CHAPTER 8 - Pathophysiology

If the baroreceptors in the aortic root sense a drop in aortic root systolic​ pressure, they will send an impulse to what region of the​ brain, and for what​ purpose? A. ​Medulla; to stimulate the sympathetic nervous system B. ​Cerebellum; to stimulate the parasympathetic nervous system C. ​Cerebrum; to stimulate the vasomotor center D. ​Hypothalamus; to stimulate the hormonal release of the adrenocorticotropic hormone​ (ACTH)

A A decrease in blood pressure prompts the baroreceptors to signal the brainstem to alter heart function and vessel size to increase the blood pressure. The cardioexcitatory and vasomotor centers send out sympathetic nervous system impulses to increase the heart rate and myocardial contractility and to constrict the vessels. Although ACTH may be released in a shock​ state, it is not from the brainstem stimulating the sympathetic nervous system.

What type of metabolism is responsible for the largest creation of​ ATP? A. Aerobic B. Anaerobic C. Mitochondrial D. Differential

A Aerobic metabolism is the breakdown of​ molecules, such as​ glucose, through a series of reactions that produce energy within the cells in the presence of oxygen​ (the term​ "aerobic" means​ "with oxygen"). The end process of this is the creation of​ ATP, which is the energy used by the cells. Anaerobic metabolism is the creation of ATP​ (albeit a small​ amount) without the availability of oxygen. Mitochondrial simply refers to the mitochondria of the cells and is not a type of metabolism. Differential is a fictitious name for cellular metabolism.

Peripheral chemoreceptors are MOST sensitive to changes in A. O2. B. pH. C. H2CO3. D. CO2.

A An increase in arterial CO2 increases the number of hydrogen ions in the cerebrospinal fluid​ (CSF), stimulating an increase in the rate and depth of respiration to blow off more CO2.

Which one of the following is MOST likely to lead to anaerobic​ metabolism? A. Hypoventilation B. Oxygen​ rich-atmosphere C. Increased blood volume D. Normotension

A Anaerobic metabolism is the breakdown of molecules in the cells without the presence of oxygen.​ (The term anaerobic means​ "without oxygen.") Hypoventilation leads to a lack of​ oxygen, which may lead to anaerobic metabolism.

What sensory structures are the FIRST to detect arterial blood pressure​ changes? A. Baroreceptors B. Barometers C. Chemoreceptors D. pH monitors

A Baroreceptors are​ stretch-sensitive receptors that are located in the aortic arch and carotid sinuses. Baroreceptors detect changes in blood pressure. As the pressure inside the vessels​ changes, it decreases or increases the stretch of the fibers of the baroreceptors. The​ baroreceptors, having thus detected the change in blood​ pressure, send impulses to the cardioregulatory and vasomotor centers in the brainstem to make compensatory alterations in the blood pressure. Barometers are associated with the​ weather, and pH monitoring is a function of the central chemoreceptors.

You are caring for a patient who was involved in a farming accident where he was exposed to insecticides used on vegetation. You contact the Poison Control​ Center, which advises you that the chemical will have significant parasympathetic effects on the body. What would you expect this to mean to the​ patient's body? A. The patient may experience significant hypotension. B. The patient may experience heightened sensitivity. C. The patient may experience significant hypertension. D. The patient may experience excessive hyperglycemia.

A Because the toxin is a parasympathetic​ stimulator, the patient will experience significant bradycardia and vasodilation. These will result in a drop in blood pressure. Remember also that the parasympathetic nervous system would cause the arterioles to dilate and the precapillary sphincters to open. Stimulation of the parasympathetic system does not result in heightened​ sensitivity, nor does it promote hyperglycemia. Hypertension would be from sympathetic​ tone, not parasympathetic.

The EMT should know that the role of oxygen in the body​ is: A. required for normal cell metabolism. B. carried in the blood as a dissolved ion. C. an end product of normal cell metabolism. D. an end product of abnormal cell metabolism.

A Cellular​ metabolism, also known as cellular​ respiration, is the process in​ which, normally, the cells break down molecules of glucose to produce energy for the body. There are two types of cellular​ metabolism: aerobic and anaerobic. Which of these two types of cellular metabolism occurs is based on whether there is an effective and continuous delivery of oxygen and energy​ sources, or fuel. Glucose is the primary​ fuel, and oxygen is the primary catalyst for metabolism within the cell. In​ fact, oxygen is required by every cell of the body in order for normal cellular metabolism to occur. Oxygen is not an end product of either normal or abnormal metabolism​ (acid is,​ actually), and oxygen is not an ion found dissolved in the​ blood, as oxygen is a​ gas, not an electrolyte.

A patient has sustained significant blood loss due to an injury. Why does this lead to​ shock? A. Loss of blood causes diminished cellular perfusion. B. The loss of clotting factors causes all the​ body's cells to bleed. C. Because the blood he loses has the​ cell's sugar supply. D. The cells leak out fluid to surrounding tissue.

A Consider a patient you encounter who has cut his radial artery on a saw and suffered severe blood loss. The patient has no chest or lung injury and has an increased rate and depth of ventilation. His minute ventilation and alveolar ventilation are​ increased; however, his cells are becoming hypoxic. Although he is moving more oxygenated air into the​ alveoli, his blood loss has significantly reduced the amount of blood flow through the pulmonary capillaries. This represents a perfusion disturbance because there is not enough blood to pick up the oxygen available in the alveoli.

A​ 25-year-old male has a stab wound on his left upper chest. What will occur if this wound breaks the continuity of the parietal​ pleura? A. Air will draw into the pleural space. B. The thorax will decrease in size. C. The left lung may overinflate. D. The pleural pressure becomes increasingly positive.

A If a break occurs in the continuity of either the parietal pleura from an open wound to the thorax or to the visceral pleura from an injury to the lung​ tissue, the negative pressure will draw air into the pleural space.

Why is it advisable to assist a patient with using his bronchodilator when he has obvious signs and symptoms of lower airway obstruction due to​ asthma? A. The drug in a bronchodilator will make it easier to breathe by reducing airway resistance. B. The medication will increase heart rate and blood flow. C. The medication will slow the heart rate and improve circulation. D. The medication will help to decrease the dead space in the airway.

A In​ asthma, irritation inflames the mucous lining of the bronchioles and causes the smooth muscle to contract and reduce the diameter of the​ bronchioles, which is referred to as bronchoconstriction. The resulting increase in airway resistance can significantly reduce airflow into the alveolar​ sacs, which diminishes oxygenation of the​ blood, leading to hypoxia. It also increases the retention of carbon​ dioxide, leading to​ hypercarbia, as the airflow becomes turbulent from passing through the constricted and inflamed bronchioles.

An EMT student who is completing his​ ride-along time is at the station working on his class workbook. He has a definition of a​ term, but he cannot remember the name of the​ term, so he asks you what is defined as the amount of air that moves into and out of the airways in a minute. You​ respond: A. minute volume. B. tidal volume. C. residual volume. D. expiration reserve volume.

A Minute​ ventilation, also known as minute​ volume, is the amount of air that is moved in and out of the lungs in one minute. It is determined by multiplying the tidal volume by the frequency of ventilation in one minute. Expiratory reserve volume is the amount of air that is left in the respiratory tree after a normal​ exhalation, dead space ventilation is the air that does not participate in gas exchange because it is still in the conducting​ airways, and residual volume is the amount of air that is left in the lungs after a forceful and maximal exhalation.

If a patient is in​ shock, why does his pulse​ increase? A. Because of sympathetic nervous system stimulation B. Because the heart is stunned C. Because the afterload has been reduced D. Because the body produces caffeine

A Neural factors are associated with the influence of the sympathetic and parasympathetic nervous systems on the heart and the blood vessels. Sympathetic nervous stimulation would cause the arterioles to constrict and precapillary sphincters to close and would cause the heart rate and cardiac output to increase. This should help to return the blood pressure to normal. The increase in the heart rate is not due to caffeine​ production, as this does not occur. A drop in afterload would cause the blood pressure to drop even further.

