Carbon monoxide combines with hemoglobin to form carboxyhemoglobin at any or all of the oxygen-binding sites of hemoglobin, It acts to increase the stability of the bond between hemoglobin and oxygen which reduce the ability of the hemoglobin molecule to release oxygen bound to other oxygen-binding sites. Answer : (c)

A Pseudostratified epithelium is a type of epithelium that, though comprising only a single layer of cells, has its cell nuclei positioned in a manner suggestive of stratified epithelia.Ciliated pseudostratified columnar epithelia are found in the linings of the trachea as well as the upper respiratory tract. Answer : (c)

Carbon monoxide is better at binding to haemoglobin than oxygen is – about 200 times better. Answer : (b)

Hamburger's phenomenon is also known as Chloride shift Answer : (d)

Acidosis is an increased acidity in the blood and other body tissue. acidosis caused by retention of carbon dioxide and abnormally elevated carbon dioxidelevels in the blood ( Hypercapnia); due to inadequate pulmonary ventilation or hypoventilation, with decrease in blood pH unless compensated by renal retention of bicarbonate Answer : (a)

Partial pressure of carbon dioxide at sea level in deoxygenated blood is between 35 mmHg and 45 mmHg Answer : (a)

Residual air mostly occurs in Alveoli During breathing out/expiration/exhalation; not all the air is removed from the lungs; the air left inside the lungs during breathing out is residual air. ... air is always left inside the lungs so that more oxygen can be removed (diffuse) into the blood stream. Answer : (a)

SO2 is the compound that dissolves in water but not in blood and so does not impede the oxygen transportation. Answer : (a)

Sneezing typically occurs when foreign particles or sufficient external stimulants pass through the nasal hairs to reach the nasal mucosa. Answer : (b)

Answer : (a)

Answer : (d)

Diagram of respiratory system of insect Other options a, c,d are also correct to some extent but option b is absolutely correct Answer : (b)

Answer:(b)

Buffers in the Human Body. Blood contains large amounts of carbonic acid, a weak acid, and bicarbonate, a base. Together they help maintain the bloods pH at 7.4. The bicarbonate neutralizes excess acids in the blood while the carbonic acid neutralizes excess bases. Answer : (c)

A spirometer is an apparatus for measuring the volume of air inspired and expired by the lungs Answer : (b)

Amount of air inspired or expired during normal breathing is called as Tidal volume which 0.5 L Answer : (d)

Answer : (a)

Oxygen dissociation curve are “S” shaped curve thence called as Sigmoid curve Answer : (a)

Haemoglobinic acid :A very weak acid formed inside red blood cells when hydrogen ions combine with haemoglobin. The presence of the hydrogen ions, which are produced by the dissociation of carbonic acid, encourages oxyhaemoglobin to dissociate into haemoglobin and oxygen. The oxygen diffuses into the tissue cells and the haemoglobin acts as a buffer for the excess hydrogen ions, which it takes up to form haemoglobinic acid. Answer : (a)

Lung volumes and lung capacities refer to the volume of air associated with different phases of the respiratory cycle. The average total lung capacity of an adult human male is about 6000 ml of air. Answer : (a)

Hemoglobin is made of four subunits (two alpha and two beta). Each subunit has a heme. Heme can bind oxygen. Thus, one hemoglobin can theoretically bind four molecules of oxygen. Answer : (d)

Myoglobin is an iron- and oxygen-binding protein found in the muscle tissue of vertebrates in general and in almost all mammals. Answer : (b)

Blood Capillaries are the smallest of the body's blood vessels. They are only one cell thick, and they are the sites of the transfer of oxygen and other nutrients from the bloodstream to other tissues in the body; they also collect carbon dioxide waste materials and fluids for return to the veins. Answer : (b)

A tracheal tube in insects develops as the invagination of the ectoderm. To prevent its collapse under pressure, a thin reinforcing wire' of cuticle called the taenidia winds spirally through. it's membranous wall. The trachea is composed of about 20 rings of tough cartilage Answer : (b)

Carbonic anhydrase An enzyme present in red blood cells, aids in the conversion of carbon dioxide to carbonic acid and bicarbonate ions. When red blood cells reach the lungs, the same enzyme helps to convert the bicarbonate ions back to carbon dioxide, which we breathe out. The enzyme carboxypeptidase A is secreted by the pancreas and is used to speed up this hydrolysis reaction. hydrolase or hydrolytic enzyme is an enzyme that catalyzes the hydrolysis of a chemical bond. Oxidoreductase, any member of a class of enzymes, commonly known as dehydrogenases or oxidases, that catalyze the removal of hydrogen atoms and electrons from the compounds on which they act. Answer : (a)

The maximum quantity of oxygen that will combine chemically with the hemoglobin in a unit volume of blood; normally it amounts to 1.34 ml of O2 per g of Hb or 20 ml of O2 per 100 mL of blood.or 20% Answer : (a)

windpipe ( trachea), is a cartilaginous tube that connects the pharynx andlarynx to the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends from the larynx and branches into the two primary bronchi Answer : (a)

Cyanosis: is defined as the bluish or purplish discolouration of the skin or mucous membranes due to the tissues near the skin surface having low oxygen saturation. Eupnoea: is normal, good, unlabored breathing, sometimes known as quiet breathing or resting respiratory rate. Coryza: catarrhal inflammation of the mucous membrane in the nose, caused especially by a cold or by hay fever, caused by a viral or bacterial infection. Answer : (a)

