Respiratory System Anatomy: Pleural Cavities and Lungs

UAG School of Medicine

Class Objectives

• Identify and describe the anatomical features of the respiratory system.
• Describe the structures in the upper respiratory system.
• Describe the structures in the lower respiratory system.
• Answer questions related to the anatomical features of the respiratory system.

Respiratory System Anatomy

Anatomically, the respiratory system can be divided into:

1. Upper Respiratory System, primarily responsible for conditioning and guiding inhaled air, formed by:
   • Nose
   • Nasal Cavity
   • Paranasal sinuses
   • Pharynx
   • Larynx
2. Lower Respiratory System, involved in the exchange of oxygen and carbon dioxide in the alveoli of the lungs formed by:
   • Trachea
   • Bronchial Tree (which includes the primary bronchi, secondary bronchi, tertiary bronchi, bronchioles, and terminal bronchioles)
   • Lungs

Upper Respiratory System

Nose Anatomy

The nose is pyramidal in shape with its apex anterior in position. The bony parts are where the nose is continuous with the skull-here the nasal bones and parts of the maxillae and frontal bones provide support. Anteriorly, and on each side, support is provided by lateral processes of the septal cartilage, major alar and three or four minor alar cartilages, and a single septal cartilage in the midline that forms the anterior part of the nasal septum.

Nose Structures

Nasal bone Lacrimal bone Nasolacrimal groove Frontal process of maxilla Lateral process of septal cartilage Superior margin of septal cartilage Major alar cartilage Septal cartilage Minor alar cartilages Naris

Nasal Cavities

Nasal Cavities Overview

The two nasal cavities are the uppermost parts of the respiratory tract and contain the olfactory receptors. The anterior openings of the nasal cavities are the cartilaginous nares. The posterior openings of the nasal cavities are the choanae that communicate with the nasopharynx. The floor of the nasal cavities is formed by the maxilla and palatine bones. The roof of the nasal cavities is formed by the cribriform plate of the ethmoid bone.

Nasal Cavity Nerves

Anterior ethmoidal nerve Olfactory bulb Olfactory nerve [1] Sphenopalatine foramen External nasal branch of anterior ethmoidal nerve Posterior superior lateral nasal nerves Posterior inferior lateral nasal nerves Internal nasal branches of infra-orbital nerve Nasal branch of anterior superior alveolar nerve

Nasal Septum

Nasal Septum Components

The NASAL SEPTUM divides the nasal cavity into right and left nasal cavities and consist of: 1. Septal nasal cartilage 2. Perpendicular plate of the ethmoid bone 3. Vomer Bone

Nasal Septum Bones

Nasal spine of frontal bone Perpendicular plate of ethmoid bone Sphenoidal sinus Nasal bone Pituitary fossa Septal cartilage Nasal crest of maxillary and palatine bones Incisor crest Vomer

Nasal Conchae (Turbinates)

Nasal Conchae Description

There are 3 nasal conchae on each nasal cavity: • Superior (part of the ethmoid bone) • Middle (part of the ethmoid bone) • Inferior (independent bone) Each nasal concha is lined with respiratory epithelium, their function is to adjust the temperature and humidity of inspired air, and trap and remove particulate matter from the airway.

Nasal Conchae and Nasopharynx

Superior concha Middle concha Opening of pharyngotympanic tube Nasopharynx Soft palate B Inferior concha

Meatuses

Meatuses Drainage

• Spaces located beneath each turbinate.
  • Superior > drains sphenoid and ethmoid sinuses
  • Middle >> drains frontal and maxillary sinuses
  • Inferior > drains nasolacrimal duct

Meatuses and Sinus Openings

Frontal sinus Sphenoid sinus opening into spheno-ethmoidal recess 00 Sphenoid sinus Frontal sinus opening Posterior ethmoidal Hiatus semilunaris Anterior ethmoidal Middle ethmoidal Bulla ethmoidalis Maxillary ostium Opening of nasolacrimal duct Eustachian orifice