What value does the intrathoracic pressure drop to during​ inhalation? A. 758 mmHg B. 760 mmHg C. 752 mmHg D. 763 mmHg

A Normal atmospheric pressure is 760 mmHg at sea level. With the expansion of the thorax immediately before​ inhalation, the pressure inside the chest drops to 758 mmHg. In accordance with​ Boyle's law, this negative pressure causes the volume of air inside the chest to increase.

What are the two basic molecules that are necessary for normal cell​ metabolism, energy​ creation, and​ function? A. Oxygen and glucose B. Glucose and carbon dioxide C. Glucose and hydrogen D. Oxygen and carbon dioxide

A One of the most fundamental purposes of emergency care is maintaining adequate perfusion of the body cells to ensure continuous delivery of oxygen and glucose and removal of waste​ by-products. These basic​ molecules, oxygen and​ glucose, are necessary for normal cell metabolism and function. Many illnesses and injuries can disturb the delivery of oxygen and glucose and removal of waste​ by-products. Understanding these disturbances will allow the EMT to better recognize and understand why certain signs and symptoms occur and to comprehend the emergency care that you will need to provide to the patient.

The process whereby blood travels to the cells of the body to deliver oxygen and nutrients is referred to​ as: A. perfusion. B. hypoperfusion. C. aerobic metabolism. D. anaerobic metabolism.

A One of the most fundamental purposes of emergency care is maintaining adequate perfusion. Perfusion is the delivery of oxygen and glucose to all the cells of the body and the removal of waste​ by-products. Hypoperfusion is the inability of the body to deliver nutrients and remove wastes. Aerobic metabolism is the conversion of glucose to ATP in the presence of​ oxygen, and anaerobic metabolism is the creation of ATP in the absence of oxygen.

What causes the pressure change known as plasma oncotic​ pressure? A. Effect of the large proteins in the bloodstream B. Contraction or relaxation of capillary beds C. The difference between the arterial and venous concentration of electrolytes D. Contraction of the left ventricle

A Plasma oncotic​ pressure, also known as colloid oncotic pressure or oncotic​ pressure, is responsible for keeping fluid inside the vessels. A force is generated inside vessels by large plasma​ proteins, especially​ albumin, that attracts water and other fluids. Opposite in action to hydrostatic​ pressure, oncotic pressure exerts a pull inside the vessel. Contraction of the left ventricle produces the hydrostatic pressure of the body. Capillary bed relaxation or contraction does not affect oncotic pressure. Electrolyte differences can produce fluid​ movement, but it is not part of oncotic pressure from plasma proteins.

Pressure and volume of blood in the left ventricle at the end of diastole is​ called: A. preload. B. cardiac output. C. systolic blood pressure. D. afterload.

A Preload is the pressure generated in the left ventricle at the end of diastole​ (the resting phase of the cardiac​ cycle). Preload pressure is created by the blood volume in the left ventricle at the end of diastole. The available venous​ volume, which determines the volume of blood in the​ ventricle, consequently plays a major role in determining preload. Afterload pertains to the resistance the left ventricle has to overcome to open the aortic valve. Systolic blood pressure is determined by multiplying the cardiac output by the systemic vascular resistance.

Which of the following cellular effects will NOT likely happen to a patient who is breathing in toxic​ gases? A. Oxygen will take on a toxic effect in the body and cause cellular death. B. Oxygen molecules may be displaced and the cells can suffocate. C. The cells may be unable to use the oxygen present. D. The cells may be unable to adequately pick up and carry oxygen to the tissues.

A Some toxic gases displace the amount of oxygen in the air and basically suffocate the patient. Other​ gases, such as carbon​ monoxide, disrupt the ability of the blood to carry adequate amounts of oxygen to the cells. In either​ condition, the cells end up hypoxic. Some toxic gases may not severely reduce the concentration of oxygen in the air or disrupt the ability of the blood to carry oxygen but may interfere with its use by the cell. One example is cyanide poisoning.

Red blood cells comprise about what percentage of blood volume in​ men? A. 48 percent B. 25 percent C. 42 percent D. 90 percent

A The formed elements in the blood are red blood​ cells, white blood​ cells, and platelets. Red blood cells​ (erythrocytes) make up approximately 48 percent of the blood cell volume in men and 42 percent in women.

The EMT should recall that if the patient has a mismatch between the ventilation and perfusion of the​ lungs, what negative outcome could​ happen? A. Hypoxia can occur at the cellular level. B. The patient exhales too much carbon dioxide. C. There is too much blood in the cells. D. There is too much glucose circulating in the bloodstream.

A The​ ventilation/perfusion (V/Q) ratio describes the dynamic relationship between the amount of ventilation the alveoli receive and the amount of perfusion through the capillaries surrounding the alveoli. This relationship determines the quality of gas exchange across the​ alveolar/capillary membrane, which influences the amount of oxygen entering the blood and the amount of carbon dioxide exiting the blood. The dynamic relationship between ventilation and perfusion in the lungs can be used to explain the etiology​ (causes) of​ hypoxemia, or inadequate oxygen concentrations in the blood. Too much blood in the cells is a fictitious outcome and is​ incorrect, glucose levels are maintained by the​ pancreas, and exhaling too much carbon dioxide is typically not a problem for the body.

Why would understanding how the body responds in a disease state be beneficial to the​ EMT? A. It will help the EMT to better recognize and understand presenting signs and symptoms. B. It allows the EMT to better discuss treatment options with the patient. C. It is not beneficial because the EMT does not make diagnoses. D. It will let the EMT know what treatment protocol to follow.

A Understanding these disturbances will enable you to better recognize and explain why certain signs and symptoms occur and to comprehend the emergency care you will need to provide to the patient.

When the diaphragm​ contracts, the​ patient: A. inhales. B. exhales. C. is able to speak. D. coughs.

A Ventilation conforms to​ Boyle's law, which states that the volume of gas is inversely proportional to the pressure. By contracting the diaphragm and the external intercostal​ muscles, the diaphragm moves slightly downward while the ribs are lifted upward and outward. This causes the thorax to increase in​ size, creating a negative pressure. This allows the drawing of a breath into the lungs.​ Speaking, exhaling, and coughing all deal with the intrathoracic pressure increasing as a result of the diaphragm returning to its normal position and the thoracic wall returning to its normal position.

What role do chemoreceptors in the body play in the regulation of blood​ pressure? A. They can stimulate the sympathetic nervous system if carbon dioxide levels rise. B. They do nothing for blood pressure. C. They monitor pulse pressure and become active if the systolic drops. D. They monitor blood pressure along with the baroreceptors.

A When the oxygen content in the arterial blood​ falls, carbon dioxide levels​ increase, or pH levels decrease​ (more acid in the​ blood), and the brainstem triggers the sympathetic nervous system through the cardioexcitatory center and vasomotor centers to increase the blood pressure by increasing the heart​ rate, myocardial​ contractility, and vasoconstriction. The increase in blood pressure is intended to improve the delivery of oxygen to the brain cells and to remove more carbon dioxide.

When​ activated, J-receptors​ stimulate: A. ​rapid, shallow ventilation. B. ​slow, deep ventilation. C. ​slow, shallow ventilation. D. ​rapid, deep ventilation.

A ​J-receptors are found in the capillaries surrounding the alveoli and are sensitive to increases in pressure in the capillary. When​ activated, the​ J-receptors stimulate​ rapid, shallow ventilation.

The basic primary fuel for the cell​ is: A. glucagon. B. glucose. C. oxygen. D. carbon dioxide.

B Glucose is the primary​ fuel, and oxygen is the primary catalyst for metabolism within the cell.

