Respiratory System

In humans, taking air through nostrils into the nasal cavity is called

1. Inhalation
2. Exhalation
3. Cellular respiration
4. Internal respiration

Answer

Inhalation

Reason — Inhalation is the physical process by which the air containing oxygen is drawn into the our lungs through nostrils into the nasal cavity.

The front opening of the wind pipe is guarded by

1. Glottis
2. Exoglottis
3. Epiglottis
4. Trachea

Answer

Epiglottis

Reason — The epiglottis is a muscular flap shaped in the throat. It closes the wind pipe at the time of swallowing of food.

The process during which food is oxidised and energy is released is called

1. Cellular respiration
2. Excretion
3. Digestion
4. Transpiration

Answer

Cellular respiration

Reason — Cellular respiration is the process of oxidation of glucose (breaking down of food) in the cells with the release of energy in the form of ATP molecules (Adenosine triphosphate).

Which of the following is not a part of the respiratory system ?

1. Nostrils
2. Lungs
3. Mouth
4. Trachea

Answer

Mouth

Reason — In humans, the organs of the respiratory system include nose, pharynx, larynx, trachea, bronchi and the lungs. One should always breathe through the nose and not through the mouth.

The common passage of wind pipe and food pipe is termed as .

1. Larynx
2. Glottis
3. Pharynx
4. Epiglottis

Answer

Pharynx

Reason — Pharynx or throat is a common passage for air and the food. It leads into two passages, one is the air tube called wind pipe or trachea and the other the gullet (food-pipe).

The energy produced during cellular respiration is .

1. ADP
2. ADH
3. ATP
4. None of the above

Answer

ATP

Reason — During Cellular respiration, energy is released in the form of adenosine triphosphate or ATP, along with carbon dioxide and water vapour.

The basic structural and functional unit of the lungs is :

1. Pleura
2. Alveolus
3. Capillary
4. Diaphragm

Answer

Alveolus

Reason — Alveolus is the basic structural and functional unit of the lungs.

Vocal cords are found in :

1. Larynx
2. Gullet
3. Pharynx
4. Glottis

Answer

Larynx

Reason — Larynx contains two ligamentous folds called 'vocal cords'.

Which of the following is a respiratory pigment ?

1. Melanin
2. Haemoglobin
3. Chlorophyll
4. None of the above

Answer

Haemoglobin

Reason — The oxygen from the lungs diffuses into the blood, and is picked up by haemoglobin in red blood cells. Carbon dioxide from the blood diffuses into the lungs and is exhaled out through the same passage.

The muscular sheet which divides the body cavity into thorax and abdomen is termed as :

1. Inner pleura
2. Rib cage
3. Outer pleura
4. Diaphragm

Answer

Diaphragm

Reason — Diaphragm is a muscular sheet which internally divides the body cavity into two cavities, the chest cavity or thoracic cavity above, and the abdominal cavity below.

Fill in the blanks with suitable words :

1. The ............... emerges from the larynx down below in the neck.
2. The inner lining of trachea consists of ............... epithelium.
3. ............... end up into microscopic alveoli.
4. The volume of chest cavity ............... during inspiration.
5. The amount of ............... gas remains the same in the inspired air and expired air.

Answer

1. trachea
2. ciliated
3. Bronchioles
4. increases
5. Nitrogen

Match the terms given in column A with those of column B

Answer

Why do our body cells require oxygen?

Answer

Our body cells require oxygen for the break down of glucose and release energy for carrying out various activities of the body.

What is the difference between breathing and respiration?

Answer

Difference between Breathing and Respiration:

Name the by-products formed during the oxidation of food.

Answer

Carbon dioxide and Water is released as by-products during the oxidation of food.

Name the agent which transports oxygen to all parts of the body.

Answer

Blood with help of haemoglobin in RBCs transports oxygen to all parts of the body.

What is the role of epiglottis during swallowing?

Answer

Epiglottis closes the wind pipe at the time of swallowing the food.

Name the gas which is expelled out during expiration. Where is it originally produced in our body?

Answer

Carbon dioxide is the gas which is expelled during expiration. It is produced in the cells of the body.

Write one important role of each of the following .

1. Epiglottis
2. Larynx
3. Alveolus
4. Pleura
5. Nasal chamber

Answer

1. Epiglottis guards the front opening (glottis) of the wind pipe. It closes the wind pipe at the time of swallowing of food, and hence prevents any wrongful entry of food into the wind pipe.

