Question 5 options:
Histamine bound to H2
Chemotactic factor binding to the receptor
Epinephrine bound to mast cells
Acetylcholine bound to mast cells
Question 6
What is the mechanism that results in type II hypersensitivity reactions?
Question 6 options:
Antibodies coat mast cells by binding to receptors that signal its degranulation, followed by a discharge of preformed mediators.
Antibodies bind to soluble antigens that were released into body fluids, and the immune complexes are then deposited in the tissues.
Cytotoxic T (Tc) lymphocytes or lymphokine-producing helper T 1 (Th1) cells directly attack and destroy cellular targets.
Antibodies bind to the antigens on the cell surface.
Question 7
Type III hypersensitivity reactions are a result of which of the following?
Question 7 options:
Antibodies coating mast cells by binding to receptors that signal its degranulation, followed by the discharge of preformed mediators
Antibodies binding to soluble antigens that were released into body fluids and the immune complexes being deposited in the tissues
Cytotoxic T (Tc) cells or lymphokine-producing helper T 1 (Th1) cells directly attacking and destroying cellular targets
Antibodies binding to the antigen on the cell surface
Question 8
Tissue damage caused by the deposition of circulating immune complexes containing an antibody against the host deoxyribonucleic acid (DNA) is the cause of which disease?
Question 8 options:
Hemolytic anemia
Pernicious anemia
Systemic lupus erythematosus
Myasthenia gravis
Question 9
Why does tissue damage occur in acute rejection after organ transplantation?
Question 9 options:
Th1 cells release cytokines that activate infiltrating macrophages, and cytotoxic T (Tc) cells directly attack the endothelial cells of the transplanted tissue.
Circulating immune complexes are deposited in the endothelial cells of transplanted tissue, where the complement cascade lyses tissue.
Receptors on natural killer (NK) cells recognize antigens on the cell surface of the transplanted tissue, which releases lysosomal enzymes that destroy tissue.
Antibodies coat the surface of the transplanted tissue to which mast cells bind and liberate preformed chemical mediators that destroy tissue.
Question 10
Oncogenes are genes that are capable of:
Question 10 options:
Undergoing mutation that directs the synthesis of proteins to accelerate the rate of tissue proliferation
Directing synthesis of proteins to regulate growth and to provide necessary replacement of tissue
Encoding proteins that negatively regulate the synthesis of proteins to slow or halt the replacement of tissue
Undergoing mutation that directs malignant tissue toward blood vessels and lymph nodes for metastasis
Question 11
After the baroreceptor reflex is stimulated, the resulting impulse is transmitted from the carotid artery by which sequence of events?
Question 11 options:
From the vagus nerve to the medulla to increase parasympathetic activity and to decrease sympathetic activity
From the glossopharyngeal cranial nerve through the vagus nerve to the medulla to increase sympathetic activity and to decrease parasympathetic activity
From the glossopharyngeal cranial nerve through the vagus nerve to the medulla to increase parasympathetic activity and to decrease sympathetic activity
From the glossopharyngeal cranial nerve through the vagus nerve to the hypothalamus to increase parasympathetic activity and to decrease sympathetic activity
Question 12
Regarding the endothelium, what is the difference between healthy vessel walls and those that promote clot formation?
Question 12 options:
Inflammation and roughening of the endothelium of the artery
Hypertrophy and vasoconstriction of the endothelium of the artery
Excessive clot formation and lipid accumulation in the endothelium of the artery
Evidence of age-related changes that weaken the endothelium of the artery
Question 13
What is the expected electrocardiogram (ECG) pattern when a thrombus in a coronary artery permanently lodges in the vessel and the infarction extends through the myocardium from the endocardium to the epicardium?
Question 13 options:
Prolonged QT interval
ST elevation myocardial infarction (STEMI)
ST depression myocardial infarction (STDMI)
Non-ST elevation myocardial infarction (non-STEMI)
Question 14
A patient reports sudden onset of severe chest pain that radiates to the back and worsens with respiratory movement and when the patient is lying down. These clinical manifestations describe:
Question 14 options:
Myocardial infarction (MI)
Pericardial effusion
Restrictive pericarditis
Acute pericarditis
Question 15
Respirations that are characterized by alternating periods of deep and shallow breathing are a result of which respiratory mechanism?
