Question 1

The liquid part of blood is called?

Accepted Answer

Answer reason: The liquid component of blood is plasma, which makes up the majority of blood volume and serves as the medium that carries dissolved proteins, electrolytes, nutrients, hormones, and waste products. Red blood cells, white blood cells, and platelets are cellular (formed) elements suspended in this fluid. Serum is plasma without clotting factors, but the question asks for the liquid part of blood, which is plasma.

Question 2

Pancreas secretes?

Accepted Answer

Answer reason: The pancreas has both endocrine and exocrine functions. Endocrine islet cells secrete insulin (beta cells) and glucagon (alpha cells) to regulate blood glucose. Exocrine acinar cells secrete digestive enzymes (e.g., amylase, lipase, proteases) into the pancreatic ducts, so all listed substances are secreted by the pancreas.

Question 3

In isometric exercise all are increased except?

Accepted Answer

Answer reason: Isometric (static) exercise causes sustained muscle contraction that compresses arterioles, increasing systemic vascular resistance and thereby increasing mean arterial pressure. Heart rate rises due to sympathetic activation, but stroke volume is limited by increased afterload and reduced venous return from compressed vessels. Because stroke volume does not rise (and may fall), cardiac output typically does not increase much compared with dynamic exercise and may be relatively unchanged, making it the best “except” choice.

Question 4

Lactase is an enzyme that breaks down?

Accepted Answer

Answer reason: Lactase is a brush-border enzyme in the small intestine that hydrolyzes lactose, the primary sugar in milk, into glucose and galactose for absorption. Protein digestion is mainly by pepsin and pancreatic proteases, fat digestion by lipase, and starch digestion by amylase and brush-border disaccharidases other than lactase. Therefore, the correct substrate for lactase is milk sugar (lactose).

Question 5

Metabolism refers to?

Accepted Answer

Answer reason: Metabolism includes the totality of chemical reactions in the body, encompassing both catabolism (breakdown of molecules with release of energy) and anabolism (building of molecules requiring energy input). Therefore, metabolism can involve either release of energy or gain/consumption of energy depending on the pathway. Options A and B describe only one side of metabolism, and option C names only one component (catabolism) rather than the whole process. Thus, the best definition among the choices is gain or release of energy.

Question 6

How Many Hours Food Is Stored In Stomach ?

Accepted Answer

Answer reason: Typical gastric emptying time for a mixed solid meal is on the order of several hours, most commonly around 4–5 hours. Liquids generally empty faster (often within 1–2 hours), while very fatty meals can take longer, but the best single general estimate among the options is 4 to 5 hours. The stomach primarily serves as a reservoir and mixer before controlled delivery of chyme into the duodenum. Therefore, option B best reflects standard physiology teaching for average meal transit from the stomach.

Question 7

What is the function of hemoglobin?

Accepted Answer

Answer reason: Hemoglobin is an iron-containing protein in red blood cells that binds oxygen in the lungs and delivers it to body tissues. It also facilitates carbon dioxide transport back to the lungs and contributes to blood buffering, but its primary tested function is oxygen transport. Clotting is mainly mediated by platelets and coagulation factors, immune defense by white blood cells/antibodies, and digestion by gastrointestinal enzymes.

Question 8

Human body is mostly made of?

Accepted Answer

Answer reason: The human body is primarily composed of water, which makes up roughly about 50–70% of body weight depending on age, sex, and body composition. Water is the main component of intracellular and extracellular fluid and is essential for cellular metabolism, temperature regulation, and transport of nutrients and waste. Bones, muscles, and blood are significant tissues but collectively account for a smaller proportion of total body mass than water.

Question 9

Which organelle is known as the powerhouse of the cell?

