Question 1

Colour of skin is affected by ...?

Accepted Answer

Answer reason: Melanin is the primary determinant of normal skin tone, while oxygenation of hemoglobin changes visible coloration (e.g., cyanosis with low oxygen saturation). Bile pigments (bilirubin) deposit in tissues and cause yellow discoloration (jaundice), altering skin appearance. Therefore, each listed factor can affect skin color, making the combined choice the best answer.

Question 2

The main source of energy for human brain ...?

Accepted Answer

Answer reason: Under normal dietary conditions, the brain uses circulating glucose as its main energy substrate because long-chain fatty acids do not cross the blood–brain barrier efficiently and are not a primary neuronal fuel. Vitamins are cofactors rather than caloric energy sources, and protein is not the preferred routine fuel for brain tissue. In prolonged fasting the brain can adapt to ketone bodies, but glucose remains the principal energy source in typical physiology.

Question 3

Which vitamin is essential for blood clotting?

Accepted Answer

Answer reason: This activation is necessary for factors II, VII, IX, and X (and proteins C and S) to bind calcium and function in the coagulation cascade. Deficiency or antagonism of this vitamin impairs clot formation and increases bleeding risk. In contrast, vitamin C primarily supports collagen synthesis and capillary integrity rather than activating clotting factors.

Question 4

Neonatal jaundice is more common in?

Accepted Answer

Answer reason: Preterm infants have more immature hepatic UDP-glucuronyl transferase activity and reduced ability to uptake and conjugate bilirubin, so unconjugated bilirubin accumulates more easily. They also often have decreased enteral intake and delayed meconium passage, increasing enterohepatic circulation and bilirubin reabsorption. Compared with term or post-term infants, these maturational limitations make jaundice both more common and more likely to reach higher levels in preterm newborns.

Question 5

The principal site of glucose production in the human body is the?

Accepted Answer

Answer reason: The liver has the enzymatic machinery to release free glucose into the bloodstream (notably glucose-6-phosphatase), making it the dominant organ for systemic glucose output. Muscle stores glycogen but lacks glucose-6-phosphatase, so it cannot export glucose to raise blood glucose and instead uses it locally. Blood is the transport medium rather than a production site, and the pituitary gland regulates metabolism via hormones but does not synthesize glucose for circulation.

Question 6

Human body contains ...?

Accepted Answer

Answer reason: This makes the highest option the closest to accepted physiology among the choices provided. Lower percentages such as 20–40% would underestimate normal body composition except in extreme dehydration or markedly increased adiposity. While exact percentage varies by age, sex, and fat mass, the item is testing the general physiologic concept that humans are mostly water.

Question 7

Which ion is critical for muscle relaxation?

Accepted Answer

Answer reason: Magnesium physiologically antagonizes calcium at voltage-gated channels and at the neuromuscular junction, decreasing acetylcholine release and intracellular calcium availability, which promotes muscle relaxation. Clinically, low magnesium is associated with increased neuromuscular irritability (tremors, tetany), consistent with impaired relaxation. By contrast, calcium primarily facilitates contraction rather than relaxation, making it an inferior choice here.

Question 8

The autonomic nervous system controls?

Accepted Answer

Answer reason: It innervates smooth muscle, cardiac muscle, and glands to control processes like heart rate, blood pressure, digestion, pupil size, sweating, and bronchial tone. In contrast, voluntary actions are governed by the somatic nervous system through skeletal muscle control. Thinking and memory are higher cerebral functions of the central nervous system, not autonomic pathways.

Question 9

What is the function of the lymphatic system?

Accepted Answer

Answer reason: Lymphatic capillaries absorb this tissue fluid to form lymph, which is then transported through lymph vessels and ultimately drained back into the bloodstream (e.g., via the thoracic duct/right lymphatic duct). This function is distinct from nutrient storage or enzyme production, which are not primary lymphatic responsibilities. While immune surveillance is another major lymphatic function, among the given choices the best match is restoration of tissue fluid to blood volume.

