1.
What body system homeostasis by communication and coordination using biochemicals secreted directly into the blood stream?
Correct Answer
D. Endocrine
Explanation
The endocrine system is responsible for maintaining homeostasis by communication and coordination using biochemicals secreted directly into the bloodstream. It consists of glands that produce hormones, which are chemical messengers that travel through the bloodstream to target cells or organs. These hormones regulate various bodily functions such as metabolism, growth and development, reproduction, and response to stress. By secreting hormones into the bloodstream, the endocrine system ensures that the body's internal environment remains stable and balanced.
2.
Which of the following are examples of catecholamines?
Correct Answer
C. EpinepHrine, norepinepHrine, and L-dopamine
Explanation
Epinephrine, norepinephrine, and L-dopamine are examples of catecholamines. Catecholamines are a class of hormones that are derived from the amino acid tyrosine. They are produced and released by the adrenal glands and play a role in the body's response to stress. Epinephrine and norepinephrine are commonly known as adrenaline and noradrenaline, respectively. They are involved in the "fight or flight" response, increasing heart rate, blood pressure, and energy availability. L-dopamine is a precursor to both epinephrine and norepinephrine and is involved in regulating movement, mood, and motivation.
3.
Insulin is released into the blood stream by what cells located in what gland?
Correct Answer
B. Beta cells, Pancreas
Explanation
Insulin is a hormone that helps regulate blood sugar levels. It is released into the bloodstream by beta cells located in the pancreas. These beta cells are responsible for producing and secreting insulin in response to changes in blood glucose levels. The pancreas plays a crucial role in maintaining proper blood sugar balance, and the release of insulin by beta cells is essential for this process.
4.
Glucagon is released into the blood stream by what cells located in what gland?
Correct Answer
E. AlpHa cells, Pancreas
Explanation
Glucagon is released into the bloodstream by alpha cells located in the pancreas. Alpha cells are a type of endocrine cells found in the islets of Langerhans in the pancreas. These cells are responsible for producing and releasing glucagon, a hormone that helps increase blood sugar levels by stimulating the liver to convert stored glycogen into glucose.
5.
What specific cells in what organ secrete the hormone testosterone?
Correct Answer
E. Leydig cells, testes
Explanation
Leydig cells are specific cells found in the testes that secrete the hormone testosterone. Testosterone is a male sex hormone that plays a crucial role in the development of male reproductive tissues and characteristics. These cells are responsible for producing and releasing testosterone into the bloodstream, which then affects various physiological processes in the body.
6.
Nervous system responses typically are widespread, react more slowly, continue long after the stimulus ceases, and adapt rather slowly; endocrine system responses, in contrast, are localized and show specific effects, endure 1-10 milliseconds, cease suddenly, and adapt quickly.
Correct Answer
B. False
Explanation
The given statement is false. The correct answer is false because it states that nervous system responses continue long after the stimulus ceases, which is incorrect. Nervous system responses are typically immediate and cease once the stimulus is removed. Additionally, the statement incorrectly states that endocrine system responses endure 1-10 milliseconds, when in fact, endocrine responses can last much longer.
7.
What is the term for the time required to clear 50% of a given hormone from the blood stream?
Correct Answer
D. Half-life
Explanation
Half-life is the term used to describe the time required for 50% of a substance, in this case a hormone, to be cleared from the blood stream. It is a measure of how quickly a substance is eliminated from the body.
8.
Assume that a particular hormone has a half-life of 30 minutes, and the initial concentration is 80 units. How many units remain after the hormone has been in the blood stream for 90 minutes?
Correct Answer
C. 10 units
Explanation
The half-life of a substance is the time it takes for half of it to decay or disappear. In this case, the hormone has a half-life of 30 minutes. After 30 minutes, half of the initial concentration of 80 units would remain, which is 40 units. After another 30 minutes (total of 60 minutes), half of the remaining 40 units would remain, which is 20 units. Finally, after another 30 minutes (total of 90 minutes), half of the remaining 20 units would remain, which is 10 units. Therefore, after 90 minutes, 10 units of the hormone would remain in the bloodstream.
9.
Oxytocin (OT) and the anti-diuretic hormone (ADH) are manufactured in the supraoptic and paraventricular nuclei of the hypothalamus of the brain and are temporarily stored in what gland?