Question 15 options:
Decreased blood flow to the medulla oblongata
Increased partial pressure of arterial carbon dioxide (PaCO2), decreased acid-base balance (pH), and decreased partial pressure of arterial oxygen (PaO2)
Stimulation of stretch or J-receptors
Fatigue of the intercostal muscles and diaphragm
Question 16
Which cytokines activated in childhood asthma produce an allergic response?
Question 16 options:
IL-1, IL-2, and interferon-alpha (IFN-α)
L-8, IL-12, and tumor necrosis factor–alpha (TNF-α)
IL-4, IL-10, and colony-stimulating factor (CSF)
IL-4, IL-5, and IL-13
Question 17
Which statement accurately describes childhood asthma?
Question 17 options:
An obstructive airway disease characterized by reversible airflow obstruction, bronchial hyperreactivity, and inflammation
A pulmonary disease characterized by severe hypoxemia, decreased pulmonary compliance, and diffuse densities on chest X-ray imaging
A pulmonary disorder involving an abnormal expression of a protein, producing viscous mucus that lines the airways, the pancreas, the sweat ducts, and the vas deferens
An obstructive airway disease characterized by atelectasis and increased pulmonary resistance as a result of a surfactant deficiency
Improvement on a trial of asthma medication
Question 18
Which statement best describes cystic fibrosis?
Question 18 options:
Obstructive airway disease characterized by reversible airflow obstruction, bronchial hyperreactivity, and inflammation
Respiratory disease characterized by severe hypoxemia, decreased pulmonary compliance, and diffuse densities on chest X-ray imaging
A pulmonary disorder involving an abnormal expression of a protein, producing viscous mucus that obstructs the airways, the pancreas, the sweat ducts, and the vas deferens
A pulmonary disorder characterized by atelectasis and increased pulmonary resistance as a result of a surfactant deficiency
Question 19
What are the abnormalities in cytokines found in children with cystic fibrosis?
Question 19 options:
A deficit of IL-1 and an excess of IL-4, IL-12, and interferon-alpha (IFN-α)
A deficit of IL-6 and an excess of IL-2, IL-8, and granulocyte colony-stimulating factor (G-CSF)
A deficit of IL-10 and an excess of IL-1, IL-8, and TNF-α
A deficit of IL-3 and an excess of IL-14, IL-24, and colony-stimulating factor (CSF)
Question 20
Examination of the throat in a child demonstrating signs and symptoms of acute epiglottitis may contribute to which life-threatening complication?
Question 20 options:
Retropharyngeal abscess
Laryngospasms
Rupturing of the tonsils
Gagging induced aspiration
Question 21
Free radicals play a major role in the initiation and progression of which diseases?
Question 21 options:
Cardiovascular diseases, such as hypertension and ischemic heart disease
Renal diseases, such as acute tubular necrosis and glomerulonephritis
Gastrointestinal diseases, such as peptic ulcer disease and Crohn disease
Muscular diseases, such as muscular dystrophy and fibromyalgia
Question 22
What is a consequence of plasma membrane damage to the mitochondria?
Question 22 options:
Enzymatic digestion halts deoxyribonucleic acid (DNA) synthesis.
Influx of calcium ions halts adenosine triphosphate (ATP) production.
Edema from an influx in sodium causes a reduction in ATP production.
Potassium shifts out of the mitochondria, which destroys the infrastructure.
Question 23
In addition to osmosis, what force is involved in the movement of water between the plasma and interstitial fluid spaces?
Question 23 options:
Oncotic pressure
Buffering
Net filtration
Hydrostatic pressure
Question 24
Venous obstruction is a cause of edema because of an increase in which pressure?
Question 24 options:
Capillary hydrostatic
Interstitial hydrostatic
Capillary oncotic
Interstitial oncotic
Question 25
At the arterial end of capillaries, fluid moves from the intravascular space into the interstitial space because:
Question 25 options:
The interstitial hydrostatic pressure is higher than the capillary hydrostatic pressure.
The capillary hydrostatic pressure is higher than the capillary oncotic pressure.
The interstitial oncotic pressure is higher than the interstitial hydrostatic pressure.
The capillary oncotic pressure is lower than the interstitial hydrostatic pressure.
