Respiratory Anatomy - Lecture Notes PDF

Chapter 23 Respiratory Anatomy...

Chapter 23 Respiratory Anatomy B305 – Human Anatomy Dr. Preston ©2020 McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw-Hill Education.  Main Functions of the Respiratory System © McGraw Hill 2  Anatomic Division Upper respiratory tract (head and neck) Lower respiratory tract (thorax) © McGraw Hill 3  Anatomic Division Upper respiratory: o Nasal cavity and nose o Paranasal sinuses o Pharynx o Larynx Lower respiratory: o Trachea o Bronchi o Lungs All incoming air stops in the alveoli © McGraw Hill 4  Functional Division Conducting zone: Passages that serve only for airflow No gas exchange! Nostrils to major bronchioles Respiratory zone: Alveoli and other minimal gas exchange regions © McGraw Hill 5  The Upper Respiratory Tract © McGraw Hill 6  Upper Respiratory Tract © McGraw Hill 7  The Nasal Cavity Nasal cavity: o From nostrils (nares) o To choanae—posterior region, opening to nasopharynx © McGraw Hill Joe DeGrandis/McGraw-Hill Education 8  Nasal Cavity Nasal Cavity Vestibule o Beginning of nasal cavity o Lined with stratified squamous epithelium Vestibule Vibrissae o Stiff hairs, blocking debris Nasal cavity (Saggital View) © McGraw Hill Anatomy & Physiology Revealved 4.0 /McGraw-Hill Education 9  The Nasal Cavity Sphenoid Sinus Roof of nasal cavity o Ethmoid bone o Sphenoid bones Floor of nasal cavity o Hard palate o Maxillary bones o Palatine bones o Separates nasal cavity from the oral cavity Hard palate © McGraw Hill Anatomy & Physiology Revealved 4.0 /McGraw-Hill Education 10  The Nasal Cavity Nasal Septum Nasal fossae: o Right and left halves of nasal cavity Nasal septum o Bone and hyaline cartilage o Vomer forms inferior region o Perpendicular plate of ethmoid forms superior region o Septal cartilage forms anterior region Nasal Fossae © McGraw Hill Anatomy & Physiology Revealved 4.0 /McGraw-Hill Education 11  The Nasal Cavity Nasal conchae: Superior, middle, and inferior nasal conchae Superior Concha (turbinates) Middle Concha o Project from lateral walls toward septum Inferior Concha o Meatus: Narrow air passage below each concha Nasal cavity (Anterior View) © McGraw Hill Anatomy & Physiology Revealved 4.0 /McGraw-Hill Education 12  Nasal Conchae Erectile tissue (swell body) o Venous plexus in inferior concha o Swelling every 30 to 60 minutes o Restricts airflow in one fossae, and directs air through other o Recover from drying o Air shifts between the right and left nostrils once or twice an hour © McGraw Hill 13  The Nasal Mucosa Respiratory epithelium o Epithelial layer o Ciliated pseudostratified columnar epithelium  Goblet cells produce mucus  Cilia (motile), propel mucus posterior toward pharynx  Mucus swallowed into digestive tract © McGraw Hill 14  The Nasal Mucosa Olfactory epithelium o Sensory neurons— detects odors o Immobile cilia bind odorant molecules o Small area of the roof of the nasal cavity, adjacent parts of the septum and superior concha © McGraw Hill 15  Olfactory epithelium © McGraw Hill 16  The Pharynx Muscular funnel (5 in.) extending from choanae to larynx Three regions of pharynx: o Nasopharynx o Oropharynx o Laryngopharynx © McGraw Hill 17  The Pharynx Nasopharynx o Above soft palate o Receives auditory tubes o Contains pharyngeal tonsil Oropharynx o Between soft palate and epiglottis o Opening of oral cavity into oropharynx is the fauces o Contains palatine tonsils Laryngopharynx o Epiglottis to cricoid cartilage o Esophagus begins at that point © McGraw Hill 18  The Larynx Voice box Cartilaginous chamber ~ 4 cm (1.5 in.) long Primary function is to keep food and drink out of airway o In animals, it has evolved the additional role of phonation—the production of sound © McGraw Hill 19  The Larynx Epiglottis Flap of tissue that guards superior opening of larynx At rest, stands almost vertically During swallowing, extrinsic muscles pull larynx upward Tongue pushes epiglottis down to meet it © McGraw Hill 20  The Larynx Framework: Nine cartilages First three are solitary and large: Epiglottic cartilage o Most superior Thyroid cartilage o Laryngeal prominence (Adam’s apple) Cricoid cartilage o Ring-like o Connects larynx to trachea © McGraw Hill 21  The Larynx Three smaller, paired cartilages Arytenoid cartilages o Posterior to thyroid cartilage Corniculate cartilages o Attached to arytenoid cartilages like a pair of little horns Cuneiform cartilages o Support soft tissue between arytenoids and epiglottis © McGraw Hill 22  The Larynx – Internal structures Interior wall has two folds on each side Extend