Question 10

The normal blood pH level at sea level is ________?

Accepted Answer

Answer reason: Acid–base homeostasis maintains arterial blood pH within a narrow range to preserve enzyme function, cellular membrane stability, and cardiovascular/neurologic performance. The standard normal arterial pH range at sea level is 7.35–7.45, reflecting the balance between respiratory (CO2) and metabolic (HCO3−) regulation. Values below 7.35 indicate acidemia and above 7.45 indicate alkalemia, so broader ranges are inaccurate. Options extending the upper limit to 7.50 or 7.53 would incorrectly classify clinically significant alkalemia as normal, while lowering the minimum to 7.30 would miss meaningful acidemia.

Question 11

Diarrhoea causes loss of ...?

Accepted Answer

Answer reason: This leads to depletion of key salts such as sodium, potassium, and bicarbonate, which can result in dehydration, weakness, and acid–base disturbances (e.g., metabolic acidosis from bicarbonate loss). While prolonged diarrhea can contribute to nutritional deficits, the most immediate and clinically important losses are fluid and electrolytes. This is why oral rehydration therapy is formulated to replace sodium and other electrolytes along with water.

Question 12

The nurse cares for a client with a heart rate of 112 beats/minute. Which could be the cause of this condition?

Accepted Answer

Answer reason: Tachycardia is commonly driven by sympathetic nervous system activation with catecholamine release, which increases SA node firing and cardiac output. Emotional stress and acute pain are classic triggers of this response and can readily raise the heart rate above 100 bpm. In contrast, straining with a bowel movement and airway suctioning are vagal stimuli that more often increase parasympathetic tone and cause bradycardia. Vomiting is also a vagal stimulus, so pairing it with stress/pain makes that option less consistently correct for a sustained rate of 112 bpm.

Question 13

Which of the following organism breathes from skin?

Accepted Answer

Answer reason: Earthworms lack lungs and rely primarily on diffusion of oxygen and carbon dioxide across their skin, so they must remain in damp environments to prevent the skin from drying out. Snakes, monkeys, and humans breathe using lungs rather than through the skin as the main respiratory organ. If an earthworm’s skin dries, diffusion is impaired and it can suffocate.

Question 14

Lab values: pH 7.31, paCo2 34, HCO3 21?

Accepted Answer

Answer reason: 31 indicates acidemia. The bicarbonate is low (HCO3 21), identifying a primary metabolic acidosis as the cause of the low pH. The PaCO2 is also low (34), which reflects respiratory compensation via hyperventilation to blow off CO2 and raise pH toward normal. Because the pH remains abnormal despite compensation, this is partial (not complete) compensation. Respiratory alkalosis is excluded because alkalosis would require alkalemic pH (>7.45).

Question 15

A 21-year-old male is brought to the ED due to overdose of heroin. His respiratory rate is 5-6 and he is unresponsive. Prior to administration of naloxone, an arterial blood gas is obtained. The nurse anticipates which of the following results?

Accepted Answer

Answer reason: Opioid overdose causes hypoventilation, leading to CO2 retention and a primary respiratory acidosis. The expected ABG pattern is low pH with elevated PaCO2, with bicarbonate normal or only minimally elevated because there has been insufficient time for renal compensation. This option matches acute respiratory acidosis (acidic pH 7.28 with PaCO2 60) and near-normal HCO3 (26). A common distractor is metabolic acidosis (low HCO3) which would not be the primary disturbance from isolated opioid-induced hypoventilation.

Question 16

Which condition causes high body temperature?

Accepted Answer

Answer reason: Pyrogens (often from infection or inflammation) trigger prostaglandin-mediated resetting of the thermoregulatory center, leading to heat conservation and generation until the new set point is reached. Hypothermia is the opposite condition, characterized by abnormally low body temperature. Shock more commonly causes cool, clammy skin and temperature instability rather than a primary elevation in core temperature, and dehydration may contribute to hyperthermia in heat illness but is not itself the classic condition defined by high body temperature.

Question 17

The part of brain that controls heartbeat and breathing is —?