Accepted Answer

Answer reason: Mitochondria are called the "powerhouse" because they generate most of the cell’s ATP through aerobic cellular respiration (oxidative phosphorylation). ATP is the primary energy currency used to power cellular processes. Ribosomes synthesize proteins, the endoplasmic reticulum synthesizes/transport proteins and lipids, and the Golgi apparatus modifies and packages proteins and lipids rather than producing ATP.

Question 10

PH value of human blood is ...?

Accepted Answer

Answer reason: Normal human arterial blood pH is tightly regulated around 7.35–7.45, making it slightly alkaline. Among the given options, 7 is the closest approximation to the physiologic blood pH range. Values like 3 or 6 would represent severe acidemia incompatible with life, and 9 is far too alkaline for normal physiology.

Question 11

Oxygen deficiency is called ...?

Accepted Answer

Answer reason: Oxygen deficiency at the tissue level is termed hypoxia (inadequate oxygen available for cellular metabolism). Dyspnea refers to the subjective sensation of difficult breathing, not necessarily low oxygen. Anemia is reduced hemoglobin/RBC mass, which can impair oxygen-carrying capacity but is not synonymous with oxygen deficiency itself. Apnea is cessation of breathing.

Question 12

Children grow faster in the?

Accepted Answer

Answer reason: Seasonal variation in linear growth has been observed in children, with height velocity tending to peak during spring/early summer and slow during autumn/winter. Proposed contributors include increased physical activity, greater sunlight exposure (vitamin D), and other circannual hormonal patterns affecting growth. Among the options given, spring is the best match for the period associated with faster growth.

Question 13

Which Acid is found in the Stomach?

Accepted Answer

Answer reason: The primary acid in gastric juice is hydrochloric acid (HCl), secreted by parietal cells in the stomach. HCl creates a very low pH that denatures proteins, activates pepsinogen to pepsin, and helps kill ingested microbes. The other listed acids are not normal physiologic secretions of the stomach.

Question 14

The scrotum helps in maintaining a temperature ____ lower than the internal body temperature?

Accepted Answer

Answer reason: Normal spermatogenesis requires the testes to be kept cooler than core body temperature. The scrotum, via the dartos and cremaster muscles and countercurrent heat exchange in the pampiniform plexus, maintains testicular temperature about 2–3°C below core temperature. Among the choices, 2 to 2.5°C best matches this physiologic range. Larger decreases (e.g., 4–4.5°C) are not typical for normal thermoregulation.

Question 15

Your patient has an increased temperature of 106°F. You should be aware that the oxygen demands of the body would change in which direction and why?

Accepted Answer

Answer reason: A very high fever increases the body's metabolic rate; as metabolism rises, cellular oxygen consumption increases to support heightened energy needs. Fever also commonly increases heart rate and respiratory rate, reflecting increased systemic demand. Therefore, oxygen demand increases because metabolism increases.

Question 16

The normal infant respiratory rate per minute is-?

Accepted Answer

Answer reason: Normal infant respiratory rate is higher than older children and adults due to higher metabolic demand and smaller lung capacity. Standard pediatric vital-sign ranges commonly cite approximately 30–60 breaths per minute for infants (especially newborns/early infancy). The other options are either far too low (10) or excessively high for a normal resting infant (80, 120). Therefore, 30–60 is the best answer.

Question 17

Which statement is right?

Accepted Answer

Answer reason: Gravitational attraction follows Newton’s law of universal gravitation: force is directly proportional to the product of the masses and inversely proportional to the square of the distance between them. Therefore, as distance increases, gravitational force decreases. Option C is also a true physics statement, but the item appears to require selecting a single correct statement; B is clearly correct as written. Options A and D are incorrect because postural drainage is aimed at secretion clearance (not treating fibrosis itself) and chest drainage is not based on osmosis.

Question 18

Which part of the brain controls heartbeat and breathing?

Accepted Answer

Answer reason: The medulla oblongata contains vital autonomic centers that regulate respiration and cardiovascular function, including heart rate and basic breathing rhythm. It integrates input from chemoreceptors and baroreceptors to adjust ventilation and blood pressure. The cerebrum and thalamus have higher-level sensory, motor, and relay functions, but they do not directly control these essential life-sustaining reflexes.