Answer : (d)

Internal respiration occurs in the metabolizing tissues, where oxygen diffuses out of the blood and carbon dioxide diffuses out of the cells. Diffusion is due to partial pressure. Oxygen defuses out of tissue is due to lower partial pressure of oxygen in blood capillary reaching tissue. Or partial pressure of oxygen is more in tissue than blood in capillary Answer : (b)

Answer : (d)

Pulmonary surfactant: Helps all alveoli in the lungs expand at the same rate, as one that expands more quickly will experience a large rise in surface tension slowing its rate of expansion. It also means the rate of shrinking is more regular, as if one reduces in size more quickly the surface tension will reduce more, so other alveoli can contract more easily than it can. Emphysema:respiratory disease where there is over-inflation of the air sacs (alveoli) in the lungs or uneven expansion and contraction of alveoli. Respiratory distress syndrome: is a syndrome in premature infants caused by developmental insufficiency of pulmonary surfactant production and structural immaturity in the lungs. Cystic fibrosis (CF) is an inherited disease that causes thickened mucus to form in the lungs, pancreas and other organs. In the lungs, this mucus blocks the airways, causing lung damage and making it hard to breathe. Answer : (c)

Carbon dioxide (CO2) is generated in tissues as a byproduct of normal metabolism. It dissolves in blood plasma to form carbonic acid (H2CO3); red blood cell (RBC) carbonic anhydrase catalyzes this reaction. Carbonic acid then spontaneously dissociates to form bicarbonate (HCO3-) and a hydrogen ion (H+) Answer : (b)

The Pleural Cavity is filled with a small amount of serous fluid which forms a thin film of liquid between the pleural layers. This is vital in that it prevents separation of the two pleural layers and lubricates the surface, so the lungs can move easily within the thoracic cavity. Answer : (c)

The medulla oblongata helps regulate breathing, heart and blood vessel function, digestion, sneezing, and swallowing. This part of the brain is a center for respiration and circulation. Sensory and motor neurons (nerve cells) from the forebrain and midbrain travel through the medulla. Answer : (c)

Answer : (d)

Nereis is a genus of polychaete worms in the family Nereidae in a polychaete worm , number of paired muscular bristle-bearing appendages used in locomotion, sensation, or respiration. Answer : (a)

The breathing centre located near the rear of the brain (medulla oblongata) regulates our breathing movements. This breathing centre uses special chemoreceptors to measure CO2 concentrations in the brain and arterial blood. Changes in CO2 produce the main effects on changes in the involuntary breathing pattern Answer : (a)

Only 3 percent of oxygen in the blood is dissolved directly into the blood itself. Most oxygen, 97 percent, is bound to a protein called hemoglobin and carried to the tissues. Answer : (a)

Carbon monoxide is better at binding tohaemoglobin than oxygen is – about 200 times better. Since the carbon monoxide sticks so tightly, there are fewer places for oxygen to bind to haemoglobin and decrease in free haemoglobin Answer : (b)

In the lung, either of two types of epithelial cells lining the alveoli Type I cells are simple thin squamous epithelical cells Type II cells secrete pulmonary surfactant. Type II cells are small in size but more in number than type I Answer : (b)

Bacillus Calmette–Guérin (BCG) vaccine is a vaccine primarily used against tuberculosis. Answer : (b)

In healthy individuals the presence of elevated carbon dioxide levels in the arterial blood is the stimulant that the Respiratory centre of brain responds to in order to signal the respiratory muscles to breathe or increases the respiratory rate to eliminate the excess Answer : (a)

carbonic anhydrase An enzyme present in red blood cells, aids in the conversion of carbon dioxide to carbonic acid and bicarbonate ions. Answer : (a)

Absorption of CO2 in blood carbonic anhydrase convert CO2 with water to produce H2CO3 Then dissociation of H2CO3 in to H+ and HCO3- Combination of H+ with haeme part of HbO2 to release O2 Answer : (c)

Only 3 percent of oxygen in the blood is dissolved directly into the blood itself. Most oxygen, 97 percent, is bound to a protein called hemoglobin and carried to the tissues. Answer : (b)

Apnoea is a term for suspension of external breathing. During apnea, there is no movement of the muscles of inhalation and the volume of the lungs initially remains unchanged. Answer : (b)

Tidal Volume: The amount of air which enters the lungs during normal inhalation at rest. The average tidal volume is 500ml Answer : (c)

The general equation for the Haldane Effect is: H+ + HbO2 → H+Hb + O2; The significance of this equation lies in realizing that oxygenation of Hb promotes dissociation of H+ from Hb, which shifts the bicarbonate buffer equilibrium towards CO2 formation; therefore, CO2 is released from RBCs Answer : (c)

Tidal Volume (TV)	0.5L
Inspiratory Reserve Volume(IRV)	2 to 3L
Expiratory Reserve Volume(ERV)	1 to 1.1L
Residual Volume(RV)	1.1to 1.2L
Functional Residual Capacity(FRC) (ERV + RV)	2500 mL
Vital Capacity (VC) [T.V. + I.R.V. + E.R.V.]	3.5 to 4.5L
Total Lung Capacity (TLC) [RV+VC]	6000 mL
Minimal Volume (MV)	500 mL
inspiratory capacity (IC = IRV + VT)	6 L

Answer : (c)