Topic 1: INTRODUCTION
Q 1: The exchange of O2 from the atmosphere with CO2 produced by the cells is called
✅ Breathing/ Respiration
Q 2: Lower invertebrates such as sponges, coelenterates, flatworms etc. respire through
✅ Body surface
Q 3: Respiration through Skin or moist cuticle is called
✅ Cutaneous respiration
Q 4: Respiratory organ of earthworms, leech, amphibians etc. is
✅ Skin or moist cuticle
Q 5: Respiratory organ of insects, centipede, millipede, spider is ……………….
✅ Tracheal tubes
Q 6: Respiration through gills is called
✅ Branchial respiration
Q 7: Fishes, tadpoles, prawn etc. respire through
✅ Gills
Q 8: Respiration through Lungs is called
✅ Pulmonary respiration
Q 9: Respiratory organ of most of the vertebrates is
✅ Lungs
Topic 2: HUMAN RESPIRATORY SYSTEM
Q 10: ………………. transports the atmospheric air into the alveoli, clears it from foreign particles, humidifies and brings the air to body temperature.
✅ Air passages (Conducting part)
Q 11: Humans have a pair of external nostrils which leads to a ………………. through the nasal passage.
✅ Nasal chamber
Q 12: The nasal chamber opens into the ………………., a portion of which is the common passage for food and air.
✅ Pharynx
Q 13: The pharynx opens through the ………………. region into the trachea.
✅ Larynx
Q 14: Trachea is a straight tube extending up to the mid-thoracic cavity, which divides at the level of 5th thoracic vertebra into a right and left ……………….
✅ Primary bronchi
Q 15: Each bronchi undergoes repeated divisions to form the secondary and tertiary bronchi and bronchioles ending up in very thin ……………….
✅ Terminal bronchioles
Q 16: Each terminal bronchiole gives rise to many very thin and vascularised ……………….
✅ Alveoli
Q 17: ………………. is a cartilaginous box which helps in sound production and hence called the sound box.
✅ Larynx
Q 18: During swallowing, a thin elastic cartilaginous flap called ………………. closes glottis to prevent entry of food into larynx.
✅ Epiglottis
Q 19: Lungs situate in thoracic chamber and rest on
✅ Diaphragm
Q 20: Lungs are covered by double-layered
✅ Pleura
Q 21: The ………………. present in between outer and inner pleural layers lubricates the surface of the lungs and prevents friction between the membranes.
✅ Pleural fluid
Q 22: The branching network of bronchi, bronchioles and alveoli comprise the
✅ Lungs
Q 23: ………………. and their ducts form the respiratory or exchange part of the respiratory system.
✅ Alveoli
Q 24: The structural and functional units of lungs are
✅ Alveoli
Topic 3: MECHANISM OF BREATHING
Q 25: Active intake of air from atmosphere into lungs is called
✅ Inspiration
Q 26: During inspiration, the ………………. contracts (flattens) causing an increase in thoracic volume in antero-posterior axis.
✅ Diaphragm
Q 27: The muscles found between ribs are called ………………
✅ Intercostal muscles
Q 28: During inspiration, contraction of ………………. lifts up the ribs and sternum causing an increase in thoracic volume in the dorsoventral axis.
✅ External intercostal muscles
Q 29: Increase in thoracic volume causes increase in
✅ Pulmonary volume
Q 30: Passive expelling of air from the lungs is called
✅ Expiration
Q 31: During expiration, intercostal muscles and ………………. relax causing a decrease in thoracic volume and thereby pulmonary volume. So, air moves out.
✅ Diaphragm
Q 32: Volume of air inspired or expired during a normal respiration is called
✅ Tidal volume (TV)
Q 33: Normal tidal volume is about ……………….
✅ 500 ml
Q 34: Additional volume of air that can inspire by a forcible inspiration is called
✅ Inspiratory reserve volume (IRV)
Q 35: Normal Inspiratory reserve volume (IRV) is about
✅ 2500-3000 ml
Q 36: Additional volume of air that can expire by a forcible expiration is called
✅ Expiratory reserve volume (ERV)
Q 37: Normal Expiratory reserve volume (ERV) is about
✅ 1000-1100 ml
Q 38: Volume of air remaining in lungs after a forcible expiration is called
✅ Residual volume (RV)
Q 39: Normal Residual volume (RV) is about
✅ 1100-1200 ml
Q 40: Total volume of air inspired after a normal expiration, i.e., TV + IRV is called
✅ Inspiratory capacity (IC)
Q 41: Normal Inspiratory capacity (IC) is about
✅ 3000-3500 ml
Q 42: Total volume of air expired after a normal inspiration, i.e., TV + ERV is called
✅ Expiratory capacity (EC)
Q 43: Normal Expiratory capacity (EC) is about
✅ 1500-1600 ml
Q 44: Volume of air remaining in the lungs after a normal expiration, i.e., ERV + RV is called
✅ Functional residual capacity (FRC)
Q 45: Functional residual capacity (FRC) of a normal person is about
✅ 2100-2300 ml
Q 46: Volume of air that can breathe in after a forced expiration or Volume of air that can breathe out after a forced inspiration is termed as
✅ Vital capacity (VC)
Q 47: The sum of ERV + TV + IRV is called
✅ Vital capacity (VC)
Q 48: Vital capacity of a normal person is
✅ 3500-4500 ml
Q 49: ………………. is the total volume of air in the lungs after a maximum inspiration.
