biology 12 chapter 14

1. Multiple choice Questions

i)       The wall of the trachea (windpipe) and bronchi of man is furnished with a series of incomplete:

a) Cartilaginous platesP                      b) chitinous rings

c) cartilaginous rings                           c) muscular rings

ii)         What does not happen during inspiration in man?

a) intercostals muscles contract               b) ribs are elevated

c) diaphragm becomes dome-shapedP   d) ribs move forwards

iii) The lateral wall of the chest cavity of man are composed of the:

a)  ribs    b) intercostals muscle                      

c) ribs &intercostals musclesP              

d) ribs, intercostals muscles & diaphragm.

iv) when the human blood leaves the capillary bed of the tissue, most of the carbon dioxide is in the form of:

a) carbonic acid                       b) bicarbonate ionsP

c) carboxylic acid                    d) none of them

v) Which sequence of organs is correct in air passageway of man?

a) nasal cavitieslarynxpharynuxtracheabronchi          

b) nasal cavitiespharynxtrachealarynxbronchi

c) nasal cavitiespharynxlarynxbronchitrachea

d) nasal cavitiespharynxlarynxtracheabronchi. P

vi) Which part of the air passage way posses cartilage plates in its wall?

a) bronchioles                                      b) distal region of bronchi

c) proximal region of bronchi              d) tracheaP

vii) Human lungs are spongy due to the presence of million of :

a) bronchi                                                        b) alveoliP

c) bronchioles                                      d) trachea

viii) Which event is not associated with the activity of expiration.

a) contraction of diaphragmP             b) more dome like shape of diaphragm           c) back ward & down ward movement of rib cage.

d) relaxation of intercostals muscles.

ix) Oxygen carrying capacity of blood does not depend upon:

a) partial pressure of                               b) partial pressure of

c) height from sea level                                   d) quantity of blood

x) When haemoglobin of the blood is fully saturated with oxygen, the 100ce of blood contains.

a) 15cc of oxygen                                           b) 20cc of oxygenP

c) 25cc of oxygen                                                       d) 10cc of oxygen

Short Question:

Short Questions

Q1.      What are the risk factors and causes of TB?

Ans: Tuberculosis:

Tuberculosis (TB) is a highly contagious chronic bacterial infection of lungs. TB infection begins when the mycobacteria  reach the alveoli, where they invade and replicate within the phagosomes (vacuole formed as a result of phagocytosis )of alveolar macrophages,  but they are unable to digest the bacterium.

Causes:

i)       TB is caused by the Mycobacterium tuberculosis by airborne droplets.

ii)      Usually this infection is passed on as a result of very close contact, so family member of an infected person are endangered if the person continues to live in the same household and has not undergone proper treatment.

Risk factors for TB include the following:

i) HIV infection (ii) low socioeconomic status, (iii) alcoholism (iv) homelessness (v) crowded living conditions (vi) diseases that weaken the immune system (vii) and health-care workers.

Q2:      State the signs and symptoms of otitis media.

Ans.     Otitis Media:  

Otitis media is an inflammation of the middle ear. The Eustachian tubes equalize the pressure between the middle ear cavity and the outside mucus to drain out of the middle ear cavity.

Inflammation of the middle ear causes the tubes to close causing the fluids to become trapped. Bacteria from the back of atmosphere and allow fluid and the nose travel through the Eustachian tube directly into the middle ear cavity and multiply in the fluid.

Causes and Risk factors of Otitis Media:

Children are more commonly affected than adults because of the small size and horizontal position of their Eustachian tube. The  four main causes of otitis media are allergy, infection , blockage of the Eustachian tube and nutritional deficiency.

Symptoms of Otitis Media:

i.          Otitis media causes

ii.         Sudden , severe earache

iii.        Deafness, and tinnitus (ringing or buzzing in the ear)

iv.        Sense of fullness in the ear

v.         Irritability

vi.        Fever, headache, a change in appetite or sleeping patterns

vii.       Fluid leaking from the ear, nausea

viii.      Difficulty in speaking and hearing

Occasionally, the eardrum can burst, which causes a discharge of pus and relief of pain.

