Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

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Tamilnadu Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Samacheer Kalvi 11th Bio Zoology Respiration Text Book Back Questions and Answers

I. Multiple Choice Questions
Question 1.
Breathing is controlled by ………..
(a) cerebrum
(b) medulla oblongata
(c) cerebellum
(d) pons
Answer:
(b) medulla oblongata

Question 2.
Intercostal muscles are found between the ………..
(a) vertebral column
(b) sternum
(c) ribs
(d) glottis
Answer:
(c) ribs

Question 3.
The respiratory structures of insects are ………..
(a) tracheal tubes
(b) gills
(c) green glands
(d) lungs
Answer:
(a) tracheal tubes

Question 4.
Asthma is caused due to ………..
(a) inflammation of bronchus and bronchioles
(b) inflammation of branchiole
(c) damage of diaphragm
(d) infection of lungs
Answer:
(d) infection of lungs

Question 5.
The Oxygen Dissociation Curve is ………..
(a) sigmoid
(b) straight line
(c) curved
(d) rectangular hyperbola
Answer:
(a) sigmoid

Question 6.
The Tidal Volume of a normal person is ………..
(a) 800 mL
(b) 1200 mL
(c) 500 mL
(d) 1100- 1200 mL
Answer:
(c) 500 mL

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 7.
During inspiration, the diaphragm ………..
(a) expands
(b) unchanged
(c) relaxes to become dome-shaped
(d) contracts and flattens
Answer:
(d) contracts and flattens

Question 8.
CO2 is transported through blood to lungs as ………..
(a) carbonic acid
(b) oxyhaemoglobin
(c) carbamino haemoglobin
(d) carboxy haemoglobin
Answer:
(c) carbamino haemoglobin

Question 9.
When 1500 mL air is in the lungs, it is called ………..
(a) vital capacity
(b) tidal volume
(c) residual volume
(d) inspiratory reserve volume
Answer:
(b) tidal volume

Question 10.
Vital capacity is ………..
(a) TV + IRV
(b) TV + ERV
(c) RV + ERV
(d) TV + TRV + ERV
Answer:
(d) TV + TRV + ERV

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 11.
After a long deep breath, we do not respire for some seconds due to ………..
(a) more CO2 in the blood
(b) more O2 in the blood
(c) less CO2 in the blood
(d) less CL in the blood
Answer:
(b) more O2 in the blood

Question 12.
Which of the following substances in tobacco smoke damage the gas exchange system?
(a) carbon monoxide and carcinogens
(b) carbon monoxide and nicotine
(c) carcinogens and tar
(d) nicotine and tar
Answer:
(d) nicotine and tar

Question 13.
Column I represents diseases and column II represents their symptoms. Choose the correctly paired option

Column I

Column II

(P) Asthma

(i) Recurring  of bronchitis

(Q) Emphysema

(ii) Accumulation of WBCs in alveolus

(R) Pneumonia

(iii) Allergy

(a) P = iii, Q = ii, R = i
(b) P = iii, Q = i, R = ii
(c) P = ii, Q = iii, R = i
(d) P = ii, Q = i, R = iii
Answer:
(a) P = iii, Q = ii, R = i

Question 14.
Which of the following best describes the process of gas exchange in the lungs?
(a) Air moves in and out of the alveoli during breathing.
(b) Carbon dioxide diffuses from deoxygenated blood in capillaries into the alveolar air.
(c) Oxygen and carbon dioxide diffuse down their concentration gradients between blood and alveolar air.
(d) Oxygen diffuses from alveolar air into deoxygenated blood.
Answer:
(c) Oxygen and carbon dioxide diffuse down their concentration gradients between blood and alveolar air.

Question 15.
Make the correct pairs.

Column I

Column II

(P) IC i. maximum volume of air breathe in after forced.
(Q) EC ii. Volume of air present after expiration in lungs.
(R) VC iii. Volume of air inhaled after expiration.
(S) FRC iv. Volume of air present after expiration in lungs.

(a) P – i, Q – ii, R – iii, S – iv
(b) P – ii, Q – iii, R – iv , S – i
(c) P – ii, Q – iii , R – i, S – iv
(d) P – iii, Q – iv , R – i, S – ii
Answer:
(d) P – iii, Q – iv, R – i, S – ii

Make the correct pairs.

Column I

Column II

(P) Tidal volume

i. 1000 to 1100 ml

(Q) Residual volume

ii. 500 ml

(R) Expiratory reserve volume

iii. 2500 to 3000 ml

(S) Inspiratory reserve volume

iv. 1100 to 1200 ml

(a) P – ii, Q – iv , R – i, S – iii
(b) P – iii. Q – ii , R – iv , S – i
(c) P – ii, Q – iv , R – iii, S – i
(d) P – iii , Q – iv , R – i, S – ii
Answer:
(a) P – ii, Q – iv, R – i, S – iii

II. Very Short Answer Questions

Question 17.
Name the respiratory organs of flatworm, earthworm, fish, prawn, cockroach, and cat.
Answer:
Flatworm – Body surface
Earthworm – Body wall
Fish -Gills
Prawn -Gills
Cockroach -Trachea
Cat -Lungs

Question 18.
Name the enzyme that catalyses the bicarbonate formation in RBCs.
Answer:
Carbonic anhydrase.

Question 19.
Air moving from the nose to the trachea passes through a number of structures. List in order of the structures.
Answer:
Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration img 1

Question 20.
Which structure seals the larynx when we swallow?
Answer:
Epiglottis.

III. Short Answer Questions

Question 21.
Resistance in the airways is typically low. Why? Give two reasons.
Answer:

  1. As the cartilaginous rings present in the trachea provide an easy way for air. The bronchi have ‘C’ shaped curved cartilage plates to ensure that the air passage does not collapse.
  2. The rigidity of bronchioles prevents them from collapsing. Thus the air reaches the lungs without any disturbances.

Question 22.
How the body makes long-term adjustments when living in high altitude?
Answer:
When a person lives at a higher altitude, the body makes respiratory and hematopoietic adjustments. Kidneys accelerate the production of the hormone erythropoietin which stimulates the bone marrow to produce more RBCs. This improves the binding of 02 with hemoglobin.

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 23.
Why is pneumonia considered a dangerous disease?
Answer:
In pneumonia there is inflammation of the lungs leads to the damage of alveoli. As there are sputum production Nasal congestion, sore throat and shortness of breath it is considered as a dangerous disease.

