the membrane potential

the 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: