Respiratory+system Vet Prep Summer 2023 PDF

Respiratory apparatus Vet Prep Summer 2023 Cristian Dezdrobitu, DVM, MSc, PhD Assistant Professor Resources: TVA, Dyce, Sacks & Wensing’s, 5th ed., Part I, Ch. 4 Learning Objectives 1. General objective: correlate structure with function, where the latter has been discussed. 2. List the segment...

Respiratory apparatus Vet Prep Summer 2023 Cristian Dezdrobitu, DVM, MSc, PhD Assistant Professor Resources: TVA, Dyce, Sacks & Wensing’s, 5th ed., Part I, Ch. 4 Learning Objectives 1. General objective: correlate structure with function, where the latter has been discussed. 2. List the segments of the respiratory apparatus; differentiate between the role of airways and essential organs. 3. Describe and identify the external and internal features of the nose. 4. Describe and identify the chambers of the pharynx; describe the passage of air and food through these segments. 5. Describe and identify the cartilages and the internal features of the larynx. 6. Describe the structure and the topography of the trachea. 7. List and identify the main segments of the bronchial tree. 8. Describe and identify the lobation and external features of the lungs. 9. Describe the functional blood supply and drainage of lungs. 10. Describe and identify the pleural membranes and cavities; describe their role in relation to the lungs. Respiratory apparatus is made up of: • Airways (air conduction): – – – – Nasal cavities Pharynx Larynx Trachea and bronchial tree • Essential organs (gas exchange): Lungs – Associated structure: pleural sacs https://i1.wp.com/blog.biostarus.com/wp-content/uploads/2018/12/airquality-respiratoryailments-diagram-web.png?ssl=1 Nose - external features External naris (pl. nares) (Nostril) Alar fold Nose pad Philtrum https://modernfarmer.com/wp-content/uploads/2014/06/dog-nose-hero.jpg Nose – 2 nasal cavities; limits: Choana – caudal ventral passage from the nasal cavity into the pharynx Guide to the dissection of the dog, deLahunta, , 8th ed., Fig. 5-17 Right nostril (oral limit) -1 Hard palate - 6 Vomer, resected - 7 TVA, Dyce, Sacks & Wensing’s, 5th ed., Fig. 4.2 Nose – role of mucosae Respiratory mucosa (retain dust particles, humidify air, heat up air) • Ventral nasal concha - 2 • Dorsal nasal concha - 3 Olfactory mucosa – sense of smell Located on ethmoconchae - 4 TVA, Dyce, Sacks & Wensing’s, 5th ed., Fig. 4.2 Paranasal sinuses: • Cavities in bones of the skull that communicate with the nasal cavities TVA, Dyce, Sacks & Wensing’s, 5th ed., Fig. 4.6 1. Maxillary recess 2. Frontal sinus - landmark - carnassial tooth Guide to the dissection of the dog, deLahunta, , 8th ed., Fig. 5-15 Pharynx - crossroad between: TVA, Dyce, Sacks & Wensing’s, 5th ed., Fig. 4.2 Oropharynx • Placed ventrally to soft palate • Oral limit: Palatoglossal arches • Major caudal limit: Base of epiglottis TVA, Dyce, Sacks & Wensing’s, 5th ed., Fig. 4.2 TVA, 4th ed., 2010, Dyce Nasopharynx • Placed dorsally to soft palate • Oral limit: Choanae • Major caudal limit: Free border of soft palate TVA, Dyce, Sacks & Wensing’s, 5th ed., Fig. 4.2 TVA, 4th ed., 2010, Dyce Laryngopharynx • Placed dorsally to larynx • Major oral limit: Free border of soft palate • Caudal limit: Pharyngoesophageal limen TVA, Dyce, Sacks & Wensing’s, 5th ed., Fig. 4.2 TVA, 4th ed., 2010, Dyce Pharynx – funnel-shaped chamber divided into: 1. Oropharynx 2. Nasopharynx 3. Laryngopharynx Nasal cavity Soft Palate Oral cavity Larynx – cough, phonation, prevents food aspiration • Ventral to the pharynx; suspended by the hyoid apparatus; attached to the trachea. Guide to the dissection of the dog, deLahunta, , 8th ed., Fig. 5-3 Larynx - Cartilages • Made up of 4 cartilages articulated between each other and operated by a set of intrinsic and extrinsic skeletal muscles. Guide to the dissection of the dog, deLahunta, , 8th ed., Fig. 5-3 This one is paired Larynx – internal features • Glottis: vocal folds + part of the arytenoid cartilages • Rima glottidis – space defined by the glottis • The glottis is to the rima glottidis what the doorframe is to the doorway • The glottis is the narrowest segment of the larynx; can be closed Oral view of larynx - laryngoscopy https://i.pinimg.com/originals/32/df/e6/32dfe6b0ab6deb7f1ecc24ace441d746.jpg Guide to the dissection of the dog, deLahunta, , 8th ed., Fig. 5-28B Trachea – structure & topography • Made up of incomplete cartilaginous rings connected by tracheal (annular) ligament Transverse sections of the canine trachea: 1- mucous membrane; 2 - tracheal cartilage; 4 - trachealis muscle Fig. 4-18A Dyce, Sack and Wensing’s Textbook of Veterinary Anatomy, 5th edition, Elsevier, 2018 • Located on the sagittal plane, at