Complete Respiratory System | GNM 1st Year

Complete Respiratory System | GNM 1st Year

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  THE RESPIRATORY SYSTEM -:Presented By:- MR.SAWANJOSHI ASSISTANT PROFESSOR Department Of MSN
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  • The respiratorysystem is one of the most important systems of the human body. • It helps us to breathe by taking in oxygen (O ) ₂ and removing carbon dioxide (CO ) ₂ . • Oxygen is needed by body cells to produce energy for normal body functions. • Carbon dioxide is a waste gas that must be removed from the body. • The respiratory system works closely with the circulatory system to transport oxygen and carbon dioxide. • A healthy respiratory system is essential for life, growth, and good health. • Nurses should understand the respiratory system to assess breathing and provide proper patient care. • Key Message • “The main function of the respiratory system is to supply INTRODUCTION
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  -:What is TheRespiratory System:- Definition The respiratory system is that helps the body to breathe. It takes oxygen (O ) ₂ from the air into the body and removes carbon dioxide (CO ) ₂ , a waste gas, from the body. Functions of the Respiratory System  Takes oxygen (O ) into the body. ₂  Removes carbon dioxide (CO ) from the body. ₂  Helps in the exchange of gases.  Supports voice production.  Helps in the sense of smell. Remember  Breathing Breathing is the process of taking air into the lungs (inhalation) and moving air out of the lungs (exhalation).  Respiration Respiration is the process by which the body takes oxygen (O ) and removes ₂ carbon dioxide (CO ) ₂ to produce energy for body cells.
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  -:Function Of TheRespiratory System:-  Provides Oxygen: Supplies oxygen (O ) to the body cells for energy production. ₂  Removes Carbon Dioxide: Removes carbon dioxide (CO ), a waste gas, from ₂ the body.  Gas Exchange: Exchanges oxygen and carbon dioxide in the alveoli of the lungs.  Voice Production: The larynx (voice box) helps in producing sound and speech.  Sense of Smell: The nose contains smell receptors that help us identify different odors.  Warms, Moistens, and Filters Air: The nose warms, moistens, and cleans the air before it reaches the lungs.  Maintains Acid–Base Balance: Helps maintain the normal pH (acid–base balance) of the blood by controlling the amount of carbon dioxide. Remember Main Function: To supply oxygen to the body and remove carbon dioxide from the body.
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  -:Structure Of TheRespiratory System:- The respiratory system is divided into two parts: 1. Upper Respiratory Tract Nose Nasal Cavity Pharynx (Throat) Larynx (Voice Box) 2. Lower Respiratory Tract Trachea (Windpipe) Right and Left Bronchi Bronchioles Lungs Alveoli (Air Sacs) Pathway of Air Nose Nasal Cavity Pharynx Larynx Trachea Bronchi Bronchioles → → → → → → → Alveoli Remember The alveoli are the main site of gas exchange, where oxygen enters the blood and carbon dioxide leaves the blood.
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  -: Nose :- Definition The nose is the first organ of the respiratory system. It is the main passage through which air enters and leaves the body.  Location Located in the center of the face. Lies between the two eyes and above the upper lip. Opens externally through two nostrils (external nares).  Shape Pyramid-shaped. The upper one-third is formed by bones, and the lower two-thirds are formed by cartilage.  Size (Adult) Length: 5–7 cm (approximately). External size varies slightly among individual  Exam Point (Small Box): The nose is the first organ of the respiratory system and is the main passage for air.
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  -: Parts OfThe Nose :-  Parts of the Nose The nose is divided into two parts: 1. External Nose It is the visible part of the nose present on the face. It forms the entrance of the respiratory tract. It allows air to enter the nasal cavity through the nostrils (external nares). 2. Internal Nose (Nasal Cavity) It is the hollow space inside the nose. It extends from the nostrils (external nares) to the posterior nasal openings which open into the pharynx. It is divided into right and left nasal cavities by the nasal septum. It is lined by a mucous membrane that helps clean, warm, and moisten the air. Remember External Nose = Visible part of the nose. Internal Nose (Nasal Cavity) = Air passage inside the nose.