A​ 48-year-old man cut his leg with a chainsaw. You observe a significant amount of blood loss. He is breathing deep at a rate of 22. Which one of the following would MOST likely cause​ hypoxia? A. Increased respiratory rate B. Blood loss C. Airway obstruction D. Vasodilation

B A perfusion disturbance can also lead to severe cellular hypoxia. Consider a patient you encounter who has cut his radial artery on a saw and suffered severe blood loss. The patient has no chest or lung injury and has an increased rate and depth of ventilation. His minute ventilation and alveolar ventilation are​ increased; however, his cells are becoming hypoxic. Although he is moving more oxygenated air into the​ alveoli, his blood loss has significantly reduced the amount of blood flow through the pulmonary capillaries.

According to the​ V/Q ratio, why might a patient with a partial airway occlusion from a severe allergic reaction suffer from​ hypoxia? A. The patient is having wasted oxygen inhalation. B. The patient is having wasted alveolar perfusion. C. The patient is experiencing too much carbon dioxide ventilation out of the alveoli. D. The patient is having wasted alveolar ventilation.

B A ventilation disturbance has been created by making less oxygen available to the blood passing through the capillaries. In this​ condition, there is wasted perfusion because the blood is available but there is an inadequate amount of oxygen to be picked up. This disturbance in ventilation leads to hypoxemia and cellular hypoxia.

During​ exhalation, what is the approximate pressure in the​ thorax? A. 763 mmHg B. 761 mmHg C. 760 mmHg D. 758 mmHg

B After​ inhalation, the diaphragm and external intercostal muscles​ relax, allowing the chest wall to move inward and downward​ and, assisted by the inward pull of the elastic lung​ tissue, decrease the size of the thoracic cavity. As the size of the thorax​ decreases, the pressure inside increases to about 761 mmHg. As this is higher than the atmospheric pressure of 760​ mmHg, air is forced out of the lungs. 763 is too high of a pressure value generated during​ exhalation, and a thoracic pressure of 758 mmHg would cause air to flow into the lungs.

Which gas is most abundant in ambient​ air? A. Oxygen B. Nitrogen C. Carbon dioxide D. Argon

B Ambient air is normal air that is breathed in by a person. It is comprised of​ 78% nitrogen,​ 21% oxygen,​ 0.9% argon, and​ 0.03% carbon dioxide.

If there is an increased stretch to the baroreceptors above​ normal, what will be the​ response? A. A message will be sent to the brainstem to increase the heart rate. B. A message will be sent to the brainstem to increase parasympathetic tone. C. The baroreceptors will slow the heart rate by direct nervous control and the release of hormones. D. A message will be sent to the kidneys to reabsorb more fluid.

B An increase in blood pressure prompts the baroreceptors to signal the brainstem to alter heart function and vessel size to decrease the blood pressure. The cardioinhibitory center responds by sending parasympathetic impulses that cause the heart to decrease heart rate and myocardial contractility. A decrease in stroke volume and heart rate decreases cardiac output.​ Additionally, the vasomotor center responds by sending parasympathetic impulses to dilate the blood vessels. Vasodilation increases the vessel diameter and decreases the systemic vascular​ resistance, which decreases the blood pressure.

If the heart rate increases​ slightly, how will this affect the cardiac​ output? A. It will not affect the cardiac output. B. It will enhance cardiac output. C. It will diminish cardiac output. D. It will decrease pulmonary perfusion.

B Because cardiac output is determined by the stroke volume and heart​ rate, if the heart rate​ increases, then so should the cardiac output. Although a faster heart rate increases cardiac​ output, if the rate is extremely​ fast, the cardiac output may actually decrease. With excessively fast heart​ rates, usually​ >160 bpm in the adult​ patient, the time between beats is so short that there is not an adequate amount of time for the ventricles to fill. This reduces the​ preload, which in turn reduces the cardiac output.

What are the main constitutes of​ plasma? A. Water B. Water and proteins C. Water and intracellular fluids D. Intracellular fluid

B Blood is composed of formed elements and plasma. The formed​ elements, which are cells and​ proteins, make up approximately 45 percent of blood composition. Plasma is the fluid component that accounts for the remaining 55 percent. The primary function of plasma is to suspend and carry the formed elements. Plasma is made up primarily of water and plasma proteins. Water makes up 91 percent of plasma. Intracellular fluid is found in the cells and is not part of the plasma volume.

The majority of carbon dioxide is transported in the body by which​ mechanism? A. Dissolved in plasma B. By the bloodstream as a bicarbonate ion C. Chemically bound by hemoglobin D. Attached to red blood cells

B Carbon dioxide is transported in the blood in three​ ways: approximately 7 percent is dissolved in​ plasma, 23 percent is attached to​ hemoglobin, and 70 percent is in the form of bicarbonate.

If a patient has multiple ribs fractured that alter his ability to increase his intrathoracic​ volume, what kind of ventilatory disturbance would this​ be? A. Change in passivity B. Change in compliance C. Change in opposition D. Change in resistance

B Conditions such as pneumonia and pulmonary​ edema, for​ example, a flail segment where two or more ribs are fractured in more than one place or a neuromuscular​ disease, can affect the ability of the chest muscles to contract.

You are treating a patient who has lost a significant amount of blood volume after a traumatic​ injury, and his systolic pressure is low. What body function will NOT be part of the compensatory mechanism trying to maintain a normal perfusion​ pressure? A. Baroreceptors B. Parasympathetic stimulation C. Heart rate D. Medulla oblongata

B During a hypoperfusion​ state, the baroreceptors will detect the drop in the heart rate and send an impulse to the medulla. The medulla will then stimulate the sympathetic nervous​ system, which in turn will increase​ (among other​ things) the heart rate in order to improve cardiac output and blood pressure.

One of the fundamental underlying causes of respiratory compromise​ is: A. dilated capillaries in the systemic system. B. failure of the​ alveolar/capillary exchange of gases. C. increased conductivity of the heart​ muscle, causing abnormal blood flow through the lungs. D. increased tidal volume that washes out too much carbon dioxide.

B For the cells to receive an adequate amount of oxygen and eliminate carbon​ dioxide, both the​ alveolar/capillary gas exchange and​ cell/capillary gas exchange must function properly. A disturbance in either will result in inadequate amounts of oxygen being delivered to the cells or will result in the accumulation of carbon dioxide.

What is the effect of poor perfusion at the cellular​ level? A. The cells accumulate fats and proteins that take up too much space in the cell. B. The​ sodium/potassium pump fails and causes cellular death. C. The cells produce too much oxygen to survive. D. The cells cannot eliminate sugar.

B If​ ATP-energy production by cells is​ lacking, as found in poor perfusion states and anaerobic​ metabolism, the​ sodium-potassium pump may fail. This would allow sodium to collect on the inside of the cell. As is well​ known, water follows sodium. So as sodium collects inside the​ cell, it attracts water. As the water continues to​ accumulate, the cell swells and eventually ruptures and dies.

If the patient experiences a drop in the respiratory rate due to a drug​ overdose, what will be the effect on the​ patient's minute​ ventilation? A. There will be no change in the minute volume. B. The minute volume will decrease. C. The minute volume will increase. D. The minute volume will initially​ increase, then it will drop.

B Minute​ ventilation, also known as minute​ volume, is the amount of air that is moved in and out of the lungs in one minute. It is determined by multiplying the tidal volume by the frequency of ventilation in one minute. If there is a drop in the frequency of​ ventilation, the minute ventilation will​ decrease, and the patient may start to hyperventilate.

What two divisions of the nervous system help to control blood flow through the​ arterioles? A. Sympathetic and antisympathetic B. Parasympathetic and sympathetic C. Voluntary and cerebellar D. Autonomic and voluntary

B Neural factors are associated with the influence of the sympathetic and parasympathetic nervous systems on the arterioles and precapillary sphincters. Sympathetic nervous stimulation would cause the arterioles to constrict and precapillary sphincters to close. Parasympathetic stimulation would cause the arterioles to dilate and the precapillary sphincters to open. The other choices are fictitious.