Q3. List two difference between haemoglobin and myoglobin.

Ans. Difference Between Hemoglobin and Myoglobin:

•        Hemoglobin transports oxygen in blood while myoglobin transports or stores oxygen in muscles.

•        Myoglobin consists of a single polypeptide chain and hemoglobin consists of several polypeptide chains.

•        Unlike the myoglobin, concentration of hemoglobin in red blood cell is very high.

•        At the beginning, myoglobin binds oxygen molecules very easily and lately become saturated. This binding process is very rapid in myoglobin than in hemoglobin. Hemoglobin initially binds oxygen with difficulty.

•        Myoglobin occurs as a monomeric protein while hemoglobin occurs as a tetrameric protein.

•        Two types of polypeptide chains (two α-chains and two β- chains) are present in hemoglobin.

•        Myoglobin can bind one oxygen molecule so called monomer, while hemoglobin can bind four oxygen molecules, so called tetramer.

•           Myoglobin binds oxygen more tightly than does hemoglobin.

•        Hemoglobin can bind and offload both oxygen and carbon dioxide, unlike the myoglobin.

Q4.    Give any two factors that affect the oxygen carrying capacity of blood?

Ans. Factors which affect the oxygen carrying capacity of (blood) hemoglobin include 
a. increased acidity 
b.presence of fever 
c. increased BPG 
d. decreased CO2 
e. presense of CO

Long Question

Q1.      Describe the structure of human respiratory system?

Ans.     Human respiratory system:

Human respiratory system:  

Respiratory system consists of nose and nasal cavities, cavities , pharynx, larynx, trachea, bronchi, bronchioles,

1.         Nose:

i)       The nose is only externally visible part of the respiratory system.

ii)      Structure:  Structure of a human nose is composed of bones,             cartilage and fibro fatty tissues.

iii)     External feature: The external feature of a nose depends upon the ethmoid bone and the cartilages.

Role of Hairs:

iv/a) Hairs are present inside the nostrils that help in the filtration of air.

b)      Nose hair serve as a defense mechanism  against the harmful pathogens and solid particulate matter present in the air.

v)      Both the nostrils and nasal cavities are lined by mucous membranes along with cilia.

vi)     Mucus: The mucous membrane secretes a sticky substance called mucus.

vii)    The mucus and cilia filter the air and prevent the entry of foreign particles such as microorganisms, dust and particulate matter inside the respiratory system.

viii)      The mucus also helps in moistening the air.

ix)     cilia move the trapped substances to the pharynx for their removal.

x)      Underneath the mucous membrane, there are blood capillaries that help to warm the air to about C, depending upon the external temperature.

2. Pharynx:

i) Pharynx is cone-shaped passageway leading from the oral and nasal cavities to the oesophagus and larynx

ii)      The pharynxes part of both the digestive and respiratory system.

3. Larynx:

Larynx is an organ of complex structure that serves as a dual function

a)      as an air canal to the lungs and controller of its access,

b)         and as the organ of voice.

ii)      The larynx is composed of an external skeleton of cartilage plates that prevents collapse of the structure.

iii)     The plates are fastened together by membranes and muscle fibers.

iv)     Two fibrous bands called vocal cords are located in the larynx.

v)      The vocal cords are composed of mucous membrane stretched horizontally across the larynx.

4.         Trachea:

i)       Below the larynx lies the trachea, a tube of 10 to 12 cm long and 2cm wide.

ii)      Its wall is stiffened by 16 to 20 characteristic horse shoe shape incomplete rings that open towards the back and are embedded in a dense connective tissue.

iii)     Trachea is lined with ciliated mucus air, moistens and warms it while it passes into the lungs, and protects the respiratory surface from an accumulation of foreign particles.

5.         Bronchi:

i)       The trachea divides into two stem bronchi, one each for the left and right lung.

ii)      The right bronchus has a larger diameter, and is shorter than the left bronchus

iii)        Structure of bronchi closely resembles that of the trachea;

iv)        They have cartilaginous plates to support their walls.

v)      The bronchi divide and re-divide forming an air way network in the lungs.

