रेस्पिरेटरी सिस्टम

फय् हिलिगु म्हकुचा पुचः

रेस्पिरेतरि सिस्तम धाःगु, साधारण अर्थय् मनू व पेपांचू पशुतेगु म्हय् दयाच्वंगु फय् हिलिगु म्हकुचातेगु छपुचः ख। साधारणतया सासः ल्हाइगु (breathing)यात हे थ्व व्यवस्थाया ज्या खः धका मनूतेसं थुइकिगु या, तर सासः ल्हाइगु धाःसा फय्‌ हिलिगु व्यवस्थाया छगू भाग जक्क ख। निश्चित रुपय् धायेमासाः थ्व म्हकुचातेगु पुचलं वातावरण व मनूया सर्कुलेतरि सिस्तमया दथुइ वायु कायेबियेगु ज्या याइ। मनू व मेमेगु दुरुपा दुपिं पशुइ सासः ल्हाइगु कुचापुचलय् फय्‌लं कुचाः (airways), सों, व फय्‌या बाहा निर्धारण याइगु सासः लाधि(respiratory muscles) मू ख। मनूतेसं सासः ल्हाइबिलय् वातावरणया फय् न्हासं व म्हुतुं फय्‌धों जुसें सोंय् थ्यनि। मनूतेगु निगु सों दूगुलिं थ्व तःधंगु फय्‌धों निता सोंय् वनेत निता चिधंगु धोंय् बाइ। सोंय् थ्यनेधुंका हानं सोंया थीथी थासय् थ्यनेत थ्व निता धोंत चिचिधंगु धोंय् बायावनि। थथे बायावंगु धोंत सिक्क चिपुया वनेधुंका आखिरय् फय् हिलेगु थाय् वा एल्भियोलस धाःगु छगू ग्वल्लागु थासय् थ्यनि। एल्भियोलस क्यापिलरि धाःगु दकलय् चिपूगु हिधोंया स्वापूलि दयाच्वनि। एल्भियोलस व क्यापिलरि नितां हे सालुसे च्वंगु छता कोषं जक्क दयाच्वंगु संरचना जूगुलिं थ्व थासय् अक्सिजन व कार्बोन दाइअक्साइद दिफ्युजन जुसें वातावरण व हिया दथुइ हिलिगु ज्या जुइ। थ्व कथं रेस्पिरेतरी सिस्तमं हि व वातावरणया दथुइ फय् हिलेगु ज्याय् ग्वहालि याइ। थ्व म्हकुचा पुचलं म्हया एसिद-बेसया मात्रा संतुलनय् तयेत नं ग्वहालि याइ।

संरचना

मनू व यक्व मेमेगु पशुइ फय्‌ हिलिगु व्यवस्था (respiratory system)यात च्वय्‌ (फय् बाहावनिगु) व क्वय् (फय् हिलिगु थाय्) धाःगु निगु भागय् बायेछिं। मनूया रेस्पिरेतरि सिस्तमय् फय् थ्व झ्वलय् वातावरणं दुहां वनि-

• न्हाय्‌प्वा
• न्यासल क्याभिटी
• फ्यारिङ्क्स् (naso-, oro-, laryngo-)
• ल्यारिङ्क्स् (स पिकाइगु थाय्)
• त्राकिया
• ब्रोङ्काइ
• ब्रोङ्कियोल्स्
• एल्भियोलाइ (फय् हिलिगु थाय्)

च्वय्‌या रेस्पिरेतरि त्राक्त/सञ्चालन क्षेत्र

The conducting zone starts with the nares (nostrils) of the nose, which open into the nasopharynx (nasal cavity). The primary functions of the nasal passages are to: 1) filter, 2) warm, 3) moisten, and 4) provide resonance in speech. The nasopharnyx opens into the oropharynx (behind the oral cavity). The oropharynx leads to the laryngopharynx, and empties into the larynx (voicebox), which contains the vocal cords, passing through the glottis, connecting to the trachea (wind pipe).

Lower respiratory tract/respiratory zone

The trachea leads down to the thoracic cavity (chest) where it divides into the right and left "main stem" bronchi. The subdivision of the bronchus are: primary, secondary, and tertiary divisions (first, second and third levels). In all, they divide 16 more times into even smaller bronchioles.

The bronchioles lead to the respiratory zone of the lungs which consists of respiratory bronchioles, alveolar ducts and the alveoli, the multi-lobulated sacs in which most of the gas exchange occurs.

Ventilation

Ventilation of the lungs is carried out by the muscles of respiration.

Control

Ventilation occurs under the control of the autonomic nervous system from the part of the brain stem, the medulla oblongata and the pons. This area of the brain forms the respiration regulatory center, a series of interconnected neurons within the lower and middle brain stem which coordinate respiratory movements. The sections are the pneumotaxic center, the apneustic center, and the dorsal and ventral respiratory groups. This section is especially sensitive during infancy, and the neurons can be destroyed if the infant is dropped or shaken violently. The result can be death due to "shaken baby syndrome."

Inhalation

Inhalation is initiated by the diaphragm and supported by the external intercostal muscles. Normal resting respirations are 10 to 18 breaths per minute. Its time period is 2 seconds. During vigorous inhalation (at rates exceeding 35 breaths per minute), or in approaching respiratory failure, accessory muscles of respiration are recruited for support. These consist of sternocleidomastoid, platysma, and the strap muscles of the neck.