Question 19

Which part of the brain controls temperature, hunger, and thirst?

Accepted Answer

Answer reason: The hypothalamus is the key homeostatic control center that regulates body temperature, appetite (hunger/satiety), and thirst through autonomic and endocrine mechanisms. It integrates signals from the body (e.g., osmolarity, nutrients, and temperature) and drives behavioral and hormonal responses to maintain internal balance. The thalamus is primarily a sensory relay, the midbrain is involved in arousal and motor/sensory pathways, and the cerebellum coordinates movement rather than homeostasis.

Question 20

Nerve cell conduct information through sound waves?

Accepted Answer

Answer reason: Neurons transmit information primarily via electrical signals: action potentials propagating along the membrane and synaptic electrical/chemical signaling at junctions. While sound waves can be converted into neural signals by the ear’s mechanoreceptors, the nerve cell itself conducts the message as electrical impulses, not as mechanical or magnetic impulses. Therefore, “Electrical impulses” is the single best choice. “All” is incorrect because magnetic impulses are not a physiologic mode of neural conduction.

Question 21

Which symptom indicates hypovolemia?

Accepted Answer

Answer reason: Hypovolemia decreases circulating blood volume, which lowers venous return and stroke volume. The body compensates via sympathetic activation to maintain cardiac output, producing tachycardia as an early, common sign. Edema and warm skin are more consistent with fluid excess or vasodilation, and hypertension is not typical of hypovolemia (hypotension occurs later).

Question 22

First sign of puberty in female is—?

Accepted Answer

Answer reason: The earliest clinically recognized sign of female puberty is thelarche (breast budding), reflecting activation of the hypothalamic-pituitary-gonadal axis and rising estrogen effect on breast tissue. Pubarche (pubic hair) is typically later and is more related to adrenal androgen production (adrenarche). Menarche occurs relatively late, usually about 2–3 years after thelarche. A height spurt generally follows early pubertal changes but is not the first sign.

Question 23

Which part of the brain controls body temperature and hunger?

Accepted Answer

Answer reason: The hypothalamus is the main homeostatic control center of the brain and regulates core body temperature via autonomic and endocrine responses. It also contains key nuclei that control appetite and satiety, integrating signals such as leptin, ghrelin, and glucose levels. The cerebellum primarily coordinates movement and balance, and the medulla mainly controls vital autonomic functions like respiration and heart rate rather than hunger and temperature set-point control.

Question 24

Name the acid which is secreted in stomach?

Accepted Answer

Answer reason: The primary acid secreted by the stomach is hydrochloric acid (HCl), produced by parietal cells in the gastric glands. HCl helps denature proteins, activates pepsinogen to pepsin, and provides an acidic environment that inhibits many ingested microbes. The other listed acids (sulfuric, acetic, nitric) are not normal physiologic gastric secretions.

Question 25

Fever above 41°C is called as ...?

Accepted Answer

Answer reason: A body temperature above 41°C is termed hyperpyrexia, indicating an extreme, potentially life-threatening elevation in temperature. Pyrexia refers to fever in general, not necessarily at this extreme threshold. Hypothermia is abnormally low body temperature, and hypoxia refers to inadequate oxygenation rather than temperature. Therefore, hyperpyrexia is the most accurate term.

Question 26

Which part of the brain is responsible for regulating body temperature?

Accepted Answer

Answer reason: The hypothalamus is the body’s primary thermoregulatory center, integrating input from peripheral and central thermoreceptors. It maintains a temperature set point and triggers heat-dissipating responses (e.g., sweating, vasodilation) or heat-conserving/producing responses (e.g., shivering, vasoconstriction). The thalamus mainly relays sensory signals, the pituitary primarily secretes hormones, and the pineal gland regulates circadian rhythms via melatonin rather than core temperature control.

