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Pneumo-Pathology & Nursing Care Chapter 1 Mrs. Rola Hallal.

2. Anatomy & Physiology Of The IRespMratory System.

nasal voice box cavity windpipe throat bronchi right lung diaphragm 0 2006 Encyclopaedia Britannica, Inc. left lung alveoli carbon cfoxide out capillary •air in capillaries oxygen in blood ce.

The Respiratory Tract. h5550999. 4.

nostrils 2. nasal passages 3. pharynx (throat): cavity in back of mouth 4. glottis 5. larynx 6. trachea.

7. bronchi: two main branches of trachea 8. bronchioles: smallest air tubes 9. alveoli (air sacs): site of respiratory gas exchange.

Alveoli. Polyhedral in shape and clustered like units of honeycomb. ~ 300 million air sacs (alveoli). Large surface area (60–80 m 2 ). Each alveolus is 1 cell layer thick. Total air barrier is 2 cells across (2 m m). 2 types of cells: Alveolar type I: Structural cells. Alveolar type II: Secrete surfactant..

Surfactant. Phospholipid produced by alveolar type II cells. Lowers surface tension. Reduces attractive forces of hydrogen bonding by becoming interspersed between H 2 0 molecules. Surface tension in alveoli is reduced. As alveoli radius decreases, surfactant’s ability to lower surface tension increases. Disorders: RDS. ARDS..

Anatomical Dead Space. Not all of the inspired air reached the alveoli. As fresh air is inhaled it is mixed with air in anatomical dead space. Conducting zone and alveoli where [0 2 ] is lower than normal and [C0 2 ] is higher than normal. Alveolar ventilation = F x (TV- DS). F = frequency (breaths/min.). TV = tidal volume. DS = dead space..

Thoracic Cavity. Diaphragm: Sheets of striated muscle divides anterior body cavity into 2 parts. Above diaphragm: thoracic cavity: Contains heart, large blood vessels, trachea, esophagus, thymus, and lungs. Below diaphragm: abdominopelvic cavity: Contains liver, pancreas, GI tract, spleen, and genitourinary tract. Intra-pleural space: Space between visceral and parietal pleurae..

Sternal notc Clavicle Manubrium 2nd Costal cartilage Sternum Xyphoid Ribs 1 2 3 4 5 6 7 8 9 10 11 12 2nd interspace 7th interspace Costal Costal margin angle RnCeus.com.

http://t2.gstatic.com/images?q=tbn:ANd9GcT2B7TvRTVdaUW5Dfiurxv00sfXRNogLXFlxtL79xK59inFzEnD.

1, Trachea. 2, Clavi&. 3, 4th posterior rib. 4, Right main b r orchus. 5, Right breast shadow. S, Gastric air bubble. 10.

Table 22.1 STRUCTURE Nose (external nose and nasal cavity) Paranasal sinuses Pharynx Larynx Trachea Bronchial tree Alveoli Lungs Pleurae Principal Organs of the Respiratory System DESCRIPTION, GENERAL AND DISTINCTIVE FEATURES Jutting external portion is supgx)rted by bone and cartilage. Internal nasal cavity is divided by midline nasal septum and lined with mucosa. Roof of nasal cavity contains olfactory epithelium. Mucosa-lined, air-filled cavities in cranial bones surrounding nasal cavity. Passageway connecting nasal cavity to larynx and oral cavity to esophagus. Three subdivisions: nasopharynx, oropharynx, and laryngopharynx. Houses tonsils (lymphoid tissue masses involved in protection against pathogens). Connects pharynx to trachea. Has framework of cartilage and dense connective tissue. Opening (glottis) can be closed by epiglottis or vocal folds, Houses vocal folds (true vcxal cords). Flexible tube running from larynx and dividing inferiorly into two main bronchi. Walls contain C-shaped cartilages that are incomplete posteriorly where connected by trachealis. Consists of right and left main bronchi, which subdivide within the lungs to form lobar and segmental bronchi and bronchioles. Bronchiolar walls lack cartilage but contain complete layer of smooth muscle. Constriction of this muscle impedes expiration. Microscopic chambers at termini Of bronchial tree. Walls Of simple squamous epithelium overlie thin basement membrane. External surfaces are intimately associated with pulmonary capillaries. Special alveolar cells produce surfactant. Paired composite organs that flank mediastinum in thorax. Composed primarily of alveoli and respiratory passageways. Stroma is fibrous elastic connective tissue, allowing lungs to recoil passively during expiration. Serous membranes. Parietal pleura lines thoracic cavity; visceral pleura covers external lung surfaces. FUNCTION Produces mucus; filters, warms, and moistens incoming air; resonance chamber for speech Receptors for sense of smell Same as for nasal cavity except no receptors for smell; also lighten skull Passageway for air and food Facilitates exposure of immune system to inhaled antigens Air passageway; prevents food from entering lower respiratory tract Voice production Air passageway; cleans, warms. and moistens incoming air Air passageways connecting trachea with alveoli; cleans, warms, and moistens incoming air Main sites Of gas exchange Reduces surface tension; helps prevent lung collapse House respiratory passages smaller than the main bronchi Produce lubricating fluid and compartmentalize lungs.

fg038_3. Breathing. 15.

Inspiration. Active process: Contraction of diaphragm, increases thoracic volume vertically. Parasternal and external intercostals contract, raising the ribs; increasing thoracic volume laterally. Pressure changes: Alveolar changes from 0 to –3 mm Hg. Intrapleural changes from –4 to –6 mm Hg. Transpulmonary pressure = +3 mm Hg..