6.         Bronchioles:

i)       The bronchioles are located at the end of the bronchi and terminate in the alveoli.

ii)      The bronchioles are approximately 1 mm or less in diameter and their walls consist of ciliated epithelium and a layer of smooth muscle.

iii)     The bronchioles are the first airway branches that do not contain cartilage.

iv)     They are responsible for controlling air distribution in the lungs.

v)      The bronchioles change diameter to either increase or reduce air flow

vi)     The bronchioles continue to divide and subdivide deep into the lungs.

vii)    Eventually the terminal bronchioles open into small collections of air sacs known as alveoli, where the actual exchange of carbon dioxide and oxygen occur.

7.         Alveoli:

i)          The alveoli form the gas exchange surface.

ii)         The wall of each alveolus is only 0.1 thick.

iii)        On its outsides is a dense network of blood capillaries.

iv)        Lining of each alveolus is moist squamous epithelium.

v)      This consists of very thin, flattened cells, reducing the distance over which diffusion must occur.

vi)     Collagen and elastic fibres are also present which allow the alveoli to expand and recoil easily during breathing.

8.         Lungs:

i)       Human have two lungs, a right and a left, which are located in the thoracic cavity,

ii)      The right lung represents of the total lung volume and is composed of three lobes, a superior, a superior, middle, and inferior lobe.

ii)      The left lung, smaller in volume because of the asymmetrical position of the heart, has only two lobes.

iii.      In the thorax the two lungs rest with their bases on the diaphragm, while their apexes extend above the first rib.

vi.      Each lung is encased in a thin membranous sac called the pleura.

vi.      It consists of two tough, flexible, transparent pleural membranes.

vii)    These protect the lungs, stop them leaking air into the thoracic cavity and reduce friction between the lungs and the wall of the thorax.

Q2.      Describe the mechanism of breathing in man?

Ans.     Control of breathing:

Breathing is an involuntary process and is not controlled consciously. However, some voluntary control is also possible.

Involuntary control:

i)       Involuntary control of breathing is carried out by a breathing centre located in the medulla oblongata.

ii)      The ventral portion of the breathing centre acts to increase the rate and depth of inspiration and is called aspiratory centre.

iii)     The dorsal and lateral portions inhibit inspiration and stimulate expiration and from the expiratory centre.

iv)     The breathing centre communicates with the intercostals muscles by the intercostals nerves and with the diaphragm by the phrenic nerves.

v)      rhythmic nerve impulse to the diaphragm and intercostals muscles bring about breathing movements.

vi)     We know that breathing consists of two phases namely breathing in or inspiration and breathing out or expiration.

Inspiration (Inhalation):

i)          In human, inspiration is an active process.

ii)      During inspiration, the intercostals muscles between the ribs contract and pull the ribs forward and out ward, pushing the sternum farther away from the vertebral column.

iii)     By the contraction of the intercostals muscles and of the diaphragm the size of the thorax as a whole is increased and the pleural cavities within it are, therefore enlarged.

iv)     Since the pleural cavities are closed, their enlargement tends to create a partial vacuum within them.

v)      the lungs are elastic and communicate with the atmosphere though air passages (trachea, bronchi).

vi)     As soon as the pressure around the lungs is lowered, the air rushes into them through the trachea by its own pressure and dilated them

vii)    In this way the lungs expand to fill the pleural cavities and the pressure on the inside and outside and outside of the thorax are equalized.

viii)   Thus the mechanism of human breathing is a suction-pump mechanism.

ix)     The lungs are made to expand and contract by movements of ribs and diaphragm.