Correct Answer
B. NeurohypopHysis
Explanation
The correct answer is Neurohypophysis. Oxytocin (OT) and the anti-diuretic hormone (ADH) are manufactured in the supraoptic and paraventricular nuclei of the hypothalamus and are temporarily stored in the neurohypophysis, which is also known as the posterior pituitary gland. The neurohypophysis releases these hormones into the bloodstream when needed. The other options (Adenohypophysis, Gall Bladder, Pancreas, and Thymus) are not involved in the storage or release of OT and ADH.
10.
What is the term used to describe a process in which 2 or more hormones act together to produce an effect greater than the sum of their separate effects?
Correct Answer
C. Synergistic effect
Explanation
A synergistic effect is when two or more hormones work together to produce an effect that is greater than the sum of their individual effects. This means that the combined action of these hormones enhances their overall effectiveness in achieving a particular outcome. It is a cooperative interaction between hormones that leads to a more powerful response in the body.
11.
The hormones estrogen, progesterone, cortisol, aldosterone, and DHEA are all ultimately derived from which "building block" or "pattern"?
Correct Answer
B. Cholesterol
Explanation
Cholesterol is the correct answer because it is the precursor for the synthesis of all the hormones listed in the question. Cholesterol serves as the building block or pattern from which these hormones are derived. It is converted into different hormones through various enzymatic reactions in the body.
12.
The hormones insulin, glucagon, OT, ADH, norepinephrine, L-dopamine, and epinephrine are ultimately derived from which "building blocks:
Correct Answer
A. L-amino acids
Explanation
Insulin, glucagon, OT, ADH, norepinephrine, L-dopamine, and epinephrine are all hormones that are derived from L-amino acids. These hormones are synthesized in the body by linking together different amino acids in specific sequences. L-amino acids are the building blocks of proteins, and hormones are a type of protein. Therefore, it makes sense that these hormones are ultimately derived from L-amino acids.
13.
What 2 hormones are normally secreted by the ovaries?
Correct Answer
D. Estrogen, progesterone
Explanation
Estrogen and progesterone are the two hormones that are normally secreted by the ovaries. Estrogen plays a crucial role in the development and regulation of the female reproductive system, as well as the growth of secondary sexual characteristics. Progesterone, on the other hand, is primarily involved in preparing and maintaining the uterus for pregnancy. These hormones work together to regulate the menstrual cycle and support reproductive functions in females.
14.
The term "endocrine axis" or "hormonal axis" refers to a negative-feedback (ie. servo) relationship among the hypothalamus, the pituitary gland, and some other endocrine gland, all designed to maintain homeostasis (i.e. balance). A perfectly valid example is CRH-ACTH-Adrenal Cortex.
Correct Answer
A. True
Explanation
The term "endocrine axis" or "hormonal axis" refers to a negative-feedback relationship among the hypothalamus, the pituitary gland, and some other endocrine gland. This relationship is designed to maintain homeostasis or balance in the body. One example of an endocrine axis is the CRH-ACTH-Adrenal Cortex axis, where the hypothalamus releases corticotropin-releasing hormone (CRH), which stimulates the pituitary gland to release adrenocorticotropic hormone (ACTH), which in turn stimulates the adrenal cortex to release cortisol. This axis operates through a negative-feedback loop, where increased cortisol levels inhibit the release of CRH and ACTH, helping to maintain balance in the body. Therefore, the statement is true.
15.
What is the name of the hormone that stimulates the secretion of T3 and T4?
Correct Answer
B. Thyroid-stimulating hormone (TSH)
Explanation
Thyroid-stimulating hormone (TSH) is the correct answer because it is the hormone that stimulates the secretion of T3 and T4. TSH is produced and released by the pituitary gland in response to thyrotropin-releasing hormone (TRH) from the hypothalamus. TSH then acts on the thyroid gland to stimulate the production and release of T3 and T4, which are important hormones for regulating metabolism and growth in the body. Insulin, glucagon, and growth hormone do not directly stimulate the secretion of T3 and T4.
16.
What is the name of the hormone so-called "salt wasting hormone" since it acts on kidney tubules to enhance hypotonic water tetention?
Correct Answer
A. Anti-diuretic hormone (ADH)
Explanation
ADH, also known as vasopressin, is a hormone that acts on the kidney tubules to enhance the retention of water. It helps the kidneys reabsorb water from the urine back into the bloodstream, thereby preventing excessive water loss and promoting water conservation. This hormone is often referred to as the "salt wasting hormone" because it increases the reabsorption of water, leading to the excretion of concentrated urine and the conservation of salt in the body.
17.