the ventral aspect of the neck, and centrally in the thoracic cavity. Right view of canine thorax FIG. 3-14, Evans and deLahunta. Guide to the Dissection of the Dog, 8th Ed., Elsevier, 2017 Trachea – aspects in the live dog https://www.vygonvet.co.uk/sites/default/files/styles/large/public/panel_images /Placing%20a%20Tracheostomy%20Tube%20Step%2019.jpg?itok=eVv1ipYI Tracheostomy – breathing tube placement http://smallanimal.vethospital.ufl.edu/files/2011/10/combined-tracheal-collpase1.jpg Endoscopy: normal trachea (A) Bronchial Tree – Principal bronchi (R/L PB)  lobar bronchi (R/L B)  segmental bronchi  branches of segmental bronchi  bronchioles  terminal bronchioles  acinus (respiratory bronchioles with alveoli) Caudal Dorsal View of Bronchial Tree Cranial deLahunta, Evans Miller's Anatomy of the Dog, 4th Edition. W.B. Saunders Company, 2013. Lungs: essential organs of respiration – The gas exchange occurs in the alveoli, where O2 and CO2 traverse the air-blood barrier https://www.merckvetmanual.com/-/media/manual/veterinary/images/ddd_dog_lungs_and_airways.gif?la=en&thn=0 Lung anatomy in situ Canine lungs and heart in situ (ventral view) Costal surface a - cranial lobe (L and R lungs) b - middle lobe (R lung) c - caudal lobe (L and R lungs) d - accessory lobe (R lung) 3 - cardiac notch 4 - caudal vena cava groove 5 - basal border 6 - trachea Diaphragmatic surface 7 - heart Basal margin 8 - esophagus R Costal surface Heart L Left lung lobation: • Cranial lobe • divided into cranial & caudal parts • Caudal lobe Fig. 8-32A Dyce, Sack and Wensing’s Textbook of Veterinary Anatomy, 5th edition, Elsevier, 2018 Costal Surface of the Left Lung of the Dog Fig. 8-27 Dyce, Sack and Wensing’s Textbook of Veterinary Anatomy, 5th edition, Elsevier, 2018 Right lung lobation: • • • • Cranial lobe Middle lobe Caudal lobe Accessory lobe Fig. 8-36A Dyce, Sack and Wensing’s Textbook of Veterinary Anatomy, 5th edition, Elsevier, 2018 Right cardiac notch = visible division between cranial and middle lobes 4th intercostal space Costal Surface of the Right Lung of the Dog Fig. 8-36A Dyce, Sack and Wensing’s Textbook of Veterinary Anatomy, 5th edition, Elsevier, 2018 Blood Supply & Drainage of Lungs Note: yellow represent a cast of the bronchial tree Main circulation (functional): • Pulmonary trunk (2) – divides into 2 pulmonary arteries supply • Pulmonary veins (3) - drainage Right Left Note: Think of how does the blood travel through these vessels: - Which type of blood do the arteries carry? From where to where? - Which type of blood do the veins carry? From where to where? - This is the pulmonary circulation Fig. 4-24 Dyce, Sack and Wensing’s Textbook of Veterinary Anatomy, 5th edition, Elsevier, 2018 Pig, corrosion cast, ventral view Pleura and pleural cavities • Each lung is pushed into a closed invaginated sac filled with a bit of fluid – a pleural cavity (sac) Dorsal view of cut through thoracic cavity CRANIAL • This sac is made up of a continuous serous membrane – the pleura – visceral or pulmonary pleura (4) – adheres to the surface of the lung – parietal pleura (1,2,3) – adheres to the inner wall of the thorax • Role: preventing the surface of the lungs to rub against the thoracic wall during breathing (Think of the pleural fluid as “engine oil”.) CAUDAL Fig. 4.19A Dyce, Sack and Wensing’s Textbook of Veterinary Anatomy, 5th edition, Elsevier, 2018 Respiratory apparatus Quiz Key is provided after each question Which label marks the location of olfactory mucosa? A. B. C. D. E. 1 2 3 4 5 Which label marks the location of olfactory mucosa? A. B. C. D. E. 1 naris 2 respiratory mucosa 3 respiratory mucosa 4 5 frontal sinus Choose the correct statement in relation to the organ pictured here. A. B. C. D. E. Is divided in three lobes. Is drained of blood by the pulmonary trunk. Is the right lung. Is an essential organ for gas exchange. Prevents food from entering the airways. Choose the correct statement in relation to the organ pictured here. A. Is divided in three lobes. – no, this has two lobes B. Is drained of blood by the pulmonary trunk. – no, lungs are drained by the pulmonary veins. C. Is the right lung. – no, it is the left lung D. Is an essential organ for gas exchange. E. Prevents food from entering the airways. – no, the lungs can’t do that. Which of the following is the name for the narrowest part of the larynx? A. Choana B. Glottis C. Lobar bronchi D. Naris E. Pleura Which of the following is the name for the narrowest part of the larynx? A. Choana – this is the caudal limit of a nasal cavity B. Glottis C. Lobar bronchi – this is part of the bronchial tree inside a lung D. Naris – this is a nostril E. Pleura – this is a lining outside the lung