Respiration (respiratory system)

Respiration

What is respiration?

Definite respiration?

Definition of respiration?

Respiration can be defined as biochemical process by which foods are oxidized to liberate energy. Overall respiration involves two processes.

You may interested in this topic.
Classification of plant and animal.
                 ...click here...

Types of Respiration

1. Aerobic 

It occurs in all higher forms (organisms) in this type Oxygen is necessary.

C₆H₁₂O₆ + 6O₂ -------- 6CO₂ + 6H₂O + 2880 K joule .

2. Anaerobic respiration 

C₆H₁₂O₆ ----------- C₂H₅OH(ethyl alcohol) + CO₂ + 210 K joule example yeast 

C₆H₁₂O₆  ----------- C₃H₂O-3 (lactic acid)+ energy example intestinal worms 

(Organ involved in respiration.

Body parts involved in respiration) 

Respiratory organ.

There is a pair of spongy conical hollow bags enclosed in pleural cavities called lungs. The plural cavities are lined by tough, flexible and transparent membranes called pleura. The plura is double walled. The outer membrane is parietal and inner membrane is visceral membrane. These membranes protect lungs and stop leaking of air into thoracic cavity. The fluid secreted by pleura reduces the friction during breathing movement. The lungs are capable of great expansion. They are inflated when filled with air. These are found in either side of heart. The right lung has three lobes and left lung has two lobes. The three lobes of right lung are right superior, right inferior and middle lobe. The two lobes of left lung are left superior and left inferior. The left lung has cardiac notch at its anteromedian border to accommodate the heart. There are about 750 millions of alveoli. These large no. of alveoli provide about 100 sq meter of surface. It is about 50 times of skin surface. Alveoli are extremely thin walled and vascular structure surrounded by capillary of network. These are the site for gases exchange.

Fig. Internal Respiratiory System

Mechanism of respiration:

Breathing is simply taking in of fresh air from atmosphere and giving out of used air from lungs. Breathing renews constantly the air present in the lungs. It is accomplished through changes in the volume and air pressure of the thoracic cavity. Change in volume and air pressure is carried out by movement of ribs, internal and external intercostals muscles, diaphragm and abdominal muscles. Breathing can be divided into inhalation and exhalation. One breath includes one inspiration or inhalation and one expiration of exhalation. The respiratory rate is the no. of breaths taken per minute. At rest, for a normal person, it is equal to 12 to 14 breaths per minute. The pulmonary air volume during breathing is measured by an apparatus called Spiro meter. 

Fig. Mechanism of respiration

Inhalation 

1.Taking in of atmospheric air 

2.Contraction of external intercostal muscle or inspiratory muscle and relaxation of internal intercostals muscle.

3.Rib cage moves forward and outward 

4.Diaphragm contracts and becomes flattened shaped.

5.Increase in the volume of thoracic cavity. 

6.Decease in air pressure(below atmospheric pressure.

7.Rushing in of air through nostril into alveolar sacs causing inflation of lung.

Exhalation

1.Giving out of air from lungs.

2.Relaxation of external intercostals muscle and contraction of intercostal  muscle.

3.Rib cage moves downward and inward.

4.Diaphragm relaxes and become dome 

5.Decrease in volume of thoracic cavity.

6.Increase in the air pressure.

7.Expulsion of air from lungs into atmosphere causing deflation of lungs.

Exchange of gases in lungs:

The air inhaled by inspiration comes to alveoli. All around the alveoli there is a network of blood capillaries. These capillaries are extremely fine tubes with only one layered wall. The deoxygenated blood collected from different parts of the body is at first brought to the heart, and from here pumped out to the lungs. This blood which may also be called venous blood is sent to the lungs where it has to pass through the network of capillaries around the alveoli. The oxygen from the alveolus diffuses out into the blood capillary due to difference in partial pressures of oxygen and is picked up by the hemoglobin molecules present inside the red blood corpuscles. Again, carbon dioxide, which is in greater amount in the venous blood, comes from the capillary into the alveolus.

Physiology of respiration:

Physiology of respiration can be studied under following headings.

External respiration: It is uptake of O₂ and release of CO₂. It takes place in the lungs called breathing.

Transport of O2 by blood:

RBC of blood contain haemoglobin as respiratory pigment. Human blood contains nearly 150 gram of Hb per 100 ml. haemoglobin readily combines with and dissociates to form free Oxygen.

                                            Hb + O₂    →    HbO₂

The maximum carrying capacity of O2 due to hemoglobin expressed in the graph oxygen dissociation curve.

Internal respiration is tissue respiration. Digested food is oxidized to liberate energy.
Transport of CO₂:

Carbon dioxide is one of the poisonous  gas which by any means should be elimate from the body. It is slightly soluble in water convert in to carbonic acid. After the exchange of gases CO2  eliminate mainly by 3 ways;

1.In the form of carbonic acid:

CO₂ dissolve in water of blood plasma to form carbonic acid, about 7 % of total CO₂  carried in this way. 