Question 24.
Diffusion of gases occurs in the alveolar region only and not in any other part of the respiratory system. Discuss.
Answer:
The alveolar region is highly vascular. Each alveolus is made up of highly permeable and thin layers of squamous epithelial cells. The barrier between the alveoli and the capillaries is thin and diffusion of gases takes place from higher partial pressure to low er partial pressure. Hence, gaseous exchange takes place in the aboral region only but not in any other part of the respiratory system.

Question 25.
Sketch a flow chart to show the pathway of airflow during respiration.
Answer:
Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration img 2

Question 26.
Explain the conditions which create problems in oxygen transport.
Answer:
When a person travels from sea level to elevations above 8000 feet where the atmospheric pressure and partial pressure of O2 are lowered, he will have symptoms of acute mountain sickness, headache, shortness of breath nausea, and dizziness due to poor binding of O2 with haemoglobin.

  • When a person descends deep into the sea the pressure in the surrounding water increases which causes the lungs to decrease in volume.
  • It leads to keep more oxygen in the circulation.
  • But that leads to an increase in blood nitrogen leads to nitrogen narcosis.
  • When he ascends to the surface he will suffer from a condition called bends.
  • Large bubbles can lodge in small capillaries blocking blood flow or can press on nerve endings.
  • Symptom: Pain in joints and muscles, Stroke.

Entrance Examination Questions Solved
Choose the correct answer
Question 1.
The length of human trachea is about ……….. [Gujarat CETQB]
(a) 6 inches
(b) 12 cm
(c) 12 inches
(d) 18 cm
Answer:
(b) 12 cm

Question 2.
Hamburger’s phenomenon is also known as ……….. [CPMT1988,1991, AMU2001, JLPMER 2002]
(a) HCO3 shift
(b) Na+ shift
(c) H+ shift
(d) Chloride shift
Answer:
(d) Chloride shift

Question 3.
Oxygen carrying capacity of blood is ……….. [CPMT1990]
(a) 20%
(b) 30%
(c) 40%
(d) 50%
Answer:
(a) 20%

Question 4.
Respiratory movements are controlled by ……….. [APMEE 1978, CPMT 1998]
(a) Cerebellum
(b) Cerebrum
(c) Medulla oblongata
(d) Crura cerebri
Answer:
(c) Medulla oblongata

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 5.
At higher CO2 concentration, oxygen dissociation curve of haemoglobin will ……….. [CPMTX 990]
(a) Move to left
(b) Move to right
(c) Become irregular
(d) Move upwardly
Answer:
(b) Move to right

Question 6.
Chloride shift is required for transport of ……….. [CPMT 1990]
(a) Nitrogen
(b) Oxygen
(c) Carbon dioxide
(d) Carbon dioxide and oxygen
Answer:
(c) Carbon dioxide

Question 7.
Volume of air inspired or expired with each normal breath is known ……….. [CMPTl 992, AMU 2000]
(a) Inspiratory capacity
(b) Total Lung capacity
(c) Tidal volume
(d) Residual volume
Answer:
(c) Tidal volume

Question 8.
Oxygen hemoglobin dissociation curve will shift to the right on the decrease of ……….. [AMU 1992]
(a) Acidity
(b) Carbon dioxide concentration
(c) Temperature
(d) pH
Answer:
(d) pH

Question 9.
Double membrane pleural sac ……….. [JKCMEE 1992]
(a) Envelops the kidneys
(b) Envelops the brain
(c) Envelops the lungs
(d) Lines the nasal passage
Answer:
(c) Envelops the lungs

Question 10.
The volume of air remaining in lungs after maximum respiratory’ effort is ……….. [JKCMEE 1992, Har. PMT 2003]
(a) Vital capacity
(b) Residual volume
(c) Total lung capacity
(d) Tidal volume
Answer:
(b) Residual volume

Question 11.
In expiration, the diaphragm becomes ………..
(a) Flattened
(b) Relaxed
(c) Straightened
(d) Arched
Answer:
(b) Relaxed

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 12.
Carbon dioxide is transported from tissues to the respiratory surface by only ………..
(a) Plasma and erythrocytes
(b) Plasma
(c) Erythrocytes
(d) Erythrocytes and leucocytes
Answer:
(a) Plasma and erythrocytes

Question 13.
Respiratory centre is situated in ……….. [CPMT1980,2002, BHU1995, MPPMT1998, RPAPT2006]
(a) Cerebellum
(b) Medulla oblongata
(c) Hypothalamus
(d) Cerebrum
Answer:
(b) Medulla oblongata

Question 14.
Air is breathed through ……….. [APMEE 1999]
(a) Trachea → lung → laiynx → phaiynx → alveoli
(b) Nose → larynx → pharynx → alveoli → bronchioles
(c) Nostrils → pharynx → larynx → trachea bronchi → bronchioles → alveoli
(d) Nose → mouth → lungs.
Answer:
(c) Nostrils → pharynx → larynx → trachea bronchi → bronchioles → alveoli

Question 15.
Which is false?
(a) Blood from the right side of the heart is carried to the lungs by the pulmonary artery
(b) Pleura is the double covering of the kidney
(c) Pancreas is both exocrine & endocrine gland
(d) Scurvy is due to a vitamin C deficiency
Answer:
(b) Pleura is the double covering of the kidney

Question 16.
The volume of air breathed in and out during effortless respiration is ………..
(a) residual volume
(b) vital volume
(c) tidal volume
(d) normal volume
Answer:
(c) Tidal volume

Question 17.
Body tissue obtain oxygen from hemoglobin due to its dissociation in tissues is caused by ……….. [MPPMT 1995]
(a) Low oxygen concentration and high carbon dioxide concentration
(b) Low oxygen concentration
(c) Low carbon dioxide concentration
(d) High carbon dioxide concentration
Answer:
(b) Low oxygen concentration

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 18.
Lungs have a number of alveoli for ………..[MPPMT 1995]
(a) Having spongy texture and proper shape
(b) More surface area for diffusion of gases
(c) More space for the increasing volume of inspired air
(d) More nerve supply
Answer:
(b) More surface area for diffusion of gases

Question 19.
Presence of large number of alveoli around alveolar ducts opening into bronchioles in mammalian lungs is ………..
(a) Inefficient system of ventilation with little of residual air
(b) Inefficient system of ventilation with high percentage of residual air
(c) An efficient system of ventilation with no residual air
(d) An efficient system of ventilation with little residual air
Answer:
(d) An efficient system of ventilation with little residual air

Question 20.
During the transport of CO2 blood does not become acidic due to ………..
(a) Neutralisation of H2CO2 by Na2CO3
(b) Absorption by leucocytes
(c) Blood buffers
(d) Non-accumulation
Answer:
(c) Blood buffers