Question 26
Secretion of antidiuretic hormone (ADH) and the perception of thirst are stimulated by:
Question 26 options:
A decrease in serum sodium
An increase in plasma osmolality
An increase in the glomerular filtration rate
A decrease in osmoreceptor stimulation
Question 27
Some older adults have impaired inflammation and wound healing because of which problem?
Question 27 options:
The circulatory system cannot adequately perfuse tissues.
Complement and chemotaxis are deficient.
Underlying chronic illnesses exist.
The number of mast cells is insufficient.
Question 28
Lead poisoning affects the nervous system by:
Question 28 options:
Interfering with the function of neurotransmitters
Inhibiting the production of myelin around the nerves
Increasing the resting membrane potential
Altering the transport of potassium into the nerves
Question 29
Carbon monoxide causes tissue damage by:
Question 29 options:
Competing with carbon dioxide so that it cannot be excreted
Binding to hemoglobin so that it cannot carry oxygen
Destroying the chemical bonds of hemoglobin so it cannot carry oxygen
Removing iron from hemoglobin so it cannot carry oxygen
Question 30
Which statement is true regarding the difference between subdural hematoma and epidural hematoma?
Question 30 options:
No difference exists, and these terms may be correctly used interchangeably.
A subdural hematoma occurs above the dura, whereas an epidural hematoma occurs under the dura.
A subdural hematoma is often the result of shaken baby syndrome, whereas an epidural hematoma rapidly forms as a result of a skull fracture.
A subdural hematoma usually forms from bleeding within the skull, such as an aneurysm eruption, whereas an epidural hematoma occurs from trauma outside the skull, such as a blunt force trauma.
Question 31
What physiologic change occurs during heat exhaustion?
Question 31 options:
Hemoconcentration occurs because of the loss of salt and water.
Cramping of voluntary muscles occurs as a result of salt loss.
Thermoregulation fails because of high core temperatures.
Subcutaneous layers are damaged because of high core temperatures.
Question 32
Hemoprotein accumulations are a result of the excessive storage of:
Question 32 options:
Iron, which is transferred from the cells to the bloodstream
Hemoglobin, which is transferred from the bloodstream to the cells
Albumin, which is transferred from the cells to the bloodstream
Amino acids, which are transferred from the cells to the bloodstream
Question 33
Hemosiderosis results in what substance being stored in excess as hemosiderin in cells of many organs and tissues?
Question 33 options:
Hemoglobin
Ferritin
Iron
Transferrin
Question 34
What two types of hearing loss are associated with noise?
Question 34 options:
Acoustic trauma and noise induced
High frequency and low frequency
High frequency and acoustic trauma
Noise induced and low frequency
Question 35
What type of necrosis results from ischemia of neurons and glial cells?
Question 35 options:
Coagulative
Liquefactive
Caseous
Gangrene
Question 36
During cell injury caused by hypoxia, sodium and water move into the cell because:
Question 36 options:
Potassium moves out of the cell, and potassium and sodium are inversely related.
The pump that transports sodium out of the cell cannot function because of a decrease in adenosine triphosphate (ATP) levels.
The osmotic pressure is increased, which pulls additional sodium across the cell membrane.
Oxygen is not available to bind with sodium to maintain it outside of the cell.
Question 37
In decompression sickness, emboli are formed by bubbles of:
Question 37 options:
Oxygen
Nitrogen
Carbon monoxide
Hydrogen
Question 38
What is an example of compensatory hyperplasia?
Question 38 options:
Hepatic cells increase cell division after part of the liver is excised.
Skeletal muscle cells atrophy as a result of paralysis.
The heart muscle enlarges as a result of hypertension.
The size of the uterus increases during pregnancy.
Question 39
Current research has determined that chemical-induced cellular injury:
Question 39 options:
Affects the permeability of the plasma membrane
Is often the result of the damage caused by reactive free radicals
Is rarely influenced by lipid peroxidation
Seldom involves the cell’s organelles
Question 40
What is the inflammatory effect of nitric oxide?
Question 40 options:
It increases capillary permeability and causes pain.
It increases neutrophil chemotaxis and platelet aggregation.
It causes smooth muscle contraction and fever.
It decreases mast cell function and decreases platelet aggregation.