KPK Board 12th Class Biology Ch 14 Respiration Short Questions Answers

Respiration is that process in which food is broken to release energy for vital activities of organisms. Types: aerobic respiration: this type of respiration takes place in the presence of oxygen. Respiration in higher plants and animals. Anaerobic respiration:  this type of respiration takes place in the absence of oxygen. Respiration in bacteria.

The taking in of oxygen into the lungs and giving out of CO2 is called breathing.

Phases: breathing is completed in two phases.

Inhalation: it is the taking of oxygen into the body.

Exhalation: it is the giving out of CO2 from the body.

Respiratory surface is the area where gases are exchanged with the environment actually takes place.

Properties: it must be permeable.

It must be thin.

It should have a large surface area.

It should possess a good transport medium.

The organs that help in respiration by providing respiratory surface for gaseous exchange are called respiratory organs. In plants: respiration takes place through stomata in leaves , they do not have special respiratory organs.

In animals: in aquatic animals the organs of respiration are gills. While in land animals lungs are the respiratory organs.

The passage of the respiratory system through which the air passes to the lungs is called air passageway.

Components: nose ,two nostrils, nasal cavity, pharynx ,larynx, trachea, bronchi, bronchioles.

When the inhaled air passes through nasal cavities, it undergoes the following changes.

It is warmed.

It is moistened by the inner lining of the nasal cavity.

It is dust free by the hair of the nasal cavity.

Epiglottis is a flap that is made of elastic tissue covered with a mucus membrane and is attached to the entrance of the larynx.

Its function is to protect  the trachea during swallowing.

Importance:  epiglottis is important to prevent the entry of food or liquid to the larynx because it closes the esophagus during inhalation.

It is impossible to swallow and inhale at same time due to the presence of epiglottis.

Vocal cord or vocal folds are also known as voice reads are two infolding of mucus membrane in the larynx. The vibrations during speech produce voice.the vocal cords remain open during inhalation closes when infolding the breath. They are white because of scant blood circulation.

It is also the windpipe . It is a tubular structure made up of open rings of cartilage.

Division: inside the thorax the trachea divide into two branches called bronchi (single bronchus) each enter to the lung’s own side. They further divide and re- divide and finally attain the diameter of one mm or less then they are called bronchioles.

Right lungs : the right lung is larger in size. It represents 56% of total lung volume. It is composed of three lobes.

Left lung: it is smaller in size than the right lung. It represents 44% of total lung volume. It is composed of two lobes.

Air sacs are the functional units of lungs which give the lungs its characteristic spongy nature. Alveoli: each air sac consisting of many microscopic structures is called alveoli, (singullar= alveolus ) from latin it means small cavity.

Number: there are about 700 million alveoli in human lungs.

Inhalation: during inhalation the volume of thorax is increased. The muscles of diaphragm contract. The ribs are raised upward. The atmospheric air rushed into the lung through the trachea.

Exhalation: thoracic volume decreases during exhalation. The diaphragm muscles relax. The ribs go down. Pressure entered on the lung to expel the air out.

The single cycle consisting of one inspiration and one expiration is known as respiratory cycle or it is the time interval between the two consecutive inspirations. Phases: inspiration = positive flow in air way.

Plateau (inspiration pause ) zero flow between end inhalation and exhalation begins. Exhalation = negative flow in air way. Period of rest. Absence of air flow.

Lung volume and capacities refer to the volume of air associated with different phases of respiratory cycle. Amount: the average adult human has a lung capacity approximately 5 liter.

It is the volume of lungs representing the normal volume of air displaced between normal inhalation and exhalation when extra efforts are not applied. Healthy adult is 500ml/ inspiration of 7ml/ kg weight. Residual volume: it is the volume of air remaining lungs after maximum exhalation. Vital capacity: it is the volume of air breathed out after deepest inhalation.

The breath center is located in the medulla oblongata that controls breathing. Inspiratory center: it  is the ventral portion and controlled rate and depth of inspiration.

Expiratory center: it comprises the dorsal and lateral portion.  It inhibits the inspiration and stimulates the expiration.

In   blood oxygen is carried through two agencies.

Haemoglobin  in the RBC s carry about  z97 of oxygen to the tissue.

Plasma:  blood plasma carries 3% of oxygen is dissolved form.

Hemoglobin  is a protein in our red blood cells. It has iron that  possesses affinity towards oxygen. Oxyhaemoglobin  when we breathe in oxygen from our lungs dissolve in blood capillaries and react with iron of hemoglobin thus forming  an unstable compound called oxyhaemoglobin.  hemoglobin + O2  oxygen haemoglobin.

The oxygen carrying capacity of the hemoglobin to bind with oxygen is called oxygen carrying capacity of the blood. it depends upon the efficiency and amount of hemoglobin in our blood. gm

Hb/dl  x 1.3 ml O2/ gm Hb.In this HB content is taken and multiplying it by oxygen capacity of 1 gm of Hb.

There are three ways of carbon dioxide transport.

As bicarbonate ions: about 70% of carbon dioxide is transported by blood as bicarbonate ions.

