BY MONALISA GAIKWAD 1st YEAR M.Sc CLINICAL RESEARCHPADMASHREE INSTITUTION
OBJECTIVES To explain the Anatomy of Respiratory System. To explain the Functions and Respiration Process. To explain the Lung Volume and Lung Capacities.
RespirationRespiration is the process of taking in oxygen (Inhaling), producing energy with it (within Cell) and excreting gaseous waste products (Exhaling).
Classification of Respiratory system Structural classifications: upper respiratory tract lower respiratory tract. Functional classifications: Conducting portion: transports air. Nose nasal cavity Pharynx Larynx Trachea progressively smaller airways, from the primary bronchi to the bronchioles Respiratory portion: carries out gas exchange. respiratory bronchioles alveolar ducts air sacs called alveoli Upper respiratory tract is all conducting Lower respiratory tract has both conducting and respiratory portions.
Structural ClassificationUpper Respiratory Tract Lower Respiratory Tract Composed of Conducting portion the nose Larynx the nasal cavity Trachea Bronchi the paranasal sinuses bronchioles and their the pharynx (throat) associated structures and associated structures Respiratory portion of the respiratory system respiratory bronchioles alveolar ducts alveoli
Nose Functions StructureThe only externally visiblepart of the respiratory systemthat functions by: Providing an airway for respiration Moistening (humidifying) and warming the entering air Filtering inspired air and cleaning it of foreign matter Serving as a resonating chamber for speech Housing the olfactory receptors
Nasal CavityLies in and posterior to the external noseIs divided by a midline nasal septumOpens posteriorly into the nasal pharynx via internal naresThe ethmoid and sphenoid bones form the roofThe floor is formed by the Anterior hard palate (bone) and posterior softpalate (muscle)The nasal cavity is separated from the oral cavity by the palate Olfactory receptors are located in the mucosa on the superior surface The rest of the cavity is lined with respiratory mucosa Moistens air Traps incoming foreign particles Lateral walls have projections called conchae Increases surface area Increases air turbulence within the nasal cavity
Paranasal Sinuses Cavities within bones surrounding the nasal cavity Frontal bone Sphenoid bone Ethmoid bone Maxillary boneCommunicate with the nasal cavity by ducts.Covered with the same pseudostratifiedciliated columnar epithelium as the nasal cavity. Function of the sinuses Lighten the skull Act as resonance chambers for speech Produce mucus that drains into the nasal cavity
PharynxCommon to both the respiratory and digestivesystems.Commonly called the throat.Funnel-shaped slightly wider superiorly and narrower inferiorly.Originates posterior to the nasal and oral cavitiesExtends inferiorly near the level of the bifurcationof the larynx and esophagus.Walls: lined by a mucosa contain skeletal muscles primarily used for swallowing.Flexible lateral walls distensible to force swallowed food into the esophagus.Partitioned into three adjoining regions: nasopharynx oropharynx Laryngopharynx The oropharynx and laryngopharynx are common passageways for air and food
NasopharynxSuperiormost region of the pharynx.Location: posterior to the nasal cavity superior to the soft palate separates it from the posterior part of the oral cavity.Normally, only air passes through.Soft palate Blocks material from the oral cavity and oropharynx elevates when we swallow.Auditory tubes paired In the lateral walls of the nasopharynx connect the nasopharynx to the middle ear.Pharyngeal tonsil posterior nasopharynx wall single commonly called the adenoids.
OropharynxThe middle pharyngeal region.Location: Immediately posterior to the oral cavity. Bounded by the soft palate superiorly, the hyoid bone inferiorly.Common respiratory and digestive pathway both air and swallowed food and drink pass through.2 pairs of muscular arches anterior palatoglossal arches posterior palatopharyngeal arches form the entrance from the oral cavity.Lymphatic organs provide the “first line of defense” against ingested or inhaled foreign materials. Palatine tonsils on the lateral wall between the arches Lingual tonsils At the base of the tongue.
LaryngopharynxInferior, narrowed region of the pharynx.Location: Extends inferiorly from the hyoid bone is continuous with the larynx and esophagus. Terminates at the superior border of the esophagus is equivalent to the inferior border of the cricoid cartilage in the larynx.The larynx (voice box) forms the anterior wallLined with a nonkeratinized stratified squamous epithelium(mucus membrane)Permits passage of both food and air.
Lower Respiratory TractLarynxShort, somewhat cylindrical airwayLocation: bounded posteriorly by the laryngopharynx, inferiorly by the trachea.Prevents swallowed materials from entering the lower respiratory tract.Conducts air into the lower respiratory tract.Produces sounds.Nine pieces of cartilage three individual pieces Thyroid cartilage Cricoid cartilage Epiglottis three cartilage pairs Arytenoids: on cricoid Corniculates: attach to arytenoids Cuniforms:inaryepiglottic fold held in place by ligaments and muscles. Intrinsic muscles: regulate tension on true vocal cords Extrinsic muscles: stabilize the larynx
Sound ProductionTwo pairs of ligamentsInferior ligaments, called vocal ligaments covered by a mucous membrane vocal folds: ligament and mucosa. are “true vocal cords” they produce sound when air passes between themSuperior ligaments, called vestibular ligaments Covered by mucosa vestibular folds: ligament and mucosa Are “false vocal cords” no function in sound production protect the vocal folds. The vestibular folds attach to the corniculate cartilages.The tension, length, and position of the vocal folds determine the quality of thesound. Longer vocal folds produce lower sounds More taunt, higher pitch Loudness based on force of airRimaglottidis: opening between the vocal folds
TracheaA flexible, slightly rigid tubular organ often referred to as the “windpipe.”Extends through the mediastinum immediately anterior to the esophagus inferior to the larynx superior to the primary bronchi of the lungs.Anterior and lateral walls of the trachea are supported by 15 to 20 C-shaped trachealcartilages. cartilage rings reinforce and provide some rigidity to the tracheal wall to ensure that the trachea remains open (patent) at all times cartilage rings are connected by elastic sheets called anular ligamentsAt the level of the sternal angle, the trachea bifurcates into two smaller tubes, calledthe right and left primary bronchi.Each primary bronchus projects laterally toward each lung.The most inferior tracheal cartilage separates the primary bronchi at their origin andforms an internal ridge called the carina.
