Anatomy and Physiology of the Respiratory Tract Prof Yaser .pptx

Anatomy and Physiology of the Respiratory Tract Prof Yaser .pptx

1. Anatomy and Physiology of the Respiratory Tract Rasha abulubbad & Yaser S. Natour

2. Upper Respiratory Tract الجهاز التنفسي العلوي Nasal Cavity Oral Cavity Pharynx Larynx

3. Nasal Cavity التجويف ال أنفي Heats, humidifies, filters, resonates sound, and olfaction Velum elevates during the swallow, closes the nasal cavity, and prevents nasal regurgitation

4. Oral Cavity تجويف الفم Primary role is respiration, but is also used for swallow, digestion and speech  Lips - seal oral cavity for swallow Tongue - oral prep, oral transit (base of tongue is the primary muscle used to propel food - it rests on the hyoid bone) Salivary Glands - secrete lubrication

5. Muscular tube that is dual passageway for respiration and swallow The 3 segments are: 1)Nasopharynx 2) Oropharynx Gag reflex (NOT a predictor of dysphagia) 3)Laryngopharynx - separates digestive and respiratory tracts Pharynx: البلعوم

6. Pharynx: البلعوم Vallecula Recess between the base of the tongue and epiglottis Common landmark during intubation  Pharyngeal muscles  Suspended from hyoid bone for laryngeal elevation and anterior motion Epiglottis Separates the respiratory and digestive system for airway protection Acts like a rudder of a ship to deflect food laterally away from the airway

7. Larynx الحنجرة Cricoid Cartilage Thyroid Cartilage (Adam's Apple) Arytenoid Cartilages Along with muscles, responsible for opening and closing vocal cords The larynx is the “gatekeeper” to prevent aspiration at multiple levels  Pharyngeal Muscles – Muscles attached to the hyoid elevate the larynx up and pull it forward Laryngeal Muscles – Close the larynx at the vocal fold level to create a seal that separates the airway from the digestive tract

8. Cricoid Hyoid Epiglottis Thyroid

9. Esophagus المريء Muscular organ for swallow Peristalsis Cricopharyngeal Sphincter or Upper Esophageal Sphincter Muscular band that relaxes to allow food to enter esophagus when larynx elevates & pulls forward, and pressures change

10. Innervation of the upper airway Three main cranial nerves innervate the upper airway: Trigeminal nerve (Cranial nerve V/5): Branches of the trigeminal nerve innervate the nose and the anterior two-thirds of the tongue. Glossopharyngeal (Cranial nerve IX/9): Branches of the glossopharyngeal nerve innervate the posterior third of the tongue, roof of the pharynx, and tonsils. Vagus (Cranial nerve X/10): The two major divisions of the vagus nerve in airway innervation are the superior laryngeal and the recurrent laryngeal nerves.

11. Sensory innervation 1. Trigeminal nerve – the sensory innervation of the nasal mucosa arises from two divisions: – The anterior ethmoidal nerve supplies the anterior septum and lateral wall; The nasopalatine nerves innervate the posterior areas.

12. 2. Glossopharyngeal nerve – supplies the posterior third of the tongue, soft palate, epiglottis, fauces and the pharyngo- oesophageal junction.

13. 3. Superior laryngeal nerve – the internal branch of the vagus nerve innervates mucosa from the epiglottis to and including the vocal cords.

14. 4. Recurrent laryngeal nerve – a branch of the vagus nerve innervates mucosa below the vocal folds to the trachea.

15. Motor innervation 1. The external branch of the superior laryngeal nerve is responsible for innervation of the cricothyroid muscle.

16. 2. The recurrent laryngeal nerve provides a motor supply to all the muscles of the larynx (posterior and lateral cricoarytenoid muscles) except the cricothyroid muscle. The lateral cricoarytenoid adducts the vocal folds The posterior cricoarytenoid abducts the folds Unilateral damage to the recurrent laryngeal nerve causes hoarseness. Bilateral damage causes respiratory distress and stridor whilst chronic damage can cause aphonia.

17. Lower Respiratory Tract الجهاز التنفسي السفلي Trachea Bronchi Right and left mainstem Bronchioles Alveoli - air sacs  Lined with surfactant, filled with air to prevent collapse/ atelectasis

18. Lower Respiratory Tract الجهاز التنفسي السفلي Lungs Fill the thorax Highly elastic properties- elastic recoil Cradled in Pleura Visceral Pleura (Covers the lung surface) Parietal Pleura ( Lines the chest wall)   Pleural fluid is lubricant, and pleural space maintains negative pressure that holds lungs open (opposes the elastic recoil)

19. Muscles of Respiration عضلات التنفس  Respiratory Muscles – Inhalation Diaphragm (phrenic nerve at C3, 4, and 5) Intercostals  Pectoralis Major and Minor Sternocleidomastoid Scalene Muscles

20. Neurophysiology of Breathing   Process of exchanging gas in the body--here red blood cells give up carbon dioxide and take on new oxygen Inhalation --air is taken through respiratory tract to lungs and held there until oxygen replaces carbon dioxide Expiration --expulsion of carbon dioxide through tract out into the atmosphere

21. Respiratory Control Center - Brainstem Medulla Oblongata Pons

22. Diseases الأمراض Obstructive Disorders COPD (Chronic Obstructive Pulmonary Disease) Irreversible airway obstruction Caused by damaged lung tissue Chronic Bronchitis Chronic cough, mucus production, narrow airways secondary to irritation Bronchospasm Emphysema Deterioration in alveolar walls  Loss of elastic recoil  Flat diaphragm

23. Diseases الأمراض Restrictive disorders Reduced lung volumes  Decreased compliance (stiff lungs)  Inability to take deep breaths Connective Tissue Disorders - fibrotic changes (scleroderma, pleurisy pulmonary fibrosis)  Thoracic Deformities - reduced volumes (arthritis, scoliosis, kyphosis, rib fractures) Pneumonia - infection and inflammation (bacterial, viral or aspiration)

24. Neuromuscular Disorders الاضطرابات العصبية العضلية Degenerative Diseases that affect respiratory muscles ALS Guillain-Barré Polio Spinal Cord Injury Ms ALS

25. Diseases الأمراض Cardiopulmonary Conditions - poor circulation of blood to lungs/body "cardiac cripple" Right Heart Failure edema Left Heart Congestive Heart Failure ( CHF)  fluid buildup in the feet, arms, lungs, and other organs, shortness of breath Total failure

26. Diseases الأمراض Adult Respiratory Distress Syndrome (ARDS) Damage to the alveolar-capillary membrane resulting in severe impairment of gas exchange (fibrotic changes may be permanent) Multi-Factorial Stroke, trauma, infection, sepsis, severe pneumonia, inhalation injury, etc.