Accepted Answer

Answer reason: The medulla contains the primary cardiac and vasomotor centers and the dorsal/ventral respiratory groups that set basic breathing rhythm and heart rate control via autonomic output. Damage or suppression of this region can rapidly cause apnea and cardiovascular collapse, which matches the functions asked. The pons modulates respiration (e.g., smoothing the pattern) but is not the main integrative center for both heartbeat and breathing, while cerebrum and cerebellum primarily handle higher cognition and coordination.

Question 18

Persistent vomiting can lead to —?

Accepted Answer

Answer reason: This fluid deficit can quickly lead to signs of dehydration such as thirst, dry mucous membranes, tachycardia, and decreased urine output. While vomiting may accompany illnesses that cause fever, vomiting itself does not directly produce fever. Swelling and weight gain are inconsistent with net fluid loss and are more typical of fluid retention states.

Question 19

The fetal lungs matures at which of the following gestational age?

Accepted Answer

Answer reason: Surfactant production rises substantially in late third trimester, with most fetuses achieving sufficient levels for extrauterine respiration around 34–36 weeks. At 28–32 weeks, many infants still have inadequate surfactant and are at high risk for neonatal respiratory distress syndrome. By 40 weeks lungs are certainly mature, but the key milestone for typical “maturity” for exam purposes is in the mid-to-late 30s weeks.

Question 20

Placental exchange of nutrients occurs by?

Accepted Answer

Answer reason: Oxygen and carbon dioxide, and several small nutrients/waste products, move primarily by simple diffusion from higher to lower concentration between maternal and fetal circulations. Osmosis mainly describes water movement, while filtration is driven by hydrostatic pressure and is not the primary mechanism for nutrient exchange. Although some nutrients (e.g., certain amino acids, calcium) require carrier-mediated active transport, the single best general mechanism tested for placental exchange is diffusion.

Question 21

What is the primary function of the liver in metabolism?

Accepted Answer

Answer reason: It converts excess glucose to glycogen (glycogenesis) for storage and later breaks it down to glucose (glycogenolysis) when circulating levels fall. Insulin production is a pancreatic beta-cell function, not a hepatic one, and nutrient absorption primarily occurs in the small intestine. Heart rate regulation is controlled by cardiac conduction and autonomic input rather than liver metabolism.

Question 22

What is the name of the gas that is transported by the blood to the body's tissues?

Accepted Answer

Answer reason: This is the key gas the circulation is designed to deliver to meet tissue oxygen demand. Carbon dioxide is mainly transported in the opposite direction—from tissues to lungs—for excretion, mostly as bicarbonate. Nitrogen is largely inert in human physiology at normal atmospheric exposure, and hydrogen is not a primary respiratory gas transported for tissue metabolism.

Question 23

What is the primary role of hemoglobin in red blood cells?

Accepted Answer

Answer reason: This binding dramatically increases the oxygen-carrying capacity of blood compared with dissolved oxygen alone, making it essential for adequate cellular respiration. It also carries a smaller fraction of carbon dioxide back to the lungs and contributes to acid–base buffering, but those are secondary roles. Immune defense and clotting factor production are functions of leukocytes and liver-derived coagulation proteins/platelets, not hemoglobin.

Question 24

Which of the following factors affects the rate of diffusion?

Accepted Answer

Answer reason: Higher temperature increases molecular kinetic energy, increasing random motion and net diffusion. A steeper concentration gradient increases the net flux from high to low concentration (Fick’s law). Larger molecular size generally diffuses more slowly because larger particles move less rapidly and experience more resistance in the medium.

Question 25

Which of the following is the function of the human liver?

Accepted Answer

Answer reason: The liver is a central metabolic organ responsible for digestion support and biochemical processing of nutrients. It produces bile, which is required for emulsification and absorption of dietary lipids. It also carries out extensive lipid handling (e.g., fatty acid oxidation, lipoprotein synthesis) and carbohydrate metabolism (e.g., glycogenesis, glycogenolysis, gluconeogenesis) to maintain energy homeostasis. Because each listed function is a true role of the liver, the most complete and accurate choice is the inclusive option.