What is the name of the hormone that induces labor contraction of the uterine myometrium and post-partum expression of mammary gland milk?
Correct Answer
B. Oxytocin (OT, Pitocin
Explanation
Oxytocin is the hormone that induces labor contractions of the uterine myometrium and post-partum expression of mammary gland milk. It is commonly referred to as OT or Pitocin.
18.
CRH, GnRH, PRH, and TRH are all releasing hormones?
Correct Answer
A. True
Explanation
The given statement is true. CRH, GnRH, PRH, and TRH are all releasing hormones. Releasing hormones are produced by the hypothalamus and they stimulate the release of other hormones from the pituitary gland. CRH (corticotropin-releasing hormone) stimulates the release of adrenocorticotropic hormone (ACTH), GnRH (gonadotropin-releasing hormone) stimulates the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), PRH (prolactin-releasing hormone) stimulates the release of prolactin, and TRH (thyrotropin-releasing hormone) stimulates the release of thyroid-stimulating hormone (TSH).
19.
CAMP, cGMP, and calcium ion (Ca+2) are all 2nd messengers?
Correct Answer
A. True
Explanation
cAMP, cGMP, and calcium ion (Ca+2) are all considered as second messengers because they play a crucial role in intracellular signaling pathways. Second messengers are molecules that transmit signals from the cell surface, where the initial signal is received, to the cell interior, where the response is generated. cAMP and cGMP are cyclic nucleotides that are involved in various cellular processes, including the regulation of enzyme activity and gene expression. Calcium ions, on the other hand, are involved in signaling pathways that regulate muscle contraction, neurotransmitter release, and many other cellular functions. Therefore, it is correct to say that cAMP, cGMP, and calcium ion (Ca+2) are all second messengers.
20.
What is the name of the hormone secreted by the kidneys that stimulates RBC production in bone marrow?
Correct Answer
E. Erythropoietin
Explanation
Erythropoietin is the correct answer because it is the hormone secreted by the kidneys that stimulates the production of red blood cells in the bone marrow. This hormone plays a crucial role in maintaining the balance of red blood cells in the body and is released in response to low oxygen levels in the blood. Erythropoietin stimulates the bone marrow to produce more red blood cells, which helps increase oxygen-carrying capacity and maintain homeostasis.
21.
What glucocorticoid hormone is associated with stress?
Correct Answer
C. Cortisol
Explanation
Cortisol is the glucocorticoid hormone associated with stress. It is produced by the adrenal glands in response to stress and helps regulate the body's response to stress by increasing blood sugar levels, suppressing the immune system, and aiding in metabolism. Cortisol also plays a role in the fight-or-flight response, helping the body to respond to stressful situations.
22.
Glucagon is secreted in response to hypoglycemia; it stimulates liver glycogenolysis (ie breakdown of glycogen to D-glucose) and gluconeogenesis (ie synthesis of new glucose from L-amino acids); the result is an elevated blood D-glucose level; and it is an antagonist to insulin.
Correct Answer
A. True
Explanation
Glucagon is indeed secreted in response to hypoglycemia. When blood sugar levels are low, the release of glucagon from the pancreas helps to raise blood glucose levels by stimulating the liver to break down stored glycogen into glucose (glycogenolysis) and by promoting the synthesis of new glucose from amino acids (gluconeogenesis). This results in an elevated blood glucose level. Additionally, glucagon has an antagonistic relationship with insulin, as insulin promotes the uptake and storage of glucose, while glucagon promotes the release of glucose into the bloodstream. Therefore, the statement "Glucagon is secreted in response to hypoglycemia; it stimulates liver glycogenolysis and gluconeogenesis; the result is an elevated blood glucose level; and it is an antagonist to insulin" is true.
23.
Aldosterone is a minerlcorticoid produced by the adrenal cortex.
Correct Answer
A. True
Explanation
Aldosterone is indeed a mineralocorticoid produced by the adrenal cortex. Mineralocorticoids are hormones that regulate electrolyte and fluid balance in the body, and aldosterone specifically helps in the reabsorption of sodium and the excretion of potassium in the kidneys. It plays a crucial role in maintaining blood pressure and electrolyte levels, making the statement true.
24.
What is the meaing of the abbreviation I-D DM?
Correct Answer
A. Insulin-dependent diabetes mellitus
Explanation
The correct answer is Insulin-dependent diabetes mellitus. This abbreviation refers to a type of diabetes in which the body is unable to produce enough insulin to regulate blood sugar levels. Insulin is a hormone that helps to control the amount of glucose in the blood. In this condition, individuals require regular insulin injections to manage their blood sugar levels. The other options provided in the question are not related to diabetes or insulin.
