Practice Questions Flashcards
Sodium (Na+), calcium (Ca++), chloride (Cl-), and sodium bicarbonate (HCO3-) are all examples of charged particles that share which of the following common feature?
More abundant in extracellular fluid (ECF)
The single largest component of the animal cell membrane is:
Protein.
Which of the following is a true statement about the function of the cell membrane?
It maintains ICF (intracellular fluid) separate from ECF (extracellular fluid).
Both lysosomes and peroxisomes digest organic molecules. A primary difference between the two is that:
Peroxisomes use molecular oxygen.
Maintaining cell volume and membrane potential are important functions of the:
Cell membrane.
Protein synthesis is a process in which organelles work together to synthesize a mature protein. Which statement best describes the process by which mature functional proteins are produced?
The rough endoplasmic reticulum manufactures proteins and the Golgi apparatus modifies them with enzymes.
The cytoskeleton is composed of actin, filaments, microtubules and intermediate filaments. Which of the following is a true statement about the cytoskeleton?
Maintains organization of organelles.
The osmolality of ECF is:
The same as ICF.
A variety of physiologic mechanisms are employed to transport fluid and solutes across the cell membrane. Which one of them is described by the equation J = [D(A) (Cin – Cout)]/X?
Diffusion.
Fick’s First Law of Diffusion states that flux is decreased when _____ is increased.
Thickness of the membrane
Membrane potential is created by the separation of charges by the cell membrane. The cell membrane gets its charge as a function of the ion:
That is drawn to the inner aspect of the membrane.
The absolute refractory period is the time during which:
No stimulus can cause a second action potential.
The pressure gradient created when there are different concentrations of a solute on either side of a membrane and the solute cannot cross the membrane is a function of:
Osmosis.
Diffusion that utilizes a carrier-mediated process to allow transport of particles that are too large to move by simple diffusion is called:
Facilitated diffusion.
When energy derived from the hydrolysis of ATP molecules is used to transport ions against the concentration gradient, this is called:
Active transport.
The upstroke of the action potential of various cell types is initiated through the:
Opening of sodium channels.
Stages of the action potential include all of the following except:
Reverse stroke.
The wave shape of the action potential can vary for different cell types. The wave shape is primarily determined by the:
Number and type of ion channels utilized.
Cellular injury due to hypoxia can be fully reversed until:
Plasma membrane is damaged.
Hypothermic injury can result in ischemia due to:
Increased blood viscosity.
Ischemia, heart disease, lung disease, and red blood cell (RBC) disorders are all examples of conditions that may result in:
Hypoxic injury.
Manifestations of electromagnetic radiation include all of the following except:
Gas emboli.
The mechanism of cellular injury that occurs as a function of superoxide and hydrogen peroxide generation is:
Free radical damage.
When a cell becomes hypoxic, a series of events occurs that will ultimately result in cell death if not interrupted. The process begins with:
Decreased ATP production.
When a cell is experiencing oxygen deficiency, the pH falls because of:
Anaerobic glycolysis producing lactate.
Which mechanism of cellular injury is characterized by the breakage of chemical bonds that hold deoxyribonucleic acid (DNA) together?
Electrical.
Which of the following can occur due to altered absorption of nutrients?
Pernicious anemia.
A clinical condition that occurs as a result of pathologic lipid metabolism is:
Tay-Sachs disease.
A pyknotic nucleus and karyolysis are typical morphologic characteristics of:
Necrotic presentation.
Malaise, fever, and leukocytosis are all systemic manifestations of:
Localized necrosis.
The difference between dry and wet gangrene is that:
Wet gangrene is typically found on internal organs.
The inflammatory response is characterized by a series of stages. Chemotaxis occurs during the _________ stage.
Emigration
When cells are repeatedly exposed to injury, they can mutate in an effort to replace themselves with a cell type better prepared to resist the injury. This is known as:
Metaplasia.
Which method of cellular adaptation is characterized by accelerated mitotic division?
