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 Hypoxemia – low oxygen level in the blood Decreased PaO2 Hypoxia - low oxygen level at the tissue level Decreased oxygen at the cellular level can cause death of the tissue Presence of anaerobic respiration

Ventilation 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 (PaCO2)

ARTIFICIAL AIRWAYS INTUBATION http://evolvels.elsevier.com/section/default.asp?id=1103%5Fglobal%5F0001 http://en.wikipedia.org/wiki/Intubation INTUBATION

ARTIFICIAL AIRWAYS Tracheotomy with tracheostomy tube: 1 - Vocal cords 2 - Thyroid cartilage 3 - Cricoid cartilage 4 - Tracheal cartilages 5 - Balloon cuff http://en.wikipedia.org/wiki/Tracheostomy 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 Muscle 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

Epithelial Cell Type Squamous Cells Cuboidal Cells Columnar Cells

HISTOLOGY 101 Lots of Surface Area aka Pavement, Sunny-side up egg http://en.wikipedia.org/wiki/Image:Illu_epithelium.jpg Lots of Surface Area aka Pavement, Sunny-side 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”

http://en.wikipedia.org/wiki/Image:Illu_epithelium.jpg

Nose to Large Bronchioles Goblet Cells Nose to Large Bronchioles Secrete mucus http://evolvels.elsevier.com/section/default.asp?id=1103%5Fglobal%5F0001

Stratified Squamous Epithelium Associated with PROTECTION Anterior portion of nasal cavity Oral cavity Oropharynx Laryngopharynx

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 “surface-active 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

Upper Airway Anatomy Nose Oral Cavity Pharynx Throat

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

Anatomy of the Nose Bone and Cartilage 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 http://en.wikipedia.org/wiki/Image:Illu_nose_nasal_cavities.jpg

Deviated Septum The nasal septum can be deviated to the right or left More often to the left http://en.wikipedia.org/wiki/Image:Deviated_septum_MRI.jpg

PURPOSE: They serve a dual purpose; the mucus secreted keeps the nose form drying out and keeps the air we breathe in moist, and because they contain air, they make the voice we produce echo and resonate. http://evolvels.elsevier.com/section/default.asp?id=1103%5Fglobal%5F0001

Rhinitis: Inflammation of the nasal membrane 20% of Population NONE Rhinitis: Inflammation of the nasal membrane 20% of Population $5.3 Billion/Year

Physiology of the Nose Nose can filter particles down to 5 m (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

NONE

Nose and Nasal Cavities http://upload.wikimedia.org/wikipedia/commons/3/34/Illu_nose_nasal_cavities.jpg

http://evolvels. elsevier. com/section/default. asp http://evolvels.elsevier.com/section/default.asp?id=1103%5Fglobal%5F0001

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.

TONSILS NONE

http://en.wikipedia.org/wiki/Image:Tonsils_diagram.jpg

Pharynx - Throat Nasopharynx Oropharynx Laryngopharynx

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 http://en.wikipedia.org/wiki/Image:Gray994-adenoid.png http://en.wikipedia.org/wiki/Image:HumanEar.jpg

Oropharynx Lies behind the oral cavity Lingual tonsils lie at the root of the tongue Statified squamous epithelium http://en.wikipedia.org/wiki/Image:Illu_pharynx.jpg

Laryngopharynx Lies between the base of the tongue and the entrance to the esophagus Lies posterior to the epiglottis Stratified squamous epithelium aka Hypopharynx