Question 21.
At high altitude, RBCs of human blood will ………..
(a) Increase in number
(b) Decrease in number
(c) Decrease in size
(d) increase in size
Answer:
(a) Increase in number

Question 22.
CO2 is transported ………..
(a) as dissolved in blood plasma
(c) as carbamino haemoglobin
Answer:
(d) as carbamino haemoglobin and carbonic acid

Question 23.
Maximum amount 70-75% of carbon dioxide transport occurs. [RPMT1996, 1998, MPPMT1998, CPMT 1998, BV 2002]
(a) Dissolved in plasma
(b) Carbaminohaemoglobin complex
(c) Bicarbonate
(d) None of the above
Answer:
(c) Bicarbonate

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 24.
Trachea is lined with incomplete rings of ………..
(a) Fibrous cartilage
(b) Calcified cartilage
(c) Elastic cartilage
(d) Hyaline cartilage
Answer:
(d) Hyaline cartilage

Question 25.
Oxygen and carbon dioxide are transported in blood through ………..
(a) Platelets and corpuscles
(b) RBCs and WBCs
(c) WBCs and serum
(d) RBCs and plasma
Answer:
(d) RBCs and plasma

Question 26.
About 1500 ml of air left in lungs is called ………..
(a) Tidal volume
(b) Inspiratory reserve volume
(c) Residual volume
(d) Vital capacity
Answer:
(c) Residual volume

Question 27.
Which one protects the lungs? [BHU1990]
(a) Ribs
(b) Vertebral column
(c) Sternum
(d) All the above
Answer:
(d) All the above

Question 28.
Which one has the lowest value?
(a) Tidal volume
(b) Vital capacity
(c) Inspiratory reserve volume
(d) Expiratory reserve volume
Answer:
(b) Vital capacity

Question 29.
A child was killed through asphyxiation. Postmortem confirmed it because a piece of lung put in water ………..[MPPMT 1996]
(a) Settled down
(b) Kept floating
(c) Had blood spots
(d) None of the above
Answer:
(b) Kept floating

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 30.
The amount of oxygen present in one gram of haemoglobin is ……….. [AII MS 1997, Har. PMT, 2000]
(a) 20 ml
(b) 1-34 ml
(c) 13-4 ml
(d) None of the above
Answer:
(b) 1-34 ml

Question 31.
A molecule of haemoglobin carries how many oxygen molecules ……….. [MPPMT 1997, CFMT 2002, JCMEE 2004]
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(d) 4

Question 32.
In carbon monoxide poisoning there is ……….. [AFMC 1997]
(a) Increase in carbon dioxide concentration
(b) Decrease in oxygen availability
(c) Decrease in free haemoglobin
(d) None of the above
Answer:
(c) Decrease in free haemoglobin

Question 33.
Exchange of gases in lung alveoli occurs through ……….. [AFMC 2002]
(a) Active transport
(b) Osmosis
(c) Simple diffusion
(d) Passive transport
Answer:
(c) Simple diffusion

Question 34.
Haemoglobin is …………
(a) Vitamin
(b) Skin pigment
(c) Blood carrier
(d) Respiratory pigments
Answer:
(d) Respiratory pigments

Question 35.
Vocal cords occur in ………..
(a) Pharynx
(b) Larynx
(c) Glottis
(d) Bronchial tube
Answer:
(b) larynx

Question 36.
The cells which do not respire ……….. [4FMC 2001]
(a) Epidermal cells
(b) Sieve cells
(c) Cortical cells
(d) Erythrocytes
Answer:
(d) Erythrocytes

Question 37.
Hiccough (hiccup) is due to the activity of ………..
(a) Intercostal muscles
(b) Food in the air tract
(e) Diaphragm
(d) Inadequate oxygen in the environment
Answer:
(c) Diaphragm

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 38.
Bicarbonate formed inside erythrocytes moves out to plasma while chloride of plasma passes into erythrocytes. The phenomenon is called ………..
(a) Bicarbonate shift
(b) Carbonation
(c) Hamburger phenomenon
(d) None of the above
Answer:
(c) Hamburger phenomenon

Question 39.
The respiratory centre of the brain is stimulated by ……….. [AllMS 2000]
(a) Carbon dioxide content in venous blood
(b) Carbon dioxide content in arterial blood
(c) Oxygen content in venous blood
(d) Oxygen content in arterial blood
Answer:
(d) Oxygen content in arterial blood

Question 40.
A higher CO2 concentration of blood causes ……….. [AMU 2001]
(a) Slow diffusion of CO2 from the blood
(b) Slow transport of CO2 from the blood
(c) Slow diffusion of O, from blood
(d) Both A and B
Answer:
(c) Slow diffusion of O2 from blood

Question 41.
Gases diffuse over the respiratory surface because of ………..
(a) O, is more in alveoli than in blood
(b) 02 is more in blood than in tissues
(c) CO2 is more in alveoli than in blood
(d) PCO2 is more in blood than in tissues
Answer:
(a) 02 is more in alveoli than in blood

Question 42.
Dissociation curve of 02 (which is dissociation from Hb) shifts to the rights ………..
(a) 02 concentration decrease
(b) CO2 concentration decreases
(c) CO2 concentration increase
(d) Chloride concentration increases
Answer:
(c) CO2 concentration increase

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 43.
Thoracic cage of man is formed of ……….. [MPPMT 2002]
(a) Ribs and sternum
(b) Ribs, sternum, and thoracic vertebrae
(c) Ribs, sternum, and lumbar vertebrae
(d) Ribs and thoracic vertebrae
Answer:
(b) Ribs, sternum, and thoracic vertebrae

Question 44.
Vital capacity of lung is equal to ……….
(a) IRV + ERV + TV
(b) IRV + ERV + TV – RV
(c) IRV + ERV + TV + RV
(d) IRV + ERV
Answer:
(a) IRV + ERV + TV

Question 45.
Dead space is ………….
(a) Upper respiratory tract
(b) Nasal chambers
(c) Alveolar space
(d) Lower respiratory tract
Answer:
(a) Upper respiratory tract

Question 46.
Carbon monoxide contained in Tobacco smoke ……….. [AIEEE 2003]
(a) Is carcinogenic
(b) Causes gastric ulcers
(c) Reduces oxygen-carrying capacity of blood
(d) Raises blood pressure
Answer:
(c) Reduces oxygen-carrying capacity of the blood