2)         Expiration (Exhalation):

i)          Expiration in human is normally passive.

ii)      During expiration, the intercostals muscles of the ribs relax, the ribs move down ward and inward.

iii)        Thus the size of the chest cavity is reduced from side to side iv)      The sternum comes to its original position, decreasing the

            size of the chest cavity from front to  back or dorso-ventrally

v)      At the same time muscles of the diaphragm relax and so the diaphragm assumes its dome shaped position.

vi)        Thus the relaxation of the muscles of diaphragm and of the

intercostals muscles the size of thorax as a whole is decreased.

vii)       and the pleural cavities within are therefore,  reduced.

viii)   This reduction in the size of the thorax exerts pressure on the lungs.

ix)     The lungs themselves are very elastic and tend to return to their original size.

x)      When the lungs are pressed, the foul air inside them is expelled or expiration occurs.

Q3:   Describe the role of respiratory pigments in transport and storage of respiratory gases.

Ans.     Respiratory pigments:

Pigment:

i)       A respiratory pigment is a molecule that involves in transport or storage of respiratory gases.

ii)      In human, hemoglobin that increases the oxygen-carrying capacity of the blood and myoglobin that store oxygen in muscles are referred as respiratory pigments.

Hemoglobin:

Hemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of almost all vertebrates.

ii)      Haemoglobin the blood carries oxygen from the respiratory organs (lungs or gills) to the rest of the body (i.e the tissues.)

iii)     Here it releases the oxygen to burn nutrients to provide energy.

iv)     This energy is used to power the functions of the organism, and collects the resultant carbon dioxide to bring it back to the respiratory organs to be dispensed from the organism.

Myoglobin:

Myoglobin (Mb) is an carrying in the cytoplasm of muscle cells.

Q4.    State the causes, symptoms, and treatment of any one disorder of lower respiratory tract.

Ans.     Pneumonia:

Pneumonia is a serious disorder of lower respiratory which is characterized by inflammation of alveolar wall and the presence of fluid and pus in alveolar sacs of one or both lungs.

Causes and Risk factors of Pneumonia:

i)       There are over 30 different causes of pneumonia, but usually pneumonia is caused by bacterial infection (including mycoplasma) and viruses, which can enter the body through the mouth, nose and eyes.

ii)      If the body’s resistance is down, the natural immunity against diseases is weakened then microorganisms are free to spread into the lungs.

iii)     Thus, alveoli become filled with fluid and pus from the infectious agent, making it more difficult for the body to get oxygen it needs, and the person may become sick.

vi)     The bacteria that cause bacterial pneumonia: the bacteria that cause bacterial pneumonia are

a)         streptococcus pneumonia,       b) Hemophilus influenza        

c)         Legionella pneumophilia.        d) Staphylococcus aureus, and

e)         Mycoplasma.

Risk factors:

if pneumonia is not treated timely, some complications may arise that include

a)         pleural effusion (fluid around the lung)

b)         emphysema (pus in the pleural cavity)

c)         hyponatremia (low blood sodium)

d)         and abscess in the lung.

Symptoms of Pneumonia:

Symptoms vary, depending on the type of pneumonia and the individual.

9. Bacterial pneumonia:

With bacterial pneumonia the person may experience

a)         fever,               b) dry cough

c) headache                 d) muscle

e)         pain and          f) weakness.

ii)      These flu0 like symptoms may be followed within one or two days by increasing  a)breathlessness.

b) dry cough becomes worse and produces a small amount of mucus,          c) higher fever             d) bluish color to the lips

b. Mycoplasma pneumonia:

With mycoplasma pneumonia, the person may experience

a)       violent coughing attacks, (b) chills, (c) fever, (d) nausea,

(e) vomiting, (f) slow heartbeat, (g) and breathlessness 

(h) bluish color to lips and nail beds diarrhea and muscle aches.

Treatment of Pneumonia:

i)       Treatment depends on the severity of symptoms and the type of organism causing the infection.

ii)         Mostly antibiotics are prescribed.

