Respiratory System Anatomy PDF

Dr. Areej Al-shehri Lecturer Anatomy Department Parts (Organs) of the respiratory system:  Function of RESPIRATORY SYSTEM It provides a route of entry for air containing oxygen  lungs and exit for air containing carbon dioxide  outside Exchange of gases (O2 &...

Dr. Areej Al-shehri Lecturer Anatomy Department Parts (Organs) of the respiratory system:  Function of RESPIRATORY SYSTEM It provides a route of entry for air containing oxygen  lungs and exit for air containing carbon dioxide  outside Exchange of gases (O2 & CO2) between the alveoli and the blood Capillary Alveoli Blood RBCs The respiratory system can be divided into: Conductive part (concerned with conduction of air) Nose * Pharynx Larynx * Trachea Bronchi Bronchioles (lobar & segmental) Terminal bronchioles *Function ?? Respiratory part (concerned with gas exchange) Alveolar ducts Alveoli  THE NOSE & Paranasal sinuses  THE NOSE External Nose: The part of the nose that projects into the face Formed by the nasal bones and nasal cartilage Nasal cavity: It is divided into two halves by the nasal septum It opens anteriorly on the face through anterior nasal apertures It opens posteriorly into the nasopharynx through posterior nasal apertures Nasal cavity Posterior nasal Anterior nasal aperture aperture Boundaries of the nasal cavity: Roof: cribriform plate of ethmoid bone Floor: hard palate Medial wall: nasal septum Lateral wall: - Irregular & shows 3 bony projections; superior, middle & inferior conchae - The spaces inferior to each conchae are called: superior, middle & inferior meatuses  Mucous membrane of the nose Olfacotory mucosa (responsible for smell) Present in the roof and adjacent part of the septum. Respiratory mucosa Lines the rest of the nasal cavity (pseudostratified ciliated columnar epithelium with goblet cells)  Paranasal Sinuses - These are air-containing spaces in the skull around the nose. - They communicate with the nasal cavity through small openings Functions of paranasal sinuses: They decrease the weight of the skull They add resonance to voice They help in warming & humidification of inspired air Frontal air sinus ethmoidal air sinuses Maxillary air sinus Sphenoidal air sinus  Paranasal Sinuses -There are 4 paired paranasal sinuses: Frontal air sinus Ethmoidal air sinuses Sphenoidal air sinus Maxillary air sinus  The Pharynx It is a musculo-membranous tube that extends behind the nose, mouth and larynx It extends from the base of the skull to the 6th cervical vertebra  3 Parts of the Pharynx Nose Soft palate  THE Pharynx It has 3 parts: 1. Nasopharynx Lies behind ‘nose Extends from the base of the skull  level of ‘soft palate The pharyngeal tonsil (adenoids) lies in the roof of the nasopharynx The nasopharynx communicates with: Nose; through the posterior nasal apertures Middle ear; through the auditory tube Oropharynx 2. Oropharynx Lies behind ‘mouth cavity Extends from the level of ‘soft palate upper border of ‘epiglottis The palatine tonsils lie in the lateral wall of the oropharynx The oropharynx communicates with Nasopharynx Mouth cavity Laryngopharynx 3. Laryngopharynx Lies behind ‘larynx and communicates with the laryngeal inlet  The Larynx It is a specialized organ that forms part of the respiratory passage It is responsible for production of voice It is made up of a number of cartilages connected together by membranes, ligaments and moved by muscles  The Tonsils The pharyngeal tonsil (adenoids) lies in the roof of the nasopharynx The palatine tonsils lie in the lateral wall of the oropharynx The lingual tonsils lie at the back of the tongue  Cartilages of the larynx: 3 single cartilages Thyroid: (prominent anteriorly Adam’s apple) Cricoid: a ring of cartilage which is broader posteriorly Epiglottis: a leaf-like cartilage 3 paired cartilages Arytenoids: small pyramidal cartilages. They give attachment to the vocal cords Corniculate & Cuneiform: small cartilages Laryngeal cavity It is lined by mucosa formed of respiratory epithelium, Except the vocal cords Functions of the larynx Sound production It is closed: During swallowing to prevent passage of food to trachea To increase intra-abdominal pressure  Cartilages of the larynx: 3 Single 3 Paired Back View epiglottis Cartilago triticea Thyroid cartilage Cuneiform cartilage