Paranasal Sinuses

Paranasal Sinuses Function

Are air-filled cavities within the skull bones that are lined with mucous membranes.They help condition the air and contribute to resonance of the voice. There are four paranasal air sinuses. Each is named according to the bone in which it is found: • Ethmoidal sinuses, · Sphenoidal sinuses, . Maxillary sinuses, and • Frontal sinuses

Paranasal Sinuses Locations

Zygomatic process of frontal bone Superior orbital fissure Frontal sinuses - Ethmoidal cells Frontal sinuses Ethmoidal cells Orbital plate of ethmoid bone Maxillary sinuses Maxillary sinus Roots of posterior upper molars Nasal septum B Foramen rotundum A Hypophyseal fossa Frontal sinus Superior concha Pituitary gland Sphenoidal sinus Inferior concha D c Middle concha

Pharynx

Pharynx Structure and Location

The pharynx is a musculofascial tube that links the oral and nasal cavities in the head to the larynx and esophagus in the neck. The pharynx is attached above to the base of the skull and is continuous below, approximately at the level of vertebra CVI, with the top of the esophagus. The pharyngeal wall is formed by skeletal muscles and by fascia.

Pharynx Connections

Nasal cavity Oral cavity Pharynx Larynx Trachea Esophagus

Pharynx Subdivisions

Pharynx Regions

The walls of the pharynx are attached anteriorly to the margins of the nasal cavities, oral cavity, and larynx. Based on these anterior relationships the pharynx is subdivided into three regions: · The nasopharynx, • The oropharynx • The laryngopharynx.

Pharynx and Laryngeal Inlet

Nasal cavities Choanae Oropharyngeal isthmus -Nasopharynx Pharyngeal isthmus Oropharynx Oral cavity Soft palate Laryngeal inlet Larynx Laryngopharynx Vertebral level CVI Trachea Esophagus

Nasopharynx

Nasopharynx Features

The nasopharynx is behind the posterior apertures (choanae) of the nasal cavities and above the level of the soft palate. The most prominent features on each lateral wall of the nasopharynx are: • The pharyngeal opening of the pharyngotympanic tube • Mucosal elevations and folds covering the end of the pharyngotympanic tube and the adjacent muscles.

Nasopharynx and Tonsils

Pharyngeal opening of the pharyngotympanic tube Pharyngeal tonsil Torus tubarius Nasal cavity Pharyngeal recess Torus levatorius (fold overlying levator veli palatini) Fold overlying palatopharyngeal sphincter Salpingopharyngeal fold Palatine tonsil Palatopharyngeal arch (overlies palatopharyngeus muscle) Tongue Laryngeal inlet Lingual tonsils Nasopharynx Oropharynx Vallecula . Laryngopharynx Esophagus Trachea

Oropharynx

Oropharynx and Waldeyer's Ring

The oropharynx is posterior to the oral cavity, inferior to the level of the soft palate, and superior to the upper margin of the epiglottis. Collections of lymphoid tissue in the mucosa of the pharynx surrounding the openings of the nasal and oral cavities (Waldeyer's tonsillar ring) are part of the body's defense system. The largest of these collections form distinct masses (tonsils).

Oropharynx and Laryngeal Inlet

Pharyngeal opening of the pharyngotympanic tube Pharyngeal tonsil Torus tubarius Nasal cavity Pharyngeal recess Torus levatorius (fold overlying levator veli palatini) Fold overlying palatopharyngeal sphincter Salpingopharyngeal fold Palatine tonsil Palatopharyngeal arch (overlies palatopharyngeus muscle) Tongue Laryngeal inlet Nasopharynx Oropharynx . Laryngopharynx Lingual tonsils Vallecula Esophagus Trachea

Waldeyer's Tonsillar Ring

Waldeyer's Ring Components

• Circular group of lymph nodes around the oro and nasopharynx
• Prevent the entry of microorganisms from external environment. "PLATe"
  • Palatine tonsil
  • Lingual tonsil
  • Adenoids
  • Tubal tonsils

Waldeyer's Ring Diagram

Nasal tonsils (adenoids) Tubal tonsils Palatine tonsils Lingual tonsils

Laryngopharynx

Laryngopharynx Extent and Role

The laryngopharynx extends from the superior margin of the epiglottis (a laryngeal cartilage) to the top of the esophagus at the level of vertebra CVI. The laryngopharynx plays an important role in both respiration and vocalization.