Expiration. passive process. After being stretched by contractions of the diaphragm and thoracic muscles; the diaphragm, thoracic muscles, thorax, and lungs recoil. Decrease in lung volume raises the pressure within alveoli above atmosphere, and pushes air out. Pressure changes: Intrapulmonary pressure changes from –3 to +3 mm Hg. Intra-pleural pressure changes from –6 to –3 mm Hg. Trans-pulmonary pressure = +6 mm Hg..

Insert fig. 16.15. 16_15. 18.

Function of Respiratory System. Respiration The term respiration includes 3 separate functions: Ventilation: Breathing. Gas exchange: Between air and capillaries in the lungs. Between systemic capillaries and tissues of the body. 0 2 utilization: Cellular respiration..

[Audio] Chest wall Thoracic cage- ribs ( 24) and sternum; protect lungs and heart Parietal pleural Visceral pleura Intrapleural space- contains pleural fluid Normal pressure in pleural space is negative Diaprhagm is major muscle or respiration- innervated by phrenic nerve ( C3-C5) est Wall.

Ventilation. Mechanical process that moves air in and out of the lungs. It depends on volume and pressure changes within thoracic cavity Diaphragm is major muscle of inspiration; also external intercostal muscles. Contraction increases diameter of thoracic cavity→ ↓ intrathoracic pressure →air flows into respiratory system Expiration is passive process d/t lung elasticity. ↑ intrathoracic pressure→ air flows out of lungs Accessory muscles.

Control of Ventilation. Neural control- respiratory center in medulla & pons Central chemoreceptors – sensitive to pH Peripheral chemoreceptors- sensitive to paO2.

Neurological control of Ventilation. Cowr•t O The McGra•w-Hill Ccn-oanieB. hc. Permission req.ir«d for reproduction display. Pontine respiratory Pons nerve to dia hra Internal intercostal muscles (involved in expiration) Intercostal nerves to inte Intercostal nerves to extern a / i 00 group Dorsal respira- tory group Ventral respira- tory group Medulla Medul- lary respira- tory center External intercostal muscles (involved in inspiration) Diaphragm (involved in inspiration) 004 oblongata — Spinal cord.

Factors Influencing Ventilation. Airway resistance- opposition to gas flow Compliance- distensibility / stretchability - Dependent on lung elasticity & elastic recoil of chest wall - Decreased compliance- lungs difficult to inflate - Increased compliance- destruction of alveolar walls & loss of tissue elasticity.

Increased Airway Resistance. Alteration of bronchial diameter can alter the rate of air flow for a normal respiration. With increased airway resistance greater than normal respiratory effort is required to achieve normal ventilation..

Oxygenation. Lung capillaries P u I o n a ry c i rcu i t Left Sy stern ic C i rc u it Systernic capillaries.

Gas Exchange. Alveoli are ventilated Pressure gradient affect diffusion: Alveoli → PO2 100mmHg → PCO2 40mmHg Venous → PO2 60mmHg → PCO2 45mmHg O2 diffuse from alveoli → Pulmonary vessels CO2 diffuse from pulmonary vessels → Alveoli.

[Audio] Oxygen & carbon dioxide move back & forth across alveolar-capillary membrane Diffusion occurs from higher to lower concentrations Ability of lungs to oxygenate arterial blood adequately is determined by PaO2 & O2 saturation.

Alveolus Net(diffusion of C02 Net diffusion of 02 40 mm Hg P 02- - 45 mm Hg P' -40 mm Hg 2 Blood flow (from body tissues) P •m Hg Capillaiy 40 mm Alveolar wall Blood flow (to tissues).

Adequate O2 Balance. O2 transports from lungs to tissues, 97% of O2 combines with RBC Hgb → Oxyhemoglobin carried to tissues, remaining O2 is dissolved in plasma & cells. CO2 transports from tissues to lungs → cell metabolism takes place: 65% carried inside RBC as bicarbonate HCO3- 30% combines with Hgb as carbhemoglobin 5% dissolved in plasma as carbonic acid H2CO3.

Oxy-hemoglobin Curve. 31.

Adequate O2 Balance. Alveoli of lungs C02 exchange at alveolar-capillary interface C02 transport C02 exchange at cells Cens C02 CO 02 2 02 02 l' I' Pulmona '*ire ulatio 2 Circulation C02 Cellular respiration ATp Oxygen exchange at alveolar-capillary interface Oxygen transport Oxygen exchange at cells Nutrients.

Perfusion. Is the actual blood flow through the pulmonary vessels The blood is pumped into the lungs by the right ventricles through pulmonary artery The PA divides into right and left branches that supply the lungs.

Diffusion Body Tissue-Blood Capillary. 34.

Ventilation-Perfusion. Adequate diffusion depends on balanced ventilation-perfusion (V/Q) ratio Normal lung: V=4L/min; Q= 5L/min (0.8) If imbalanced: gas exchange interrupted - High V/Q= “wasted” or dead-space ventilation - Low V/Q= blood “shunted” past area; no gas exchange occurs.

Mucous plu rapped a üA/ö = o C02 02 Fig. 14-2 Three Alveoli And Gas a02 61 aC02 a02 10 Exchange P102 5.3 14.4 P102 = 00 Embolus No bloodflow.

Ventilation-Perfusion Ratios(V/Q). Normal. Shunts.

Age Related Pulmonary Changes: Pathological changes Effect Decreased efficiency of lung parenchyma Decreased Muscle strength Alveolar septal destruction Brohchiolar damage Dilated upper airways Decreased reactivity Decreased VC Increased RV Decreased Compliance, FEVI Decreased alveolar area Increased closing volume Increased VD Decreased laryngeal reflexes Decreased vent response to hypoxia, hypercarbia Implications Respiratory Failure Poor cough Infection Decreased gas exchange Air trapping Decreased Pa02 Decreased gas exchange Increased Aspiration Increased resp. failure.

Terms Used to Describe Lung Volumes and Capacities.

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