25.
Which disease is the worlds most prevalent metabolic disease and leading cause of adult blindness, renal failure, gangrene, and the necessity for limb amputations?
Correct Answer
C. Diabetes mellitus
Explanation
Diabetes mellitus is the correct answer because it is the most prevalent metabolic disease worldwide and it is also the leading cause of adult blindness, renal failure, gangrene, and the necessity for limb amputations. Diabetes mellitus is a chronic condition characterized by high blood sugar levels due to the body's inability to produce or effectively use insulin. It can lead to various complications, including damage to the eyes, kidneys, and extremities.
26.
Name this endocrine disorder. Patients exhibit abnormal fat deposition between the shoulders ("buffalo hump") or in the face ("moon face") and have an adrenal disorder characterized by excess cortisol and especially aldosterone?
Correct Answer
A. Cushing syndrome
Explanation
Cushing syndrome is the correct answer because it is an endocrine disorder characterized by excess cortisol and aldosterone. Patients with Cushing syndrome exhibit abnormal fat deposition, such as a "buffalo hump" between the shoulders or a "moon face" due to the redistribution of fat. Additionally, Cushing syndrome is associated with adrenal disorders, which further supports the correct answer choice.
27.
Graves disease is a type of toxic goiter and an autoimmune disease that mimics the effects of TSH on the thyroid gland causing thyroid gland hypersecretion as well as hypertrophy.
Correct Answer
A. True
Explanation
Graves disease is indeed a type of toxic goiter and an autoimmune disease. It occurs when the body's immune system mistakenly attacks the thyroid gland, causing it to produce excessive amounts of thyroid hormones. This leads to hypersecretion of the thyroid gland, resulting in symptoms such as weight loss, rapid heartbeat, and enlarged thyroid gland. Therefore, the statement is true.
28.
What is the term of the current scientific model describing the specificity between hormone and its binding site on target cell membranes and is similar to the model describing the interaction between an enzyme and a specific substrate?
Correct Answer
A. Induced fit
Explanation
The term "induced fit" describes the current scientific model that explains the specificity between a hormone and its binding site on target cell membranes. This model is similar to the model that describes the interaction between an enzyme and a specific substrate. In the induced fit model, the hormone molecule undergoes conformational changes upon binding to its receptor, resulting in a tighter fit between the two molecules. This conformational change is induced by the binding and allows for optimal interaction and signaling between the hormone and its target cell.
29.
What vitamin is calcitriol?
Correct Answer
D. Vitamin D3
Explanation
Calcitriol is the active form of Vitamin D3 in the body. It is produced in the kidneys and plays a crucial role in regulating calcium and phosphate levels in the blood. Vitamin D3 is essential for maintaining strong bones and teeth, supporting immune function, and promoting overall health.
30.
What endocrine gland produces the hormones thymosin, thymulin, thymopoietin?
Correct Answer
C. Thymus
Explanation
The thymus gland produces the hormones thymosin, thymulin, and thymopoietin. These hormones play a crucial role in the development and maturation of T-lymphocytes, which are important for the immune system. The thymus gland is located in the upper chest, behind the sternum, and is most active during childhood and adolescence. It gradually decreases in size and function as a person ages.
31.
What gland secretes calcitonin produced in parafollicular cells (ie C cells)?
Correct Answer
E. Thyroid gland
Explanation
The thyroid gland secretes calcitonin, which is produced in the parafollicular cells (C cells). Calcitonin helps to regulate calcium levels in the body by inhibiting the breakdown of bone and promoting calcium excretion by the kidneys. The parathyroid gland, on the other hand, secretes parathyroid hormone (PTH), which has the opposite effect of increasing blood calcium levels. The pancreas secretes insulin and glucagon to regulate blood sugar levels, the pineal gland produces melatonin to regulate sleep-wake cycles, and the pituitary gland produces various hormones to regulate growth, reproduction, and other functions.
32.
What hormone is produced by the stomach and stimulates the release of HCl?
Correct Answer
A. Gastrin
Explanation
Gastrin is the hormone produced by the stomach that stimulates the release of HCl. HCl is an important component of gastric acid, which aids in the digestion of food. Gastrin is released in response to the presence of food in the stomach, and it acts on the parietal cells of the stomach to stimulate the production and release of HCl. This hormone helps in the breakdown of proteins and the absorption of certain nutrients in the stomach.