Hyperplasia.
With respect to the developing red blood cell, the nucleus is ejected when the cell is at which of the following stages of development?
Reticulocyte.
Based upon a knowledge of the physiology of iron deficiency anemia, the clinician knows that when an adult presents with microcytic anemia and no apparent cause of blood loss, evaluation and management should include:
Gastrointestinal endoscopic evaluation.
Division of red blood cells and subsequent development of an adequate red blood cell count relies on the presence of ______________ in the maturation stages.
A nucleus
Hemoglobin synthesis occurs during the reticulocyte stage of red blood cell production. It is a product of the assembly of:
Four protein chains – two alpha and two beta.
In order to absorb vitamin B12, the patient must be able to produce intrinsic factor from a healthy:
Gastric parietal cell.
Mature red blood cell (RBC) development is best described by the following progression:
Bursting form unit, pro-erythroblast, reticulocyte.
The predominant form of healthy hemoglobin in a healthy individual is:
Hemoglobin A1.
When evaluating causes of common anemias, the clinician recognizes that the majority of iron for heme synthesis comes from:
Recycled red blood cells.
Which of the following anemias is characterized by a single amino acid substitution?
Sickle cell anemia.
Adhesion, aggregation, and secretion are all characteristic of:
Platelet functional activity.
Hemostasis and subsequent arrest of bleeding after vessel injury is a two-step process. Intrinsic and extrinsic pathway activation are mechanisms of clotting that share which common feature?
Activation of factor X
In the cell-based model of clotting, thrombin activates all of the following except:
Plasminogen.
The cell-based model of clotting highlights the role of thrombin as _________ activator which results in a positive feedback cycle of clot extension.
Platelet
The cell-based model of clotting is a relatively new theory and offers a different approach to the relationship between primary and secondary clotting. The defining feature of this theory is that it:
Reflects the interrelated role that thrombin plays in both fibrinogen and platelet activation.
The primary function of plasmin is to:
Degrade the clot.
The three phases of the cell-based model of clotting are:
Initiation, amplification, propagation.
Clotting disorders include all of the following except:
Peripheral arterial disease.
The majority of cases of hemophilia are due to a deficiency of:
Factor VIII.
The type of leukocyte responsible for fighting bacterial infections is:
Neutrophils.
The type of leukocyte responsible for responding to allergic events and parasitic infection is:
Eosinophils.
For a patient with thrombocytopenia, the risk of appreciable bleeding is negligible until the platelet count reaches:
<50,000/mm3.
Which of the following is consistent with a “left shift” differential?
Neutrophils at 82%.
Treatment of a patient with excessive bleeding caused by disseminated intravascular coagulation can include the use of:
Heparin.
Rate-setting slow response cardiac tissue will depolarize independent of autonomic influence. However, in the presence of sympathetic stimulation, what is the physiologic process that increases heart rate?
Lower depolarization threshold
Parasympathetic stimulation of rate-setting tissue results in:
K+ channels opening.
The primary difference between fast response and slow response cardiac action potentials is that:
Fast response potentials are approximately 300 msec in duration.
The term “inward rectifier” is another name for:
K+ channels open at rest.
Open ___ channels are responsible for maintaining voltage in resting state.
Potassium (K+)
After an electrical stimulus is generated by the atrioventricular (AV) node, which ion channels open to affect the depolarization stage 0?
Na+
Cardiac contraction occurs when calcium channels open and calcium influx occurs. What is the stimulus that opens calcium channels?
Depolarization from Na+ influx
In contractile cells, what is happening to Na+ channels in phase 3?
h gates recover.
Which ion is not generally regarded to be a factor in fast response action potentials?
Cl-
Which of the following is a unique feature of action potentials in atria?
The plateau phase is not as prominent as fast response cells.
Among the variety of tissue types found in cardiac muscle, which type has the greatest ability to beat autonomously?
