okay today i will start chapter 22 the respiratory system so the respiratory system the process of respiration pulmonary ventilation pulmonary ventilation air is moved into and out of the lungs during inhalation and exhalation external respiration oxygen diffuses from the lungs to the blood and carbon dioxide diffuses from the blood to the lungs transport oxygen is transported from the lungs to the tissue cells and carbon dioxide is transported from the tissues to the blood internal respiration oxygen diffuses from the blood to the tissues and carbon dioxide diffuses from the tissues into the blood respiratory system includes upper respiratory tract and lower respiratory tract upper respiratory threat begins with nose and ends into fairings pharynx is a passageway which is shared by the respiratory and the digestive system both lower respiratory tract begins at larynx and it will continue until we reach to alveoli so the upper respiratory system include nostrils nasal cavity fairies the lower respiratory tract begins from the larynx trachea bronchi lungs alveoli the nose it's always advisable to breathe through the nose because the nose when the air passes through the nose it is humidified it is warmed the air is filtered the microbes and the dust are removed so besides humidifying warming filtering and cleaning the air the nose also actually participates in the speech actually resonating chambers the nose has the olfactory receptors which provide the sensation of smell nasal cavity olfactory mucosa epithelium which contains olfactory receptors the the mucosa in the news is made up of pseudostratified seriated columnar epithelium so goblet cells produce mucus mucus contains lysozyme and antimicrobial proteins defensive celia sweep the dust and the microbes pharynx pharynx actually is a muscular tube it connects nasal cavity to the larynx and the issue figures pharynx is divided into three parts nasopharynx oropharynx and laryngeal pharynx so nasopharynx has pseudostratified ciliated columnar epithelium whereas oropharynx and laryngeal pharynx has stratified squamous epithelium now the functional anatomy respiratory zone is the site for gas exchange so the respiratory zone will include respiratory bronchiole alveolar duct alveoli conducting zone where the air is conducting so the conducting zone will include for example the trachea the primary bronchi the secondary bronchi the territory bronchi which conduct the eight larynx larynx is known as the voice box larynx connects to the trachea actually and it is responsible for voice production epiglottis is made up of elastic cartilage and it covers the glottis when we are swallowing the food air passage actually air enters through the nose it goes through the pharynx then it goes through the layering straight here trachea bifurcate into primary bronchi so from trachea until we reach to the respiratory bronchiole there they branch 23 times like trachea will branch into primary bronchi primary bronchi will branch into secondary bronchi secondary bronchi will branch into territory bronchi so 23 orders of branching into right and left primary bronchi so trachea is about four inches long and it is about so like about 10 centimeter long and average and it is about 2.5 centimeter wide trachea has the cartilage rings and those rings are c-shaped like this so they are open at the back and they are closed in the front the cartilage rings so because they are open at the back they allow the trachea to extract like expand and these cartilaginous rings prevent the collapsing of the trachea and they provide support and stability to the trachea trachea bifurcate into primary and the two primary bronchi right primary bronchi is more wider and vertical so like when the young children sometimes they get um suppose they are eating a peanut or something and it goes into the it is there are more chances that it will stuck into the primary bronchi because it is more vertical each primary bronchi will branch into secondary bronchi secondary bronchi are also known as lower bronchi three secondary bronchi on the right and two secondary bronchi to the left lung then each lower or secondary bronchus actually will branch into tereshri bronchi like each slovak bronchus branches into segmental or territory bronchi and then these storage tree bronchi will branch further terminal bronchioles are like they keep on branching until they reach to the respiratory bronchus so here is a trachea these are the cartilage rings which are c-shaped open at the back these are the primary bronchi the primary bronchi branch into secondary bronchi secondary bronchi enter into each lobe of the lung so they are also known as lower bronchi then secondary bronchi branch into segmental bronchi so this is the right lung right lung has three lobe the left lung has the two low cartilage rings so we said that the trachea has the c-shaped cartilage rings then the primary bronchi will also have cartilage as we go away from trachea towards respiratory bronchiole the amount of cartilage decreases and amount of elastic tissue and the smooth muscle increases as we are going away from trachea towards the further branching so respiratory zone begins as terminal bronchus branch into respiratory bronchiole respiratory bronchiole lead into alveolar duct alveolar duct open into alveolar set alveolar sac actually contains cluster of alveoli means it is like bunch of grapes that is alveolar set about 300 million alveoli and they increase the surface area for gas exchange so we see here this is the respiratory bronchiole here is the alveolar duct and here is the alveolar set so alveolar sac is like bunch of grapes alveoli are connected through alveolar pore so suppose one respiratory bronchiole is blocked these alveolar pore will provide the alternate route for gas exchange respiratory membrane so it is important to know what is respiratory membrane the respiratory membrane includes the alveolar wall the capillary wall and the basement membrane so the respiratory membrane will include the alveolar ball which is simply squamous epithelium it will include the capillary wall and the basement membrane gas exchange occurs at the respiratory membrane by simple diffusion oxygen and carbon dioxide are exchanged across the respiratory membrane by simple diffusion fine elastic fibers cover the lvo line so as we said alveolar ball includes like respiratory membrane include alveolar wall capillary wall and the basement membrane alveolar wall is made up of simply squamous epithelium and they are also known as type one alveolar cell that simply squamous epithelium between the a simply squamous epithelium we have type 2 alveolar cell and these type 2 alveolar cells secrete detergent like substance known as surface surfactant surfactant reduces the surface tension and it prevents all alveoli from collapsing the premature babies do not produce their type 2 alveolar cell do not produce enough surfactant so the health officials need to spray the surfactant until the baby reaches to their maturity actually because they are born premature so they will have that distress syndrome due to the lack of surfactant so no respiratory membrane gas exchange those things so alveoli are covered by fine elastic fibers and they are covered by pulmonary capillaries alveoli are connected through alveolar pores alveolar macrophages keep alveoli actually surface ester so now check your understanding which structural feature of the trachea allow it to expand and contract those are c c cartilage rings and they also keep trachea from collapsing now this question what is structure of the alveoli and their respiratory membrane suit actually so alveoli are very tiny so these many tiny alveoli together have a large surface area and their thin respiratory membrane make an ideal place for gas exchange for this question a three year old is brought so for this question the peanut actually it was most likely in the right main bronchus because the right main bronchus is wider and more vertical than the left actually so now lung anatomy so the pointed tip of the lung is known as epics base is the part which sits on the diaphragm hialum is the indentation in the middle of the lung where the pulmonary trunk will enter pulmonary bronchi will enter pulmonary vein will exit so higher is that in point of entry and exit in the lung left lung is smaller in comparison to the right lung left lung actually has two lobes a superior low and a inferior lobe by they are separated by oblique fissure the right lung has three loops superior midday and inferior loop so the right lung will have a horizontal fissure between superior and middle lobe and between middle and inferior lobe it will have an oblique fissure so each lung each separated into the loops and