Question 47
What is correct?
(a) Pulmonary ventilation is equal to alveolar ventilation
(b) Alveolar ventilation is less than pulmonary ventilation
(c) Alveolar ventilation is more than pulmonary ventilation
(d) Both are variable
Answer:
(b) Alveolar ventilation is less than pulmonary ventilation

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 48.
An increase in CO2 concentration shall cause ………..
(a) Slower and shallower breathing
(b) Slower and deeper breathing
(e) Faster and deeper breathing
(d) No effect on breathing
Answer:
(c) Faster and deeper breathing

Question 49.
Alveoli become enlarged and damaged with reduced surface area in heavy smokers. the condition is called ………..
(a) Silicosis
(b) Emphysema
(c) Asthma
(d) Bronchitis
Answer:
(b) Emphysema

Question 50.
SARS is caused by a variant of ……….. [AIIMS 2004]
(a) Pneumococcus pneumonia
(b) Common cold by Corona virus
(c) Asthma
(d) Bronchitis
Answer:
(b) Common cold by Corona virus

Question 51.
During inspiration ……….. [JJPMER 2004, RPMT 20051
(a) Diaphragm and external muscles relax
(b) Diaphragm and internal intercostal muscles relax
(c) Diaphragm and external intercostal muscles contract
(d) Diaphragm and internal intercostal muscles contract
Answer:
(c) Diaphragm and external intercostal muscles contract

Question 52.
Mountain sickness at high altitude is due to ……….. [CPMT 2005]
(a) Excess CO2 in blood
(b) Decreased CO2 in air
(c) Decreased partial pressure of oxygen
(d) Decreased efficiency of haemoglobin
Answer:
(c) Decreased partial pressure of oxygen

Question 53.
Capacity of human lungs for air in a healthy person is ………..
(a) 3000 ml
(b) 1500 ml
(c) 1000 ml
(d) 500 ml
Answer:
(a) 3000 ml

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 54.
Rate of breathing is controlled by ………….
(a) Amount of freely available oxygen
(b) Carbon dioxide in the blood
(c) Muscular functions of the body
(d) All the above
Answer:
(b) Carbon dioxide in the blood

Question 55.
During strenuous exercise, glucose is converted into ………..
(a) Glycogen
(b) Pyruvic acid
(c) Starch
(d) Lactic acid
Answer:
(d) Lactic acid

Question 56.
How much pulmonary air is expired normally? [ PMT 2005]
(a) 70°io
(b) 20%
(c) 25%
(d) 32%
Answer:
(d) 32%

Question 57.
Which is incorrect?
(a) Presence of non-respiratory air sacs increases the efficiency of respiration in birds
(b) In insects, circulation body fluids serve to distribute oxygen to tissues
(c) Principle of counter-current flow facilitates efficient respiration in gills of fishes
(d) Residual air in the lungs slightly decreases the efficiency of respiration in mammals
Answer:
(b) In insects, circulation body fluids serve to distribute oxygen to tissues

Question 58.
The percentage of oxygen being carried by blood plasma is ………..
(a) 6-9%
(b) 3-6%
(c) 2-3%
(d) 1-2%
Answer:
(c) 2-3%

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 59.
Name of the pulmonary disease in which alveolar surface area involved in gas exchange is drastically reduced due to damage in the alveolar walls: [RE-NEET 2015]
(a) Asthma
(b) Pleurisy
(c) Emphysema
(d) Pneumonia
Answer:
(c) Emphysema

Question 60.
Asthma may be attributed to ……….. [AIPMT/NEET 2016]
(a) bacterial infection of the lungs
(b) an allergic reaction of the mast cells in the lungs
(c) inflammation of the trachea
(d) accumulation of fluid in the lungs
Answer:
(b) an allergic reaction of the mast cells in the lungs

Question 61.
Name the chronic respiratory disorder caused mainly by cigarette smoking: [RE-NEET 2016]
(a) Emphysema
(b) Asthma
(c) Respiratory acidosis
(d) Respiratory alkalosis
Answer:
(a) Emphysema

Question 62.
Lungs are made up of air-filled sacs, the alveoli. They do not collapse even after forceful expiration. [NEET 20171]
(a) Inspiratory Reserve Volume
(b) Tidal Volume
(c) Expiratory Reserve Volume
(d) Residual Volume
Answer:
(d) Residual Volume

Samacheer Kalvi 11th Bio Zoology Respiration Additional Questions & Answers

I. Multiple Choice Questions
Choose the correct answer

Question 1.
Insects respire through ………..
(a) body surface
(b) trachea
(c) gills
(d) book lungs
Answer:
(b) trachea

Question 2.
Which of the following does not belong to the conducting zone of the respiratory system?
(a) trachea
(b) bronchioles
(c) larynx
(d) alveoli
Answer:
(d) alveoli

Question 3.
The trachea is supported by the ………..
(a) long structure
(b) cartilage
(c) multiple cartilaginous rings
(d) ligaments
Answer:
(c) multiple cartilaginous rings

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 4.
Which of the following is right regarding the bronchioles?
(a) the trachea divides into bronchioles
(b) bronchioles have cartilaginous rings
(c) bronchioles collapse when the air pressure is more
(d) bronchioles are without cartilaginous rings
Answer:
(d) bronchioles are without cartilaginous rings

Question 5.
The lungs are protected ventrally by ………..
(a) vertebral column
(b) sternum
(c) ribs
(d) diaphragm
Answer:
(b) sternum

Question 6.
The function of pleural fluid is to ………..
(a) keep the lungs intact
(b) protect the lungs from getting firm
(c) maintain the texture of the lungs
(d) reduces friction when lungs expand and contract
Answer:
(d) reduce friction when lungs expand and contract

Question 7.
Which of the following happens during inspiration?
(a) Diaphragm becomes dome-shaped
(b) internal intercostal muscles contract
(c) volume of the thoracic chamber increases
(d) ribs are pulled downward
Answer:
(c) volume of the thoracic chamber increases

Question 8.
The amount of air inspired or expired with each normal breath is called the ………..
(a) residual volume
(b) inspiratory reserve volume
(c) dead space
(d) tidal volume
Answer:
(d) tidal volume

Question 9.
The normal value of IRV is ………..
(a) 500 mL
(b) 2500-3000 mL
(c) 1100-1200 mL
(d) 150 mL
Answer:
(b) 2500-3000 mL

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 10.
UV + RV =
(a) EC
(b) TLC
(c) IC
(d) VC
Answer:
(b) TLC

Question 11.
Which of the following is not involved in gaseous exchange?
(a) expiratory reserve volume
(b) inspiratory reserve volume
(c) residual volume
(d) dead space
Answer:
(d) dead space

