NUR 631 PART1 MIDTERM EXAM NEWEST

NUR 631 PART1 MIDTERM EXAM NEWEST

/ ACTUAL EXAM 200 QUESTIONS AND

CORRECT DETAILED ANSWERS (VERIFIED

ANSWERS) |ALREADY GRADED A+

The stage during which the patient functions normally, although the disease processes are well established, is referred to as a. latent.

• subclinical.
• prodromal.
• convalescence.

ANS: B

The stage during which the patient functions normally, although the disease processes are well established, is called the subclinical stage. The interval between exposure of a tissue to an injurious agent and the first appearance of signs and symptoms may be called a latent period or, in the case of infectious diseases, an incubation period. The prodromal period, or prodrome, refers to the appearance of the first signs and symptoms indicating the onset of a disease. Convalescence is the stage of recovery after a disease, injury, or surgical operation.

An increase in extracellular potassium ion from 4.0 to 6.0 mEq/L would a.hyperpolarize the resting membrane potential.

• make it more difficult to reach threshold and produce an action potential.
• hypopolarize the resting membrane potential. d. alter the threshold potential.

ANS: C

An increase in extracellular potassium hypopolarizes the cell (makes it less negative) because more K + ions stay inside the cell owing to the reduced concentration gradient. Hyperpolarization of the resting membrane potential (makes it more negative) is caused by a decrease in extracellular potassium.Hyperpolarization resulting from a decrease in extracellular potassium makes it more difficult to reach threshold and produce an action potential. The threshold for action potential does not change with a change in extracellular potassium.

GTP-binding proteins (G-proteins) function to

• activate receptors on the extracellular surface. b. degrade second-messenger molecules.
• activate intracellular enzyme systems.
• synthesize ATP.

ANS: C

G-proteins activate specific target enzymes within the cell and these enzymes then produce secondmessenger molecules that trigger specific intracellular function. Membrane-bound G-protein channels are a component of the cell membrane; they do not activate other receptors on the 1 / 4

extracellular surface. G-proteins do not degrade second messengers, but instead produce these. G- proteins do not synthesize ATP.

Phospholipids spontaneously form lipid bilayers because they are a.polar.

• charged.
• insoluble.
• amphipathic.

ANS: D

Phospholipids have a hydrophilic (water-loving) polar end and a hydrophobic (water-fearing) polar end.This amphipathic nature causes the lipids to form bilayers. It is the water-loving and water-fearing nature of the end rather than simply being polar, charged, or insoluble that forms the bilayers.

Cell-to-cell communication through secretion of chemical signals into the bloodstream to target cells throughout the body is called signaling.

• synaptic
• paracrine
• endocrine
• autocrine

ANS: C

Endocrine signaling is accomplished by specialized endocrine cells that secrete hormones that travel via the bloodstream to target cells throughout the body. Synaptic signaling occurs at specialized junctions between the nerve cell and its target cell; the neuron secretes a chemical neurotransmitter into a small space between the nerve and target cell. In paracrine signaling, chemicals are secreted into a localized area, and only those cells in the immediate area are affected. Autocrine signaling occurs when cells respond to signaling molecules that they secrete and provides feedback to that cell rather than other cells.

Ribosomes are very important organelles within the cell that have the function of a.detoxifying substances.

• synthesizing proteins.
• converting energy to forms that can be used.
• coding for protein synthesis.

ANS: B

Ribosome's primary function is the synthesis of proteins. Lysosomes and peroxisomes detoxify substances. Mitochondria convert energy to forms that can be used to drive cell reactions. The nucleus contains genomic DNA that codes for protein synthesis.

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The cardiac drug digitalis enhances myocardial contraction because it a.increases intracellular calcium level in cardiac cells.

• inhibits sodium from entering cardiac cells.
• enhances the sodium-potassium pump.
• increases the sodium gradient across the cell membrane

ANS: A

Digitalis inhibits the sodium-potassium pump and allows the accumulation of intracellular sodium, decreasing the sodium gradient across the cell membrane. This leads to less efficient calcium removal by the sodium-dependent calcium pump. Increased calcium inside the cardiac cell leads to more forceful cardiac muscle contraction to treat congestive heart failure caused by cardiac muscle weakness.

The organelle that contains enzymes necessary for oxidative phosphorylation to produce ATP is the a.mitochondria.

• ribosome.
• lysosome.
• nucleus.

ANS: A

The inner membrane of the mitochondria contains many enzymes that promote oxidative phosphorylation which produces ATP. Ribosomes synthesize proteins. Lysosomes and peroxisomes detoxify substances. The nucleus contains genomic DNA that codes for protein synthesis.Ion channels open and close in response to all the following except a.mechanical pressure.

• ligand binding.
• voltage changes.
• temperature changes.

ANS: D

No temperature change channels are present on the cell membrane. Mechanically gated channels respond to mechanical deformation. Ligand-gated channels respond to the binding of a signaling molecule (neurotransmitter or hormone). Voltage-gated channels respond to a change in membrane potential.

Gap junctions are connecting channels that allow passage of small molecules from one cell to the next and are especially important for a. distance signaling.

• tissues requiring synchronized function.
• communication within a cell.
• passage of large molecules.

ANS: B

Gap junctions are especially important in tissues in which synchronized functions are required such as in cardiac muscle contraction. Gap junctions are channels between adjacent cells, not distant cells. Gap 3 / 4

junctions function to promote communication not within a cell, but between adjacent cells. Gap junctions allow passage of small molecules, but not large molecules.

An increase in organ size and function caused by increased workload is termed a.atrophy.

• hypertrophy.
• metaplasia.
• inflammation.

ANS: B

Increased function of an organ such as the heart or skeletal muscle results in organ hypertrophy because of cellular enlargement. Atrophy refers to reduction in size of an organ because of cellular shrinkage.Metaplasia refers to replacement of one differentiated cell type with another. Inflammation results from immune response rather than workload.

Apoptosis is a process that results in cellular a.atrophy.

• death.
• proliferation.
• mutation.

ANS: B

Apoptosis results in death of a cell when it is no longer needed. Atrophy refers to reduction in size of an organ because of cellular shrinkage. Proliferation refers to growth of new cells. Mutation refers to alteration in the genetic structure of cellular DNA.

. Necrotic death of brain tissue usually produces necrosis. a.coagulative

• caseous
• liquefactive
• fat

ANS: C

Liquefactive necrosis is produced when brain tissue dies, as it is rich in enzymes and has little connective tissue. Coagulative necrosis occurs from ischemic injury in any tissue. Caseous necrosis occurs in lung tissue damaged by tuberculosis. Fat necrosis occurs in adipose (fat) tissue.

Indicators that an individual is experiencing high stress include all the following except a.tachycardia.

• diaphoresis.
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