from thyroid cartilage to arytenoid cartilages Endoscopic View of the Larynx © McGraw Hill a: CNRI/Science Photo Library; b: BSIP/Newscom 23  The Lower Respiratory Tract © McGraw Hill 24  The Lower Respiratory Tract © McGraw Hill 25  The Trachea Rigid tube, 12 cm (4.5 in.) long and 2.5 cm (1 in.) in diameter Anterior to esophagus © McGraw Hill 26  The Trachea Formed by 16 to 20 rings of hyaline cartilage: o Flexible, allows esophagus to expand o Opening in C-rings faces posteriorly o Trachealis muscle in opening of rings o Contracts or relaxes to adjust airflow © McGraw Hill 27  The Main Bronchi Right and left main bronchi Trachea forks at level of sternal angle Carina (internal ridge at edge of trachea) o Directs the airflow to the right and left Bronchoscopy view of left main bronchus (LMB) and the right main bronchus (RMB) Conti L, Zammit © McGraw Hill C, BMJ Case Reports CP 2019;12:e229579. 28  The Main Bronchi © McGraw Hill 29  The Lungs Base: broad concave portion resting on diaphragm Apex: tip that projects just above the clavicle Costal surface: pressed against the ribcage Mediastinal surface: faces medially toward the heart © McGraw Hill 30  The Lungs Hilum—slit for entering of main bronchus, blood vessels, lymphatics, and nerves Structures near hilum constitute root of lung © McGraw Hill 31  The Lungs Right lung Shorter than left because liver rises higher on the right Three lobes, separated by horizontal and oblique fissures: o Superior o Middle o Inferior © McGraw Hill 32  The Lungs Left lung Tall and narrow Has indentation—cardiac impression o The heart occupies more space on mediastinum Has two lobes, separated by a single oblique fissure: o Superior o Inferior © McGraw Hill 33  The Bronchial Tree Branching system of air tubes in each lung o From main bronchus to 65,000 terminal bronchioles Main (primary) bronchi o Arise from fork of trachea © McGraw Hill 34  The Bronchial Tree Right main bronchus is wider and more vertical than left Left main bronchus is about 5 cm long Right main bronchus 2 to 3 cm long Aspiration (inhaled) of foreign objects lodge in right main bronchus more often © McGraw Hill 35  The Bronchial Tree Lobar and segmental bronchi are supported by crescent-shaped cartilage plates Lobar (secondary) bronchi o Three right lobar (secondary) bronchi: superior, middle, inferior o Two left lobar bronchi: superior and inferior Segmental (tertiary) bronchi o 10 on right, 8 on left o Bronchopulmonary segment, functionally independent unit of the lung tissue © McGraw Hill 36  Normal Bronchoscopy https://youtu.be/ThYHLG50pH0?si=OSMBBj6DJY5Suyzh © McGraw Hill 37  The Bronchial Tree Bronchioles o 1 mm or less in diameter o Pulmonary lobule: portion of lung ventilated by one bronchiole o Divides into 50 to 80 terminal bronchioles © McGraw Hill 38  Terminal Bronchioles Final branches of conducting zone Measure 0.5 mm or less in diameter Have no mucous glands or goblet cells Have cilia that move mucus draining into them back by mucociliary escalator Each terminal bronchiole gives off two or more smaller respiratory bronchioles © McGraw Hill 39  Respiratory bronchioles Have alveoli budding from their walls Considered the beginning of the respiratory zone Divide into 2 to 10 alveolar ducts o End in alveolar sacs o Atrium: Clusters of alveoli around a central space © McGraw Hill 40  Alveoli There are 150 million alveoli in each lung o 70 m2 of surface for gas exchange © McGraw Hill a: MICROSCAPE/Science Source; b: Biophoto Associates/Science Source 41  Alveoli Each alveolus surrounded by a basket of capillaries Afferent, Pulmonary arteriole Efferent, Pulmonary venule © McGraw Hill 42  Alveoli Types of cells in alveolus: o Squamous alveolar cells (Type I) o Great alveolar cells (Type II) o Alveolar macrophages (Dust cells) © McGraw Hill 43  Alveoli Respiratory membrane Thin barrier between the alveolar air and blood Consists of three layers: o Squamous alveolar cells o Endothelial cells of blood capillary o Their shared basement membrane © McGraw Hill 44  The Pleurae Visceral pleura o Serous membrane that covers lungs Parietal pleura o Adheres to mediastinum, inner surface of the rib cage, and superior surface of the diaphragm Pleural cavity o Potential space between pleurae o Contains a film of slippery pleural fluid © McGraw Hill 45  Chest Xray normal © McGraw Hill 46  Chest Xray normal © McGraw Hill 47  Chest Xray – Pneumothorax © McGraw Hill 48  End of Main Content Because learning changes everything. ® www.mheducation.com © 2021 McGraw Hill. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw Hill.