In a healthy​ adult, the respiratory rate and depth is regulated primarily by detecting the level of what in the blood​ stream? A. Amounts of red blood cells B. Carbon dioxide levels C. Saturated hemoglobin D. Oxygen levels

B Normally, a​ person's rate and depth of breathing are regulated primarily by the amount of carbon dioxide in the blood. This is referred to as a hypercapnic or hypercarbic drive.

Why should the patient who is in shock be administered​ oxygen? A. The oxygen helps to increase the blood flow through the lungs. B. The patient may be hypoxic at the cellular level. C. The oxygen will help to lower the body temperature. D. The vessels in the brain are dilated.

B Oxygen is the catalyst that is used during normal cellular metabolism as the cells break down molecules of glucose to produce energy for the body. There are two types of cellular​ metabolism: aerobic and anaerobic. Which of these two types of cellular metabolism occurs depends on whether there is an effective and continuous delivery of oxygen and fuel. A patient who is in shock is not getting adequate delivery of oxygen at the cellular​ level, and one way to mediate this is by increasing the concentration of oxygen in the inspired air. This helps to increase the amount of oxygen that is dissolved into the​ bloodstream, transported by red blood​ cells, and delivered to peripheral tissues. Oxygen is not administered on the basis of cerebral blood vessel​ size, and there is no way the EMT would even know the vessel size. Perfusion from the heart is what drives blood through the​ lungs, not oxygen.

The percentage of oxygen that is carried in the body attached to hemoglobin is​ approximately: A. 100 percent. B. 98 percent. C. 95 percent. D. 90 percent.

B Oxygen is transported by the blood in two​ ways: dissolved in plasma and attached to hemoglobin. A small​ amount, only 1.5 to 3​ percent, is dissolved in plasma. The majority of​ oxygen, approximately 97 to 98.5​ percent, is attached to hemoglobin molecules.

Which of the following factors is not considered to be a determinant of stroke​ volume? A. Contractility B. Heart rate C. Preload D. Afterload

B Stroke volume is defined as the volume of blood ejected by the left ventricle with each contraction. Stroke volume is determined by​ preload, myocardial​ contractility, and afterload. The heart rate is a determinant of cardiac output and is affected by both intrinsic and extrinsic influences on the conduction system of the heart.

Because of dilation of the vascular system in neurogenic​ shock, you would expect the blood pressure​ to: A. increase as a result of an increase in the heart rate that occurs. B. decrease. C. increase. D. remain the same.

B Systemic vascular resistance is the resistance that is offered to blood flow through a vessel. As a vessel constricts​ (decreases its​ diameter), resistance inside the vessel​ increases, which typically increases pressure inside the vessel.​ Conversely, as a vessel dilates​ (increases its​ diameter), resistance inside the vessel​ decreases, which typically decreases pressure inside the vessel. Vasoconstriction decreases vessel​ size, increases​ resistance, and increases blood pressure. Vasodilation increases vessel​ diameter, decreases​ resistance, and decreases blood pressure. Since neurogenic shock causes systemic​ vasodilation, the blood pressure will drop. There is usually no increase in the heart rate because the mechanism behind the loss of nervous stimuli to the blood vessels also occurs to the heart in neurogenic​ shock, so it is difficult to get the heart rate to increase.

The MOST abundant formed element of blood​ is: A. plasma. B. red blood cells. C. platelets. D. white blood cells.

B The formed elements in the blood are red blood​ cells, white blood​ cells, and platelets. Red blood cells​ (erythrocytes) make up approximately 48 percent of the blood cell volume in men and 42 percent in women. The red blood​ cells, which contain​ hemoglobin, are primarily responsible for carrying oxygen and delivering it to cells for metabolism. The white blood cells​ (leukocytes) protect the body against infection and eliminate dead and injured cells and other debris. The platelets​ (thrombocytes) are not actual cells but fragments that play a major role in blood clotting and the control of bleeding.

What is the name of the amount of air breathed in and out with each individual​ breath? A. Tidal ventilation B. Tidal volume C. Residual volume D. Minute volume

B The tidal volume​ (VT) is the volume of air that is breathed in with each individual breath. The frequency of ventilation​ (f) is generally calculated as the number of ventilations in one minute. Minute​ ventilation, also known as minute​ volume, is the amount of air that is moved in and out of the lungs in one minute. It is determined by multiplying the tidal volume by the frequency of ventilation in one minute.​ Finally, residual volume is the amount of air that is left in the lungs after a maximal forceful exhalation.

If a patient develops shock due to a severe traumatic injury and loses a large amount of​ blood, each of the following may occur EXCEPT​ the: A. blood vessels will constrict. B. heart rate will initially decrease. C. respirations will increase. D. SVR will increase.

B The​ body's compensation mechanisms are geared toward maintaining pressure inside the vessel and perfusion of the cells. If the patient loses a large amount of blood​ (which causes a drop in blood returning to the​ heart), blood pressure will decrease and the blood vessels will start to constrict​ (elevating SVR); the heart rate and respiratory rate will increase as well. If the heart rate were to decrease​ initially, the blood pressure would drop even lower.

For the appropriate​ V/Q ratio, the patient will need to have each of the​ following, EXCEPT: A. sufficient air in the alveoli. B. decreased fluid volume traveling to the bottom lung fields. C. sufficient blood in the blood vessels. D. normal cardiac output from the heart.

B The​ ventilation/perfusion (V/Q) ratio describes the dynamic relationship between the amount of ventilation the alveoli receive and the amount of perfusion through the capillaries surrounding the alveoli​ (as delivered by a normal cardiac​ output). This relationship determines the quality of gas exchange across the​ alveolar-capillary membrane, which influences the amount of oxygen entering the blood and the amount of carbon dioxide exiting the blood. Part of the​ V/Q ratio is not decreased fluid volume traveling to the bottom of the lung​ fields; in​ actuality, the bottom of the lung fields typically receive more blood flow than the​ top, owing to the effects of gravity on blood distribution.

For the body to remain within normal limits of fluid balance between capillary and interstitial​ compartments: A. oncotic pressure must exceed hydrostatic pressure. B. oncotic pressure must equal hydrostatic pressure. C. hydrostatic pressure must exceed oncotic pressure. D. hydrostatic pressure must exceed renal perfusion pressure.

B This question involves applying the principles of hydrostatic pressure and oncotic pressure. A balance between hydrostatic pressure and plasma oncotic pressure must be maintained for equilibrium of fluid balance. If hydrostatic pressure is​ excessive, tissue edema will be present and vascular volume may diminish. If oncotic pressure is greater than hydrostatic​ pressure, the interstitial spaces may become dehydrated. The relationship between hydrostatic pressure and renal perfusion pressure does not exist.

The distribution of blood flow through the microcirculation is primarily responsive​ to: A. the postcapillary sphincter. B. local tissue needs. C. parasympathetic stimulation. D. sympathetic stimulation.

B Three regulatory influences control blood flow through the​ capillaries: 1 - local​ factors 2 - neural​ factors, and 3 - hormonal factors. Local factors are found in the immediate environment around or within the capillary​ structure, such as​ temperature, hypoxia,​ acidosis, and histamine.​ Microcirculation, comprising the small vessels​ (the arterioles,​ capillaries, and​ venules), is primarily responsive to these local tissue needs. This allows some vessels in the capillary network to adjust their diameter to permit the microcirculation to selectively supply undernourished​ tissue, while temporarily bypassing tissues that have no immediate need. Sympathetic and parasympathetic influence occurs if local factors are​ overwhelmed, and postcapillary sphincters​ (in and of​ themselves) do not control the local perfusion needs.