Question 12.
Each haemoglobin can combine with molecules of oxygen.
(a) one
(b) four
(c) three
(d) two
Answer:
(b) four

Question 13.
The ferric state of haemoglobin ………..
(a) binds with oxygen
(b) binds with carbon dioxide
(c) does not bind with oxygen
(d) does not bind with carbon dioxide
Answer:
(c) does not bind with oxygen

Question 14.
Which of the following is incorrect with regard to the formation of oxyhemoglobin in the alveoli?
(a) high pCO2
(b) less H+ concentration
(c) low pCO2
(d) low temperature
Answer:
(a) high pCO2

Question 15.
Carbon dioxide is carried in the RBCs as ………..
(a) bicarbonate ions
(b) carbon dioxide
(c) carbonic acid
(d) carbaminohaemoglobin
Answer:
(d) carbaminohaemoglobin

Question 16.
The formation of is catalysed by the enzyme carbonic anhydrase in RBCs ………..
(a) carbonates
(b) carbaminohaemoglobin
(c) carbonic acid
(d) bicarbonates
Answer:
(c) carbonic acid

Question 17.
The chemosensitive area found close to the rhythm center is highly sensitive to ………..
(a) CO2 alone
(b) H+ alone
(c) O2
(d) CO2 and H+
Answer:
(d) CO2 and H+

Question 18.
Which is known as the respiratory rhythm centre?
(a) cerebellum
(b) pons varoli
(c) medulla oblongata
(d) infundibulium
Answer:
(c) medulla oblongata

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 19.
When a person travels to higher elevations, he may develop the symptoms of acute mountain sickness. This is because of ………..
(a) nitrogen narcosis
(b) high level of carbon dioxide in the blood
(c) low immunity
(d) poor binding of O2 with haemoglobin
Answer:
(d) poor binding of O2 with haemoglobin

Question 20.
Erythropoietin hormone stimulates the bone marrow to produce more ………..
(a) WBCs
(b) RBCs
(c) Platelets
(d) Electrolytes
Answer:
(b) RBCs

Question 21.
When a person goes deep into the sea, he/she develops complications due to ………..
(a) the increased partial pressure of O2
(b) increase in blood nitrogen content
(c) the increased partial pressure of CO2
(d) the decrease in the pressure in the surrounding water
Answer:
(b) increase in blood nitrogen content

Question 22.
Scuba divers need to face the problem of ………..
(a) nitrogen narcosis
(b) low oxygen content
(c) high carbon dioxide content
(d) lower pressure
Answer:
(a) nitrogen narcosis

Question 23.
Narrowing and inflammation of bronchi and bronchioles is called as ………..
(a) emphysema
(b) bronchitis
(c) asthma
(d) pneumonia
Answer:
(c) asthma

Question 24.
Gradual break down of the thin walls of the alveoli decreasing the total surface area of the gaseous exchange is ………..
(a) bronchitis
(b) emphysema
(c) asthma
(d) tuberculosis
Answer:
(b) emphysema

Question 25.
What causes bronchitis?
(a) Decrease in the surface area of alveoli
(b) inflammation of bronchi and bronchioles
(c) inflammation of bronchi
(d) collection of fluid in the bronchi
Answer:
(c) inflammation of bronchi

Question 26.
Which of the following is caused by bacteria?
(a) pneumonia
(b) emphysema
(c) silicosis
(d) tuberculosis
Answer:
(d) tuberculosis

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 27.
Which of the following is occupational respiratory disease?
(a) tuberculosis
(b) emphysema
(c) silicosis
(d) pneumonia
Answer:
(c) silicosis

Question 28.
Why does smoking affect the oxygen supply to the body?
(a) haemoglobin fails to bind with O2
(b) haemoglobin binds with carbon monoxide
(c) Nicotine makes the heart heat faster
(d) Blood vessels are narrowed
Answer:
(b) haemoglobin binds with carbon monoxide

Question 29.
COPD is the ………..
(a) emphysema and chronic bronchitis
(b) asthma and emphysema
(c) emphysema
(d) asthma, chronic bronchitis and emphysema
Answer:
(d) asthma, chronic bronchitis, and emphysema

II. Fill in the Blanks

Question 1.
Oxygen is necessary for the breakdown to release energy.
Answer:
Glucose.

Question 2
……………. produce sound in human beings.
Answer:
Larynx/vocal cords.

Question 3.
……………… are the respiratory organs in most of the aquatic arthropods and molasses.
Answer:
Gills.

Question 4.
The ciliated epithelial cells lining the trachea, bronchi, and bronchioles secrete …………….
Answer:
Mucus.

Question 5
divides thoracic cavity and abdominal cavity.
Answer:
Diaphragm.

Question 6.
The movement of air between the atmosphere and the lungs is known as …………
Answer:
Ventilation/breathing.

Question 7
……………. is the movement of atmospheric air into the lungs.
Answer:
Inspiration.

Question 8.
……………… In a relaxed stage, the diaphragm is shaped.
Answer:
Dome.

Question 9.
The expulsion of air from the lungs to the atmosphere is known as ……………..
Answer:
Expiration.

Question 10
………….. in an instrument used to measure the volume of air involved in breathing movements.
Answer:
Spirometer.

Question 11.
The volume of air remaining in the lungs after a forceful expiration is ……………
Answer:
Residual volume.

Question 12.
The maximum volume of air that can be moved out during a single breath following a maximal inspiration is …………..
Answer:
Vital capacity.

Question 13.
The total volume of air a person can inhale after normal inspiration is …………….
Answer:
Inspiratory capacity.

Question 14.
The total volume of air a person can exhale after normal inspiration is ……………..
Answer:
Expiratory capacity.

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 15.
…………….. is the total volume of air which the lungs can accommodate after forced inspiration.
Answer:
Total lung capacity.

Question 16.
The amount of air that moves into the respiratory passage per minute is called ……………
Answer:
Minute respiratory volume.

Question 17
……………… is the air that is not involved in gaseous exchange.
Answer:
Dead space.

Question 18
………………. is the pressure contributed by an individual gas in a mixture of gases.
Answer:
Partial pressure.

Question 19.
Haemoglobin belongs to the class of …………..
Answer:
Conjugated protein.

Question 20.
Haemoglobin is made up of iron and the rest colourless protein
Answer:
Haem, globin.

Question 21.
The ferric state of haemoglobin is called …………….
Answer:
Methemoglobin.