✅ Total lung capacity (TLC)
Q 50: The sum of RV + ERV + TV + IRV or VC + RV is called
✅ Total lung capacity (TLC)
Q 51: Total lung capacity of a normal person is about
✅ 5000-6000 ml
Q 52: On an average, a healthy human breathes ………………. times/minute.
✅ 12-16
Q 53: Name the instrument used to estimate the volume of air involved in breathing movements.
✅ Spirometer
Topic 4: GAS EXCHANGE
Q 54: ………………. are the primary sites of gas exchange.
✅ Alveoli
Q 55: O2 & CO2 are exchanged by a physical process called
✅ Simple diffusion
Q 56: In atmospheric air, pO2 is 159 mm Hg and pCO2 is ……………….
✅ 0.3 mm Hg
Q 57: In alveoli, pO2 is 104 mm Hg and pCO2 is ……………….
✅ 40 mm Hg
Q 58: In tissues, pCO2 is 45 mm Hg and pO2 is ……………….
✅ 40 mm Hg
Q 59: Solubility of CO2 is ………………. times higher than that of O2.
✅ 20-25
Q 60: The diffusion membrane is made up of three major layers namely, the thin squamous epithelium of alveoli, endothelium of alveolar capillaries and the ………………. in between them.
✅ Basement substance
Topic 5: GAS TRANSPORT
Q 61: The transport of respiratory gases (O2 & CO2) from alveoli to the systemic tissues and vice versa is called
✅ Gas transport
Q 62: About ………………. of O2 is carried in a dissolved state through plasma.
✅ 3%
Q 63: About 97% of O2 is transported by haemoglobin as
✅ Oxyhaemoglobin
Q 64: O2 can bind with haemoglobin in a reversible manner to form ……………….
✅ Oxyhaemoglobin
Q 65: Each haemoglobin molecule can carry a maximum of ………………. oxygen molecules.
✅ 4
Q 66: In the alveoli, high pO2, low pCO2, lesser H+ ion concentration and lower temperature favours the formation of ……………….
✅ Oxyhaemoglobin
Q 67: Every 100 ml of oxygenated blood can deliver around ………………. of O2 to the tissues under normal physiological conditions.
✅ 5 ml
Q 68: ………………. is a sigmoid curve obtained when percentage saturation of Hb with O2 is plotted against the pO2.
✅ Oxygen dissociation curve
Q 69: ………………. is used to study the effect of factors like pCO2, H+ concentration etc., on binding of O2 with Hb.
✅ Oxygen dissociation curve
Q 70: The conditions in tissues favourable for CO2 transport are
✅ high pCO2 and low pO2
Q 71: In tissues, 7% of CO2 is dissolved in plasma water to form ………………. and carried to lungs.
✅ Carbonic acid
Q 72: In tissues, 20-25% of CO2 binds to haemoglobin to form
✅ Carbamino-haemoglobin
Q 73: 70% of CO2 is transported as
✅ Bicarbonates
Q 74: Name the enzyme in RBC that has crucial role in the CO2 transport as bicarbonates.
✅ Carbonic anhydrase
Q 75: Every 100 ml of deoxygenated blood delivers about ………………. of CO2 to the alveoli.
✅ 4 ml
Topic 6: REGULATION OF RESPIRATION, DISORDERS
Q 76: Respiratory rhythm centre (Inspiratory & Expiratory centres) is seen in
✅ Medulla oblongata
Q 77: Pneumotaxic centre is found in
✅ Pons
Q 78: Name the respiratory centre that moderates functions of respiratory rhythm centre.
✅ Pneumotaxic centre
Q 79: The ………………. seen adjacent to the rhythm centre is activated by the increase in the concentration of CO2 and H+, which in turn signals rhythm centre.
✅ Chemosensitive area
Q 80: Receptors in ………………. and carotid artery also recognize changes in CO2 & H+ concentration and send signals to rhythm centre.
✅ Aortic arch
Q 81: Role of ………………. in the regulation of respiratory rhythm is quite insignificant.
✅ Oxygen
Q 82: Difficulty in breathing causing wheezing due to inflammation of bronchi and bronchioles is called
✅ Asthma
Q 83: Due to cigarette smoking, the alveolar walls are damaged causing decrease in respiratory surface. It is called
✅ Emphysema
Q 84: Long exposure of dusts causes inflammation of lungs leading to proliferation of fibrous tissues. It is called
✅ Fibrosis