Respiratory System 1 PDF

RESPIRATORY SYSTEM IN THIS TOPIC WE WILL LEARN: PARTS OF RESPIRATORY SYSTEM - NOSE - NASAL CAVITY - PHARYNX - LARYNX - TRACHEA - LUNG - ALVEOLI BRONCHOPULMONARY SEGMENTS LUNG AND PLEURA NAMES OF PARANASAL SINUS Parts of respiratory system: The...

RESPIRATORY SYSTEM IN THIS TOPIC WE WILL LEARN: PARTS OF RESPIRATORY SYSTEM - NOSE - NASAL CAVITY - PHARYNX - LARYNX - TRACHEA - LUNG - ALVEOLI BRONCHOPULMONARY SEGMENTS LUNG AND PLEURA NAMES OF PARANASAL SINUS Parts of respiratory system: The airways can be divided into the conducting and respiratory zones. The conducting zone begins at the nose and ends at smaller bronchioles. The respiratory zone contains the terminal bronchioles and the alveoli – the sites where gas exchange occurs. The nose and the mouth form the main external openings and mark the beginning of the conducting zone of the airway or respiratory tract. The nasal cavity situated behind the nose contains hair and filters and humidifies air. Air then passes into the pharynx, which is also involved in swallowing. The epiglottis prevents the movement of food into the respiratory tract and the misdirection of air towards the esophagus. The larynx follows the pharynx and its main function is the production of sound. Air then enters the trachea, a long tube that is covered by a series of cartilaginous rings, which help this tubular structure retain its shape during inhalation and exhalation.  The trachea splits to form two primary bronchi, called the left and right bronchi. Each of these leads towards a lung and then undergoes repeated branching to produce secondary, tertiary bronchi, and bronchioles, with successively smaller diameters. When the bronchioles are less than a millimeter in diameter, they are called terminal bronchioles, whose purpose is to end in vascularized alveoli. LUNGS The lung are a pair of respiratory organs situated in the thoracic cavity Each lung is enclosed by the corresponding pleural cavity. The right and left lung are separated by the mediastinum. The lungs are spongy in texture In young, the lungs are brown or grey in colour. Gradually , they become mottled black because of deposition of carbon particles. Weighs about 700g. Features : Conical in shape A apex- upper end A base resting on the diaphragm  Three borders- anterior, posterior and inferior Two surfaces- costal and medial medial surfaces is divided into vertebral and mediastinal parts. Fissures and lobes of the lungs: The right lung is divided into three lobes ( upper, middle and lower) by two fissures that is ( oblique and horizontal). The left lung is divided into two lobes by the oblique fissure. ROOT OF THE LUNG: The hilum of the lung is found on the medial aspect of each lung, and it is the only site of entrance or exit of structures associated with the lungs Root of lung is a short ,broad pedicle which connects the medial surface of the lung of the mediastinum. Formed by the structures which either enter or come out of the lung at the hilum. - Arrangement of structures in the root Right side: 1- Eparterial bronchus, Hyparterial bronchus with bronchial vessels and posterior pulmonary plexus 2- pulmonary artery in midplane between two bronchi. 3- superior and inferior pulmonary veins in anterior part. 4- anterior pulmonary plexus, lymph nodes and lymph vessels in the anterior and inferior parts. Left side: 1.Single bronchus with bronchial vessels and posterior pulmonary plexus 2.Pulmonary artery in middle area 3.Superior and inferior pulmonary veins in anterior part 4.Anterior pulmonary plexus , lymph nodes and lymph vessels in the anterior and inferior parts. DIFFRENCE BETWEEN THE RIGHT AND LEFT LUNGS RIGHT LUNG LEFT LUNG SHORTER AND BROADER LONGER AND NARROWER LARGER AND HEAVIER WEIGHS SMALLER AND LIGHTER , WEIGHS ABOUT 700 G ABOUT 600G ANTERIOR BORDER IS STRAIGHT ANTERIOR BORDER IS INTERRUPTED BY THE CARDIAC NOTCH CARDIAC IMPRESSION ABSENT CARDIAC IMPRESSION DEEP ABSENCE OF LINGULA LINGULA PRESENT IT HAS 2 FISSURES AND 3 LOBES IT HAS 1 FISSURES AND 2 LOBES ARTERIAL SUPPLY On the right side , there is one bronchial artery On the left side, there are two bronchial arteries,. Deoxygenated blood is brought to the lungs by the two pulmonary arteries and oxygenated blood is returned to the heart by the pulmonary veins. Pleurae: It is a serous membrane It has an outer layer, the parietal pleura, and an inner layer the visceral or pulmonary pleura. 1. The parietal pleura – - thicker than the pulmonary pleura, and is subdivided into the following four parts. - costal - diaphragmatic - mediastinal - cervical 2- The visceral / pulmonary pleura- Serous layer covers the surfaces and fissures of the lung , except the hilum Recesses of pleura: There are two recesses of parietal pleura, which act as reserve spaces for the lung to expand during deep inspiration. 1- the costomediastinal recess - between costal and mediastinal pleurae 2- the costo diaphragmatic recess- lies between the costal and diaphragmatic pleurae. Bronchopulmonary segments: Well defined anatomical / functional surgical segments of the lung. Each one is aerated by a tertiary or segmental bronchus. Pyramidal in shape with apex directed towards hilum Base directed towards periphery having their own arterial supply. Each segment has a segmental bronchus , segmental artery, autonomic nerves and lymph vessels. BRONCHIAL TREE PARANASAL SINUSES:- The paranasal sinuses are air-filled extensions of the nasal cavity. There are four paired sinuses – named according to the bone in which they are located – maxillary, frontal, sphenoid and ethmoid. - The function of the paranasal sinuses : Lightening the weight of the head Supporting immune defense of the nasal cavity Humidifying inspired air Increasing resonance of the voice 1.FRONTAL SINUSES: There are two frontal sinuses located within the frontal bone of the skull. They are the most superior of the paranasal sinuses and are triangular in shape. 2.SPHENOID SINUSES: The sphenoid sinuses are situated within the body of the sphenoid bone. They open out into the nasal cavity in an area supero-posterior to the superior concha – known as the spheno- ethmoidal recess. 3. ETHMOIDAL SINUSES: There are three ethmoidal sinuses located within the ethmoid bone: Anterior – Opens onto the hiatus semilunaris (middle meatus) Middle – Opens onto the lateral wall of the middle meatus Posterior – Opens onto the lateral wall of the superior meatus 4. MAXILLARY SINUSES: The maxillary sinuses are the largest of the sinuses. They are located laterally and slightly inferiorly to the nasal  The nose has two cavities, separated from one another by a wall of cartilage called the septum. The external openings are known as nares or nostrils The roof of the mouth and the floor of the nose are formed by the palatine bone, the mouth part of which is commonly called the hard palate; a flap of tissue. The forward section, within and above each nostril, is called the vestibule. Behind the vestibule and along each outer wall are three elevations, running generally from front to rear. Each elevation, called a nasal concha.  ASSINGMENT 1. Describe the structure of lungs with lobes and fissures? 2. What is hilum. describe the structure of root of the lung? 3. Explain the pleurae with its types? 4. Describe the bronchopulmonary segments with its diagram? 5. Name the paranasal sinuses?