33.
What hormone is secreted by the small intestine duodenum; it used to be called pancreozymin (PCZ); and it stimulates fat and protein digestion and the release of bile by the gall bladder?
Correct Answer
E. Choleccytokinin (CCK)
Explanation
Cholecystokinin (CCK) is the hormone secreted by the small intestine duodenum. It was previously known as pancreozymin (PCZ). CCK plays a crucial role in the digestion process by stimulating the release of bile from the gall bladder, which aids in the digestion of fats. Additionally, CCK also stimulates the digestion of proteins. Therefore, CCK is the correct answer to the question.
34.
Hormones A, B, C and D have the following respective MCRs in the units/minute: 80, 40, 20 and 10. Which hormone has the greatest half-life?
Correct Answer
D. Hormone D
Explanation
Hormone D has the greatest half-life because it has the lowest MCR (Metabolic Clearance Rate) of 10 units/minute. The half-life of a substance is the time it takes for half of the substance to be eliminated from the body. A lower MCR indicates that the hormone is cleared from the body at a slower rate, resulting in a longer half-life. Therefore, Hormone D, with the lowest MCR, has the greatest half-life.
35.
The hospital laboratory reported that at noon a patients level of a given hormone was 20 units. You know the half-life is 1 hour and that the hormone was injected into the patient at 8 a.m. How many units were originally injected?
Correct Answer
D. 320
Explanation
The half-life of the hormone is 1 hour, which means that the amount of hormone in the patient's body is halved every hour. Since the hormone was injected at 8 a.m. and the level at noon was 20 units, that means 4 hours have passed since the injection. If the level at noon is 20 units, then the level at 8 a.m. (right after the injection) would have been double that, which is 40 units. Therefore, the originally injected amount must have been 320 units.
36.
What is the approx. blood volume of the human body?
Correct Answer
D. 5 - 5.5 liters
Explanation
The approximate blood volume of the human body is 5 - 5.5 liters. This is the correct answer because it is within the range of normal blood volume for an average adult human. Blood volume can vary slightly depending on factors such as age, sex, and body size, but 5 - 5.5 liters is a commonly accepted range.
37.
Name the erythrocyte respiratory pigment giving blood its color and transporting oxygen.
Correct Answer
E. Hemoglobin
Explanation
Hemoglobin is the erythrocyte respiratory pigment that gives blood its color and transports oxygen. It is a protein found in red blood cells and is responsible for binding to oxygen in the lungs and delivering it to tissues throughout the body. Hemoglobin contains iron, which gives it its red color. Without hemoglobin, the blood would not be able to effectively transport oxygen, leading to oxygen deprivation in the body's tissues.
38.
What is the approx, average hematocrit numerical value?
Correct Answer
D. 44
Explanation
The average hematocrit numerical value is approximately 44. Hematocrit is a measure of the proportion of red blood cells in the blood. A normal hematocrit range for adult males is typically between 40% and 52%, while for adult females it is usually between 35% and 47%. Therefore, a value of 44 falls within the normal range for both males and females.
39.
Which type of leukocyte would you expect to find as the most common in a Wrights blood smear?
Correct Answer
A. NeutropHil
Explanation
In a Wrights blood smear, the most common type of leukocyte would be a neutrophil. Neutrophils are the most abundant type of white blood cells and play a crucial role in the immune response. They are responsible for phagocytosis, which involves engulfing and destroying pathogens and foreign particles. This makes them highly effective in combating infections and inflammation.
40.
What is the specific name of the heart valve located between the left atrium and left ventricle?
Correct Answer
D. Bicuspid, mitral
Explanation
The specific name of the heart valve located between the left atrium and left ventricle is the bicuspid valve, also known as the mitral valve. This valve consists of two leaflets or cusps that open and close to regulate blood flow from the left atrium to the left ventricle. It prevents the backflow of blood and ensures that blood flows in one direction, allowing for efficient pumping of oxygenated blood throughout the body.
41.
What is the specific of the heart valve through which blood passes as it departs the right ventricle and enters the pulmonary trunk on its way to the lungs?
Correct Answer
C. Pulmonary semilunar
Explanation
The specific heart valve through which blood passes as it departs the right ventricle and enters the pulmonary trunk on its way to the lungs is the pulmonary semilunar valve. This valve prevents the backflow of blood from the pulmonary trunk into the right ventricle and ensures that blood flows in one direction, from the right ventricle to the lungs.
42.
What type of vessels carry blood away from the heart?
