Module A2: Upper Airway Anatomy & Physiology Objectives Classify epithelial tissue based on cell type and tissue layers. Identify location of tissue epithelium in the respiratory system. Describe the major structures and functions of the upper and lower airways. Contrast and compare mouth and nose breathing. Explain how placing an endotracheal tube in the airway will affect the humidification and filtering process. The lung is for gas exchange. John B. West Respiratory Physiology: The Essentials Function of the Lungs/Heart Provide Ventilation Provide Respiration Exchange of Carbon Dioxide and Oxygen Humidify and Protect Pump oxygen to vital organs Cellular metabolism Failure of the Lungs/Heart Ventilation Hypoxemia low oxygen level in the blood Decreased PaO 2 Hypoxia - low oxygen level at the tissue level Decreased oxygen at the cellular level can cause death of the tissue Presence of anaerobic respiration Brain Muscles Lungs Inability of the lungs to remove carbon dioxide leads to hypercarbia, which is an elevated amount of carbon dioxide in the blood stream (PaCO 2 ) 1
ARTIFICIAL AIRWAYS ARTIFICIAL AIRWAYS Tracheotomy with tracheostomy tube: 1 - Vocal cords 2 - Thyroid cartilage 3 - Cricoid cartilage 4 - Tracheal cartilages 5 - Balloon cuff INTUBATION INTUBATION Intubation Insertion of an Endotracheal Tube Extubation Removal of the Endotracheal Tube Anatomy of the Respiratory System Tissue Epithelium Upper Airway Lower Airway Site of Gas Exchange Pulmonary Vascular System Neural Control Lungs Mediastinum Thorax Muscles of Ventilation Four Tissue Types Epithelial Tissue Connective Tissue Bone, Cartilage, Blood, Fibrous Muscle Tissue Nervous Tissue Neurons conduct electrical impulses Epithelial Tissue Epithelium Covers and protects the body surface Lines body cavities Forms many glands Specializes in moving substances into and out of the blood 2
Epithelial Cell Type HISTOLOGY 101 Squamous Cells Cuboidal Cells Columnar Cells Lots of Surface Area aka Pavement, Sunnyside up egg Great for Diffusion of Gases Lots of Volume Volume = Cytoplasm Cytoplasm means metabolism Less diffusion Height is 2x Width Usually associated with secretion or absorption of material Very little diffusion Classification of Epithelium by Layers Simple Epithelium Single Layer Simple squamous Simple cuboidal Simple columnar Stratified Epithelium Multiple Layers Pseudostratified Single Layer but appears stratified Pseudo means false Goblet Cells Nose to Large Bronchioles Secrete mucus Stratified Squamous Epithelium Associated with PROTECTION Anterior portion of nasal cavity Oral cavity Oropharynx Laryngopharynx 3
Pseudostratified Columnar Epithelium SECRETION OF AND SWEEPING OF MUCUS Posterior 2/3 of nose Tracheobronchial tree Function of cilia Simple Cuboidal Epithelium PRIMARY FUNCTION IS SECRETION, FILTRATION & ABSORPTION Bronchioles Clara Cells Non-ciliated cells that secrete surfaceactive agents which prevent collapse. Simple Cuboidal also found in alveoli (Type II cells that secrete surfactant) Simple Squamous Epithelium PRIMARY FUNCTION GAS EXCHANGE Alveoli (Type I pneumocytes) Pulmonary capillaries Anatomy Nose Oral Cavity Pharynx Throat Upper Airway Upper Airway Function of the Upper Airway Conduct Air To prevent foreign materials from entering the lower airway Smell/Speech Nose Function Heat, Humidify and Filter the incoming gas Smell Speech 4
Bone and Cartilage Anatomy of the Nose Partition in the nose is called the nasal septum Air enters through the nostrils or nares Two nasal passages are called choanae Vibrissae filter the incoming gas Whiskers First 1/3 is stratified squamous epithelium (PROTECTION) Posterior 2/3 is pseudostratified ciliated columnar epithelium (MUCUS SECRETION) Anatomy of the Nose Mucous secreting glands are found in the posterior 2/3 of nose Bony Protrusions on the lateral wall are called nasal turbinates or conchae Separate incoming gas into turbulent airstreams more contact Extensive capillary network Constrict or dilate to change blood flow Nasal Conchae Deviated Septum The nasal septum can be deviated to the right or left More often to the left Rhinitis: Inflammation of the nasal membrane 20% of Population $5.3 Billion/Year 5
Physiology of the Nose Nose can filter particles down to 5 microns in diameter Two factors which decrease the humidification and filtering ability of the nose is: Mouth Breathing Placement of an ET (endotracheal) tube Paranasal Sinuses Empty air spaces found in the bones of the skull; Paired Frontal Ethmoid Sphenoid Maxillary They contain mucous secreting goblet cells which drain into the nasal cavity Nose and Nasal Cavities Anatomy of the Oral Cavity Roof of the mouth is formed by the hard and soft palate Hard Bony portion Soft Fleshy portion Uvula is the soft fleshy structure Epithelium is stratified squamous epithelium which is non-ciliated. Palatine (faucial) tonsils are located on each side of the oral cavity. 6
TONSILS Nasopharynx Oropharynx Laryngopharynx Pharynx - Throat Nasopharynx Located posterior to nasal cavity Pseudostratified ciliated columnar epithelium Includes pharyngeal tonsils or adenoids Eustachian Tubes (auditory tubes) Connects the middle ear and nasopharynx Middle ear infection is called otitis media Complication of ET tubes Lies behind the oral cavity Lingual tonsils lie at the root of the tongue Statified squamous epithelium Oropharynx Laryngopharynx Lies between the base of the tongue and the entrance to the esophagus Lies posterior to the epiglottis Stratified squamous epithelium aka Hypopharynx 7
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