Respiratory_2020.ppsx

Chapter 15 The Respiratory System http://www.youtube.com/watch?v=9vCbPq_orXI Differentiate between internal and external respiration. List the secondary functions of the respiratory system. Learning Objectiv es List the components of the upper respiratory tract and describe their structure and...

Chapter 15 The Respiratory System http://www.youtube.com/watch?v=9vCbPq_orXI Differentiate between internal and external respiration. List the secondary functions of the respiratory system. Learning Objectiv es List the components of the upper respiratory tract and describe their structure and functions. List the components of the lower respiratory tract and describe their structure and functions. Describe the events that occur during inspiration and expiration. List the muscles involved in inspiration and expiration. Respiratory System Primary Function: bring O2 into the body and CO2 out of it Respiratory system works together with the cardiovascular system • Phonation (voice Seconda ry function s production) • Regulation of body temperature • Regulation of acid-base balance • Sense of smell External respiration exchange of O2 and CO2 between the inhaled air and the blood flowing through the pulmonary capillaries Respirati on Internal respiration exchange of O2 and CO2 between the blood in the systemic capillaries and all the cells and tissues of the body Structures of Upper Respirator y System •Outside the lungs •Nostrils •Nasal passages •Pharynx •Larynx •Trachea Nose and Nasal Passages •Nares (nostrils): external openings of the respiratory tube •Lead into the nasal passages •Nasal Passages: between the nostrils and the pharynx Nose and Nasal Passages Nasal septum: separates the left and right nasal passage Hard and soft palates: separate the nasal passages from the mouth. Nose and Nasal Passages Turbinates (nasal conchae): Divide each nasal passage into 3 main passageways Thin, scroll-like bones covered with nasal epithelium Nose and Nasal Passages Nasal passages lined with pseudostratified columnar epithelium Cilia project from the cell surfaces up into a layer of mucus Mucus is secreted by mucous glands and goblet cells Nasal Passages Functions Warm, humidify, and filter inhaled air Air is warmed by blood flowing through blood vessels just beneath the nasal epithelium. Air is humidified by mucus and other fluids on the epithelial surface. Air is filtered as it passes through the winding passages produced by the turbinates. Nasal Passage Particles do not readily pass o trapped in the mucous layer o cilia move mucus and trapped foreign material upward to the pharynx, mouth Pharynx Common passageway for respiratory and digestive systems Soft palate divides pharynx into the dorsal nasopharynx (respiratory passageway) and the ventral oropharynx (digestive passageway) Caudal end of pharynx opens dorsally into the esophagus and ventrally into the larynx Reflexes control actions of the muscles around the pharynx. Larynx and pharynx work together to prevent swallowing from interfering with breathing, and vice versa. Swallowing – • breathing stops • opening into larynx is covered • material to be swallowed moves to rear of pharynx • esophagus opens After swallowing, larynx is reopened and breathing resumes Pharynx-how it works https://youtu.be/wqMCzuIiPaM Larynx Short, irregular tube connecting pharynx with the trachea Composed of segments of cartilage Epiglottis Arytenoid Thyroid Cricoid All supported in place by the hyoid bone Epiglottis - single, leaf-shaped; projects forward from the ventral portion of larynx During swallowing, thethe epiglottis is pulled back to cover the opening of the larynx (glottis) Larynx Cartilages Arytenoid cartilages - paired; attachment is the site of the vocal cords Muscles adjust the tension of the vocal cords by moving the cartilages. Arytenoid cartilages and the vocal cords form the boundaries of the glottis. Larynx Function Prevention of foreign material being inhaled During swallowing, muscle contractions pull the larynx forward and fold the epiglottis back over its opening. Control airflow to and from the lungs Small adjustments in the size of the glottis aid movement of air. Trachea Short, wide tube Extends from the larynx into the thorax Divides into the two main bronchi that enter the lungs Bifurcation of the trachea Composed of fibrous tissue and smooth muscle held open by hyaline cartilage rings Lined with ciliated epithelium Trachea C-shaped rings of hyaline cartilage Open part of tracheal rings face dorsally Gap between the ends of each ring bridged by smooth muscle Structure s of Lower Respirat ory System Bronchi Bronchioles Alveolar ducts Alveolar sacs Alveoli Bronchial Tree Each bronchus divides: smaller bronchi divide into even smaller bronchi tiny bronchioles Bronchioles subdivide into alveolar ducts Bronchial Tree Alveolar ducts end in groups of alveoli Arranged like bunches of grapes Alveolar sacs: groups of alveoli Autonomic nervous system controls smooth muscle fibers in wall of bronchial tree Bronchodilation - bronchial smooth muscle relaxes Aids respiratory effort during intense physical activity Bronchoconstriction- bronchial smooth muscle partially contracts Reduces size of the air passage Irritants in inhaled air can cause bronchoconstriction Bronchial Tree Alveoli Site of external respiration Tiny, thin-walled sacs of simple squamous epithelium Surrounded by networks of capillaries Lined with fluid that contains surfactant Lungs Each lung has a base, an apex, and a convex lateral surface. Base is in the caudal aspect of thoracic cavity Lies directly on cranial surface of diaphragm Apex lies in cranial portion of thoracic cavity Lungs Convex lateral surface lies against inner surface of the thoracic wall Mediastinum - area between the lungs Lungs Lungs are divided into lobes (in most species) Pattern varies with species Left- 3 lobes Cranial, middle, caudal Right-4 lobes Cranial, middle, caudal, accessory Lobes are distinguished by the major branches of the bronchi Hilus - small, well-defined area on medial side of lung Site where air, blood, lymph, and nerves enter and leave the lung Pulmona ry Circulati on Deoxygenated blood enters the lungs fromartery right ventricle of heart Pulmonary Pulmonary through the pulmonary artery splits into left and right pulmonary arteries that enter the two lungs arterioles enter capillary networks around the alveoli Oxygenated blood returns to the left side of heart through the pulmonary veins. Thoracic Cavity Bound by thoracic vertebrae dorsally, ribs & intercostal muscles laterally, the sternum ventrally Mediastinum – area between lungs Contains heart, trachea, esophagus, blood vessels, nerves, lymphatic structures Pleura Thin membrane that lines thoracic cavity and covers organs and structures in the thorax Visceral layer covers thoracic organs and structures Parietal layer lines the cavity Space between the two pleural layers is filled with a small amount of pleural fluid Helps ensure that surfaces of organs slide smoothly along the lining of the thorax during breathing Diaphragm Thin, dome-shaped skeletal muscle sheet Forms caudal boundary of thorax Important respiratory muscle Flattens when it contracts Enlarges volume of the thorax and aids inspiration Pneumothorax Presence of free air in the thorax Negative intrathoracic pressure •Without this negative pressure breathing cannot happen •Result of free air in the thorax causes the lungs to slip or fall away from the thoracic wall collapsed lung Atelectasis Causes Air from the outside enters the thorax All are temporary interruptions in normal breathing pattern Cough Sneezes Yawn Sigh Irritations (cough & sneezes) Causes: Attempts to correct an imbalance (yawns & sighs) Unknown (hiccups) Cough, Sneezes, Yawns, Sighs, Hiccups Review What are the functions of the respiratory systems? What is internal respiration? What is external respiration? What anatomy is included in the upper respiratory vs. the lower respiratory? Be able to identify location and describe any important features How are the lungs lobes divided and what are they called? How are the lungs described anatomically Anatomy of the thoracic cavity