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  -: Structure ofthe Nose :-
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  -: Parts OfThe Nose :- External Nose Definition The external nose is the visible part of the nose present on the face. It forms the entrance of the respiratory system and allows air to enter the nasal cavity. Parts of the External Nose 1. Root The upper fixed part of the nose. Located between the two eyes. Formed mainly by the nasal bones. 2. Bridge (Dorsum) Extends from the root to the tip of the nose. Forms the upper surface of the nose. Supported by bone and cartilage. 3. Apex (Tip) The lower pointed end of the nose. Formed mainly by cartilage. Soft and flexible.
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  4. Alae (Wings) Softand rounded sides of the nose. Form the outer boundary of the nostrils. Help keep the nostrils open during breathing. 5. External Nares (Nostrils) Two external openings of the nose. Allow air to enter and leave the respiratory tract. Lead into the nasal cavity. Exam Point The external nose consists of five main parts: Root, Bridge (Dorsum), Apex, Alae, and External Nares. -: Parts Of The Nose :- https://youtu.be/TrY2rjYjXJA
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  -: Parts OfThe Nose :- Internal Nose (Nasal Cavity) Definition The internal nose, also called the nasal cavity, is the hollow space inside the nose. It is the main passage through which air flows before reaching the pharynx. Location Extends from the external nares (nostrils) to the posterior nasal openings Opens posteriorly into the pharynx. Structure Divided into right and left nasal cavities by the nasal septum. Lined by a mucous membrane. Contains cilia (tiny hairs) that trap dust and microorganisms. The lateral wall contains three nasal conchae (turbinates): Superior nasal concha Middle nasal concha Inferior nasal concha
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  1. Air Passage Providesa passage for air to enter and leave the respiratory system. 2. Filters the Air Cilia and mucus trap dust, germs, and other foreign particles. 3. Warms the Air The rich blood supply of the nasal cavity warms the inspired air before it reaches the lungs. 4. Moistens the Air The mucous membrane adds moisture to the inspired air and prevents dryness of the respiratory tract. 5. Sense of Smell The olfactory receptors in the roof of the nasal cavity help us detect different smells. 6. Resonating Chamber The nasal cavity acts as a resonating chamber, which improves the quality and tone of the voice. Clinical Importance A deviated nasal septum (DNS) can obstruct airflow and make breathing difficult. Infection of the nasal cavity or sinuses may cause sinusitis. Inflammation of the nasal mucosa causes rhinitis. Exam Point The main functions of the nasal cavity are to filter, warm, moisten the air, and provide the sense of smell. -: Functions of the Nose :-
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  -: Blood Supply,Nerve Supply & Lymphatic Drainage of the Nose :- Blood Supply The nose receives a rich blood supply from: • Facial artery • Maxillary artery • Ophthalmic artery These arteries form a rich network in the anterior part of the nasal septum called Kiesselbach’s plexus (Little’s area), which is the most common site of nosebleed (epistaxis). Nerve Supply o Sensory Nerve Trigeminal nerve (CN V) supplies general sensation to the nose. o Special Sensory Nerve Olfactory nerve (CN I) supplies the sense of smell. Lymphatic Drainage • Anterior part → Submandibular lymph nodes • Posterior part → Retropharyngeal and Deep cervical lymph nodes
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  -: Paranasal Sinuses:- Definition The paranasal sinuses are air-filled cavities present in the bones of the skull around the nasal cavity. They are lined with mucous membrane and communicate with the nasal cavity through small openings. Types of Paranasal Sinuses Frontal Sinuses – Located in the frontal bone (forehead). Maxillary Sinuses – Located in the maxillary bones (cheeks). They are the largest paranasal sinuses. Ethmoidal Sinuses – Located in the ethmoid bone, between the two eyes. Sphenoidal Sinuses – Located in the sphenoid bone, behind the nasal cavity.