Laryngopharynx and Pharyngeal Structures

Pharyngeal opening of the pharyngotympanic tube Pharyngeal tonsil Torus tubarius Nasal cavity Pharyngeal recess Torus levatorius (fold overlying levator veli palatini) Fold overlying palatopharyngeal sphincter Salpingopharyngeal fold Palatine tonsil Palatopharyngeal arch (overlies palatopharyngeus muscle) Tongue Laryngeal inlet Nasopharynx Oropharynx . Laryngopharynx Lingual tonsils Vallecula Esophagus Trachea

Larynx

Larynx Structure and Function

The larynx is a hollow musculoligamentous structure with a cartilaginous framework. The cavity of the larynx is continuous below with the trachea, and above opens into the pharynx The larynx is both a valve (or sphincter) to close the respiratory tract, and an instrument to produce sound.

Larynx and Trachea

Epiglottis Laryngeal inlet Hyoid bone - Larynx Thyroid cartilage Cricoid cartilage Trachea

Laryngeal Cartilages

Laryngeal Cartilages Types

The cartilaginous framework of the larynx is composed of: · Three large unpaired cartilages (cricoid, thyroid, and epiglottis) • Three pairs of smaller cartilages (arytenoid, corniculate, and cuneiform)

Laryngeal Cartilages Diagram

Epiglottis Cuneiform cartilages Comiculate cartilages Arytenoid cartilages Thyroid cartilage Cricoid cartilage

Laryngeal Membranes & Ligaments

Laryngeal Suspension

The larynx is suspended from the hyoid bone above and attached to the trachea below by membranes and ligaments. The thyrohyoid membrane is a tough fibro-elastic ligament that spans between the superior margin of the thyroid cartilage below and the hyoid bone above. The posterior borders of the thyrohyoid membrane are thickened to form the lateral thyrohyoid ligaments. The membrane is also thickened anteriorly in the midline to form the median thyrohyoid ligament.

Laryngeal Ligaments

Hyo-epiglottic ligament Hyoid bone Lateral thyrohyoid ligaments Triticeal cartilage Aperture for internal branch of superior laryngeal nerve and associated artery Thyrohyoid membrane Median thyrohyoid ligament Cricotracheal ligament

Laryngeal Cavity

Laryngeal Cavity Folds

The central cavity of the larynx is tubular and lined by mucosa. Two pairs of mucosal folds, the vestibular folds (false vocal chords) and the vocal folds (true vocal chords), project medially from the lateral walls of the laryngeal cavity.

Laryngeal Cavity Views

Laryngoal Iniet Epiglotis Ary-epiglotio lold Laryngeal -Cut edge of mucosa Cunaltom tubercle -Cut edge of right İyrold amina Middle part at cavity Vostibule Comiculata tubordle Laryngoel sacoula Laryngeal vuntricia Dwortying vestibular ligament) Intragiottic space- Interarytunok! nuich Crlood arch yoost fold (mucosa owortying vocal ligamont) Trachea Epiglotis A Vocal tok Vestibular tok !. Rima vestibul Ary-epiglottic fold Filma glotich Cunstorm tubercia Comicuteto tuborçlu C intorarytanoid lokt Arturor Tongue- Vestibular fold (talso vocal cord) Epiglotis Laryngoal Inket Vocal Boxt (trua vocal cords) Ary-apiglotte folket- Cunatom Moore- Pirtorm rocess Laryngopharyn# Comiculato suborcio- D Fama giotich (opening betwuon vocal cords) Vestibular folket