Corniculate cartilage Arytenoid cartilage Cricoid cartilage  The Trachea It is a fibro-cartilaginous tube, 10-12 cm long It lies partly in the neck and partly in the thorax Its wall is formed of 15-20 C-shaped cartilages to prevent its collapse It is closed posteriorly by fibroelastic membrane It extends from the lower border of cricoid cartilage the sternal angle It ends by dividing into right & left main bronchi The right bronchus is shorter, wider & more vertical than the left Each bronchus enters the hilum of the corresponding lung and branches forming the bronchial tree NOTE: So that, inhaled foreign body usually enters RT bronchus as it is wider, shorter & more vertical than LT bronchus  THE Lungs The lungs occupy the lateral compartments of the thoracic cavity The mediastinum lies between the 2 lungs Each lung is surrounded by a closed serous sac called “pleura”  External features of the Lungs The Lungs are cone-shaped, they have: Apex: extend upward into the neck Base: concave & rests on the diaphragm Costal surface: convex & related to the thoracic wall Medial (mediastinal) surface: concave and faces the mediastinum Anterior border: thin/ sharp , it is curved around the heart Posterior border: thick/ broad, it lies beside the vertebral column Inferior border: thin lower margin around the base Apex Anterior border Costal surface Posterior border Medial surface Inferior border Base  Lobes & Fissures of the lung Each lung is divided into lobes The right lung is divided into 3 lobes by horizontal & oblique fissures The left lung is divided into only 2 lobes by an oblique fissure Each lobe is further divided into bronchopulmonary segments So, which one is Rt, Lt ??? Rt Lt  The difference between Right & Left lungs Right Lung Left Lung Size Larger , Smaller Wider Narrower (due to ‘heart) Shorter (due to ‘liver) Longer Anterior border Straight Has a cardiac notch & lingula Fissures Oblique Oblique Horizontal Lobes Upper Upper Middle Lower Lower The medial surface presents the hilum of the lung, which gives passage to: (Anterior to posterior order): Two Pulmonary veins Pulmonary artery Primary bronchus  The important Relations on the medial surface of the Rt lung 1- RT atrium 2-SVC (superior vena cava) 3- IVC ( inferior vena cava) 4- Azygos vein 2 4 5- Esophagus 5 4 1 3  The important Relations on the medial surface of the Lt lung 1- Lt ventricle 2- arch of aorta 3- descending aorta 4- Esophagus 2 4 1 3  The important impressions on the medial surface of the Rt lung These are grooves of the structures related to medial surface of the RT lung: Groove for: 4 1- RT atrium 2 2-SVC (superior vena cava) 3- IVC ( inferior vena cava) 4- Azygos vein 5 5- Esophagus 1 3  The important impressions on the medial surface of the Lt lung These are grooves of the structures related to medial surface of theLT lung: 2 Groove for: 1- Lt ventricle 2- arch of aorta 3- descending aorta 3 4- Esophagus 1 4  The Pleura A closed serous sac that surrounds each lung. It is composed of: Visceral layer; (inner) covers the lung Parietal layer; (outer) lines the thoracic cavity The 2 layers are separated by a slitlike space called “pleural cavity”  contains pleural fluid to facilitate (lubricate) movement of lungs during respiration  The thorax It is formed of a bony thoracic cage which encloses the thoracic cavity The thoracic cavity is separated from the abdominal cavity by the diaphragm The thoracic cavity is divided into: Mediastinum; centrally, contains the heart Two lateral compartments; laterally, contain the lungs  The thorax The thoracic cage is formed of: Thoracic vertebrae, posteriorly Ribs; laterally Sternum; anteriorly The ribs are separated by intercostal spaces The Intercostal spaces are occupied by intercostal muscles  Respiratory Muscles They include the diaphragm & intercostal muscles The intercostal muscles are arranged in 3 layers: External intercostal muscles Internal intercostal muscles Innermost intercostal muscles  The diaphragm It is a musculotendinous partition which separates the thoracic from the abdominal cavity It has 3 main openings: Vena Caval opening; at level of 8th thoracic vertebra and transmits IVC Oesophageal opening; at level of 10th thoracic vertebra & transmits oesophagus Aortic opening; at level of 12th thoracic vertebra and transmits the aorta