Question 27

Most dangerous complication of dehydration in infants?

Accepted Answer

Answer reason: In infants, dehydration can rapidly reduce circulating intravascular volume, leading to hypovolemic shock with poor tissue perfusion and potential multi-organ failure. This is the most immediately life-threatening complication and requires urgent fluid resuscitation. Seizures can occur (especially with severe electrolyte disturbances like hypernatremia), but they are typically secondary to the underlying hemodynamic and electrolyte derangements. Fever and hypothermia may be associated findings but are not the most dangerous complication compared with shock.

Question 28

How much percentage of plasma is present in the blood?

Accepted Answer

Answer reason: Whole blood is composed of plasma and formed elements (primarily red blood cells, plus white blood cells and platelets). In normal adults, plasma makes up about 55% of total blood volume, with the remaining ~45% being formed elements (hematocrit). Therefore, 55% is the best answer among the options provided. Values like 10%, 30%, or 100% do not reflect normal blood composition.

Question 29

Most effective wavelength of light for phototherapy is?

Accepted Answer

Answer reason: Phototherapy for neonatal hyperbilirubinemia is most effective in the blue light spectrum, with peak efficacy around 460 nm. This wavelength maximally converts unconjugated bilirubin into water-soluble photoisomers (e.g., lumirubin) that can be excreted without hepatic conjugation. Wavelengths outside this blue range are less efficient at bilirubin photoisomerization. Therefore 450–460 nm is the best choice.

Question 30

Total calcium present in the human body is in the blood?

Accepted Answer

Answer reason: In the human body, about 99% of calcium is stored in bones and teeth as hydroxyapatite, leaving only about 1% in extracellular fluid including the blood. The calcium in blood exists as ionized (active), protein-bound (mainly to albumin), and complexed forms. Because only a very small fraction of total body calcium circulates in blood at any moment, 1% is the best answer among the options.

Question 31

The sense of smell is also known as?

Accepted Answer

Answer reason: Smell is termed olfaction and is mediated by olfactory receptor neurons in the nasal epithelium that transmit signals via cranial nerve I to the olfactory bulb and related brain regions. Auditory sense refers to hearing, vision refers to sight, and gustation refers to taste. Therefore, the correct term for the sense of smell is olfaction.

Question 32

Which one of the following is used for blood clotting?

Accepted Answer

Answer reason: Calcium (factor IV) is an essential cofactor in multiple steps of the coagulation cascade, facilitating activation of vitamin K–dependent clotting factors on phospholipid surfaces. Without adequate ionized calcium, both intrinsic and extrinsic pathway reactions are impaired and clot formation is reduced. Sodium and potassium are major electrolytes for membrane potentials and fluid balance, not direct coagulation cofactors. Phosphate is important in energy metabolism and buffering but is not the key ion required for coagulation reactions.

Question 33

The blood bank of human body is?

Accepted Answer

Answer reason: The liver is considered a major blood reservoir (“blood bank”) because its large venous sinusoids can hold a substantial volume of blood and release it into circulation during sympathetic stimulation (e.g., hemorrhage). This reservoir function helps buffer acute changes in circulating blood volume and venous return. The heart, lungs, and kidneys are essential for circulation, gas exchange, and filtration respectively, but they are not primary storage sites for blood volume like the liver.

Question 34

In human body, Urea is synthesized by ...?

Accepted Answer

Answer reason: Urea is synthesized in the liver via the urea cycle (ornithine cycle), which converts toxic ammonia produced from amino acid metabolism into urea. This detoxification process is a key hepatic function to maintain safe blood ammonia levels. The kidneys primarily excrete urea in urine but do not synthesize it. The bladder only stores urine, and the spleen is involved in immune and blood filtration functions.

Question 35

The condition of low oxygen in tissue is called?