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  Functions Of ParanasalSinuses  Make the skull lighter.  Produce mucus to keep the nasal cavity moist.  Warm and humidify inspired air.  Improve the quality of the voice (resonance).  Protect the skull by acting as an air cushion. Exam Point There are four pairs of paranasal sinuses: Frontal, Maxillary, Ethmoidal, and Sphenoidal. Tips:-“FEMS” F – Frontal E – Ethmoidal M – Maxillary S – Sphenoidal -: Paranasal Sinuses :-
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  -: Pharynx :- Definition Thepharynx is a muscular, funnel-shaped tube that connects the nasal cavity and oral cavity to the larynx and esophagus. It acts as a common passage for both air and food. Location Located behind the nose and mouth. Extends from the base of the skull to the lower border of the sixth cervical vertebra (C6). Continues with the esophagus. Shape Funnel-shaped (widest at the top and narrow at the bottom). Size (Adult) Length: Approximately 12–14 cm. Width: About 5 cm at the upper end (varies among individuals). Important Point The pharynx is a part of both: Respiratory System (Passage for air) Digestive System (Passage for food) Exam Point The pharynx is a common passage for both air and food.
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  -: Parts OfThe Pharynx :- The pharynx is divided into three parts according to its location. 1. Nasopharynx Upper part of the pharynx. Located behind the nasal cavity. Extends from the base of the skull to the soft palate. Only air passes through this part. 2. Oropharynx Middle part of the pharynx. Located behind the oral cavity (mouth). Extends from the soft palate to the upper border of the epiglottis. Both air and food pass through this part. 3. Laryngopharynx (Hypopharynx) Lower part of the pharynx. Located behind the larynx. Extends from the epiglottis to the lower border of the cricoid cartilage (C6 vertebra). Continues as the esophagus. Both air and food pass through this part.
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  Definition The nasopharynx isthe upper part of the pharynx. It is located behind the nasal cavity and acts as a passage for air only. Location • Lies behind the nasal cavity. • Extends from the base of the skull to the soft palate. Structure • Connected to the nasal cavity through the choanae (posterior nasal openings). • Lined by ciliated pseudostratified columnar epithelium (respiratory epithelium). • Contains the pharyngeal tonsil (adenoids) on its posterior wall. • The opening of the Eustachian (auditory) tube is present on each side. Functions • Provides a passage for air from the nasal cavity to the oropharynx. • Helps equalize air pressure in the middle ear through the Eustachian tube. • The pharyngeal tonsil helps protect the body from infection. Clinical Importance Enlargement of the adenoids may block the airway and cause difficulty in breathing, snoring, and mouth breathing. Infection of the nasopharynx may cause a sore throat or upper respiratory infection. -: Nasopharynx :-
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  -: Oropharynx :- Definition Theoropharynx is the middle part of the pharynx. It is located behind the oral cavity (mouth) and serves as a common passage for air and food. Location • Lies behind the oral cavity. • Extends from the soft palate to the upper border of the epiglottis. Structure • Connected to the mouth through the oral cavity. • Lined by non-keratinized stratified squamous epithelium. • Contains the palatine tonsils on both sides. • The base of the tongue forms the anterior wall. Functions • Provides a passage for air and food. • Helps in swallowing (deglutition). • Plays an important role in speech. • The palatine tonsils help protect the body from infection. Clinical Importance Infection of the palatine tonsils causes tonsillitis. Symptoms include sore throat, pain during swallowing, fever, and enlarged tonsils.
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  -: Laryngopharynx :- Definition Thelaryngopharynx, also called the hypopharynx, is the lowest part of the pharynx. It is located behind the larynx and serves as a common passage for air and food. Location • Lies behind the larynx. • Extends from the upper border of the epiglottis to the lower border of the cricoid cartilage (C6 vertebra). • Continues below as the esophagus. Structure • Lined by non-keratinized stratified squamous epithelium. • Opens anteriorly into the larynx. • Continues posteriorly into the esophagus. Functions • Provides a common passage for air and food. • Directs air into the larynx. • Directs food and liquids into the esophagus during swallowing. Clinical Importance • During swallowing, the epiglottis closes the opening of the larynx to prevent food from entering the airway.