2. Larynx contains two ligamentous folds called 'vocal cords'. Air expelled forcibly through the vocal cords vibrates them to produce sound.

3. Alveoli are richly supplied with blood capillaries covering their walls. The walls of the alveoli are extremely thin and moist for allowing faster diffusion of gases.

4. Pleura protects the lungs. The fluid filled in the space between the outer and inner pleura acts as a shock absorber for the lungs.

5. The lining of the nasal chamber has mucous (a sticky fluid) which traps germs and dust, so they don't enter our body.

Define the terms given below :

1. Respiration
2. Breathing
3. Lungs
4. Inhalation
5. Exhalation

Answer

1. Respiration — Respiration is the process of releasing energy by breaking down food (glucose) needed for various activities of the body.

2. Breathing — The process during which the air containing oxygen is drawn into the lungs and the air containing carbon dioxide is forced out from the lungs is called breathing. Breathing is a physical process.

3. Lungs — The lungs are a pair of pink and spongy, elastic organs located in the chest cavity and help in the exchange of gases. They take in oxygen from the air and remove carbon dioxide from the blood during the process of breathing.

4. Inhalation — Inhalation is the process of drawing in the air through the nostrils into the nasal cavity and finally into the lungs.

5. Exhalation — Exhalation is the process of forcing out of the air from the lungs.

Name the following.

1. Respiratory process in which oxygen is not utilized.
2. Respiratory process in which oxygen is utilized.
3. The microscopic air-sacs of the lungs.
4. The two membranes which protect the lungs.
5. Six main parts of the human respiratory system.
6. Two types of respiration.
7. Three phases of respiration.
8. Two steps of breathing.
9. Three common respiratory diseases.

Answer

1. Anaerobic Respiration.
2. Aerobic Respiration.
3. Alveoli.
4. Outer and inner pleura.
5. Nose, Pharynx, Larynx, Trachea, Bronchi and the Lungs
6. Aerobic respiration and Anaerobic respiration
7. Breathing, Gaseous transport, and Cellular respiration
8. Inspiration and Expiration
9. Bronchitis, Asthma, and Pneumonia

Correct the following statements by changing the first/ last word only :

1. BCG is a kind of vaccine used to prevent Pneumonia.
2. Streptomycin is a kind of vaccine.
3. Breathing is a bio-chemical process.
4. The amount of oxygen in expired air is 21%.
5. The front opening of the trachea is guarded by a muscular flap called diaphragm.

Answer

1. BCG is a kind of vaccine used to prevent Tuberculosis.
2. Streptomycin is a kind of antibiotic.
3. Respiration is a bio-chemical process.
4. The amount of oxygen in expired air is 16%.
5. The front opening of the trachea is guarded by a muscular flap called epiglottis.

Why is a respiratory system necessary?

Answer

Respiration is a vital process in all living organisms.

Respiratory system is necessary because:

1. Respiration is a vital process in all living organisms. Every cell of a plant, an animal or of human body requires energy for various activities. Respiratory system provides this energy by the oxidation of glucose using oxygen.
2. Respiratory system helps in breathing through which oxygen from the air is pulled into the lungs and the air containing carbon dioxide is forced out of the lungs.
3. Respiratory system helps in gaseous transport. Oxygen of the inhaled air is absorbed by the blood in the lungs where it combines with the haemoglobin present in RBCs. The Oxygen is carried from lungs to the body tissues where the Oxygen is utilised and Carbon dioxide is released.

What factors are most likely to affect the breathing rate?

Answer

Some of the factors that affect the breathing rate are:

1. While exercising or doing intense physical activity, the body requires more energy due to which the demand of oxygen increases. This increases the rate of breathing of the person.
2. While sleeping and resting, the breathing rate decreases as the body requires less energy.
3. Allergic reactions increase the rate of breathing as allergic reactions narrow the nasal passage leading to a demand for more oxygen.
4. Stress and anxiety increases the breathing rate as the stress hormones trigger the body's fight or flight response.

What happens to the energy liberated during respiration?

Answer

The energy liberated during respiration is not all in the form of heat but a large part of it is converted into chemical energy in the form of ATP (Adenosine Triphosphate). This energy is utilised by the body cells for a vast variety of activities like:

1. Digestion of food.
2. Production of enzymes.
3. Contraction of muscles for movement.
4. Conduction of electrical impulse in a nerve cell.
5. Production of new cells by cell division.
6. Keeping the body warm in warm-blooded animals.