CO2 + H2O =  H2CO3

H2CO3 is an unstable compound that is dissociated as follows.

H2CO3+ H

It is a process which occurs in the cardiovascular system and refers to the exchange of Bicarbonate chloride across the membrane of red blood cells. It is also known as a hamburger phenomenon named after hartog jakob hamburger.

respiratory pigment is a molecule that increases the oxygen carrying capacity of the blood

It is for chemical cases of respiratory pigments that are metalloproteins.

Hemoglobin, haemocyanin,  chlorocruorin, Hemerythrins. They bind  reversibly with O2 at specific  O2  binding sites associated with metal atoms in their molecular structures.

Sinusitis Is the inflammation of  nasal  sinuses.

Causes  bacteria, virus, allergic reactions.

Symptoms:  fever, nasal obstruction, nasal discharge, loss of sense of smell, facial pain are headache.

Treatment: of sinusitis includes  antibiotics, sulfa drugs, anti-allergic, and decongestants.

Otitis media:  is the inflammation of the Middle ear.

The main cause of the otitis media include allergy infection blockage of the eustachian tube and nutritional deficiency. Symptoms: symptoms of otitis media are ,sudden severe earache.

Deafness,  sense of fullness in ear, irritability,  fever,  difficulty in speaking and hearing.

Treatment: otitis media is 80% clear up without treatment ever complicated cases are treated with antibiotics and painkillers.

The eustachian tube, Also known as auditory tube is a tube that links the nasopharynx to the middle ear.

In adult humans it is approximately 35 mm and is named after anatomist bartolommeo eustachio.

Function under normal conditions the human eustachian  tube is closed but it can open to let a small amount of air through it to prevent that damage by equalising pressure between the middle ear And Atmosphere.

lungs are respiratory organs of man and other land animals.

Structure lungs are sac-like structures inside the thoracic cavity; they are covered by a protective layer called pleura.

Alveoli are the functional unit of lungs which give the characteristic spongy nature to the lungs.

The function of lungs is to supply oxygen be disturbed to tissue and collect carbon dioxide from tissue for removal.

Bronchitis is the lower  respiratory disorder in which the lining of the bronchial tubes become inflamed or infected. The condition is called bronchitis.

Affecting bronchitis reduces the amount of oxygen that can flow into the lungs.

Treatment can be treated with medication and bronchodilators .

pneumonia is a respiratory disease in which one is both lungs are infected during this disease a fluid and pus are filled in air sacs in which bacteria multiply. Causes  pneumonia is caused by different strains of bacteria and some viruses.

Symptoms:  symptoms of bacterial pneumonia are very high fever, sweating, Rapid breathing, chattering teeth. Symptoms  of viral pneumonia:  fever, dry cough, headache, muscle pain and weakness. Treatment of this is mostly dependent on its variety and causing agents mostly it is treated by antibiotics and vaccines.

disease in which bacteria make small tuberculi in lungs and affect them. Causes  TB is caused by mycobacterium tuberculosis risk factor being contagious TB has the following risk factors HIV infection loss socioeconomic status alcoholism crowded living condition. Symptoms: symptoms of T.B are. Loss of weight. Poor appetite. Fever. Productive cough. Night sweat. Treatment: treatment is done by a course of antibiotic taken over several months. EG ionised and rifampin.

T.B can be prevented by.

Vaccinating the infants with BCG vaccine. Isolating infectious patients. Improving hygienic conditions. Using properly boiled milk.

BCG stands for bacillus calmette – guerin. It is a live bacterial vaccine given for the protection against T.B. It is prepared from a strain of weakened live mycobacterium bovis. It is used in infants for immunity against T.B. The vaccine may be given to a person at high risk of developing T.B.

Emphysema is a severe type of lung disease during which the alveoli walls are damaged. Effects: It badly affects the health.it causes difficulty in breathing.

Symptoms: shortness of breath. Coughing. Fatigue. Cyanosis.

Causes: mostly emphysema caused by smoking and long term exposure to pollutants or dust.

Treatment: oxygen therapy. Bronchodilators. Lung transplant in severe cases.

Lung cancer is abnormal cell division inside the lungs.

Effects: it is a very painful condition. In severe conditions it is no more curable so it can become fatal.

Causes: high pollution. Radiation. Alcoholism. Common symptoms of lung cancer include.

Worse cough. Constant chest pain. Swelling of neck and face. Coughing up blood. Fatigue.

Treatment: the lung cancer is treated by chemotherapy , radiation and surgery.

Smoking badly affects the respiratory system. Some harms of smoking are listed below.

Irritation of trachea and larynx.reduce lung functions. Accumulation of poisonous substances in the respiratory system.increased risk of respiratory disease.permanent damage to lungs.

According to their location site.

Sinusitis is the inflammation of nasal sinuses.

Otitis media is the inflammation of the middle ear.

Lower respiratory disorder: pneumonia is the inflammation of alveoli.

T.B is the infection of lungs.

Lungs disorder: emphysema it is the infection and damage of alveoli.

Lung cancer: it is destruction of the normal lungs structure and functions.