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  -: Blood Supply,Nerve Supply & Lymphatic Drainage of the Pharynx -: Blood Supply The pharynx receives blood mainly from the following arteries: • Ascending pharyngeal artery (main blood supply) • Facial artery • Maxillary artery • Lingual artery • Superior thyroid artery Venous Drainage • Blood is drained by the pharyngeal venous plexus. • The pharyngeal venous plexus drains into the internal jugular vein. Nerve Supply Motor Nerve Supply • Vagus nerve (CN X) supplies most muscles of the pharynx. • Stylopharyngeus muscle is supplied by the Glossopharyngeal nerve (CN IX). Sensory Nerve Supply • Nasopharynx Maxillary nerve ( → CN V₂) • Oropharynx Glossopharyngeal nerve ( → CN IX) • Laryngopharynx Vagus nerve ( → CN X) Lymphatic Drainage The lymph from the pharynx drains into: • Retropharyngeal lymph nodes • Deep cervical lymph nodes
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  -: Function OfPharynx :- Functions of the Pharynx 1. Passage for Air Carries air from the nasal cavity to the larynx. 2. Passage for Food Carries food and liquids from the mouth to the esophagus. 3. Swallowing (Deglutition) Helps move food from the mouth to the esophagus during swallowing. 4. Voice Resonance Acts as a resonating chamber and improves the quality of the voice. 5. Protection Pharyngeal and palatine tonsils help protect the body from microorganisms. 6. Pressure Equalization The Eustachian tube opens into the nasopharynx and helps maintain equal air pressure in the middle ear.
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  -: Larynx :- Definition Thelarynx is a hollow, cartilaginous organ of the respiratory system. It connects the pharynx to the trachea and is commonly called the voice box because it contains the vocal cords. Location Located in the anterior part of the neck. Lies opposite the C3–C6 vertebrae. Extends from the laryngopharynx to the trachea. Shape Triangular or box-shaped. Formed by nine cartilages connected by ligaments and muscles. Size (Adult) Length: Approximately 4–5 cm Width: About 4 cm in males and slightly smaller in females. More prominent in males, forming the Adam’s apple (laryngeal prominence). Associated Structures Superiorly → Laryngopharynx Inferiorly → Trachea Anteriorly → Thyroid gland (partly) Posteriorly → Laryngopharynx Exam Point
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  -: Diagram:-
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  -: Cartilages ofthe Larynx :- The larynx is supported by 9 cartilages. These cartilages are divided into two groups: 1. Unpaired Cartilages (3 Single Cartilages) Thyroid cartilage – Largest cartilage; forms the Adam’s apple. Cricoid cartilage – The only complete ring-shaped cartilage of the respiratory tract. Epiglottis – Leaf-shaped cartilage that prevents food from entering the trachea during swallowing. 2. Paired Cartilages (3 Pairs = 6 Cartilages) 1 Pair of Arytenoid cartilages (2) 1 Pair of Corniculate cartilages (2) 1 Pair of Cuneiform cartilages (2) Total Cartilages = 3 (Unpaired) + 6 (Paired) = 9 Cartilages Exam Point The larynx contains 9 cartilages: 3 Unpaired cartilages 3 Pairs of paired cartilages (6 cartilages)
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  -: Blood Supply,Nerve Supply & Lymphatic Drainage of the Larynx :- Blood Supply The larynx receives blood from: Arteries • Superior laryngeal artery (branch of the Superior thyroid artery) • Inferior laryngeal artery (branch of the Inferior thyroid artery) Veins • Superior laryngeal vein • Inferior laryngeal vein These veins drain into the Superior and Inferior thyroid veins. Nerve Supply Motor Nerve Supply • Recurrent laryngeal nerve (branch of the Vagus nerve – CN X) supplies all intrinsic muscles of the larynx except the cricothyroid muscle. • External branch of the Superior laryngeal nerve supplies the cricothyroid muscle. Sensory Nerve Supply • Internal branch of the Superior laryngeal nerve supplies the mucosa above the vocal cords. • Recurrent laryngeal nerve supplies the mucosa below the vocal cords. Lymphatic Drainage • Above the vocal cords → Deep cervical lymph nodes • Below the vocal cords → Pretracheal and Deep cervical lymph nodes
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  -: Functions ofthe Larynx :- 1. Air Passage Provides a passage for air from the pharynx to the trachea. 2. Voice Production (Phonation) The true vocal cords vibrate to produce sound during speech. 3. Protection of the Airway During swallowing, the epiglottis closes the laryngeal inlet to prevent food and liquids from entering the trachea. 4. Cough Reflex Helps remove dust, mucus, and foreign particles from the airway. 5. Helps in Breathing Keeps the airway open and allows the free passage of air.
