HESI A2 Reading Comprehension V1 2024 Related

Lub-dub! Lub-dub! Lub-dub! This sound is made by the rapid contracting and extending of the chamber doors on the inside of theheart. This ventricular contracting injects roughly 70 mL of blood into a vascular system with a given volume at differing pressure.Blood pressure refers to the pressure in the arterial system; and it is typically taken in the brachial artery of the arm because the pressure at different places along the circulatory route is different. Blood pressure is simply the force that the blood exerts in all directions within any given area and is the basis for the movement of blood from the heart, through the body, and back to the heart. This pressure is commonly expressed as a ratio of the systolic pressure over the diastolic pressure.The systolic pressure or “high peak†pressure takes place within the arterial system as ventricles contract and force blood into the arteries. The diastolic pressure or “low peak†pressure takes place within this arterial system just before the next ventricular contraction.An increase in blood pressure can occur if the arterial walls lose some of their elasticity with age or disease.

What is the meaning of the word 'elasticity' in the last paragraph?

• A. Something that is able to resist and be flexible
• B. Something that is like plastic
• C. Something that is dynamic and electrifying
• D. Something that is silly

Beep!…Beep!…Beep! is the audible rhythmic sound made as the strength of the heart muscle is measured. The signal cadence has a characteristic record that varies in every individual. This record is called an electrocardiogram, or ECG.
In the body, an array of systemic neural responses constantly occur, emitting electric currents. The electric currents can be detected on the surface of the body, and if a person is hooked to an amplifier, these impulses are recorded by an electrocardiograph. Most of the information obtained is about the heart because the heart sends out electric currents in waves. This “wave of excitation†spreads through the heart wall and is accompanied by electric changes.
The wave takes place in three distinct steps. Initially, the “wave of excitation†accompanied by an electric change lasts for approximately 1 to 2 seconds after the contraction of the cardiac muscle. The electric impulses are discharged rhythmically from the sinoatrial (SA) node, the pacemaker of the heart. This spread of excitation over the muscle of the atrium indicates that the atrium has contracted. Next, the peak of the ECG reading is due to the atrioventricular (AV) node, causing the ventricle to become excited. Finally, the ventricles relax, and any changes in the wave indicate to trained medical staff any abnormalities within the heart.

What is the author's primary purpose in writing the essay?

• A. To persuade the reader to have an ECG
• B. To entertain the reader with a heartwarming story
• C. To inform the reader how an electrocardiograph reads the electric currents emitted by the heart
• D. To analyze the difference between the SA node and the AV node

Foodborne illnesses are contracted by eating food or drinking beverages contaminated with bacteria, parasites, or viruses. Harmful chemicals can also cause foodborne illnesses if they have contaminated food during harvesting or processing. Foodborne illnesses can cause symptoms ranging from upset stomach to diarrhea, fever, vomiting, abdominal cramps, and dehydration. Most foodborne infections are undiagnosed and unreported, though the Centers for Disease Control and Prevention estimates that every year about 76 million people in the United States become ill from pathogens in food. About 5,000 of these people die.Harmful bacteria are the most common cause of foodborne illness. Some bacteria may be present at the point of purchase. Raw foods are the most common source of foodborne illnesses because they are not sterile; examples include raw meat and poultry contaminated during slaughter. Seafood may become contaminated during harvest or processing. One in 10,000 eggs may be contaminated with Salmonella inside the shell. Produce, such as spinach, lettuce, tomatoes, sprouts, and melons, can become contaminated with Salmonella, Shigella, or Escherichia coli (E. coli). Contamination can occur during growing, harvesting, processing, storing, shipping, or final preparation. Sources of produce contamination vary, as these foods are grown in soil and can become contaminated during growth, processing, or distribution. Contamination may also occur during food preparation in a restaurant or a home kitchen. The most common form of contamination from handled foods is the calicivirus, also called the Norwalk-like virus.When food is cooked and left out for more than two hours at room temperature, bacteria can multiply quickly. Most bacteria don't produce an odor or change in color or texture, so they can be impossible to detect. Freezing food slows or stops bacteria's growth, but does not destroy the bacteria. The microbes can become reactivated when the food is thawed. Refrigeration also can slow the growth of some bacteria. Thorough cooking is required to destroy the bacteria.

What is the meaning of the word 'sterile' as it is used in the second paragraph?

• A. free of bacteria
• B. healthy
• C. delicious
• D. impotent

The immune system is a network of cells, tissues, and organs that defends the body against attacks by foreign invaders. These invaders are primarily microbes—tiny organisms such as bacteria, parasites, and fungi—that can cause infections. Viruses also cause infections, but are too primitive to be classified as living organisms. The human body provides an ideal environment for many microbes. It is the immune system's job to keep the microbes out or destroy them.The immune system is amazingly complex. It can recognize and remember millions of different enemies, and it can secrete fluids and cells to wipe out nearly all of them. The secret to its success is an elaborate and dynamic communications network. Millions of cells, organized into sets and subsets, gather and transfer information in response to an infection. Once immune cells receive the alarm, they produce powerful chemicals that help to regulate their own growth and behavior, enlist other immune cells, and direct the new recruits to trouble spots.Although scientists have learned much about the immune system, they continue to puzzle over how the body destroys invading microbes, infected cells, and tumors without harming healthy tissues. New technologies for identifying individual immune cells are now allowing scientists to determine quickly which targets are triggering an immune response. Improvements in microscopy are permitting the first-ever observations of living B cells, T cells, and other cells as they interact within lymph nodes and other body tissues.In addition, scientists are rapidly unraveling the genetic blueprints that direct the human immune response, as well as those that dictate the biology of bacteria, viruses, and parasites. The combination of new technology with expanded genetic information will no doubt reveal even more about how the body protects itself from disease.

What is the meaning of the word 'ideal' as it is used in the first paragraph?

• A. thoughtful
• B. confined
• C. hostile
• D. perfect

Beep!…Beep!…Beep! is the audible rhythmic sound made as the strength of the heart muscle is measured. The signal cadence has a characteristic record that varies in every individual. This record is called an electrocardiogram, or ECG.In the body, an array of systemic neural responses constantly occur, emitting electric currents. The electric currents can be detected on the surface of the body, and if a person is hooked to an amplifier, these impulses are recorded by an electrocardiograph. Most of the information obtained is about the heart because the heart sends out electric currents in waves. This “wave of excitation†spreads through the heart wall and is accompanied by electric changes. The wave takes place in three distinct steps.Initially, the “wave of excitation†accompanied by an electric change lasts for approximately 1 to 2 seconds after the contraction of the cardiac muscle. The electric impulses are discharged rhythmically from the sinoatrial (SA) node, the pacemaker of the heart. This spread of excitation over the muscle of the atrium indicates that the atrium has contracted.Next, the peak of the ECG reading is due to the atrioventricular (AV) node, causing the ventricle to become excited.<p>Finally, the ventricles relax, and any changes in the wave indicate to trained medical staff any abnormalities within the heart.

What is the best summary of the passage?

• A. Electric currents within the body are due to electrostatic charges set off by the heart. Medical staff are trained to recognize any abnormalities within the heart.
• B. Every individual has unique electric currents on the surface of the body. The ECG measures and records these electric currents.
• C. The ECG systematically and rather quickly measures the stages at which the 'wave of excitation' occurs within the heart and records them. This wave has three distinct steps that spread from the SA node to the AV node.
• D. The ECG measures the electric currents within the body. These currents are detected on the surface of the body when the body is connected to an amplifier.