Question 26

Which organ is responsible for detoxification in the human body?

Accepted Answer

Answer reason: Hepatocytes perform phase I and phase II metabolism and convert ammonia to urea, making the liver the central organ for systemic detoxification. The kidneys mainly excrete substances already in a form suitable for removal and are not the primary site of metabolic detoxification. Lungs and skin contribute to excretion (e.g., CO2, sweat) but do not provide the body’s major detoxifying metabolic pathways.

Question 27

The client is admitted with chronic obstructive pulmonary disease. ABG reveal pH 7.36, CO2 45, O2 84, bicarb 28. The nurse would assess the client to be in?

Accepted Answer

Answer reason: The pH is low-normal (7.36) rather than frankly acidemic, suggesting the body has partially/fully compensated. The bicarbonate is elevated (28), indicating renal retention of HCO3− as compensation for chronic CO2 load, even if the PaCO2 is near the upper limit of normal at this moment. This pattern fits compensated respiratory acidosis rather than metabolic acidosis (which would have low bicarbonate) or alkalosis (which would trend pH upward).

Question 28

Which of the following reduces cerebral edema by constricting cerebral veins?

Accepted Answer

Answer reason: Lowering PaCO2 via hyperventilation causes cerebral vasoconstriction, which reduces cerebral blood volume and thereby lowers intracranial pressure and associated cerebral edema. This effect is rapid but temporary and is used as a short-term measure in acute intracranial hypertension. Mannitol reduces brain water primarily through an osmotic gradient rather than vasoconstriction. Ventriculostomy decreases ICP by draining CSF, and dexamethasone reduces vasogenic edema from tumors by stabilizing capillary permeability, not by CO2-mediated constriction.

Question 29

Melanin is a ..... that protects the eyes from ultraviolet light?

Accepted Answer

Answer reason: In the eye, melanin in the iris and retinal pigment epithelium helps limit UV/light penetration and protects underlying ocular tissues from oxidative injury. Minerals and vitamins are nutrients rather than light-absorbing pigments with this direct protective optical function. Glycerol is a simple alcohol used in metabolism and formulations and does not serve as a UV-protective ocular absorber.

Question 30

What is the liquid component of blood?

Accepted Answer

Answer reason: This fluid portion contains mostly water plus electrolytes, proteins (albumin, clotting factors), nutrients, hormones, and waste products. Platelets, white blood cells, and red blood cells are all cellular/formed elements rather than the liquid medium. Therefore the liquid component is the portion that remains after removing the cells, which is plasma.

Question 31

The nurse is reading a health care provider’s (HCP’s) progress notes in the client’s record and reads that the HCP has documented “insensible fluid loss of approximately 800 mL daily.” The nurse makes a notation that insensible fluid loss occurs through which type of excretion?

Accepted Answer

Answer reason: A typical adult loses several hundred milliliters per day this way, and it increases with fever, tachypnea, and low humidity. Urinary output and gastrointestinal losses are measurable (sensible) and are tracked as part of intake/output. Wound drainage is also measurable and therefore not categorized as insensible loss.

Question 32

Which process describes the movement of molecules with the help of a carrier protein?

Accepted Answer

Answer reason: This passive, carrier-mediated movement is termed facilitated diffusion and is typical for polar molecules like glucose via GLUT transporters. Simple diffusion does not require a carrier protein, and osmosis specifically refers to water movement. Active transport also uses carrier proteins but is defined by movement against a gradient with energy input, which is not implied in the question.

Question 33

What is the normal range for body temperature in adults?

Accepted Answer

Answer reason: 36.5 C to 37 C Normal adult core temperature is tightly regulated by hypothalamic thermoregulation, producing a typical resting oral range around the high 36s to about 37°C. This option best matches the commonly accepted “normal” range used in fundamentals and vital-signs teaching for adults. The higher ranges listed move into low-grade fever territory (≥38°C is generally considered febrile). Minor diurnal and measurement-site variation exists, but among these choices this range is the most accurate baseline.