Science and technology, and Society Connections

Q1.    Describe the development working of artificial breathing apparatus(for use under water and at high altitudes by fireman)

Ans.

i.        SCUBA (Self-Contained Underwater Breathing Apparatus) Jeabyun Yeon created the concept for a new SCUBA, known as the Triton Oxygen Respirator, which essentially acts as an artificial gill, allowing the possibility for humans to breathe underwater for extended periods of time.

ii.       The device consists of only the specially designed mouthpiece, making it easier to use than a common snorkeling device.

iii.      Using a very small micro compressor powered by a next generation micro battery,

iv.      The Triton compresses oxygen – which is filtered in the gill-like arms that extend from the mouthpiece – and stores it for the user, allowing for a constant oxygen feed while submerged.

v.       The gill arms operate by sucking in water through the scale-like surface, which then filters the water into a series of chambers that filter the oxygen from the water using fine threads with holes smaller than water molecules.

vi.      The separated oxygen is delivered to the user simply by biting down on the Triton, eliminating the usual difficulties that come with a conventional SCUBA, like expelling water from the mouthpiece and the clunky oxygen tanks and hoses.

vii.     However, there are definite hurdles to overcome in the production and use of the Triton Oxygen Respirator. Obviously the air humans breathe isn’t made entirely of oxygen, so the dangers of oxygen poisoning exist when at lower depths.

viii.    The sheer amount of oxygen filtration needed to adequately supply a diver with air just for surface diving might prove unfeasible.

ix.      And any certified SCUBA instructor can easily list some of the dangers a device like this could pose to a trained professional, let alone an unqualified diver.

x.       B. self contained breathing apparatus, or SCBA, sometimes referred to as a compressed air breathing apparatus (CABA), or simply breathing apparatus(BA), is a device worn by rescue workers, firefighters, and others to provide breathable air in an IDLH(immediate danger to life and health) atmosphere.

xi.      When not used underwater, they are sometimes called industrial breathing sets.

xii.     The term "self-contained" means that the breathing set is not dependent on a remote supply (e.g., through a long hose).

xiii.    If designed for use under water, it is called SCUBA (self-contained underwater breathing apparatus).

xiv.      An SCBA typically has three main components:

(a)     a high-pressure tank (e.g., 2,216 to 4,500 psi (15,280 to 31,030 kPa), about 150 to 300 atmospheres),

(b)        a pressure regulator, and

(c)     an inhalation connection (mouthpiece, mouth mask or face mask), connected together and mounted to a carrying frame.

xv.     A self-contained breathing apparatus may fall into two different categories. These are open circuit and closed circuit.

Q2.    Justify why birds perform much better than man at high altitudes?

Ans.

         

            Birds perform much better than man  at High Altitudes

. The highest peaks in the Himalayas represent the altitudinal limit for humans, above which even basal aerobic metabolism cannot be sustained. Similar limits probably constrain exercise performance in other mammals as well. Some birds fly at these altitudes —an impressive feat considering that flight is more costly than other forms of vertebrate locomotion and that its cost increases as barometric pressure declines. The ability to sustain high rates of metabolism in hypoxia appears to arise from unique enhancements across the O₂ cascade.

i.          O₂ transport and the respiratory system.

i.        The lungs of birds have a higher capacity for transporting O₂ during hypoxia than the lungs of man.

ii.       Airflow is unidirectional through the terminal gas-exchange units of avian lungs (parabronchioles), and the arrangement of airway and vascular vessels creates a functionally cross-current gas exchanger.

iii.      This mechanism of gas exchange is inherently more efficient than that in man lungs during moderate hypoxia, such that O₂tensions in the arterial blood of birds can exceed those in the expired gas.

iv.      The capacity for pulmonary O₂ diffusion is also higher in birds due to the exceptional thinness and large surface area of the gas-exchange tissue.

v.       The advantage of the avian respiratory system for loading O₂into the blood is well exemplified by the bar-headed goose, a species that flies over the Himalayas at nearly 9,000 m elevation.

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Q3.    Describe the purpose of mouth to mouth method for artificial respiration in first aid?

Ans.     Mouth-to-mouth resuscitation: 

A technique used to resuscitate a person who has stopped breathing, in which the rescuer presses his or her mouth against the mouth of the victim and, allowing for passive exhalation, forces air into the lungs at intervals of several seconds.

Or

a method of artificial respiration in which a person rhythmically blows air into the victim's lungs.

Q4.    Relate the transportation of gases to hiccup, sneezing, and snoring?