If the patient has a drop in the preload to the​ heart, what will be the effect in the​ patient's peripheral perfusion​ status? A. Peripheral perfusion will increase whenever stroke volume decreases. B. Peripheral perfusion will likely drop. C. Blood vessels will dilate in order to elevate the systolic pressure. D. Peripheral perfusion will not be altered.

B To have an adequate stroke​ volume, the left ventricle must be able to generate enough force to effectively eject its blood volume. An increase in myocardial contractility will increase the stroke volume and improve cardiac output.​ Conversely, a decrease in myocardial contractility will lead to a decrease in stroke volume and a resulting decrease in cardiac output.

The ability of the body to ventilate is an example of what law of​ physics? A. ​Henry's law B. ​Boyle's law C. ​Charles's law D. ​Dalton's law

B Ventilation is a mechanical process that relies on changes in pressure inside the thorax to move air into and out of the lungs. The alterations in pressure occur as a result of changes to the size of the thorax. Ventilation conforms to​ Boyle's law, which states that the volume of gas is inversely proportional to the pressure.​ Charles's law deals with the effect of temperature on gas​ volume, Henry's law deals with the effect of how a gas dissolves into fluid under​ pressure, and​ Dalton's law deals with how the total pressure value of a gas is a function of the individual pressures of each gas contained in the whole.

From what negative affect regarding gas diffusion in the alveoli would a patient with pulmonary edema​ suffer? A. Too much blood flow causes too much carbon dioxide removal B. Inability to oxygenate the blood and remove carbon dioxide C. Excessive hyperoxia causing free radical damage to healthy tissue D. Respirations starting to slow and become shallow

B When the left ventricle fails to empty​ effectively, blood backs up into the left atrium and pulmonary​ vessels, which increases the pressure within them. The increased hydrostatic pressure inside the pulmonary capillaries forces fluid out of them. The extruded fluid tends to collect in the spaces between the alveoli and capillaries and around the​ alveoli, which reduces the ability of oxygen and carbon dioxide to be exchanged across the​ alveolar/capillary membrane. This disturbance reduces the blood oxygen​ content, leading to cellular​ hypoxia, and it causes the blood to retain carbon dioxide. The fluid eventually begins to collapse and fill the​ alveoli, further diminishing gas exchange. This condition is known as pulmonary edema.

Why would a hypoxic patient who has severe bleeding NOT benefit that greatly from the administration of supplemental​ oxygen? A. He does not have white blood cells to carry the oxygen. B. People who have lost blood have also lost the hemoglobin that carries oxygen. C. People with heavy bleeding also have dysfunctional alveoli. D. Bleeding blocks the ability of tissues to use oxygen.

B Without​ hemoglobin, the negligible amount of oxygen that can be transported by plasma would not be enough to sustain normal cellular function or life. A loss of​ hemoglobin, which commonly occurs as a result of​ bleeding, can easily lead to severe cellular​ hypoxia, even though an adequate amount of oxygen is available in the alveoli.

During anaerobic metabolism in​ cells, what is responsible for creating the acidic state of the​ blood? A. Alcohol fermentation B. Acetaldehyde development C. Lactic acid accumulation D. Pyruvate diminishment

C A shift to anaerobic metabolism occurs when oxygen is not made available to cells during​ metabolism, which results in the production of lactic acid as the primary​ by-product. Acid can have a detrimental effect on cell structure and function.

The lack of oxygen at the cellular level causes the cells​ to: A. shift to aerobic metabolism. B. increase ATP production. C. shift to anaerobic metabolism. D. disperse waste products.

C A shift to anaerobic metabolism occurs when oxygen is not made available to cells during​ metabolism, which results in the production of lactic acid as the primary​ by-product. Acid can have a detrimental effect on cell structure and function.

You are treating a patient with respiratory distress secondary to COPD. The patient has a low pulse ox and presents as hypoxic. What type of cellular metabolism will occur if you cannot correct the​ patient's hypoxia? A. Differential B. Aerobic C. Anaerobic D. Mitochondrial

C A shift to anaerobic metabolism occurs when oxygen is not made available to cells during​ metabolism, which results in the production of lactic acid as the primary​ by-product. Acid can have a detrimental effect on cell structure and function.

The restriction of airflow that is related to the diameter of the airways is called​ the: A. alveolar ventilation. B. pulmonary circulation. C. airway resistance. D. dead air space.

C Airway resistance is related to the ease of airflow down the conduit of airway structures leading to the alveoli. A higher airway resistance from​ bronchoconstriction, for​ example, will make it more difficult to move air through the conducting airways. Higher airway resistance requires the patient to work harder to​ breathe, expending more energy and possibly using accessory​ muscles, which may accelerate respiratory muscle fatigue and failure.

The area in the respiratory passages that CANNOT participate in gas exchange is​ called: A. nonperfused space. B. unperfused space. C. dead space. D. alveolar space.

C Alveolar ventilation is related to the concept of anatomical dead air space. Dead space air​ (VD) consists of anatomical areas in the respiratory tract where air collects during inhalation but no gas exchange occurs.​ Thus, the air that moves into and out of these areas is not involved in gas exchange and is wasted. In the​ average-sized adult, approximately 150 mL of the tidal volume is lost in the dead air space. Unperfused and nonperfused space are both fictitious terms. Alveolar space is the actual site where gas exchange does take place.

Oxygen is transported through the blood by binding​ to: A. white blood cells. B. alveoli. C. hemoglobin. D. potassium sites.

C Approximately​ 1,000 mL of oxygen is delivered to the cells every minute. Oxygen is transported by the blood in two​ ways: dissolved in plasma and attached to hemoglobin. A small​ amount, only 1.5 to 3​ percent, is dissolved in plasma. The majority of​ oxygen, approximately 97 to 98.5​ percent, is attached to hemoglobin molecules.

What would be the expected result of the body when a patient has massive vasodilation secondary to a severe blood​ infection? A. The heart rate will slow down and the stroke volume will increase. B. The respiratory rate will slow down. C. The heart rate and stroke volume will attempt to increase. D. Preload will increase due to venous​ congestion, and thus stroke volume will rise.

C As blood pressure is determined by cardiac output and systemic vascular​ resistance, if the pressure drops owing to vasodilation from the severe blood​ infection, the cardiac output will attempt to compensate by increasing the rate and force of contraction. During this​ compensation, the respiratory rate also​ increases, and there is not an increase in​ preload, as the vasodilation will cause peripheral pooling of blood.

If too much sodium accumulates inside the​ cell, the cell begins​ to: A. lose its protective membrane. B. reproduce. C. expand. D. shrink.

C As is well​ known, water follows sodium. So as sodium collects inside the​ cell, it attracts water. As the water continues to​ accumulate, the cell swells and eventually ruptures and dies.

When a patient has a heart irregularity that causes a very fast​ pulse, this can lead to shock due​ to: A. an increase in pressure in the arteries. B. a shift of water into the cells. C. the very limited amount of time for the ventricles to fill. D. too much blood being moved through the vascular system.

C Because cardiac output is determined by the stroke volume and heart​ rate, if the heart rate​ increases, then so should the cardiac output. Although a faster heart rate increases cardiac​ output, if the rate is extremely​ fast, the cardiac output may actually decrease. With excessively fast heart​ rates, usually​ >160 bpm in the adult​ patient, the time between beats is so short that there is not an adequate amount of time for the ventricles to fill. This reduces the​ preload, which in turn reduces the cardiac output. The drop in blood pressure from extreme tachycardia will not cause too much blood to be moved through the vascular​ system, nor will it cause water to shift into the​ cells, as this is controlled by variables within the cell itself.

Why is less pressure required to perfuse the lower lobes compared to the upper lobes of the​ lungs? A. Surface tension is higher in the lower lobes. B. The alveoli in the lower lobes are larger. C. Gravity pulls blood downward. D. The lower lobes have a greater residual volume of air.