Accepted Answer

Answer reason: Low oxygen at the tissue level is termed hypoxia, meaning inadequate oxygen availability for cellular metabolism. This can result from decreased arterial oxygen content, reduced blood flow (ischemia), or impaired oxygen utilization. The other options are unrelated: septicemia is bloodstream infection, and amenorrhea is absence of menstruation.

Question 36

Red blood cells are responsible for transporting?

Accepted Answer

Answer reason: Red blood cells primarily transport oxygen bound to hemoglobin, delivering it from the lungs to body tissues. While blood carries glucose and hormones mainly in plasma, RBCs are specialized for gas transport (oxygen and some carbon dioxide). Heat is distributed by circulating blood overall, but RBCs are not specifically responsible for heat transport as their primary function.

Question 37

Human body doesn’t produce?

Accepted Answer

Answer reason: The body synthesizes hormones (endocrine glands), enzymes (produced by many cells including digestive organs), and blood cells (hematopoiesis in bone marrow). In contrast, most vitamins are essential nutrients that must be obtained from the diet because humans cannot synthesize them in adequate amounts. While there are limited exceptions (e.g., vitamin D synthesized in skin with UV exposure; vitamin K partly produced by gut flora), the best overall answer is vitamins.

Question 38

Which organ is responsible for detoxification in the body?

Accepted Answer

Answer reason: The liver is the body’s primary organ for detoxification, metabolizing and inactivating drugs, alcohol, and endogenous toxins via hepatic enzyme systems (e.g., cytochrome P450) and conjugation pathways. It also converts ammonia to urea for safer excretion and produces bile to help eliminate certain waste products. Kidneys mainly excrete substances after they have been processed, lungs primarily remove CO2, and the pancreas is mainly endocrine/exocrine for glucose regulation and digestion rather than detoxification.

Question 39

What is the powerhouse of the cell?

Accepted Answer

Answer reason: Mitochondria are called the powerhouse of the cell because they generate most cellular ATP through aerobic respiration and oxidative phosphorylation. This ATP provides the energy needed for cellular processes such as active transport, biosynthesis, and muscle contraction. Ribosomes synthesize proteins, the nucleus stores genetic material and regulates gene expression, and the Golgi apparatus modifies and packages proteins/lipids rather than producing ATP.

Question 40

At High altitudes, O2 is delivered to tissues because of?

Accepted Answer

Answer reason: At high altitude, hypoxemia stimulates increased 2,3-BPG production in red blood cells over time, which decreases hemoglobin’s affinity for oxygen and shifts the oxyhemoglobin dissociation curve to the right. A right shift facilitates unloading (delivery) of O2 to peripheral tissues at a given PO2. In contrast, high pH and decreased temperature shift the curve left, increasing Hb-O2 affinity and reducing tissue unloading. Therefore the mechanism that improves tissue O2 delivery is the right shift of the curve.

Question 41

Most of the fluid in the body is found ...?

Accepted Answer

Answer reason: Total body water is primarily distributed between intracellular fluid (ICF) and extracellular fluid (ECF). The largest compartment is ICF, which contains about two-thirds of total body water, whereas ECF (interstitial + plasma) contains about one-third. Therefore, most fluid in the body is located inside the cells rather than in blood, lymph/CSF, or the gastrointestinal lumen prior to absorption.

Question 42

Which hormone stimulates the secretion of gastric juice?

Accepted Answer

Answer reason: Gastrin is released by G cells in the stomach (especially the antrum) in response to food, stomach distension, and vagal stimulation. It stimulates gastric acid (HCl) secretion by parietal cells directly and indirectly via histamine release from enterochromaffin-like cells, increasing overall gastric juice production. Secretin generally inhibits gastric acid secretion while stimulating pancreatic bicarbonate secretion. Insulin and glucagon primarily regulate blood glucose and do not physiologically stimulate gastric juice secretion.

Question 43

What fraction of Human Blood is Plasma?