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  -:Trachea (Windpipe):- Definition The trachea,also called the windpipe, is a tube-like organ of the respiratory system. It carries air from the larynx to the right and left bronchi. Location Begins at the lower border of the cricoid cartilage (C6 vertebra). Lies in front of the esophagus. Ends at the sternal angle (T4–T5 vertebra), where it divides into the right and left main bronchi. Shape Cylindrical (tube-shaped). Flexible but kept open by C-shaped hyaline cartilage rings. Size (Adult) Length: Approximately 10–12 cm Diameter: Approximately 2–2.5 cm Associated Structures Superiorly: Larynx Inferiorly: Right and Left Main Bronchi Anteriorly: Thyroid gland (upper part) and sternum Posteriorly: Esophagus Exam Point The trachea extends from the C6 vertebra to the T4–T5 vertebra and divides into the right and left
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  -: Diagram OfTrachea :-
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  -:Structure of theTrachea:- The wall of the trachea is made up of four layers. 1. Mucosa (Inner Layer) Lined by ciliated pseudostratified columnar epithelium. Contains goblet cells, which produce mucus. Cilia move mucus and trapped dust upward toward the throat. 2. Submucosa Contains blood vessels, nerves, and mucous glands. Helps keep the trachea moist. 3. Cartilaginous Layer Formed by 16–20 C-shaped hyaline cartilage rings. The open part of the rings lies posteriorly. The trachealis muscle joins the open ends of the cartilage rings. Prevents the trachea from collapsing during breathing. 4. Adventitia (Outer Layer) Outermost connective tissue layer. Supports and attaches the trachea to surrounding structures. Important Structures Carina A ridge present at the lower end of the trachea. Located at the point where the trachea divides into the right and left main bronchi.
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  -: Blood Supply,Nerve Supply & Lymphatic Drainage of the Trachea :- Blood Supply Arteries The trachea receives blood from: Inferior thyroid artery (Cervical part) Bronchial arteries (Thoracic part) Veins Blood is drained by: Inferior thyroid veins Bronchial veins Lymphatic Drainage Lymph from the trachea drains into: Pretracheal lymph nodes Paratracheal lymph nodes Tracheobronchial lymph nodes Nerve Supply Parasympathetic Nerve Vagus nerve (CN X) Causes bronchoconstriction and increases mucus secretion. Sympathetic Nerve Fibers from the sympathetic trunk Cause bronchodilation and reduce mucus secretion.
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  -:Functions & ClinicalImportance of the Trachea :- 1. Air Passage • Provides a passage for air between the larynx and the bronchi. 2. Maintains an Open Airway • C-shaped hyaline cartilage rings keep the trachea open and prevent it from collapsing during breathing. 3. Filters the Air • Mucus traps dust, bacteria, and other foreign particles. • Cilia move the trapped particles upward toward the pharynx for removal. 4. Warms and Moistens the Air • The mucous membrane warms and humidifies the inspired air before it reaches the lungs. 5. Cough Reflex • The carina is highly sensitive and triggers the cough reflex when foreign particles enter the airway.
