initiate an action potential?

initiate an action 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.