Question 22
……………. is the respiratory pigment present in the blood.
Answer:
Haemoglobin.

Question 23.
The blood of human being is red due to the presence of …………….
Answer:
Haemoglobin.

Question 24.
Every 100 ml of oxygenated blood can deliver about mL of O, to the tissues.
Answer:
5.

Question 25.
About 70% of CO2 transport occurs as ions.
Answer:
Bicarbonate.

Question 26.
The reversible reaction of formation of carbonic acid from carbon dioxide and water is catalyzed by the enzyme called …………………
Answer:
Carbonic anhydrase.

Question 27
center present in pons Varoli region of the brain moderates the function of the respiratory rhythm center.
Answer:
Pneumotaxic.

Question 28
……………… is the hormone secreted by kidneys to stimulate the bone marrow to produce more RBCs.
Answer:
Erythropoietin.

Question 29.
The increase in the nitrogen content in blood heads to a condition called ………………..
Answer:
Nitrogen narcosis.

Question 30.
The skin turns bluish-black during poisoning.
Answer:
Carbon dioxide.

Question 31.
Dust, drugs, pollen grains, fish, prawns are common for asthma.
Answer:
Allergens.

Question 32.
Cigarette smoking reduces the respiratory surface of the alveolar walls and it is known as ……………….
Answer:
Emphysema.

Question 33.
Cough, shortness of breath, and sputum in the lungs are the symptoms of ………………
Answer:
Bronchitis.

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 34.
Tuberculosis is caused by ……………….
Answer:
Mycobacterium tubercular

Question 35.
Collection of fluid between the lungs and the chest wall is the complication of the disease …………..
Answer:
Tuberculosis.

Question 36.
Long exposure to dust gives rise to inflammation leading to ………………
Answer:
Fibrosis.

Question 37
……………… and asbestosis are occupational respiratory diseases resulting from inhalation of particles of silica from sand grinding and asbestos into the respiratory tract.
Answer:
Silicosis.

Question 38
……………… causes narrowing of blood vessels resulting in an increase in blood pressure and coronary heart disease.
Answer:
Nicotine.

Question 39.
……………….. Smoking lowers the count in men.
Answer:
Sperm.

Question 40
…………….. is the chemical present in the cigarette smoke that causes addiction.
Answer:
Nicotine.

Question 41.
Chronic obstructive pulmonary disease is due to
Answer:
Smoking.

Question 42.
A non-smoker who inhales cigarette smoke involves in smoking.
Answer:
Passive.

Question 43.
Emphysema, chronic bronchitis, and asthma, COPD, cancer may be caused due to
Answer:
Smoking.

Question 44.
Cigarette smoke contains thousands of chemicals and even small quantities of
Answer:
Arsenic.

Question 45.
The presence in the cigarette smoke damages the gaseous exchange.
Answer:
Tar.

III. Answer the following Questions

Question 1.
What is Tidal volume?
Answer:
Tidal volume is the amount of air inspired or expired with each normal breath
Ex. 500 ml

Question 2.
What are the functions of the respiratory system?
Answer:
The five primary functions of the respiratory system are –

  • To exchange O2 and CO2 between the atmosphere and the blood.
  • To maintain homeostatic regulation of body pH.
  • To protect us from inhaled pathogens and pollutants.
  • To maintain the vocal cords for normal communication (vocalization).
  • To remove the heat produced during cellular respiration through breathing.

Question 3.
What is inspiratory reserve volume?
Answer:

  • The additional volume of air a person can inspire by forceful inspiration is called inspiratory reserve volume.
  • The normal value is 2500 – 3000 ml.

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 4.
What is the function of hairs and mucus in the nasal cavity?
Answer:
The hairs and mucus filter the dust particles present in the air passing through the nostrils.

Question 5.
What is meant by vital capacity?
Answer:

  • The maximum volume of air that can be moved out during a single breath following a maximal inspiration.
  • VC = ERV + TV + IRV

Question 6.
What are the layers of the diffusion membrane of the alveolus?
Answer:
The diffusion membrane of the alveolus is made up of three layers. They are:

  • The thin squamous epithelial cells of the alveoli.
  • The endothelium of the alveolar capillaries and
  • The basement substance found in between them.

Question 7.
What are the cells of the squamous epithelial cells of the alveoli?
Answer:
The thin squamous epithelial cells of the alveoli are composed of Type I and Type II cells. Type I cells are very thin so that gases can diffuse rigidly through them. Type II cells are thicker. They synthesize and secrete a substance called surfactant. It lowers the surface tension in the alveoli and prevents pulmonary edema.

Question 8.
What is meant by total lung capacity?
Answer:

  • The total volume of air which the lungs can accommodate after forced inspiration is called total lung capacity.
  • Total lung capacity = Vital capacity + Residual volume.
  • TLC = VC + RV

Question 9.
What is pleura? What is its function?
Answer:
The lungs are covered by a double-layered pleural membrane containing several layers of elastic connective tissues and capillaries. It encloses the pleural fluid which reduces friction when the lungs expand and contract.

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 10.
What is the function of Goblet cells?
Answer:

  • The mucous membrane lining the airway contains goblet cells which secrete mucus rich in glycoprotein.
  • Microorganisms and dust particles attach to the mucus films and are carried upwards to pass down the gullet during normal swallowing.

Question 11.
Explain the human respiratory system.
Answer:
The human respiratory system constitutes the conducting zone and the respiratory zone. The conducting zone includes the external nostril, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and the lungs which contain alveoli.

The parts from the external nostrils up to the bronchioles conduct the air and hence they are called the conducting zone. This zone humidifies and warms the incoming air. The nasal cavity has fine hairs and mucus which filter dust particles in the incoming air.

At the junction of the pharynx and larynx, there is a flap called epiglottis. This closes the respiratory tract while swallowing thus preventing the entry of food particles into the trachea and choking. The ciliated epithelial cells of the trachea, bronchi, and bronchioles secrete mucus rich in glycoprotein.

Microorganisms and dust particles attach to the mucus films and are carried upwards to pass down the gullet during normal swallowing. The trachea is a semi-flexible tube supported by multiple cartilaginous rings that expands upto the mid-thoracic cavity.

And the level of the 5th theoretic vertebra, it divides into right and left bronchi which divide into secondary and tertiary bronchi and further divide into terminal bronchioles and respiratory bronchioles. Bronchi have ‘c’ shaped curved Cartilage plates to ensure that the air passage does not collapse as air pressure changes during breathing. The bronchioles do not have cartilaginous rings but they have the rigidity to prevent them from collapsing but are surrounded by smooth muscle which contracts or relaxes to adjust the diameter of these airways.
Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration img 3
Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration img 4

The fine respiratory bronchioles terminate into highly vascularised thin-walled-pouch-like air sacs called alveoli. It is made up of thin squamous epithelial cells, the endothelium of the alveolar capillaries, and the basement substance are found in between them.