Question 34

What is the name of the sensory receptor in the skin that detects touch?

Accepted Answer

Answer reason: These receptors are concentrated in dermal papillae of fingertips and other areas needing fine tactile discrimination, matching the function asked. Pacinian corpuscles are deeper and specialize in vibration and deep pressure, making them a common distractor. Free nerve endings mainly mediate pain, temperature, and crude touch/itch rather than fine touch discrimination. Merkel cells detect sustained pressure and texture (slowly adapting) rather than the classic “touch” receptor emphasized in basic physiology questions.

Question 35

Which of the following is a function of skeletal muscle?

Accepted Answer

Answer reason: This makes heat generation an important physiologic role of skeletal muscle in thermoregulation. Gas exchange is primarily an alveolar-capillary function of the lungs, and blood filtration is a renal glomerular function. While skeletal muscle can release myokines, routine “hormone secretion” is not the standard primary function tested compared with heat production, movement, and posture.

Question 36

What is the scientific term for the "killing" of cells?

Accepted Answer

Answer reason: It involves controlled signaling pathways leading to cell shrinkage, DNA fragmentation, and formation of apoptotic bodies that are cleared with minimal inflammation. In contrast, mitosis and meiosis are forms of cell division (somatic and gamete formation, respectively), not cell death. Photosynthesis is a plant metabolic pathway for energy production and is unrelated to cellular death mechanisms.

Question 37

Which part of the eye controls the amount of light entering?

Accepted Answer

Answer reason: The sphincter pupillae constricts the pupil in bright light (parasympathetic), while the dilator pupillae widens it in dim light (sympathetic). This dynamic control function is performed by the colored diaphragm at the front of the eye rather than by focusing or light-detecting structures. A common distractor is the lens, which changes shape for accommodation but does not set the pupil size.

Question 38

Which part of the brain controls breathing?

Accepted Answer

Answer reason: The medulla contains the dorsal and ventral respiratory groups that drive inspiratory and expiratory muscle activity and respond to CO2/pH via chemoreceptor input. Damage or depression of this area (e.g., opioid overdose, brainstem stroke) can cause hypoventilation or apnea. The cerebrum and cerebellum can modulate voluntary breathing and coordination, but they do not provide the primary automatic control of ventilation.

Question 39

What is the process of cell division in somatic cells?

Accepted Answer

Answer reason: This requires one round of DNA replication followed by one nuclear division that equally separates sister chromatids. Meiosis is reserved for germ cells and reduces chromosome number to form haploid gametes. Binary fission is a prokaryotic replication method, and budding is typical of some yeasts and simple organisms rather than human somatic tissues.

Question 40

Which part of the brain controls hunger and thirst?

Accepted Answer

Answer reason: It contains feeding and satiety centers that respond to nutrients and hormones (e.g., leptin, ghrelin) to modulate appetite. It also houses osmoreceptors that detect plasma osmolality and trigger thirst as well as ADH-related responses to conserve water. In contrast, the cerebellum coordinates movement and balance, and the medulla primarily controls vital cardiorespiratory reflexes rather than appetite/thirst regulation.

Question 41

The nurse reviews a client's arterial blood gas values and notes a pH of 7.50 (7.50), a Paco2 30 mm Hg (30 mm Hg), and an HCO3 of 25 mEq/L (25 mmol/L). The nurse should interpret these values as an indication of which condition?

Accepted Answer

Answer reason: The PaCO2 is low (30 mm Hg), which raises pH and therefore points to a primary respiratory alkalosis. The bicarbonate is normal (25 mEq/L), showing the kidneys have not yet adjusted to buffer the alkalemia, so there is no metabolic compensation. Metabolic acidosis options are inconsistent because they would lower pH and/or show decreased HCO3, and respiratory acidosis would have an elevated PaCO2 with acidemia.

Question 42

Cytochromes are found in?