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  -: Bronchi :- RightMain Bronchus Left Main Bronchus Length: 2–2.5 cm Length: 4–5 cm Wider Narrower Shorter Longer More Vertical More Horizontal Definition The bronchi are the two main branches of the trachea that carry air from the trachea to the lungs. They are known as the right main bronchus and left main bronchus. Location • Begin at the carina (bifurcation of the trachea) at the level of T4–T5 vertebra. • The right bronchus enters the right lung. • The left bronchus enters the left lung. Shape • Tube-shaped structures. • Supported by irregular plates of hyaline cartilage. Size (Adult) Associated Structures • Superiorly: Trachea • Inferiorly: Bronchioles • Laterally: Right and Left Lungs Difference:-
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  -: Structure ofthe Bronchi :- The bronchi are formed by the division of the trachea at the carina. Each main bronchus enters the lung through the hilum and divides into smaller branches. Bronchial Tree Trachea ↓ Right & Left Main Bronchi (Primary Bronchi) ↓ Lobar Bronchi (Secondary Bronchi) Right lung – 3 lobar bronchi Left lung – 2 lobar bronchi ↓ Segmental Bronchi (Tertiary Bronchi) Supply individual bronchopulmonary segments. ↓ Bronchioles Smaller airways. No cartilage in their walls. ↓ Terminal Bronchioles Last part of the conducting airway. ↓ Respiratory Bronchioles Beginning of the respiratory zone. Lead to alveolar ducts and alveoli. Wall of the Bronchi The bronchial wall consists of: Mucosa – Ciliated epithelium with goblet cells. Smooth Muscle – Controls airway diameter. Hyaline Cartilage Plates – Keep the bronchi open. Connective Tissue – Provides support.
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  -: Blood Supply,Nerve Supply & Lymphatic Drainage of the Bronchi :- Blood Supply Arterial Supply The bronchi receive blood from the bronchial arteries. Right bronchial artery – Usually arises from the 3rd posterior intercostal artery or the left bronchial artery. Left bronchial arteries – Usually two in number and arise directly from the thoracic aorta. Venous Drainage Blood is drained by: Bronchial veins Some blood also drains into the pulmonary veins. Nerve Supply The bronchi are supplied by the pulmonary plexus. Parasympathetic Supply Vagus nerve (CN X) Causes bronchoconstriction Increases mucus secretion Sympathetic Supply Fibers from the sympathetic trunk (T1–T5) Cause bronchodilation Decrease mucus secretion Lymphatic Drainage Lymph from the bronchi drains into: • Pulmonary lymph nodes • Bronchopulmonary (Hilar) lymph nodes • Tracheobronchial lymph nodes • Paratracheal lymph nodes
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  -: Functions ofthe Bronchi :- 1. Conduct Air Carry air from the trachea to the lungs and back during expiration. 2. Distribute Air Divide into smaller branches to deliver air evenly to all parts of the lungs. 3. Keep the Airway Open Hyaline cartilage plates prevent the bronchi from collapsing during breathing. 4. Filter the Air Mucus traps dust, bacteria, and other foreign particles. Cilia move trapped particles upward toward the pharynx (mucociliary escalator). 5. Regulate Airflow Smooth muscles control the diameter of the bronchi. They relax to increase airflow (bronchodilation). They contract to decrease airflow (bronchoconstriction). 6. Warm and Humidify Air The bronchial mucosa warms and moistens inspired air before it reaches the alveoli.