Bronchial TreeA highly branched system air-conducting passages originate from the left and right primary bronchi.Progressively branch into narrower tubes as they divergethroughout the lungs before terminating in terminal bronchioles.Primary bronchi Incomplete rings of hyaline cartilage ensure that they remain open. Right primary bronchus shorter, wider, and more vertically oriented than the left primary bronchus. Foreign particles are more likely to lodge in the right primary bronchus.
Bronchial Tree DivisionPrimary bronchi enter the hilum of each lungSecondary bronchi (or lobar bronchi) Branch of primary bronchus left lung: two lobes two secondary bronchi right lung three lobes three secondary bronchi.Tertiarybronchi (or segmental bronchi) Branch of secondary bronchi left lung is supplied by 8 to 10 tertiary bronchi. right lung is supplied by 10 tertiary bronchi supply a part of the lung called a bronchopulmonarysegment.
Respiratory ZoneDefined by the presence of alveoli; begins as terminal bronchioles feed intorespiratory bronchiolesRespiratory bronchioles lead to alveolar ducts, then to terminal clusters ofalveolar sacs composed of alveoliAn alveolus is about 0.25 to 0.5 millimeter in diameter.Its thin wall is specialized to promote diffusion of gases between thealveolus and the blood in the pulmonary capillaries.Gas exchange can take place in the respiratory bronchioles and alveolarducts as well as in the lungs, which contain approximately 300–400 millionalveoli.The spongy nature of the lung is due to the packing of millions of alveolitogether
Respiratory Bronchioles, AlveolarDucts, and Alveoli
LUNGSOccupy most of the thoracic cavityEach lung has a conical shape.Its wide, concave base rests upon the muscular diaphragm.Its relatively blunt superior region, called the apex or (cupola), projectssuperiorly to a point that is slightly superior and posterior to the clavicle.Both lungs are bordered by the thoracic wall anteriorly, laterally, and posteriorly,and supported by the rib cage.Toward the midline, the lungs are separated from each other by themediastinum.The relatively broad, rounded surface in contact with the thoracic wall is calledthe costal surface of the lung.
LUNG cont….Left lungdivided into 2 lobes by oblique fissuresmaller than the right lungcardiac notch accommodates the heartRight lungdivided into 3 lobes by oblique and horizontal fissurelocated more superiorly in the body due to liver on right side
Pleura and Pleural CavitiesThe outer surface of each lung and the adjacent internal thoracic wall arelined by a serous membrane called pleura, which is formed from simplesquamous epithelium.The outer surface of each lung is tightly covered by the visceral pleura, whilethe internal thoracic walls, the lateral surfaces of the mediastinum, and thesuperior surface of the diaphragm are lined by the parietal pleura.The parietal and visceral pleural layers are continuous at the hilum of eachlung.The potential space between these serous membrane layers is a pleuralcavity.The pleural membranes produce a thin, serous fluid that circulates in thepleural cavity and acts as a lubricant, ensuring minimal friction during breathingcalled as pleural fluid.
Functions of Respiratory System supplies the body with oxygen and disposes of carbon dioxide filters inspired air produces sound contains receptors for smell rids the body of some excess water and heat helps regulate blood pH
Respiration ProcessA collective term for the following processes:Pulmonary Ventilation Movement of air into the lungs (inspiration) Movement of air out of the lungs (expiration)External Respiration Movement of oxygen from the lungs to the blood Movement of carbon dioxide from the blood to the lungsTransport of Respiratory Gases Transport of oxygen from the lungs to the tissues Transport of carbon dioxide from the tissues to the lungsInternal Respiration Movement of oxygen from blood to the tissue cells Movement of carbon dioxide from tissue cells to blood
Lung VolumeTIDAL VOLUME (TV): Volume inspired or expired with eachnormalﾊbreath. = 500 mlINSPIRATORY RESERVE VOLUME (IRV): Maximum volume that canbe inspired over the inspiration of a tidal volume/normalbreath. Used during exercise/exertion.=3100 mlEXPIRATRY RESERVE VOLUME (ERV): Maximal volume that can beexpired after the expiration of a tidal volume/normal breath. =1200 mlRESIDUAL VOLUME (RV): Volume that remains in the lungs after amaximal expiration.ﾊ CANNOT be measured by spirometry.=1200 ml
Lung CapacityINSPIRATORY CAPACITY ( IC): Volume of maximal inspiration:IRV + TV =3600 mlFUNCTIONAL RESIDUAL CAPACITY (FRC): Volume of gas remaining in lungafter normal expiration, cannot be measured by spirometry because itincludes residual volume:ERV + RV = 2400 mlVITAL CAPACITY (VC): Volume of maximal inspiration and expiration:IRV+ TV + ERV = IC + ERV = 4800 mlTOTAL LUNG CAPACITY (TLC): The volume of the lung after maximalinspiration.ﾊ The sum of all four lung volumes, cannot be measuredby spirometry because it includes residual volume:IRV+ TV + ERV +RV = IC + FRC = 6000 ml
Respiratory rate throughout life Infants – 30 respirations per minute Age 5 – 25 respirations per minute Newborns – 40 to 80 respirations per minute Adults – 12 to 18 respirations per minute Rate often increases somewhat with old age