Correct Answer
B. Arteries
Explanation
Arteries are the correct answer because they are the blood vessels that carry oxygenated blood away from the heart to the rest of the body. They have thick, elastic walls that allow them to withstand the high pressure of blood being pumped out of the heart. Arteries branch out into smaller vessels called arterioles, which eventually lead to capillaries where the exchange of oxygen and nutrients with body tissues occurs. Veins, on the other hand, carry deoxygenated blood back to the heart, while capillaries are the smallest blood vessels where the exchange of substances between blood and tissues takes place.
43.
What is the approx range of blood pressue on the left side of the heart in mm Hg?
Correct Answer
C. 80 - 120
Explanation
The approximate range of blood pressure on the left side of the heart is 80 - 120 mm Hg. This range is considered normal for a healthy individual. Blood pressure measures the force exerted by blood against the walls of the arteries. The left side of the heart pumps oxygenated blood to the rest of the body, so the blood pressure in this area is typically higher than the right side of the heart. A blood pressure reading within the range of 80 - 120 mm Hg indicates that the heart is functioning properly and maintaining a healthy blood flow.
44.
Regarding the functioning of the heart, the term "automaticity" refers to what?
Correct Answer
A. Self-pacing of the SA node
Explanation
Automaticity refers to the ability of the SA (sinoatrial) node, which is located in the right atrium of the heart, to generate electrical impulses spontaneously and initiate the heartbeat. These electrical impulses then spread throughout the heart, causing it to contract and pump blood. Therefore, the correct answer is "Self-pacing of the SA node."
45.
Which member of the heart conducting tissue immediately follows the atrioventricular (AV) node?
Correct Answer
D. Bundle of His
Explanation
The correct answer is Bundle of His. The Bundle of His is a specialized group of cardiac muscle fibers that conducts the electrical impulses from the atrioventricular (AV) node to the ventricles of the heart. It is responsible for coordinating the contraction of the ventricles, ensuring that blood is efficiently pumped out of the heart. The SA node is responsible for initiating the electrical impulses in the heart, while the Purkinje fibers are responsible for spreading the impulses throughout the ventricles. Bachman's bundle is not directly related to the conduction system of the heart.
46.
What is the approx. range of resting (ie. sedentary) heart rate in BPM's?
Correct Answer
D. 70-75
Explanation
The approximate range of resting (ie. sedentary) heart rate in BPM's is 70-75. This means that when a person is at rest and not engaging in any physical activity, their heart rate is expected to be within this range. A resting heart rate in this range is considered to be normal and healthy.
47.
If a patient has a blood pressue of "120 over 80" what is the patients diastolic pressure?
Correct Answer
B. 80
Explanation
The diastolic pressure is the bottom number in a blood pressure reading, representing the pressure in the arteries when the heart is at rest between beats. In this case, the blood pressure is given as "120 over 80," where 120 is the systolic pressure (top number) and 80 is the diastolic pressure (bottom number). Therefore, the patient's diastolic pressure is 80.
48.
If a patient has a blood pressue of "120 over 80" what is the patients pulse pressure?
Correct Answer
D. 40
Explanation
Pulse pressure is the difference between the systolic and diastolic blood pressure readings. In this case, the systolic blood pressure is 120 and the diastolic blood pressure is 80. Therefore, the pulse pressure is calculated by subtracting the diastolic blood pressure from the systolic blood pressure: 120 - 80 = 40.
49.
During which component of the EKG does ventricular depolarization occur?
Correct Answer
B. QRS complex
Explanation
The QRS complex represents ventricular depolarization in an EKG. This is when the electrical activity spreads through the ventricles, causing them to contract and pump blood out of the heart. The P wave represents atrial depolarization, the T wave represents ventricular repolarization, and an inverted T wave is an abnormal finding that may indicate various cardiac conditions.
50.
Calcium plays a crucial role in the process of blood coagulation.
Correct Answer
A. True
Explanation
Calcium is essential for blood coagulation because it is involved in several steps of the coagulation cascade. When there is an injury or damage to blood vessels, a series of reactions occur to form a blood clot and stop bleeding. Calcium ions are required for the activation of various clotting factors, including factor X and factor II (prothrombin). These factors then lead to the formation of fibrin, which is the main component of a blood clot. Without sufficient calcium, the clotting process would be impaired, leading to prolonged bleeding or difficulty in stopping bleeding altogether. Therefore, it is true that calcium plays a crucial role in the process of blood coagulation.