Accepted Answer

Answer reason: In normal adult blood, plasma makes up about 55% of total blood volume, with the remaining ~45% being formed elements (primarily red blood cells, plus white blood cells and platelets). This corresponds to a typical hematocrit around 45%, leaving the rest as plasma. Therefore, 55% is the best answer among the options.

Question 44

The enzyme salivary amylase begins the digestion of?

Accepted Answer

Answer reason: Salivary amylase (ptyalin) is secreted by the salivary glands and initiates chemical digestion in the mouth by hydrolyzing starch (a polysaccharide) into smaller carbohydrates such as maltose and dextrins. Protein digestion begins primarily in the stomach via pepsin, and most fat digestion occurs in the small intestine via pancreatic lipase (with a minor role for lingual lipase). Vitamins are not digested by enzymes; they are absorbed largely unchanged.

Question 45

Which organ detoxifies chemicals, metabolizes drugs, and stores energy in the form of glycogen?

Accepted Answer

Answer reason: The liver is the primary organ responsible for detoxifying chemicals and metabolizing many drugs via hepatic enzyme systems (e.g., cytochrome P450). It also plays a key role in carbohydrate metabolism by converting glucose to glycogen for storage (glycogenesis) and releasing glucose when needed (glycogenolysis). The kidney primarily excretes wastes, the pancreas produces digestive enzymes and hormones, and the gallbladder stores bile rather than glycogen.

Question 46

Deoxygenated blood meaning ...?

Accepted Answer

Answer reason: Deoxygenated blood refers to blood that has delivered much of its oxygen to tissues and therefore has a lower oxygen content (lower oxyhemoglobin saturation) compared with oxygenated arterial blood. In systemic circulation, venous blood is typically deoxygenated because tissues extract oxygen for metabolism. While deoxygenated blood still contains some dissolved oxygen, it is best described as lacking oxygen relative to oxygenated blood. Therefore, the option stating lack of oxygen is the most accurate among the choices.

Question 47

The digestion of starch begins in the?

Accepted Answer

Answer reason: Starch (a polysaccharide) digestion begins in the mouth due to salivary amylase (ptyalin), which starts breaking starch into smaller carbohydrates like maltose and dextrins. The esophagus has no digestive enzymes and mainly transports the bolus. In the stomach, acidic pH inactivates salivary amylase, so significant starch digestion does not begin there. Although most carbohydrate digestion continues in the small intestine via pancreatic amylase, the first site where it begins is the mouth.

Question 48

Pepsin works best in which type of environment?

Accepted Answer

Answer reason: Pepsin is a gastric protease that has maximal activity at a low pH (about 1.5–2), which is created by hydrochloric acid in the stomach. Acid also converts the inactive precursor pepsinogen into active pepsin. In neutral or alkaline/basic environments, pepsin activity decreases markedly and it can become inactivated. Therefore, an acidic environment is optimal for pepsin function.

Question 49

Vomiting is controlled by?

Accepted Answer

Answer reason: Vomiting is coordinated by the vomiting center in the medulla oblongata of the brainstem, which integrates inputs from the chemoreceptor trigger zone, vestibular system, and gastrointestinal vagal afferents. This central control then activates the patterned motor responses (diaphragm, abdominal muscles, and GI tract) that produce emesis. Therefore, the controlling site is the brain, not an individual peripheral organ like the stomach, lungs, or liver.

Question 50

Human Heart Is?

Accepted Answer

Answer reason: The human heart is myogenic because its rhythmic contractions are initiated by pacemaker cells within the heart, primarily in the sinoatrial (SA) node. This intrinsic automaticity allows the heart to generate impulses without requiring direct nervous system initiation. Autonomic nerves modulate the rate and force of contraction but do not start the heartbeat. Therefore, “Myogenic” is the best answer.

Train with a large NCLEX question bank and jump into a full exam-style simulator

Physiology NCLEX Practice Test

Continue Learning