2.In the form of bicarbonates of Na and K:

CO₂ enters into the RBC to dissolve into water. It is catalysed by carbonic anhydrase enzyme. H₂CO₃ ionises to form bicarbonate and hydrogen. The bicarbonate ions combine with Potassium ion to form Potassium bicarbonate. Upon saturation, Potassium bicarbonate ionizes into Potassium and bicarbonate ion, These ions being at higher conc. within red cells, come out into plasma and combine with available Na ion to form Sodium bicarbonates. The loss of bicarbonate ions is balanced by chloride ions diffusing into RBC from plasma . the exchange of Cl and HCO₃ between plasma and RBC is known as Chloride shift or Hamberger’s phenomenon. In the lungs, these reactions are reversed. The exchange of Cl and HCO₃ is reversed. H₂CO₃ is formed again which break down into water and CO₃. CO₃ in exhaled. In this way about 70 % of CO₂ is transported.

3.By RBC in the form of carbamino compounds:

Amino acid present in RBC get oxidized to release amino group and carboxyl group. Carbon dioxide combines with amino group to form carbamino compounds. About 23 % is transported in this form.

What is laser

LASER

THE PRINCIPLE OF LASER:

The laser light is a source that produces a beam of highly coherent and a very monochromatic light as a result of a co – operative emission from many atoms.

Principle of laser: Let is consider an assembly of atoms of some kind ‘hf’. If we somehow raise the atoms of the metastable level and let a light of frequency ‘f’ fall upon them, there will be more induced emission from the metastable level than that of induced absorption by the lower level. As a result an amplification of the original light is obtained. This is the principle of laser.

Ruby laser:

The ruby is a crystal of Aluminum oxide (Al2O3) mixed with it 0.05% of chromium oxide (Cr2O3).

Construction: A ruby laser consists of a cylindrical ruby rod whose ends are optically flat. One end is fully silvered and the other end is partially silvered. The ruby rod is enclosed in a glass tube which is surrounded by a xenon flash tube which acts as an optical pumping device in figure.

Working: The chromium atoms are excited from E1 state to E3 state by absorption of light of wavelength 350 nm produced by xenon flash tube. The excited chromium atoms then undergo non radioactive transition to E2 state which is metastable state having means time about 10-3 sec. When population inversion (N2> N1) is achieved, some of the atoms undergo spontaneous transition from E2 to E1, thus emitting photons of frequency f = E3 – E1/h. The photons moving not parallel to the ruby rod escapes out and those moving not parallel to the ruby rod escape out and those moving parallel to the rod gets deflected back by the silvered surface. The photons which are moving parallel to the ruby rod can cause the stimulated emission. As a result, a beam of coherent photons moving in phase and parallel to the ruby rod comes out of the partially silvered end of the rod.

What is quantum physics..

Click the link below..

https://edufact9.blogspot.com/2019/05/quantum-physics.html?m=1

Population inversion:

Let N1 and N2be the number of atoms lying in the ground state E1 and E2 respectively. Under ordinary condition of thermal equilibrium the number of atoms in the higher energy state is considerably smaller than that of the number of atoms in the lower energy state is N2< N1. In such a situation of a light of frequency f = E2−E1h$\frac{{\mathrm{E}}_2-{\mathrm{E}}_1}{\mathrm{h}}$ is incident on a large collection of such atoms, the atoms are excited due to absorption of photons and raise to the excited state E2than that in the lower energy state E1 i.e. N2> N1. This phenomenon of having more number of atoms in the excited state than in the ground state is called population inversion.

The process by which population inversion is carried out is called optical pumping.

Optical pumping is a method of achieving population inversion. For this atom which have three energy states E1, E2 and E3 are taken when E3> E2> E1. E1 is a ground state, E2in metastable state and E3 is short lived state. The atoms in the E1 state are pumped into E3stated by photon of energy hf = E3 – E1 by stimulated absorption. E3 is shortly lived state and E3 to E1 transition is prohibited. Since, N3> N2 cannot be achieved, so simulated emission results from E3 to E2 transition. Thus, the atoms in the atoms in the E3 state then go to the E2 state either by simultaneous emission or by non radioactive transition in which the energy E3 – E2 is converted into vibration energy of the atom forming the substance. Since E2 is metastable state, atoms can remain in this state for comparatively longer time. As a result, population inversion (i.e. N2> N1) takes place. Now, the atoms in E2 state are bombarded by a photon of energy hf = E2 – E1to cause them to a stimulated emission of radiation of energy hf in the direction of incident photon. As a result a highly intense coherent and unidirectional beam of radiation comes. The beam is called laser beam.