C Because gravity pulls the blood​ downward, less pressure is required to perfuse the lower lobes of the lungs compared to the apexes. Surface tension is higher in the upper lobes. The upper alveoli are larger and there is a greater residual volume of air in the apex.

The component of whole blood that is primarily composed of water is​ the: A. electrolytes. B. electrolytes in solute. C. plasma. D. albumin.

C Blood is composed of formed elements and plasma. The formed​ elements, which are cells and​ proteins, make up approximately 45 percent of blood composition. Plasma is the fluid component that accounts for the remaining 55 percent. The primary function of plasma is to suspend and carry the formed elements. Plasma is made up primarily of water and plasma proteins. Water composes 91 percent of plasma.

What effect on lung compliance will occur if a patient has a traumatic lung injury that is causing the pleural cavity to fill with​ blood? A. It will decrease resistance. B. It will increase lung compliance. C. It will decrease lung compliance. D. It will increase resistance.

C Compliance is a measure of the ability of the chest wall and lungs to​ stretch, distend, and expand. A condition that would cause the lungs or chest wall to become stiff would decrease compliance. A decrease in compliance would make it more difficult for the patient to move air into and out of the lungs. This also would make it more difficult to ventilate the patient artificially. Conditions such as​ pneumonia, a hemothorax​ (blood filling up the pleural​ cavity), and pulmonary edema can decrease compliance within the lungs. Increasing compliance means that it is easier to for the lungs to​ inflate, and resistance changes refer to the degree of bronchoconstriction or bronchodilation.

Which of the following may be caused by a disturbance in the​ cell/capillary gas exchange process of peripheral tissue during an episode of​ hypotension? A. Neurogenic shock B. Hypoglycemia C. Hypoxia D. Asthma

C For cells to receive adequate oxygen and eliminate carbon​ dioxide, both the​ alveolar/capillary gas exchange and the​ cell/capillary gas exchange must be functioning properly. In the​ periphery, if a patient is experiencing​ hypoperfusion, the tissues will starve for​ oxygen-rich blood and will become hypoxic or even anoxic. Hypoglycemia is a diabetic​ emergency, not a pulmonary​ one, and asthma is a bronchoconstriction disease that affects the lung tissue.​ Finally, neurogenic shock occurs with spinal cord​ trauma, not pulmonary dysfunction.

You are treating a patient with a lung injury that results in a drop in his tidal volume. What will be the clinical effect on the amount of air that is available for gas exchange in the​ alveoli? A. Greatly increase B. Slightly increase C. Decrease D. Not change

C Increasing the frequency of ventilation may improve the amount of air moved in and out of the respiratory tract in one​ minute; however, if the tidal volume is too​ low, an adequate amount of air may never make it completely down to the alveoli for gas exchange but will instead remain in the trachea and major bronchi.

The normal minute volume is​ about: A. ​12,000 mL. B. 500 mL. C. ​6,000 mL. D. ​4,000 mL.

C Minute​ ventilation, also known as minute​ volume, is the amount of air that is moved in and out of the lungs in one minute. It is determined by multiplying the tidal volume by the frequency of ventilation in one minute. An​ average-sized adult has a tidal volume of approximately 500 mL and breathes approximately 12 times per minute at rest. An​ average-sized adult moves approximately​ 6,000 mL, or 6​ L, of air in and out of the lungs in one minute.

What is the name of the ventilatory volume that is calculated by multiplying the tidal volume by the frequency of​ ventilation? A. Tidal volume B. Respiration frequency C. Minute ventilation D. Ventilation volume

C Minute​ ventilation, also known as minute​ volume, is the amount of air that is moved in and out of the lungs in one minute. It is determined by multiplying the tidal volume by the frequency of ventilation in one minute. The tidal volume​ (VT) is the volume of air breathed in with each individual breath. The frequency of ventilation​ (f) is generally calculated as the number of ventilations in one minute. Ventilation volume is a fictitious term.

Oxygen that is bound to hemoglobin is​ called: A. deoxyhemoglobin. B. dioxyhemoglobin. C. oxyhemoglobin. D. carboxyhemoglobin.

C Once an oxygen molecule binds with​ hemoglobin, it is referred to as oxyhemoglobin.

A patient has fallen and suffered an injury that caused a drop in the​ body's systemic vascular resistance. What will this do to the​ patient's blood​ pressure? A. The blood pressure will be unaffected. B. The blood pressure will increase. C. The blood pressure will decrease. D. The blood pressure will initially rise but then return to normal.

C Systemic vascular resistance is the resistance that is offered to blood flow through a vessel. As a vessel constricts​ (decreases its​ diameter), resistance inside the vessel​ increases, which typically increases pressure inside the vessel.​ Conversely, as a vessel dilates​ (increases its​ diameter), resistance inside the vessel​ decreases, which typically decreases pressure inside the vessel. Vessel size can influence blood pressure. Vasoconstriction decreases vessel​ size, increases​ resistance, and increases blood pressure. Vasodilation increases vessel​ diameter, decreases​ resistance, and decreases blood pressure.

A patient has an initial blood pressure of​ 120/78, with a heart rate of 86 per minute. Five minutes later his blood pressure is​ 128/92, with a heart rate of 82 per minute. Which of the following statements about the change in the vitals is MOST​ correct? A. The patient is probably bleeding into his GI system unnoticed. B. The patient has arterial constriction and venous dilation. C. The patient has experienced an increase in his systemic vascular resistance. D. The patient has experienced an increase in his pulmonic vascular resistance.

C The determinants of blood pressure are heart rate and systemic vascular resistance. In this​ situation, the systolic pressure climbed 8 mmHg and the diastolic pressure climbed 14 mmHg with a concurrent drop in the heart rate. The likely cause is an increase in​ vasoconstriction, which would elevate the systolic​ pressure, narrow the pulse​ pressure, and slow the heart rate owing to the baroreceptor reflex arc. An increase in pulmonic resistance cannot be determined by the vital​ signs, and if there was a bleed in the GI​ system, the heart rate would continue to climb to ensure an adequate cardiac output.​ Finally, arterial constriction and venous dilation would widen​ (not narrow) the pulse pressure.

The peripheral chemoreceptors are MOST sensitive​ to: A. sugar levels. B. acid-base balance. C. oxygen concentration. D. COF1 level.

C The peripheral chemoreceptors are located in the aortic arch and the carotid bodies in the neck. These chemoreceptors are also somewhat sensitive to COF1 and pH but are most sensitive to the level of oxygen in the arterial blood. As the level of oxygen in the blood​ decreases, the peripheral chemoreceptors signal the respiratory center in the brainstem to increase the rate and depth of respiration. It takes a significant decrease in the arterial oxygen content to trigger the peripheral chemoreceptors to stimulate the respiratory center. COF1 levels are monitored primarily by the central​ chemoreceptors, as are acid-base ​(pH) levels. Glucose levels are not detected by the chemoreceptors.

Which of the following​ elements, if diminished or absent in a​ patient's bloodstream, could cause uncontrolled​ bleeding? A. Albumin proteins B. White blood cells C. Platelets D. Red blood cells

C The platelets​ (thrombocytes) are not actual cells but fragments that play a major role in blood clotting and the control of bleeding. Red blood cells carry​ oxygen, white blood cells fight​ infections, and albumin proteins are used for fluid balance and other purposes in the bloodstream.

An accumulation of air in which space can disrupt the negative pressure normally present and lead to​ hypoventilation? A. Parietal space B. Pulmonary space C. Pleural space D. Positive space

C The potential space between the pleura maintains a negative pressure. If a break occurs in the continuity of either the parietal pleura from an open wound to the thorax or the visceral pleura from an injury to the lung​ tissue, the negative pressure will draw air into the pleural space. With each​ inhalation, the thorax increases its size and the pleural pressure becomes negative again. This draws even more air into the pleural​ space, increasing its volume and collapsing the lung because eventually the pressure in the pleural lining will become positive and collapse the lung. Occluding any open wound to the chest is done very early in the primary assessment of a patient because it will help to stop this progressing injury so that the negative pressure will not be entirely lost. It has no effect on the CNS control over​ ventilations, nor does it prevent blood from leaking into lung tissue.​ Finally, if the plural pressure becomes​ positive, this means that the lung will​ collapse, which is not a desired outcome.

