Human Body : Respiratory System
Exercise
SECTION I
A. Name the following.
1. A process involving breakdown of food to release energy.
= Respiration;
2. Structures present within the nasal passage to filter air.
= Tiny hair and cilia;
3. The form of energy stored in mitochondria.
= ATP;
4. Product formed in muscle cells due to anaerobic respiration.
= Lactic acid;
5. The pigment that carries oxygen.
= Haemoglobin;
B. Choose the correct option.
1. The part of the respiratory system connecting larynx to bronchi.
a. Pharynx. [ ]
b. Vocal cord. [ ]
c. Trachea. [✓]
d. Bronchioles. [ ]
2. Respiration occurs in
a. cytoplasm and mitochondria. [✓]
b. only mitochondria. [ ]
c. mitochondria and nucleus. [ ]
d. cytoplasm and nucleus. [ ]
3. The minute air sacs at the end of each bronchiole is called
a. bronchus. [ ]
b. alveolus. [✓]
c. air bladder. [ ]
d. capillary. [ ]
4. The following are released during aerobic respiration.
a. CO2, water and energy. [✓]
b. Lactic acid and energy. [ ]
c. Alcohol and energy. [ ]
d. Water and energy. [ ]
5. A condition caused by bacterial infection in the lungs.
a. Asthma. [ ]
b. Bronchitis. [ ]
c. Silicosis. [ ]
d. Pneumonia. [✓]
C. Correct the false statement by changing the underlined word/s.
1. Breathing is a biochemical process.
= Breathing is a physical process.
2. When we exhale air into distilled water, it turns milky.
= When we exhale air into limewater, it turns milky.
3. A flap-like structure, called the glottis is present at the junction of food pipe and windpipe.
= A flap-like structure, called the epiglottis is present at the junction of food pipe and windpipe.
4. Each alveolus is surrounded by a network of arteries.
= Each alveolus is surrounded by a network of bronchioles.
5. Alveoli contains carbon dioxide rich air during inhalation.
= Alveoli contains oxygen rich air during inhalation.
6. Tuberculosis is a viral disease.
= Tuberculosis is a bacteria disease.
D. State the exact location of the following.
1. Pharynx.
= Pharynx is a common passage located in the throat for air to enter from the nose and food to enter from the mouth.
2. Trachea.
= Trachea runs down the neck region.
3. Diaphragm.
= Diaphragm is situated at the floor of the chest cavity.
4. Bronchiole.
= Bronchiole are located in lungs.
5. Lungs.
= Lungs are located within the chest cavity close to the heart.
E. Write the functions of each of the following.
1. Epiglottis.
= Guards the entry of the oesophagus and the trachea. It prevents the food from entering the trachea by closing it while we are swallowing food.
2. Nose.
= Air enters the body through nose.
3. Larynx.
= It has vocal cords to produce sound.
4. Bronchus.
= Carry oxygenated air to and deoxygenated air from lungs.
5. Alveolus.
= It helps in exchanging of oxygen and carbon dioxide.
SECTION II
F. Give reasons for the following.
1. The nasal cavity is lined by hairs.
= The nasal cavity is lined by hairs to filter air entering into it.
2. Walls of trachea are supported by cartilaginous rings.
= Walls of trachea are supported by cartilaginous rings because they prevent the trachea from collapsing and allow the air to reach the lungs without any obstruction.
3. Pleura covers the surface of lungs.
= Pleura covers the surface of lungs because it protects and allows each lung to expand and relax smoothly during breathing.
4. The muscle cells respire anaerobically during heavy exercise.
= The muscle cells respire anaerobically during heavy exercise because there is a shortage of oxygen supply for energy consumption, glucose is converted into lactic acid in muscle cells and this causes muscle fatigue.
5. People exposed to air pollutants are susceptible to respiratory disorder.
= People exposed to air pollutants are susceptible to respiratory disorder as occupational hazard. They many be suspected to severe respiratory diseases such as silicosis, asbestosis, and byssinosis.