What do you understand by inhalation and exhalation? How are they different from each other?

Answer

Inhalation is the physical process by which the air containing oxygen is drawn into the lungs.

Exhalation is the physical process by which the air containing carbon dioxide is forced out from the lungs.

Differences between Inhalation and Exhalation are:

What do you understand by the term respiratory diseases? Name any three common respiratory diseases.

Answer

The diseases that affect the respiratory organs of the body making respiration difficult are termed as respiratory diseases.

The three common respiratory diseases are:

1. Bronchitis
2. Asthma
3. Pneumonia

State the cause and treatment for the following diseases:

1. Tuberculosis
2. Pneumonia
3. Bronchitis

Answer

1. Tuberculosis
   Cause — This respiratory infection is caused by bacteria that can spread by air, dust or sputum.
   Treatment — BCG vaccine, antibiotic Streptomycin.

2. Pneumonia
   Cause — This respiratory disease is mainly caused by bacteria inhaled through air or by contact.
   Treatment — Antibiotic - Penicillin.

3. Bronchitis
   Cause — This respiratory infection is mainly caused by a virus. Air pollution and smoking can also cause bronchitis.
   Treatment — Drinking plenty of fluids, following a well balanced diet, frequent hand washing and adequate rest can prevent and improve bronchitis.

Describe in brief the function of ribs and diaphragm in breathing.

Answer

The function of Ribs and Diaphragm is to aid respiration:

1. Ribs — In breathing during inhalation, the Ribs move upwards and outward. This function increases the volume of chest cavity. As a result lungs expand and atmospheric air rushes into the lungs. During Exhalation, the Ribs move downwards and inward. This function decreases the volume of chest cavity as a result lungs contract and air rushes out of the lungs.
2. Diaphragm — The diaphragm helps in breathing by changing its shape. During inhalation, it contracts and flattens, allowing the lungs to expand. During exhalation, it relaxes and becomes dome-shaped, helping push air out of the lungs.

The diagram given alongside is an experimental set up mimicking a certain process occurring in living beings. Study the figure and answer the following questions :

(i) Name the process and define it.

(ii) What are the two phases of the above mentioned process shown as (A) and (B) ?

(iii) Name the particular organs of the body shown in the figure with :
(a) Bell jar (b) Balloons (c) Rubber sheet

(iv) How do these phases (A) and (B) differ with respect to the position of ribs ?

(v) Does the breathing rate of a young boy and an old person differ ? Explain.

Answer

(i) The given diagram shows an experimental set up to demonstrate the process of Breathing.

Breathing is the process during which the air containing oxygen is drawn into the lungs and the air containing carbon dioxide is forced out from the lungs. It is a physical process.

(ii) Phase (A) shows Inspiration, and Phase (B) shows Expiration.

(iii) The particular organs of the body shown in the figure are:
     (a) Bell jar — Chest cavity
     (b) Balloons — Lungs
     (c) Rubber sheet — Diaphragm

(iv) During Inspiration [Phase (A)], ribs move upwards and outwards while during Expiration [Phase (B)] ribs move downwards and inwards.

(v) Yes, the breathing rate of a young boy and an old person typically differ. Young children have a higher breathing rate than adults, due to their higher metabolic needs and smaller lung capacity relative to their body size. In contrast, older people breathe more slowly as their metabolic rate is lower and lung function may decline with age.

The diagram given alongside shows the "Human Respiratory System". Study the same and answer the following questions :

(i) Label the guidelines 1 to 4.

(ii) Define the structure shown as part 2.

(iii) Name the basic structural and functional unit of part 3.

(iv) Write one specific structural feature of the inner lining of part 1.

(v) What is the muscular sheet on which part 3 rests ?

Answer

(i) The guidelines 1 to 4 show:

1. Trachea
2. Larynx
3. Lung
4. Bronchus

(ii) At the entrance of the trachea, there is a voice box called larynx. It contains two ligamentous folds called 'vocal cords'. Air expelled forcibly through the vocal cords vibrates them, to produce sound.

(iii) Alveoli is the basic structural and functional unit of part 3, i.e., lungs.

(iv) The inner linings of the trachea, bronchi and bronchioles have ciliated epithelium. The continuous movement of the cilia pushes out the unwanted particles that may be present in the inhaled air.

(v) Diaphragm is the muscular sheet upon which the lungs rest.