Sinoatrial (SA) node tissue
One of the consequences of ischemic myocardium is coronary artery disease (CAD). This can lead to dysrhythmia because it:
Depolarizes myocardium.
The specialized rapid conduction tissue that is important to ventricular muscle contraction is known as:
The His-Purkinje System.
The conduction block phenomenon characterized by slow conduction and unidirectional block is known as:
A re-entry block.
Contraction of cardiac cells occurs as a consequence of filament sliding and binding. Which of the filaments is anchored onto Z bands of the sarcomere?
Actin
Which of the following events occurs first during mechanical contraction of the myocardium?
Calcium is released from sarcoplasmic reticulum.
According to the Frank-Starling Performance Curve, all of the following are indices of cardiac performance except:
Sympathetic nervous system.
The force that the myocardium must develop for the cells of the ventricle to shorten is called:
Afterload.
Which of the following statements is false regarding preload?
An overstretched sarcomere will result in excessive force.
Which of the following events occurs first during mechanical contraction of the myocardium?
Calcium is released from sarcoplasmic reticulum.
According to the Frank-Starling Performance Curve, all of the following are indices of cardiac performance except:
Sympathetic nervous system.
The most inner layer of cells in the artery is called the:
Endothelium.
Macrophages that become engorged with oxidized LDLs are called:
Foam cells.
Atherosclerotic plaque develops when engorged macrophages:
Lodge in the intimal layer of vascular muscle.
The American Heart Association classification of atherosclerotic lesions categorizes an endothelial break as:
Grade IV.
Endothelial dysfunction is a key event in early vascular disease. A primary problem is that dysfunctional endothelial cells cannot:
Produce nitric oxide.
Theories of the etiology of heart disease include all of the following except:
Psychosocial stressors.
Coronary artery disease has been significantly linked to chronic infection caused by:
Chlamydia pneumoniae.
Recommended treatment to reduce elevated homocysteine is:
Folic acid.
Stimulation of the sympathetic nervous system (SNS) results in:
Epinephrine and norepinephrine release.
All of the following characteristics about vasopressin are true except:
Produced in the kidney.
Renin secretion is increased as a function of:
Beta adrenergic stimulation and renal baroreceptors.
Hypertension causes hypertensive heart disease as a consequence of:
Increased afterload.
One of the consequences of hypertension-mediated endothelial damage is:
Stimulation of clotting cascade.
Common forms of target organ damage due to hypertension include all of the following except:
Pulmonary fibrosis.
Congestive heart failure is often precipitated by:
Valvular disease.
The straight and steady flow of blood through a valve is best described as:
Laminar.
Conditions that can trigger hyperactive coagulation include all of the following except:
Use of daily low-dose aspirin.
Which of the following statements regarding venous blood flow is inaccurate?
Arterial blood pressure plays a significant role in driving venous blood flow.
Clinical shock becomes a concern when:
Systolic blood pressure is <90 mm Hg.
Clinical shock that is characterized by high pulmonary arterial pressure (PAP), high pulmonary capillary wedge pressure (PCWP), and low mixed venous saturation (SvO2) is:
Cardiogenic shock.
Which of the following management options is most effective in minimizing edema of the lower extremities resulting from chronic venous insufficiency?
Elevation of the legs
The valve responsible for preventing backflow into the left atrium is the:
Mitral valve.
The most common cause of acute pericarditis is:
Viral infection.
The most outer layer of the heart is the:
Fibrous pericardium.
Transmission of a hormonal signal through the bloodstream to a distant target cell is called a (n) ________ function.
Endocrine
Hormones that are synthesized as prehormones and stored in secretory granules are known as __________ hormones.
Peptide
A second messenger system is the mechanism by which _____ hormones produce their effect.
Peptide and catecholamine
Thyroid hormone is a classic example of a hormone that:
Has a receptor site on or near DNA.
When a hormone receptor is subjected to very high levels of its ligand hormone it is subject to:
Down regulation.