Ans.     The transportation of gases to hiccup:

A hiccup( also spelledhiccough) is an involuntary contraction (myoclonic jerk) of the diaphragm that may repeat several times per minute. In medicine, it is known as synchronous diaphragmatic flutter (SDF), or singultus The hiccup is an involuntary action involving a reflex arcOnce triggered, the reflex causes a strong contraction of the diaphragm followed about 0.25 seconds later by closure of the vocal cords, which results in the classic "hic" sound. At the same time, the normal peristalsis of the esophagus is suppressed.

Hiccups may occur individually, or they may occur in bouts. The rhythm of the hiccup, or the time between hiccups, tends to be relatively constant.

A bout of hiccups, in general, resolves itself without intervention, although many home remedies are often used to attempt to shorten the duration. Medical treatment is occasionally necessary in cases of chronic hiccups.

transportation of gases to sneezing

A sneeze, or sternutation, is a semi-autonomous, convulsive expulsion of air from the lungs through the nose and mouth, usually caused by foreign particles irritating the nasal mucosa. A sneeze expels air forcibly from the mouth and nose in an explosive, spasmodic involuntary action resulting chiefly from irritation of the nasal mucous membranee. transportation of gases to snoring

Snoring is the vibration of respiratory structures and the resulting sound, due to obstructed air movement during breathing while sleeping. In some cases the sound may be soft, but in other cases, it can be loud and unpleasant. Snoring during sleep may be a sign, or first alarm, of obstructive sleep apnea (OSA)

Q5.    Describe carbon monoxide poisoning (caused by gas heaters left on over night in close environment?

Ans.     More than 200 people die each year from carbon monoxide poisoning, and thousands of others develop symptoms that require emergency medical attention. Carbon monoxide poisoning is the most common cause of accidental poisoning-related deaths and is often called "the silent killer." Unborn babies, infants, children and pregnant women are especially vulnerable to carbon monoxide poisoning.

What causes carbon monoxide poisoning?

Carbon monoxide (CO) is a poisonous, colorless, tasteless, odorless gas that is produced from the incomplete burning of fuels that contain carbon, such as wood, charcoal, gasoline, coal, natural gas or kerosene. Breathing carbon monoxide fumes decreases the blood's ability to carry oxygen. Low levels of oxygen can lead to cell death, including cells in the vital organs such as the brain and heart.

Extra Question

Q1.      What do you know about transport of oxygen in blood?

Ans.     Transport of oxygen in blood:

i)       Approximately 97% of oxygen is carried by the red blood cells as oxyhaemoglobin,

ii)         While 3% is transported as dissolved oxygen in the plasma.

iii)     At high partial pressure of oxygen, oxygen binds with hemoglobin

iv)     This binding is a reversible reaction that occurs in the alveoli of the lungs in the presence of enzyme carbonic anhydrase.

v)      Each molecule of haemoglobin can bind with four molecules of oxygen to form oxyhaemoglobin.

vi)     The ability of haemoglobin to bind with oxygen is called oxygen carrying capacity of blood.

vii)    The oxygen carrying capacity of blood is directly proportional to the partial pressure of oxygen ( )

viii)   Maximum oxygen carrying capacity of arterial blood is 20ml/ (100% saturated) which is achieved at 100 mmHg .

ix)     This is because the amount of haemoglobin is 15gms/100ml of blood. Since lgm Hb can combine with 1.34ml of , therefore 100 ml combines with 20ml (100% saturated)

x)      Normally each 100ml of arterial blood contains 19.4ml   (i.e. it is 97% saturated; is 40 mmHg). Thus, 5 ml of  is released to the tissues by each 100 ml blood.

Transport of oxygen during exercise:

i)       During exercise, the need of oxygen is greatly increase in the tissue so more oxygen is released by the arterial blood to the tissues.

ii)         The venous blood that leaves an active tissue has only 4.4ml  per 100 ml of blood (20% saturated;  is 18mmHg).

iii)     Normally each 100ml blood contain 0.29 ml ( is 95 mmHg) and this capacity may increase up to 0.3ml/100ml blood at 100 mmHg .

iv)     While the 100ml of venous blood has 0.12 ml of dissolved is 40 mmHg.

v)      Thus, 0.17ml of is transported by each 100ml blood through the tissues per cycle in the dissolved state.