While working with an ALS​ partner, you observe her starting an IV on a trauma patient with an arterial bleed. You know that this is beneficial​ because: A. it will increase the amount of clotting factors in the​ patient's blood. B. it will help carry and prevent free radical formations from hyperoxia. C. extra fluid will increase the preload to the heart. D. it will cause the heart rate to slow down.

C When a patient is in​ shock, fluid is administered to fill the container​ (the vascular​ space). By filling the vascular​ space, there will be an increase in the preload to the​ heart, which will increase diastolic filling and subsequent stroke volume and cardiac output. This will help to maintain peripheral perfusion. The fluid is not given to carry free radicals from​ hyperoxia, as these should be avoided by titrating oxygen on the basis of​ need, and fluids do not increase the clotting speed of the body.

Which of the following statements is accurate with regard to the​ ventilation/perfusion ratio? A. The alveoli located in the bases have a higher surface tension. B. Under normal​ conditions, ventilation exceeds the amount of available perfusion. C. The alveoli located in the apexes are larger. D. The apexes of the lungs receive a greater amount of blood.

C ​Interestingly, the alveoli in the apexes of the lungs have a greater residual volume of​ air, are​ larger, and have a higher surface​ tension, but they are fewer in number compared to other areas of the lungs.

During the relaxation of the diaphragm and intercostal​ muscles, what happens to the intrathoracic size and​ pressure? A. The size stays the​ same, but the pressure increases. B. The size stays the​ same, but the pressure decreases. C. The size decreases and pressure decreases. D. The size decreases and the pressure increases.

D After​ inhalation, the diaphragm and external intercostal muscles​ relax, allowing the chest wall to move inward and downward​ and, assisted by the inward pull of the elastic lung​ tissue, decrease the size of the thoracic cavity. As the size of the thorax​ decreases, the pressure inside increases to about 761 mmHg at sea​ level, this causes air to be forced out of the lungs.

What is the approximate percentage of oxygen in the inspired​ air? A. 79 percent B. 56 percent C. 18 percent D. 21 percent

D Ambient air at sea level contains approximately 79 percent​ nitrogen, 21 percent​ oxygen, 0.9 percent​ argon, and 0.03 percent carbon dioxide. There are trace amounts of other gases.

Ambient air contains​ MOSTLY: A. argon. B. carbon dioxide. C. oxygen. D. nitrogen.

D Ambient air at sea level contains approximately 79 percent​ nitrogen, 21 percent​ oxygen, 0.9 percent​ argon, and 0.03 percent carbon dioxide. There are trace amounts of other gases. Nitrogen is not a gas that is used by the body for metabolic​ processes; however, oxygen is.

Which of the following will occur if central chemoreceptors detect an increase in CO2​? A. Decreased rate and decreased depth of respiration B. Increased rate and decreased depth of respiration C. Decreased rate and increased depth of respiration D. Increased rate and increased depth of respiration

D An increase in arterial CO2 increases the number of hydrogen ions in the cerebrospinal fluid​ (CSF), stimulating an increase in the rate and depth of respiration to blow off more CO2.

What should happen to cardiac output and systolic blood pressure if there is an increase in heart rate from 86 per minute to 94 per​ minute? A. The cardiac output will​ increase, but the blood pressure will decrease. B. Both should decrease. C. The cardiac output will​ decrease, but the blood pressure will increase. D. Both should increase.

D Because cardiac output is determined by the stroke volume and heart​ rate, if the heart rate​ increases, then so should the cardiac output. Although a faster heart rate generally increases cardiac​ output, if the rate is extremely​ fast, the cardiac output may actually decrease. With excessively fast heart​ rates, usually​ >160 bpm in the adult​ patient, the time between beats is so short that there is not an adequate amount of time for the ventricles to fill. This reduces the​ preload, which in turn reduces the cardiac output.

The inability to maintain a​ patient's airway or ventilatory status can lead to what detrimental cellular​ event? A. Hormonal hypersensitivity B. Increased biochemical reactions C. Drop in oxygen need by peripheral tissues D. Cellular death

D Cellular​ metabolism, also known as cellular​ respiration, is the process in​ which, normally, the cells break down molecules of glucose to produce energy for the body. There are two types of cellular​ metabolism: aerobic and anaerobic. Aerobic metabolism creates the most adenosine triphosphate​ (ATP) from glucose in the presence of oxygen. Anaerobic metabolism produces far less ATP and overwhelming acidosis when oxygen is inadequate or absent. Anaerobic​ metabolism, if not​ corrected, will cause so much acidosis that the cells will die.

What is the basic function of hydrostatic​ pressure? A. It helps to shift fluid from the interstitial spaces into the cellular spaces. B. It is a pulling force that keeps fluid in the cells. C. It helps to shift fluid from the interstitial spaces into the vascular spaces. D. It is a force that pushes fluid out of the vessel or capillary bed.

D Hydrostatic pressure is the force inside the vessel or capillary bed generated by the contraction of the heart and the blood pressure. Hydrostatic pressure exerts a push inside the vessel or​ capillary; that​ is, it acts to push fluid out of the vessel or capillary through the vessel wall and into the interstitial space. A high hydrostatic pressure would force more fluid out of the vessel or capillary and promote edema - swelling from excess fluid outside the vessels. Oncotic pressure is responsible for keeping the fluid inside the blood vessels or helping to pull fluid from the interstitial pressure into the vascular space.

What generates the force that results in hydrostatic​ pressure? A. Blood flow through the lungs during breathing B. The effects of large proteins in the blood C. Gravity flow of venous blood from the brain and upper extremities D. Contraction of the left ventricle

D Hydrostatic pressure is the force inside the vessel or capillary bed generated by the contraction of the heart and the blood pressure. Hydrostatic pressure exerts a push inside the vessel or​ capillary; that​ is, it acts to push fluid out of the vessel or capillary through the vessel wall and into the interstitial space. Blood flow through the lungs is subject to the same hydrostatic pressure as blood flow in the rest of the body. Oncotic pressure is what is generated by large plasma proteins. Gravity return of blood to the heart does not play a role in hydrostatic pressure.

You are treating a patient with a gunshot wound on his right chest. What will occur if this injury causes a break in the continuity of the parietal​ pleura? A. The lung will increase in size. B. Less air is drawn into the pleural space. C. The pleural pressure becomes more positive. D. The thorax will increase in size with each inhalation.

D If a break occurs in the continuity of either the parietal pleura from an open wound to the thorax or to the visceral pleura from an injury to the lung​ tissue, the negative pressure draws air into the pleural space. With each​ inhalation, the thorax will increase in size and the pleural pressure will become more negative.

Which ion will start to accumulate within the cell should the​ sodium-potassium pump fail following a period of​ hypoxia? A. Potassium B. Magnesium C. Carbon dioxide D. Sodium

D If​ ATP-energy production by cells is​ lacking, as found in poor perfusion states and anaerobic​ metabolism, the​ sodium-potassium pump may fail. This would allow sodium to collect on the inside of the cell. As is well​ known, water follows sodium. So as sodium collects inside the​ cell, it attracts water.

The​ moment-to-moment control of microcirculation is provided by what​ mechanism? A. Neural influences B. Adrenal gland release of epinephrine C. Hormonal influences D. Local influences

D In a resting​ state, the local factors predominantly control blood flow through the capillaries. When adaptation is​ necessary, the neural factors change the capillary blood flow. Hormones are usually responsible for a sustained effect on the arterioles and capillaries.