Accepted Answer

Answer reason: The inner membrane is folded into cristae, increasing surface area for oxidative phosphorylation and housing complexes I–IV and cytochrome c. The matrix primarily contains TCA cycle enzymes and mitochondrial DNA, not the membrane-bound cytochrome complexes. Lysosomes and the outer mitochondrial membrane are not the primary sites of the respiratory chain cytochromes.

Question 43

The total volume of blood in the human body is around?

Accepted Answer

Answer reason: This value reflects the normal circulating volume needed to maintain preload, cardiac output, and tissue perfusion at rest. The lower values listed would correspond to severe hypovolemia rather than normal physiology. While total blood volume varies with body size, sex, and pregnancy, 5 L is the best single estimate among the options.

Question 44

Which enzyme is present in saliva?

Accepted Answer

Answer reason: The key enzyme in saliva is salivary amylase (ptyalin), which initiates carbohydrate digestion by breaking down starch into smaller sugars. Trypsin is a pancreatic protease acting in the small intestine, and pepsin is a gastric enzyme active in acidic stomach conditions. Rennin (chymosin) is primarily associated with milk protein coagulation in infants and is not a typical adult salivary enzyme.

Question 45

Which of the following is NOT a function of the digestive system?

Accepted Answer

Answer reason: Oxygen transport is performed by the respiratory and cardiovascular systems via gas exchange in the lungs and hemoglobin-mediated delivery through the bloodstream. The other choices describe classic digestive functions: breaking down food, absorbing nutrients into circulation, and removing solid waste. A common confusion is “eliminating waste products,” but in this context it refers to fecal elimination, which is a gastrointestinal function distinct from renal excretion.

Question 46

What is the name of the protein found in red blood cells that carries oxygen?

Accepted Answer

Answer reason: This protein is abundant in erythrocytes and loads oxygen in the lungs and unloads it in tissues according to partial pressure gradients and pH/CO2 effects. Myoglobin is the oxygen-binding protein in muscle cells rather than circulating red cells. Collagen and keratin are structural proteins and do not function in gas transport.

Question 47

Which gas is the primary stimulus for controlling breathing rate?

Accepted Answer

Answer reason: Rising CO2 increases hydrogen ion concentration, strongly stimulating increased respiratory rate and tidal volume to restore acid-base balance. Oxygen becomes a dominant driver mainly in chronic hypercapnia (e.g., some COPD patients) where peripheral chemoreceptors respond to low PaO2, but this is not the usual primary control in healthy physiology. Nitrogen is inert in respiratory control, and carbon monoxide affects oxygen carrying capacity rather than serving as a physiologic ventilatory stimulus.

Question 48

Which type of muscle is found in the walls of internal organs?

Accepted Answer

Answer reason: g., intestines, blood vessels, bronchi, bladder, uterus) require involuntary contractions to move contents and regulate lumen diameter. This function is performed by non-striated muscle under autonomic and hormonal control. Cardiac muscle is restricted to the myocardium, while skeletal/striated muscle is primarily voluntary and attached to bones (with limited exceptions like parts of the upper esophagus). Therefore the muscle type characteristically found in internal organ walls is the involuntary visceral type.

Question 49

What is the process of cell division for growth and repair?

Accepted Answer

Answer reason: This process produces two genetically identical diploid daughter cells, allowing replacement of damaged or aging cells without changing genetic dosage. Meiosis is specialized for gamete formation and reduces chromosome number, so it is not used for typical body tissue repair. Binary fission and budding are common asexual reproduction methods in prokaryotes/yeast rather than the primary mechanism of human tissue regeneration.

Question 50

Which process results in two genetically identical daughter cells?

Accepted Answer

Answer reason: This occurs when replicated chromosomes are evenly separated into two nuclei followed by cytokinesis, yielding two genetically identical daughter cells. Meiosis, in contrast, involves two rounds of division with crossing over and independent assortment, producing genetically diverse haploid gametes. Fertilization combines genetic material from two gametes, and osmosis is water movement across a semipermeable membrane rather than a cell-division process.

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