G. Differentiate between the following.
1. Respiration and breathing.
=
|
Respiration |
Breathing |
|---|---|
|
1. It is a physical process in which oxygen rich air is taken in and
carbon dioxide rich air is given out. |
1. It is a biochemical process in which food is broken down by utilizing
oxygen. |
|
2. It takes place outside the cell and involves the nose and lungs. |
2. It takes place inside the body cells. |
|
3. No energy is released. |
3. Food is broken down to release energy. |
|
4. The process of breathing is different in different organisms. |
4. The process of respiration is similar in all organisms. |
2. Pharynx and epiglottis.
= Pharynx is the common pathway for air and food. But epiglottis is the divider of epiglottis and oesophagus.
3. Bronchus and alveolus.
= Bronchus are the two main branches entering into the lungs. But alveolus are the further divisions of the bronchus into the lungs.
4. Inhalation and exhalation.
= By inhalation, air rich in oxygen enters into the lungs through the nose.
But by exhalation, air rich in carbon dioxide rushes out of the lungs.
5. Bronchitis and tuberculosis.
= In bronchitis, the bronchial tubes get inflamed and more mucus is accumulated than usual. Some to the causes of bronchitis are exposure to tobacco smoke, dust, fumes, chemical vapours, and air pollution.
But in tuberculosis, the lungs are fully affected. It is caused by a type of bacteria.
H. Short answer questions.
1. Give the word equations of aerobic and anaerobic respiration.
= The word equation of aerobic respiration is -
Glucose + Oxygen → Carbon dioxide + Water + Energy (more)
The word equation of anaerobic respiration is -
Glucose (absence of oxygen) → Lactic acid + Energy (less)
2. Define respiration.
= The process by which food molecule (glucose) is broken down in the body cells to release energy is called respiration.
3. How is the lung protected?
= A two-layered, fluid-filled membrane, called pleura protects the lungs.
4. How will you test the presence of carbon dioxide in exhaled air?
= By blowing air in limestone, it becomes milky. Carbon dioxide is present in the exhaled air being blown into the lime water. Thus, exhaled air contains carbon dioxide.
5. Name any two respiratory diseases caused due to short-term exposure to air pollutants.
= Two respiratory diseases caused due to short-term exposure to air pollutants are - tiredness and allergies.
I. Long answer questions.
1. Describe the parts of human respiratory system.
= The respiratory system in human beings comprises organs that help in the passage of air from the atmosphere to the lungs. The nose, pharynx, trachea and alveoli together make up our respiratory system.
❐ Nose : Air enters the body through the nose, which has two openings, called nostrils, that lead into a pair of nasal chambers. The nasal chambers are lined with hair to filter air entering into it. In addition, mucus is secreted within the nasal passage to trap germs and dust particles that enter the nose during breathing.
❐ Pharynx : The nasal pathway opens into a common passage called pharynx, for air to enter from the nose and food to enter from the mouth. The pharynx leads to two tubes, the trachea (windpipe) in the front and the oesophagus (food pipe) at the back. A flap-like structure, the epiglottis, guards the entry of the oesophagus and the trachea. It prevents the food from entering the trachea by closing it while we are swallowing food.
❐ Trachea : Trachea runs down the neck region, and above it, a small tube-like structure called the larynx, or voice box, is present. It has vocal cords to produce sound. Trachea connects the larynx to bronchi of the lungs. The walls of the trachea are supported by several C-shaped cartilaginous rings. They prevent the trachea from collapsing and allow the air to reach the lungs without any obstruction.
❐ Bronchi and bronchioles : Trachea divides into two tubes, called bronchi, which lead into the left and right lungs, respectively. Each bronchus further divided into several many branches called bronchioles. The bronchioles end in minute air sacs called alveoli.
❐ Lungs : Lungs are a pair of spongy organs located within the chest cavity close to the heart. The right lung is three-lobed and the left lung is two-lobbed. A two-layered, fluid-filled membrane, called pleura, protects and allows each lung to expand and relax smoothly during breathing. The lungs are protected from damage by the bony ribcage. They are supported by a muscular sheet, called the diaphragm situated at the floor of the chest cavity. There are millions of alveoli in each lung. Each alveolus is surrounded by a network of thin-walled capillaries. It is here that the exchange of gases takes place by diffusion. The lungs expand when filled with air and reduce in size when air is expelled.