Construction of He-Ne laser:

It consist of a long and narrow discharge tube about 8ocm long and 1cm in diameter, fill with the mixture of Heat a pressure of 1mm and Ne at a pressure 0.1mm of Hg, which forms the leaser medium. Two electrodes P and Q fitted to the discharge tube as shown in figure M and N are the two mirrors which form a resonant cavity. The mirror M is fully reflecting whereas N is partially reflecting so, allow the laser beam to pass out of it.

Working:

 As soon as the electric discharge passes through the mixture of He and Ne gases electron in the tube are accelerated. Theses collide with helium atom and excited them to higher energy level S2 and S3.as shown in figure. These levels of the helium atoms are metastable and the excited helium atom s remains in these for a long time before being de-excited. On the other hand, some of the excited energy state, say E4and E6 of neon correspond very approximately to the energy state S2 and S3.

Because of this when helium atoms in the energy state S2and S3 collide with neon atoms in the ground state E1, Ne atom absorb energy and are excited to the energy state E4and E6whereas He atom lose energy and are de-excited to the ground state S1. This process is continuously transfer more and more neon atom from the ground state to the excited energy sate E4 and E6

There are to more energy E3 and E5 slightly below the sates E4and E6 and another energy state E2 in Ne. Since the energy state E4and E6are highly populated, there is a population inversion between the state E4and E6and the lower energy sate E3and E5. And the emission of the radiation are transition between E6and E5,E4 and E3, and E6and E2 respectively lead to emission of wavelength 3.539μm, 1.15μm and 6328A0. The first two lies on the infra red region and the last cross ponds to the red light from He-Ne laser in the visible region.

In an improved of the He-Ne laser, the resonator mirror, P and Q are used externally to the lase cavity because the mirror sealed inside the discharge tube are eroded by gas discharge and have to replaced.

Further for the minimization of the loss due to reflection at the ends of the discharge tube, Brewster windows W1 and W2 are used as shown in figure these are fitted at an angle called Brewster angle and given by tan⁡ɵB=μ

Where μ is the refractive index of the material of which the window are made.

Uses:

It is used in holography

It is used in scientific research.

It is used in medical treatment.

Heisenberg’s uncertainty principle:

In classical mechanics position co-ordinates, component of momentum, components of angular momentum are measured in an arbiter precision but in quantum mechanics particle is considered as wave and components of position and momentum are measured with highly improved precision as compared to classical mechanics.

The amplitude of the wave remaining almost zero in wide range of wave but specific value in narrow region of wave indicates high precision in position of the particle measured as momentum is conjugate quantity with position, high precision in position reflects worst precision in momentum. Hence, Heisenberg states that ‘it is impossible to determine position and momentum simultaneously with 100% accuracy.

These quantities are related as:

Δx. Δp ∼ h

Where Δx is uncertainty in position

Δp is uncertainty in momentum

Planks constant

This equation was further improved by Heisenberg which can be expressed as

                                            Δx.Δp≥h2π$\mathrm{\Delta }\mathrm{x}.\mathrm{\Delta }\mathrm{p}\ge \frac{\mathrm{h}}{2\pi }$

Uncertainty principle proposed by Heisenberg was further modified by Kennard and obtained the result as:

Δx.Δp≥h4π$\mathrm{\Delta }\mathrm{x}.\mathrm{\Delta }\mathrm{p}\ge \frac{\mathrm{h}}{4\pi }$

The most important thing is that uncertainty principle holds true for both microscopic and microscopic particle and it is independent with the method of measurement.

Electron cannot be constituents of nucleus:

Let electron lie inside the nucleus. Then its uncertainty in position is equal to diameter (size) of nucleus which is about 2 * 10-14m.

So, uncertainty in position of electron,

Or, Δ$\mathrm{\Delta }$x = 2 * 10-14m

Using, Heisenberg’s uncertainty principle the uncertainty in momentum of electron is given by:

Or, ΔP$\mathrm{\Delta }\mathrm{P}$ = h2πΔn$\frac{\mathrm{h}}{2\pi \mathrm{\Delta }\mathrm{n}}$

So, Uncertainty in speed of electron is:

Or, ΔV=ΔPme$\mathrm{\Delta }\mathrm{V}=\frac{\mathrm{\Delta }\mathrm{P}}{\mathrm{m}\mathrm{e}}$

= h2πΔn.me$\frac{\mathrm{h}}{2\pi \mathrm{\Delta }\mathrm{n}.{\mathrm{m}}_{\mathrm{e}}}$

= 6.62∗10−342π∗2∗10−14∗9.1∗10−31$\frac{6.62\ast {10}^{-34}}{2\pi \ast 2\ast {10}^{-14}\ast 9.1\ast {10}^{-31}}$

= …… ms-1 >>>> C

Where, C is the speed of light. Since, speed of electron cannot be greater than speed of light, electron cannot be constituents of nucleus. 

         THE END