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  -: Introduction tothe Lungs :- Definition • Pair of soft, spongy, cone-shaped organs present in the thoracic cavity. • Main organs of respiration. • Exchange oxygen (O ) and carbon dioxide (CO ). ₂ ₂ Location • Located in the thoracic cavity. • One lung lies on each side of the mediastinum. • Rest on the diaphragm. • Protected by the rib cage. Shape • Cone-shaped. • Apex – Upper pointed end. • Base – Broad lower surface resting on the diaphragm. Size • Right lung – Shorter and wider. • Left lung – Longer and narrower. Average Weight • Right lung – 550–650 g • Left lung – 450–550 g Covering • Visceral pleura – Covers the lung surface. • Parietal pleura – Lines the thoracic cavity. ⭐ Exam Point Right lung is larger and heavier than the left lung because the heart occupies more space on the left side.
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  -: External Featuresof the Lungs :- External Features of the Lungs 1. Apex The upper pointed end of the lung. Extends about 2–3 cm above the clavicle into the root of the neck. 2. Base Broad lower surface of the lung. Rests on the diaphragm. Also called the diaphragmatic surface. 3. Surfaces Each lung has three surfaces: Costal Surface – Faces the ribs and sternum. Mediastinal Surface – Faces the mediastinum and contains the hilum. Diaphragmatic Surface – Rests on the diaphragm. 4. Borders Each lung has three borders: Anterior Border Posterior Border Inferior Border 5. Cardiac Notch Present only in the left lung. Provides space for the heart. Exam Point
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  -: Lobes ofthe Lungs :- Lobes of the Lungs Right Lung Divided into three lobes: Superior (Upper) Lobe Middle Lobe Inferior (Lower) Lobe Left Lung Divided into two lobes: Superior (Upper) Lobe Inferior (Lower) Lobe Lingula A tongue-like projection of the superior lobe of the left lung. It corresponds anatomically to the middle lobe of the right lung.
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  -: Fissures ofthe Lungs :- Fissures of the Lungs Fissures are deep grooves that divide the lungs into different lobes. Right Lung The right lung has two fissures: 1. Horizontal Fissure Separates the Superior Lobe from the Middle Lobe. 2. Oblique Fissure Separates the Middle Lobe from the Inferior Lobe. Left Lung The left lung has one fissure: Oblique Fissure Separates the Superior Lobe from the Inferior Lobe. Importance of Fissures Divide the lungs into lobes. Allow the lobes to expand independently during breathing. Help localize lung diseases on X-ray and CT scan. Important landmarks during lung surgery.
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  -: Hilum ofthe Lung :- Definition The hilum is a triangular depression present on the mediastinal surface of each lung. It is the entry and exit point for structures that enter or leave the lung. Location • Present on the mediastinal surface of both lungs. • Faces the mediastinum. • Forms the gateway between the lung and the mediastinum. Structures Passing Through the Hilum • Main (Primary) Bronchus • Pulmonary Artery • Two Pulmonary Veins • Bronchial Arteries and Veins • Lymphatic Vessels • Pulmonary Lymph Nodes • Pulmonary Nerves Functions • Provides a passage for air, blood vessels, nerves, and lymphatics. • Connects the lungs with the mediastinum. • Supports communication between the lungs and the rest of the body.
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  -: Root ofthe Lung :- Definition The root of the lung is a short, broad bundle of structures that connects each lung to the mediastinum. It passes through the hilum and is enclosed by a sleeve of pleura. Location • Situated at the hilum on the mediastinal surface of each lung. • Connects the lung with the heart, trachea, and mediastinum. Structures Present in the Root of the Lung • Main (Primary) Bronchus • Pulmonary Artery • Two Pulmonary Veins (Superior & Inferior) • Bronchial Arteries • Bronchial Veins • Lymphatic Vessels • Pulmonary Lymph Nodes • Pulmonary Nerves • Pleural Sleeve Functions • Anchors the lung to the mediastinum. • Provides a pathway for air, blood vessels, nerves, and lymphatics. • Supports communication between the lungs and the rest of the body.