2. How is the inhaled air filtered in the nose?
= Air enters the body through the nose, which has two openings, called nostrils, that lead into a pair of nasal chambers. That nasal chambers are lined with hair to filter air entering into it. In addition, mucus is secreted within the nasal passage to trap germs and dust particles that enter the nose during breathing.
3. Describe the role of ribs and diaphragm in breathing.
= The following changes take place during inhalation -
❐ The ribcage moves upwards and outwards.
❐ The diaphragm moves downwards and flattens.
❐ The volume of the chest cavity increases.
❐ The lungs expand due to which there is a fall in the air pressure inside the lungs as compared to the atmosphere.
❐ The atmospheric air rich in oxygen rush into the lungs through the nostrils.
The following changes take place during exhalation -
❐ The ribcage moves downwards and inwards.
❐ The diaphragm arches up acquiring a dome shape.
❐ The volume of the chest cavity decreases.
❐ The lungs reduce in size due to which there is rise in air pressure inside the lungs.
❐ The air rich in carbon dioxide is forced to move out from the lungs through the nostrils.
4. How does exchange of respiratory gases take place in the alveolus?
= The gaseous exchange occurs in lungs between the alveoli and a network of blood capillaries located in its walls. Blood is the medium for transport of oxygen and carbon dioxide. The red blood cells have an iron-containing pigment, called haemoglobin, which carries oxygen and carbon dioxide to and from the body cells, respectively. The biconcave shape of RBC increases the surface area to accommodate more haemoglobin so that efficient gaseous exchange takes place. Blood that is rich in oxygen is called oxygenated blood, while the blood that is rich in carbon dioxide is called deoxygenated blood.
Gaseous exchange happens by the process of diffusion from a region of higher concentration to lower concentration. Alveoli are rich in oxygen obtained from inhalation. The oxygen diffuses into blood capillaries where its concentration is low. Simultaneously, the carbon dioxide diffuses into the capillaries from the alveoli.
The oxygenated blood is carried to the left side of the heart, from where it is pumped to all parts of the body, while carbon dioxide is expelled through nose during exhalation. This is a continuous cycle.
5. What are the adverse effects of air pollution on respiratory system? Explain.
= When inhaled, air pollutants cause various respiratory disorders. Short-term exposure to air pollutants may cause people to experience chest pain, tiredness, inflammation, allergies, narrowing of airways, shortness of breath, wheezing, sore throat, nausea, cough, and acute bronchitis. Children under 14 years of age are especially affected as their lungs are still in the developing stage.
Long-term exposure to air pollutants may lead to severe damage of the respiratory system, decrease in lung capacity, and can cause diseases such as chronic bronchitis, asthma, pneumonia, tuberculosis, emphysema, cardiac problems, and even lung cancer.
Some people are exposed to higher amount of air pollutants as occupational hazard. They may be susceptible to severe respiratory diseases such as silicosis, asbestosis, and byssinosis.
PICTURE STUDY
1. Figures A and B are part of the lung showing exchange of gases during inhalation and exhalation. Study the same and answer the questions that follow.
a. Label parts 1 -3 in the Figure A.
= 1 - bronchus;
2 - Alveoli;
3 - Capillaries;
b. Name the gases represented by the arrows numbered 4 and 5 in Figure B.
= 4 - Oxygen;
5 - Carbon dioxide;
c. Which pigment is present on the surface of the part labelled 6?
= 6 - RBC;
d. What is the function of this pigment?
= Red Blood Corpuscle carries oxygen.
2. Observe the image and answer the questions that follow.
a. Name the organ system and label the parts 1 to 4 in the diagram.
= 1 - wind pipe or trachea;
2 - lungs;
3 - Diaphragm;
4 - Alveoli;
b. What is the position of diaphragm in the figure?
= In the figure, the diaphragm is in upward position. It is at the time of exhalation.
c. State two ways by which part labelled 2 is protected.
= Two ways by which part labelled 2 is protected are -
❐ Bony structure called Ribcage;
❐ A two-layered, fluid-filled membrane, called pleura.