Q2.      Discuss Transport of carbon Dioxide in blood?

Transport of Carbon dioxide:

Carbon dioxide is transported in the blood in three main ways i.e.

i)       In the form of bicarbonate

ii)      ions in the form of carboxyhaemoglobin and

iii)     dissolved in plasma.

1)         As bicarbonate ions:

i)       approximately 70% of carbon dioxide is carried in the blood as bicarbonate ions.

ii)      Carbon dioxide diffuses into the blood and combines with water to form  carbonic acid in the presence of enzyme carbonic anhydrase.

iii)        The chemical reaction can be depicted as follows:

           

iv)     Carbonic acid, is an unstable compound and dissociate to form hydrogen ions and bicarbonate ions.

           

Formation of Haemoglobinic Acid:

i)       Accumulation of H ions increases acidity in the blood, i.e leads to the decrease in pH.

ii)      This does not occur since haemoglobin buffer the hydrogen formed.

iii)     The hydrogen ion readily associates with oxyhaemoglobin to form haemoglobinic acid and oxygen is released to the tissue.

Hamburger’s phenomenon:

i)       From inside of the erythrocytes negatively charged ions diffuse to the plasma.

ii)      This is balanced by the diffusion of chloride ions, in the opposite direction.

iii)     This is achieved by special bicarbonate-chloride carrier proteins that exist in the RBC membrane.

iv)        This protein moves the two ions in opposite direction s maint           aining the balance of ions on either side.

v)      This is called the chloride shifts or Hamburger’s phenomenon.

Formation of Bicarbonates:

The chloride ions that enters the RBC combine with potassium (K+) to form potassium chloride, whereas bicarbonate ions in the blood plasma combines with to form bicarbonates.

Maintenance of Blood PH:

The blood pH is thus maintained at approximately 7.4 by the  buffer mechanism that exists in blood.

Transport of : Depends on the partial pressure of . In case the partial pressure of is higher in tissues than blood, the reaction proceeds as drawn above. However, in case the partial pressure of   is higher in the blood than outside of the blood (as in case of the lungs), the equation reverse and bicarbonate ions with hydrogen ion to release carbon dioxide and water.

ii)         As carboxyhaemoglobin:

i)       About 23% of carbon dioxide is carried as carboxyaemoglobin.

ii)          combines with the globin part of  haemoglobin.

iii)        The reaction depends upon the partial Pressure of

iv)     when the is higher in the tissues than blood, formation of carboxyhamoglobin occurs.

v)      When the is higher in the blood than tissues as in case of lungs, carboxyhaemoglobin releases it

iii)        As dissolved in plasma:

i)          Only 7% of carbon dioxide is carried this way.

ii)      This is rather inefficient way to carry carbon dioxide, but it does occur.

Q3.    Write causes, Risk factors, symptoms and treatment of sinusitis?

Ans.  Sinusitis:

i)       Sinusitis is an inflammation of the nasal sinuses that may be acute (symptoms last 2-8 weeks) or chronic (symptoms last much longer).

ii)         the sinuses are holes in the skull between the facial bones.

iii)     There are four large sinuses: two inside the cheekbones (the maxillary sinuses) and two above the eyes (the frontal sinuses.)

iv)     The sinuses are lined with membranes that secrete antibody-containing mucus, which protects the respiratory passages from the irritants in the air we breathe.

Causes and Risk factors of Sinusitis:

i)       It is usually caused by infection (bacterial or viral)

ii)      But can also be caused by allergic reactions dust, pollen etc.

iii)     Environmental agents, such as excessive dryness in homes and offices from dry-air heating and air-conditioning systems can also inflame the sinuses.