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  -: Blood Supplyof the Lungs :- The lungs receive blood from two different circulations: 1. Pulmonary Circulation (Functional Blood Supply) • Carries deoxygenated blood from the right ventricle to the lungs through the pulmonary arteries. • Gas exchange occurs in the alveoli. • Oxygenated blood returns to the left atrium through the pulmonary veins. 2. Bronchial Circulation (Nutritional Blood Supply) • Bronchial arteries arise from the thoracic aorta. • Supply oxygenated blood to: o Bronchi o Connective tissue o Visceral pleura o Supporting tissues of the lungs • Bronchial veins drain into the azygos vein (right side) and hemiazygos/accessory hemiazygos veins (left side).
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  -: Nerve Supply& Lymphatic Drainage of the Lungs :- Nerve Supply of the Lungs The lungs receive nerve supply through the pulmonary plexus, which is formed by: Parasympathetic Nerve Supply • Vagus Nerve (Cranial Nerve X) • Causes bronchoconstriction. • Increases mucus secretion. • Helps regulate normal breathing. Sympathetic Nerve Supply • Fibres arise from the thoracic sympathetic trunk (T2–T5). • Causes bronchodilation. • Decreases mucus secretion. • Increases airflow during exercise and stress. Lymphatic Drainage of the Lungs • Lymph from the lungs drains through the following lymph nodes: • Pulmonary (Intrapulmonary) Lymph Nodes • Bronchopulmonary (Hilar) Lymph Nodes • Tracheobronchial Lymph Nodes • Paratracheal Lymph Nodes • Finally drains into the Bronchomediastinal Lymph Trunk.
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  -: Diaphragm :- Definition •The diaphragm is a dome-shaped musculotendinous partition that separates the thoracic cavity from the abdominal cavity. • It is the principal muscle of respiration. Location • Located between the thoracic and abdominal cavities. • Forms the floor of the thoracic cavity and the roof of the abdominal cavity. Main Features • Dome-shaped muscle. • Has a right dome and a left dome. • The right dome is slightly higher than the left because of the liver. • The centre is formed by the central tendon. Functions • Principal muscle of respiration. • Contracts during inspiration and relaxes during expiration. • Increases the volume of the thoracic cavity. • Assists in coughing, sneezing, vomiting, defecation, urination and childbirth.
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  -: Functions ofthe Lungs :- A. Respiratory Functions  Gas Exchange o Oxygen (O ) enters the blood. ₂ o Carbon dioxide (CO ) is removed from the body. ₂  Oxygenation of Blood o Maintains adequate oxygen supply to body tissues.  Removal of Carbon Dioxide o Eliminates CO produced during cellular ₂ metabolism.  Regulation of Blood pH o Helps maintain acid–base balance by controlling CO levels. ₂ B. Non-Respiratory Functions  Filtration of Blood o Removes small blood clots, air bubbles, and other particles from the pulmonary circulation.  Defence Mechanism o Mucus, cilia, alveolar macrophages, and immune cells protect against microorganisms and dust.  Production of Surfactant o Type II alveolar cells produce surfactant, which reduces surface tension and prevents alveolar collapse.  Metabolic Functions o The lungs convert Angiotensin I Angiotensin → II by the enzyme ACE (Angiotensin-Converting Enzyme).  Heat and Water Loss o Small amounts of heat and water are lost during exhalation.
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  -: Common Disordersof the Respiratory System :- 1. Asthma Chronic inflammatory disease of the airways. Causes wheezing, cough, chest tightness, and shortness of breath. 2. Pneumonia Infection of the lung tissue (alveoli). Common symptoms include fever, productive cough, chest pain, and difficulty in breathing. 3. Tuberculosis (TB) Infectious disease caused by Mycobacterium tuberculosis. Mainly affects the lungs. Symptoms include persistent cough, weight loss, fever, and night sweats. 4. Chronic Obstructive Pulmonary Disease (COPD) Progressive disease that limits airflow. Commonly associated with smoking. Includes chronic bronchitis and emphysema. 5. Lung Cancer Uncontrolled growth of abnormal cells in the lungs. Major risk factors include smoking, air pollution, and occupational exposure. 6. Pneumothorax Presence of air in the pleural cavity. Causes partial or complete collapse of the lung.