Why should EMS providers administer oxygen to a patient suspected of​ hypoxia? A. More oxygen in the inspired air will decrease the absorption of other gases present. B. More oxygen in the inspired air will raise the respiratory rate. C. More oxygen in the inspired air will slow the respiratory rate. D. More oxygen in the inspired air will increase the amount absorbed by the blood.

D Increasing the concentration of oxygen in breathed air increases the number of oxygen molecules in the​ alveoli, the​ blood, and the cells.​ Thus, one way to improve cellular oxygenation is by increasing the concentration of oxygen in the air breathed in by the patient.

What is the term used to describe what a hemoglobin molecule is when it binds with an oxygen​ molecule? A. Oxyhemoglobule B. Deoxyhemoglobule C. Deoxyhemoglobin D. Oxyhemoglobin

D Once an oxygen molecule binds with​ hemoglobin, it is referred to as oxyhemoglobin. A hemoglobin molecule that has no oxygen attached is referred to as deoxyhemoglobin. Oxyhemoglobule and deoxygemoglobule are fictitious terms.

What effect would systemic vasoconstriction have on the blood pressure​ (B/P)? A. The​ B/P increases only if the heart rate increases. B. The​ B/P decreases. C. The​ B/P remains the same. D. The​ B/P increases.

D Systemic vascular resistance is the resistance that is offered to blood flow through a vessel. As a vessel constricts​ (decreases its​ diameter), resistance inside the vessel​ increases, which typically increases pressure inside the vessel.​ Conversely, as a vessel dilates​ (increases its​ diameter), resistance inside the vessel​ decreases, which typically decreases pressure inside the vessel. Vasoconstriction decreases vessel​ size, increases​ resistance, and increases blood pressure. Vasodilation increases vessel​ diameter, decreases​ resistance, and decreases blood pressure.

The passage of oxygen and carbon dioxide gases between the alveoli and the capillaries of the lungs is referred to​ as: A. ​alveolar/capillary mismatch. B. arterial gas division. C. ​OF1/COF1 reversal. D. ​alveolar/capillary exchange.

D The passage of oxygen and carbon dioxide in the alveoli is known as​ alveolar/capillary exchange. After​ inhalation, the alveoli are filled with​ oxygen-rich air that contains very little carbon dioxide.​ Conversely, the venous blood that flows through the capillaries surrounding the alveoli contains low levels of oxygen and higher amounts of carbon dioxide. As gas molecules naturally move from an area of high concentration to an area of low​ concentration, the high oxygen content in the alveoli moves across the membranes and into the capillaries where the oxygen content is very low.​ Simultaneously, carbon dioxide moves in the opposite​ direction, from the high levels in the capillaries into the​ alveoli, where the COF1 content is low.

Which one of the following is correct in regard to the pleural​ space? A. Damaged visceral pleura pushes air out of the thorax. B. Lung collapse has minimal effect on the process of gas exchange. C. Open chest wounds should be occluded during the secondary assessment. D. The potential space between the pleura maintains a negative pressure.

D The potential space between the pleura maintains a negative pressure. If a break occurs in the continuity of either the parietal pleura from an open wound to the thorax or to the visceral pleura from an injury to the lung​ tissue, the negative pressure draws air into the pleural space. With each​ inhalation, the thorax increases its size and the pleural pressure becomes more negative. This draws even more air into the pleural​ space, increasing its volume and collapsing the lung. Lung collapse severely interferes with the ability of the alveoli to fill with air and to create an interface with the pulmonary​ capillaries, which reduces gas exchange with the blood and leads to hypoxia.​ Therefore, occluding any open wound to the chest is done early in the primary assessment of a patient.

Increased negative pressure in the pleural space will lead​ to: A. overinflated alveoli. B. decreased thorax size. C. increased positive pressure. D. lung collapse.

D The potential space between the pleura maintains a negative pressure. If a break occurs in the continuity of either the parietal pleura from an open wound to the thorax or to the visceral pleura from an injury to the lung​ tissue, the negative pressure draws air into the pleural space. With each​ inhalation, the thorax increases its size and the pleural pressure becomes more negative. This draws even more air into the pleural​ space, increasing its volume and collapsing the lung. Lung collapse severely interferes with the ability of the alveoli to fill with air and to create an interface with the pulmonary​ capillaries, which reduces gas exchange with the​ blood, thereby leading to hypoxia.

An​ average-sized adult has a tidal volume of approximately how many​ mL? A. ​1,000 B. 750 C. 250 D. 500

D The tidal volume​ (VT) is the volume of air that is breathed in with each individual breath. An​ average-sized adult has a tidal volume of approximately 500 mL. The volumes of​ 250, 750, and​ 1,000 are either too large or too small for a normal tidal volume.

According to the​ V/Q ratio, why might a patient with an inhalation injury from a burn have poor cellular​ oxygenation? A. The patient is having wasted alveolar ventilation. B. The patient is having wasted oxygen inhalation. C. The patient is having wasted carbon monoxide ventilation. D. The patient is having wasted alveolar perfusion.

D The​ ventilation/perfusion ratio is never at an ideal state in any zones of the lungs. In the​ apexes, the amount of available ventilation in the alveoli exceeds the amount of perfusion through the pulmonary​ capillaries; that​ is, there is more oxygen available in the alveoli than the supply of blood can pick up and transport. This is wasted ventilation. In the​ bases, the amount of perfusion exceeds the amount of​ ventilation; this means more blood moves through the pulmonary capillaries than there is alveolar oxygen available for it to pick up. This is wasted perfusion.​ Overall, under normal​ conditions, perfusion exceeds the amount of available ventilation.

Which of the following situations could cause poor tissue oxygenation of the extremities despite the arterial blood being​ oxygenated? A. A brain tumor B. Spinal injury C. A narcotic overdose D. Dropping systolic blood pressure

D This is a fundamental question that asks you to connect body physiology to pathophysiology as it relates to blood oxygenation. Since the lungs sit on either side of the​ heart, it does not take as high a perfusion pressure to perfuse the lungs adequately as it does to perfuse the distal extremities.​ Therefore, if the blood pressure is​ dropping, there may still be adequate levels of oxygen in the bloodstream from the​ lungs, but the pressure may not be high enough to get sufficient oxygen to the peripheral tissues. A spinal​ injury, a narcotic​ overdose, and a brain tumor can all affect the neural control of the respiratory​ muscles, causing a drop in the ability of the body to oxygenate the blood because of ineffective respirations.

When a patient is severely burned over MOST of his​ body, the cellular and vascular damage created by the burn results in large protein molecules leaving the vascular space. As a result of​ this, which of the choices will the patient​ experience? A. High hydrostatic pressure B. Low hydrostatic pressure C. High oncotic pressure D. Low oncotic pressure

D This question involves applying the principles of hydrostatic pressure and oncotic pressure of the body as it relates to a traumatic burn injury. As a result of the loss of plasma​ proteins, the​ patient's oncotic pressure will drop and not exert an adequate pull effect to counteract the push of hydrostatic pressure. This will result in the loss of greater than normal amounts of vascular volume to the interstitial spaces​ (promoting global tissue​ edema). High hydrostatic pressure occurs when the systolic pressure in the capillary beds​ increases, high oncotic pressure occurs when there is a greater pull of fluids back into the vascular​ space, and a low hydrostatic pressure just means the fluid will not cause as much fluid to exit the capillary bed.

Cardiac output is composed​ of: A. blood pressure and heart rate. B. systemic vascular resistance​ (SVR) and heart rate. C. blood pressure. D. stroke volume and heart rate.

D To have adequate blood pressure and​ perfusion, the myocardium must work effectively as a pump. The pump function is typically expressed as the cardiac output. Cardiac output is defined as the amount of blood ejected by the left ventricle in one minute. The cardiac output is determined by the heart rate and the stroke volume. Cardiac output is expressed by the following​ equation: cardiac output​ = heart rate x stroke volume.