Symptoms of Sinusitis:

            The classic symptoms of acute (short lasting) sinusitis are:

·         Fever

·         Nasal obstruction

·         Pus-like (purulent) nasal discharge

·         Loss of sense of smell

·         Facial pain or headache

·         Entering of nasal fluid into pharynx

Treatment of sinusitis:

If a bacterial infection is present, antibiotics, or sulfa drugs, are usually prescribed.

Q4.      How Otitis Media  is treated?

Ans.  Treatment of Otitis Media:

i)       Around 80% of cases of otitis media clear up within three or four days without treatment

ii)      Perforated eardrums also usually heal on their own without the need for treatment.

iii)     However, for complicated cases, following treatment options may be taken into consideration.

a)       Antibiotics, may be prescribed to treat severe cases of middle ear infection or cases that get worse after two or three days.

b)      Painkillers, may be used to control the main symptoms of middle ear infection (pain and fever).

Q5.    Write symptoms of tuberculosis?

Ans.  Symptoms of TB:

.

ii)         (a) Loss of weight (b) loss of energy (c) poor appetite,

(d) fever  (e) a productive cough, and (f) night sweats---might easily be blamed on another disease. Only about 10% of people infected with M. tuberculosis ever develop tuberculosis disease.

iii)     many of those who suffer TB do so in the first few year following infection , but the bacillus may lie dormant in the body for decades.

Q6.      How TB can be treated?

Ans.  Treatment of TB:

i)       Tuberculosis can be cured by a course of antibiotics taken over several months.

ii)      Isoniazid and rifampin are the most common drugs used for TB.

iii)     Inexpensive, effective and easy to take, these can prevent most cases of TB.

The disease can also be prevented by:

a)         Vaccinating infants with BCG vaccine.

b)         Isolating infectious patients.

c)         Improving hygienic condition and housing.

d)         Using pasteurized and properly boiled milk,

Q7.      Write a short not on Emphysema?

Ans.     Emphysema:

i)          Emphysema is a lung disease which is characterized by

a)       shortness of breath with exertion , eventually breathlessness all time

b)         Coughing

c)         fatigue

d)         Cyanosis (a blue tinge to the skin) due to lack of oxygen

ii)      The exchange of oxygen and carbon dioxide takes place in the small air sacs of the lungs (alveoli).

iii)        In a person with emphysema, the alveoli are damaged.

iv)     The main tubes leading into the lungs (bronchi are also damaged and narrowed).

v)      The airways of the lungs are elastic. After repeated exposure to chemical irritants, such as cigarette, the alveoli and bronchioles lose their elasticity.

vi)     The movement of oxygen from the air to the blood becomes more difficult.

vii)    emphysema is generally caused by cigarette smoking or long-term exposure to certain industrial pollutants or dust.

Q8.      Write common symptoms of lung cancer?

Ans.     Lung cancer:

Lung cancer is one of the most common cancers in the world. Cigarette smoking is one of the major causes of most lung cancers. The more cigarettes you smoke per day and the earlier you started smoking, the greater is the risk of lung cancer. High levels of pollution, radiation and asbestos exposure may also increase risk.

Common symptoms of lung cancer include:

—          A cough that doesn’t go away and get worse over time

—          Constant chest pain

—          Coughing up blood

—          Shortness of breath,

—          Repeated problems with pneumonia or bronchitis

—          Swelling of the neck and face

—          Loss of appetite or weight loss

—          Fatigue

Types:

There are many types of lung cancer. Each type of lung cancer grows and spreads in different ways and is treated differently.

Treatment also depends on the stage, or how advance it is. Treatment may include chemotherapy, radiation and surgery.

Q9.      Write some effects of smoking on the respiratory system?

Ans.     Effects of smoking on the respiratory system:

The effects of tobacco smoke on the respiratory system include:

—    Irritation of trachea (windpipe) and larynx (voice box)

—    Reduced hung function and breathlessness due to swelling and narrowing of the lung airways and excess mucus in the lung passages.

—    Impairment of the lungs’ clearance system, leading to the build-up of poisonous substances, which results in lung irritation and damage

—          Increased risk of lung infection and symptoms such as coughing and permanent damage to the air sacks of the lungs.