The thin squamous epithelial cells of the alveoli, the endothelium of the alveolar capillaries, and the basement substance found in between them. The thin squamous epithelial cells of the alveoli are composed of Type I and Type II cells.

Type I cells are very thin so that gases can diffuse rapidly through them. Type II cells are thicker, synthesize, and secrete a substance called Surfactant. The lungs are light spongy tissues endorsed in the thoracic cavity bound dorsally by the vertebral column and ventrally by the sternum, laterally by the ribs, and on the lower side by the dome-shaped diaphragm. The lungs are covered by a double-walled pleural membrane containing several layers of elastic connective tissues and capillaries. It encloses the pleural fluid. It reduces friction when the lungs expand and contract.

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 12.
Explain the mechanism of breathing.
Answer:
The movement of air between the atmosphere and the lungs is known as ventilation or breathing. Inspiration and expiration are the two phases of breathing. Inspiration is the movement of atmospheric air into the lungs and expiration is the movement of alveolar air that diffuses out of the lungs.

Lungs do not contain muscle fibres but expands and contracts by the movement of the ribs and diaphragm. The diaphragm is a sheet of tissue which separates the thorax from the abdomen. In a relaxed state, the diaphragm is dome-shaped.

Ribs are moved by the intercostal muscles. External and internal intercostal muscles found between the ribs and the diaphragm helps in creating pressure gradients. Inspiration occurs if the pressure inside the lungs (intrapulmonary pressure) is less than the atmospheric pressure; likewise, expiration takes place when the pressure within the lungs is higher than the atmospheric pressure.

Inspiration is initiated by the contraction of the diaphragm muscles and external intercostal muscles, which pulls the ribs and sternum upwards and outwards and increases the volume of the thoracic chamber in the dorso-ventral axis, forcing the lungs to expand the pulmonary volume. The increase in pulmonary volume and decrease in the intrapulmonary’ pressure forces the fresh air from outside to enter the air passages into the lungs to equalize the pressure.

This process is called inspiration. Relaxation of the diaphragm allows the diaphragm and sternum to return to its dome shape and the internal intercostal muscles contract, pulling the ribs downward reducing the thoracic volume and pulmonary volume. This results in an increase in the intrapulmonary pressure slightly above the atmospheric pressure causing the expulsion of air from the lungs. This process is called expiration.

Question 13.
Write a short note on respiratory volumes.
Answer:
Tidal Volume (TV) Tidal volume is the amount of air inspired or expired with each normal breath. It is approximately 500 mL., i.e. a normal human adult can inspire or expire approximately 6000 to 8000 mL of air per minute. During vigorous exercise, the tidal volume is about 4-10 times higher.

Inspiratory Reserve Volume (IRV) Additional volume of air a person can inspire by forceful inspiration is called Inspiratory Reserve Volume. The normal value is 2500-3000 mL.

Expiratory Reserve Volume (ERV) Additional volume of air a person can forcefully exhale by forceful expiration is called Expiratory Reserve Volume. The normal value is 1000-1100 mL. Residual Volume (RV) The volume of air remaining in the lungs after a forceful expiration. It is approximately 1100 – 1200 mL.

Question 14.
Write a short note on respiratory capacities.
Answer:
Vital capacity (VC) the maximum volume of air that can be moved out during a single breath following a maximal inspiration. A person first inspires maximally then expires maximally. VC = ERV + TV + IRV

1. Inspiratory capacity (IC) The total volume of air a person can inhale after a normal expiration. includes tidal volume and inspiratory reserve volume. IC = TV + IRV

2. Expiratory capacity (EC) The total volume of air a person can exhale after a normal inspiration. It includes tidal volume and expiratory reserve volume. EC = TV + ERV

3. Total Lung Capacity (TLC) The total volume of air which the lungs can accommodate after forced inspiration is called Total Lung Capacity. This includes the vital capacity and the residual volume. It is approximately 6000 mL. TLC = VC+ RV

4. Minute Respiratory Volume The amount of air that moves into the respiratory passage per minute is called minute respiratory volume.

Question 15.
What is the reason for the lungs to lose elasticity?
Answer:

  • The elastin present in the Songs gives its elastic nature.
  • People with emphysema and bronchitis have difficulty in exhaling because the enzyme elastase destroys the elastin around the alveoli and reduces the elasticity of the lungs.

Question 16.
How does a gaseous exchange take place in the alveoli?
Answer:
The primary site for the exchange of gases in the alveoli. The uptake of 02 and the release of CO2 occur between the blood and tissues by simple diffusion driven by partial pressure gradient of O2 and CO2. Partial pressure is the pressure contributed by an individual gas in a mixture of gases.

It is represented as pO2 for oxygen and pCO2 for carbon- dioxide. Due to pressure gradients, O2 from the alveoli enters the blood and reaches the tissues. CO2 enters into the blood from the tissues and reaches alveoli for elimination. As the solubility of CO2 is 20-25 times higher than that of O2, the partial pressure of CO2 is much higher than that of O2.

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 17.
Write the note on respiratory pigments.
Answer:
Haemoglobin belongs to the class of conjugated protein. The iron-containing pigment portion haem constitutes only 4% and the rest colourless protein of the histone class globin. Hemoglobin has a molecular weight of 68,000 and contains four atoms of iron, each of which can combine with a molecule of oxygen.

Methaemoglobin If the iron component of the haem moieties is in the ferric state, then the normal ferrous state, is called methemoglobin. Methaemoglobin does not bind O2. Normally RBC contains less than 1% methemoglobin.

Question 18.
Explain the transport of oxygen In blood.
Answer:
Molecular oxygen is carried in blood in two ways: bound to hemoglobin within the red blood cells and dissolved in plasma. Oxygen is poorly soluble in water, so only 3% of the oxygen is transported in the dissolved form. 97% of oxygen binds with haemoglobin in a reversible manner to form oxyhaemoglobin (HbO2). The rate at which haemoglobin binds with O2 is regulated by the partial pressure of O2.

Each haemoglobin carries maximum of four molecules of oxygen. In the alveoli high pO2, low pCO2, low temperature and less H+ concentration, favours the formation of oxyhaemoglobin, whereas in the tissues low p02, high pCO2, high H+ and high temperature favours the dissociation of oxygen from oxyhaemoglobin.