Regardless of atypical sleep patterns or any other artificial manipulation to the day-night cycle, which of the following hormones is consistently secreted at higher levels in the morning and lower levels later in the day?
Cortisol
All of the following are expected actions of the hormone insulin except:
Growth hormone synergy.
Fasting, prolonged exercise, high protein diet, and physiologic stress are also stimuli for:
Gluconeogenesis.
Counterregulatory hormones to insulin include all of the following except:
Dopamine.
The release of insulin is stimulated when the concentration of glucose surrounding the Islets of Langerhans exceeds a concentration of:
80 mg/dL (4.44 mmol/L).
The earliest mechanism in the onset of type 2 diabetes mellitus is typically:
Peripheral tissue receptor insensitivity.
Glucagon-like peptide (GLP-1) is secreted by the:
Small intestine.
The physiologic effects of GLP-1 include:
Beta cell proliferation.
Which enzyme is responsible for GLP-1 catabolism?
Dipeptidyl peptidase-4
The primary role of the thyroid follicular cell is:
Uptake of iodine from plasma.
Which amino acid becomes iodized in the formation of thyroid hormone?
Tyrosine
The majority of thyroid hormone released from the thyroid gland is bound by thyroxine binding _________.
Globulin
Thyroid hormone accelerates the rate of gene transcription and metabolism. Consequently, all of the following are accelerated by thyroid hormone except:
Cholesterol transport.
A central feature of the pathophysiology of Grave’s disease is the presence of:
Thyroid stimulating immunoglobulins (TSI).
Which of the following events occurs first during mechanical contraction of the myocardium?
Calcium is released from sarcoplasmic reticulum.
Atherosclerotic plaque develops when engorged macrophages:
Lodge in the intimal layer of vascular muscle.
Endothelial dysfunction is a key event in early vascular disease. A primary problem is that dysfunctional endothelial cells cannot:
Produce nitric oxide.
Conditions that can trigger hyperactive coagulation include all of the following except:
Use of daily low-dose aspirin.
Which of the following statements regarding venous blood flow is inaccurate?
Arterial blood pressure plays a significant role in driving venous blood flow.
Thyroid hormone is a classic example of a hormone that:
Has a receptor site on or near DNA.
Regardless of atypical sleep patterns or any other artificial manipulation to the day-night cycle, which of the following hormones is consistently secreted at higher levels in the morning and lower levels later in the day?
Cortisol
Coronary artery disease has been significantly linked to chronic infection caused by:
Chlamydia pneumoniae.
Recommended treatment to reduce elevated homocysteine is:
Folic acid.
Thyroid hormone accelerates the rate of gene transcription and metabolism. Consequently, all of the following are accelerated by thyroid hormone except:
Cholesterol transport.
Decreased body weight, increased heart rate, increased red blood cell volume, and widening pulse pressure are all characteristic of symptomatic:
Thyroid hormone excess.
A diagnosis of Conn’s syndrome (primary mineralocorticoid excess) should be suspected in a patient who presents with hypertension along with:
Hypokalemia.
Hashimoto’s thyroiditis is characterized by the presence of:
Anti-thyroid antibodies.
An excess of somatotropin is likely to produce:
Insulin receptor insensitivity.
Which of the following calcium balance hormones promotes osteoblastic activity?
Calcitonin
Two conditions characterized by an extracellular calcium deficiency include:
Rickets and osteomalacia.
Hormones produced by the anterior pituitary include all of the following except:
Dehydroepiandrosterone (DHEA).
A hormone involved in stimulating the Islets of Langerhans as well as increasing osteoblastic activity is:
Growth hormone.
Vitamin D and __________work together to facilitate reabsorption of calcium in the renal tubule.
Parathyroid hormone.
The actions of cortisol include all of the following except:
Increases the inflammatory response.
A diagnosis of Addison’s disease should be suspected in a patient who presents with:
Hyponatremia and hyperkalemia.
