Gas


Exchange in Humans

 

 Question: How does gaseous exchange occur in humans? Or Explain the respiratory system in humans.

 Ans. Human and higher Animals of the land have a developed respiratory system.

 This respiratory system can be developed into two parts. 

 1) Air passageway      2) The Lungs


     Sometimes the normal respiratory system disturbed due to the presence of many air pollutants in urban as well as in rural areas. 

 The main respiratory disorders are: 

   1)Bronchitis.        2) Emphysema  3) Pneumonia.    4) Asthma.          5) Lung cancer

     

1) Bronchitis: 

         Bronchitis disease is due to the inflammation or infection of bronchi are bronchioles. It is caused by viruses, bacteria or due to chemicals in tobacco are other industrial smoke. Bronchitis may be acute bronchitis and chronic bronchitis. 


(i) Acute Bronchitis: 

          There is no damage of bronchi and Bronchitis in acute bronchitis. The patients recover within two weeks by taking proper medicine.


 (ii) Chronic Bronchitis: 

          Chronic bronchi occurs due to smoking. Chronic Bronchitis damages ciliated epithelium. As a result excessive secretion of mucus causes the swearing of the wall of the tube. It lasts 3 months to 2 years. 


CAUSES: 

● Viruses 

● Bacteria 

●Exposure chemical irritants e.g. Tobacco smoke 

● Poor food 

● Air pollution 


SYMPTOMS: 

■ Continuous cough 

■ Fever 

■ Chills 

■ Shortness of breath while doing herd job

■ Tightness in the chest while moving 


TREATMENT: 

       Common method of treatment is used OF antibiotics, bronchodilators and oxygen therapy. 


(2)EMPHYSEMA:

 

     It is the disease in which alveoli are destroyed. The tissues of lungs breakdown and the lungs never come back to their original shape after exhalation. So air cannot be pushed out and is trapped in the lungs. It causes serious complications in gaseous exchange. It results in inflammation and collapsing of bronchioles. 


CAUSES:

 ● Cigarette smoking 

● Air pollution


 SYMPTOMS:

 ■ Shortness of breathing 

■ Loss of weight 

■ Fatigue


 (3) Pneumonia:

 

             Pneumonia is an infection of the lungs. If both the lungs become infected then it is called double Pneumonia. It is caused by a bacterium streptococcus influenza virus or Punjabi fungal infections. This disease is transmitted from person to person through coughing and sneezing. 


CAUSES:

 ● Viruses bacteria

 ● Fungi 


SYMPTOMS: 

● Higher fever with cold

 ● Cough with sputum

 ● Change in skin color

 ● Shivering 


 (4)ASTHMA:

          Asthma Is a form of allergy. It causes inflammation of the bronchi, move mucus production, and narrowing of the Airways. This reduces the amount of inhaled air. 


CAUSES:

● Domestic animals

● Cold weather 

● Mold 

● Pollen 


SYMPTOMS: 

■ Cough 

■ Chest pain 

■ Shortness of breath 

■ Wheezing (whistling sound during exhalation) 


 (5) LUNG CANCER:

           Lung cancer is due to uncontrolled growth that occurs in the tissues of lungs. The cells continue to divide without any control and form tumors. It is more common in men than women.


 CAUSES: 

● Pollution 

● Ionizing radiation 

● Viral infection 

● Cause applying cancer is smoking 

● Radiations 


SYMPTOMS: 

■ Shortness of breath 

■ Coughing(including blood) 

■ Loss of weight 


PREVENTION: 

▪︎ Lung cancer is prevented by eliminating tobacco smoking.


NEGATIVE EFFECT OF SMOKING 

        Smoking has many negative biological effects on the human body. Tobacco smoke contains about 4,000 different Chemicals at least 50 of these cause cancer and other dangerous diseases. Tobacco smoke contains carbon monoxide, tar, carcinogens(cancer causing agent) nicotine and metals.


 1) CANCERS:

        Tar is the major cause of lung cancer. Smoking may cause cancer in the kidney, oral cavity, larynx, breast, urinary bladder and pancreas. 


2) Damage to the air passageway: 

        Many toxic chemicals present in tobacco smoke cause damage to the air passageways which leads to emphysema and other respiratory disorders. 


3) Effect on circulating system:

         Carbon monoxide is a poisonous gas. It decreases concentration of oxygen in the blood cells, the production of blood platelets is increased and makes the blood viscous which causes arteriosclerosis. 


4) Effect on heart and brain: 

          Nicotine is a powerful poison. When nicotine is inhaled through smoking, it reaches our circulating system, which causes the hardness of the Wall of the arteries and damages the brain tissue. Constrict the blood vessels, damage the hormonal system and metabolism.