A sigmoid curve (S-shaped) is obtained when the percentage saturation of haemoglobin with oxygen is plotted against pO2. This curve is called the oxygen haemoglobin dissociation curve. This S-shaped curve has a steep slope for pO2 values between 10 and 50 mm Hg and then flattens between 70 and 100 mm Hg. Under normal physiological conditions, every 100 mL of oxygenated blood can deliver about 5 mL of O2 to the tissues.

Question 19.
Explain the transport of carbon dioxide.
Answer:
Blood transports CO2 from the tissue cells to the lungs in three ways:
1. Dissolved in plasma:
About 7 – 10% of CO2 is transported in a dissolved form in the plasma.

2. Bound to haemoglobin:
About 20 – 25% of dissolved CO2 is bound and carried in the RBCs as carbaminohaemoglobin (Hb CO2)
CO2 + Hb → Hb CO2

3. As bicarbonate ions in plasma about 70% of CO2 is transported as bicarbonate ions. This is influenced by pC02 and the degree of haemoglobin oxygenation. RBCs contain a high concentration of the enzyme, carbonic anhydrase, whereas small amounts of carbonic anhydrase is present in the plasma.

At the tissues, the pCO2 is high due to catabolism and diffuses into the blood to form HCO2 and H+ ions. When CO2 diffuses into the RBCs, it combines with water forming carbonic acid (H2CO2) catalyzed by carbonic anhydrase. Carbonic acid is unstable and dissociates into hydrogen and bicarbonate ions.

Carbonic anhydrase facilitates the reaction in both directions.
Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration img 5
The HCO3 moves quickly from the RBCs into the plasma, where it is carried to the lungs. At the alveolar site where pCO2 is low, the reaction is reversed leading to the formation of CO2 and water. Thus CO2 trapped as HCO3 at the tissue level is transported to the alveoli and released out as CO2. Every 100 mL of deoxygenated blood delivers 4 mL of CO2 to the alveoli for elimination.

Question 20.
How is respiration regulated?
Answer:
A specialized respiratory center present in the medulla oblongata of the hindbrain called the respiratory rhythm center is responsible for this regulation. Pneumotaxic centre present in ponsvaroli region of the brain moderates the function of the respiratory rhythm centre to ensure normal breathing.

The chemosensitive area found close to the rhythm center is highly sensitive to CO2 and H+. And H+ are eliminated out by the respiratory process. Receptors associated with the aortic arch and carotid artery send necessary signals to the rhythm center for remedial action. The role of O2 is insignificant in the regulation of respiratory rhythm.

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Question 21.
Write the flow chart of the events during inspiration and expiration.
Answer:
Events in inspiration and expiration
Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration img 6

Question 22.
What is nitrogen narcosis? What is its effect?
Answer:
When a person descends deep into the sea, the pressure in the surrounding water increases which causes the lungs to decrease in volume. This decrease in volume increases the partial pressure of the gases within the lungs. This effect can be beneficial, because it tends to drive additional oxygen into the circulation, but this benefit also has a risk, the increased pressure can also drive nitrogen gas into the circulation. This increase in blood nitrogen content can lead to a condition called nitrogen narcosis.

When the diver ascends to the surface too quickly a condition called ‘bends’ or decompression sickness occurs and nitrogen comes out of solution while still in the blood-forming bubbles. Small bubbles in the blood are not harmful, but large bubbles can lodge in small capillaries, blocking blood flow or can press on nerve endings. Decompression sickness is associated with pain in joints and muscles and neurological problems including a stroke.

The risk of nitrogen narcosis and bends is common in scuba divers. During carbon-dioxide poisoning, the demand for oxygen increases. As the O2 level in the blood decreases it leads to suffocation and the skin turns bluish-black.

Question 23.
Explain the disorders of the respiratory system.
Answer:
Asthma – It is characterized by narrowing and inflammation of bronchi and bronchioles and difficulty in breathing. Common allergens for asthma are dust, drugs, pollen grains, certain food items like fish, prawns and certain fruits etc. Emphysema – Emphysema is chronic breathlessness caused by the gradual breakdown of the thin walls of the alveoli decreasing the total surface area of gaseous exchange, i.e., widening of the alveoli is called emphysema. The major cause for this disease is cigarette smoking, which reduces the respiratory surface of the alveolar walls.

Bronchitis- The bronchi when it gets inflated due to pollution smoke and cigarette smoking, causes bronchitis. The symptoms are cough, shortness of breath, and sputum in the lungs. Pneumonia- Inflammation of the lungs due to infection caused by bacteria or viruses is called pneumonia. The common symptoms are sputum production, nasal congestion, shortness of breath, sore throat, etc.

Tuberculosis- Tuberculosis is caused by Mycobacterium tuberculate. This infection mainly occurs in the lungs and bones. The collection of fluid between the lungs and the chest wall is the main complication of this disease. Occupational respiratory disorders- The disorders due to one’s occupation of working in industries like grinding or stone breaking, construction sites, cotton industries, etc.

Samacheer Kalvi 11th Bio Zoology Solutions Chapter 6 Respiration

Dust produced affects the respiratory tracts. Long exposure can give rise to inflammation leading to fibrosis. Silicosis and asbestosis are occupational respiratory diseases resulting from the inhalation of particles of silica from sand grinding and asbestos into the respiratory tract. Workers, working in such industries must wear protective masks.

Question 24.
What are the effects of smoking?
Answer:
Smoking is inhaling the smoke from burning tobacco. There are thousands of known chemicals which include nicotine, tar, carbon monoxide, ammonia, sulfur dioxide, and even small quantities of arsenic. Carbon monoxide and nicotine damage the cardiovascular system and tar damages the gaseous exchange system.

Nicotine is the chemical that causes addiction and is a stimulant which makes the heart beat faster and the narrowing of blood vessels results in raised blood pressure and coronary heart diseases. The presence of carbon monoxide reduces oxygen supply. Lung cancer, cancer of the mouth, and larynx are more common in smokers than non-smokers.

Smoking also causes cancer of the stomach, pancreas, and bladder and lowers sperm count in men. Smoking can cause lung diseases by damaging the airways and alveoli and results in emphysema and chronic bronchitis. These two diseases along with asthma are often referred to as Chronic Obstructive Pulmonary Disease (COPD).

When a person smokes, nearly 85% of the smoke released is inhaled by the smoker himself and others in the vicinity, called passive smokers, are also affected. Guidance or counseling should be done in such users to withdraw from this habit.

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