Inhalation is driven primarily by the diaphragm. When the diaphragm contracts, the ribcage expands and the contents of the abdomen are moved downward. This results in a larger thoracic volume, which in turn causes a decrease in intrathoracic pressure. As the pressure in the chest falls, air moves into the conducting zone. Here, the air is filtered, warmed, and humidified as it flows to the lungs.

During forced inhalation, as when taking a deep breath, the external intercostal muscles and accessory muscles further expand the thoracic cavity.

Exhalation

Exhalation is generally a passive process, however active or forced exhalation is achieved by the abdominal and the internal intercostal muscles.

The lungs have a natural elasticity; as they recoil from the stretch of inhalation, air flows back out until the pressures in the chest and the atmosphere reach equilibrium.

During forced exhalation, as when blowing out a candle, expiratory muscles including the abdominal muscles and internal intercostal muscles, generate abdominal and thoracic pressure, which forces air out of the lungs.

Circulation

The right side of the heart pumps blood from the right ventricle through the pulmonary semilunar valve into the pulmonary trunk. The trunk branches into right and left pulmonary arteries to the pulmonary blood vessels. The vessels generally accompany the airways and also undergo numerous branchings. Once the gas exchange process is complete in the pulmonary capillaries, blood is returned to the left side of the heart through four pulmonary veins, two from each side. The pulmonary circulation has a very low resistance, due to the short distance within the lungs, compared to the systemic circulation, and for this reason, all the pressures within the pulmonary blood vessels are normally low as compared to the pressure of the systemic circulation loop.

Virtually all the body's blood travels through the lungs every minute. The lungs add and remove many chemical messengers from the blood as it flows through pulmonary capillary bed . The fine capillaries also trap blood clots that have formed in systemic veins.

Gas Exchange

The major function of the respiratory system is gas exchange. As gas exchange occurs, the acid-base balance of the body is maintained as part of homeostasis. If proper ventilation is not maintained two opposing conditions could occur: 1) respiratory acidosis, a life threatening condition, and 2) respiratory alkalosis.

Upon inhalation, gas exchange occurs at the alveoli, the tiny sacs which are the basic functional component of the lungs. The alveolar walls are extremely thin (approx. 0.2 micrometres), and are permeable to gases. The alveoli are lined with pulmonary capillaries, the walls of which are also thin enough to permit gas exchange. All gases diffuse from the alveolar air to the blood in the pulmonary capillaries, as carbon dioxide diffuses in the opposite direction, from capillary blood to alveolar air. At this point, the pulmonary blood is oxygen-rich, and the lungs are holding carbon dioxide. Exhalation follows, thereby ridding the body of the carbon dioxide and completing the cycle of respiration.

In an average resting adult, the lungs take up about 250ml of oxygen every minute while excreting about 200ml of carbon dioxide. During an average breath, an adult will exchange from 500 ml to 700 ml of air. This average breath capacity is called tidal volume.

Development

The respiratory system lies dormant in the human fetus during pregnancy. At birth, the respiratory system is drained of fluid and cleaned to assure proper functioning of the system. If an infant is born before forty weeks gestational age, the newborn may experience respiratory failure due to the under-developed lungs. This is due to the incomplete development of the alveoli type II cells in the lungs. The infant lungs do not function due to the collapse of the alveoli caused by surface tension of water remaining in the lungs. Surfactant is lacking from the lungs, leading to the condition. This condition may be avoided if the mother is given a series of steroid shots in the final week prior to delivery. The steriods accelerate the development of the type II cells.

Role in communication

The movement of gas through the larynx, pharynx and mouth allows humans to speak, or phonate. Because of this, gas movement is extremely vital for communication purposes.

Conditions of the respiratory system

Disorders of the respiratory system can be classified into four general areas:

• Obstructive Conditions (e.g., Emphysema, Bronchitis, asthma attacks

• Restrictive Conditions (e.g., Fibrosis, Sarcoidosis, Alveolar Damage, Pleural Effusion)
• Vascular Diseases (e.g., Pulmonary Edema, Pulmonary Embolism, Pulmonary Hypertension)
• Infectious, Environmental and Other "Disease"s (e.g., Pneumonia, Tuberculosis, Asbestosis, Particulate Pollutants) Coughing is of major importance, as it is the body's main method to remove dust, mucus, saliva, and other debris from the lungs. Inability to cough can lead to infection. Deep breathing exercises may help keep finer structures of the lungs clear from particulate matter, etc.

The respiratory tract is constantly exposed to microbes due to the extensive surface area, which is why the respiratory system includes many mechanisms to defend itself and prevent pathogens from entering the body.

Disorders of the respiratory system are usually treated internally by a Pulmonologist.

Gas exchange in plants

Plants inhale and then use carbon dioxide gas in their bodily functions, and then exhale waste oxygen gas, as opposed to animals, which inhale oxygen and exhale carbon dioxide.

Plant respiration is limited by the process of diffusion. Plants take in carbon dioxide through holes on the undersides of their leaves known as stoma. However, most plants require little air. Most plants have relatively few living cells outside of their surface because air (which is required for metabolic content) can penetrate only skin deep. However, most plants are not involved in highly aerobic activities, and thus have no need of these living cells.

स्वया दिसं

• Liquid breathing
• Aquatic respiration
• Involuntary control of respiration
• Gill
• Respiratory tract

श्रोत

• Perkins, M. 2003. Respiration Power Point Presentation. Biology 182 Course Handout. Orange Coast College, Costa Mesa, CA.
• Medical Dictionary

पिनेयागु स्वापूतः

• Science aid: Respiratory System A simple guide for high school students
• Introduction to Respiratory System
• A high school level description of the respiratory system