Voice Disorders Lecture 1.pdf

SLP 286 – Voice Disorders Presentation 1 Dr. Ahmed Nagy Associate Professor , Department of Speech and Language Pathology UAEU Anatomy & Physiology • Anatomy is the science that studies the structure of the human body • Physiology is the science that studies the way in which the Anatomical structu...

SLP 286 – Voice Disorders Presentation 1 Dr. Ahmed Nagy Associate Professor , Department of Speech and Language Pathology UAEU Anatomy & Physiology • Anatomy is the science that studies the structure of the human body • Physiology is the science that studies the way in which the Anatomical structures of a living organism perform their function In Anatomy , the focus is on : • Location, where is the structure in relation to other structures and to the whole body • Tissue type, What is the structure made of : 1. Gross Anatomy : Direct visualization with no magnification 2. Microanatomy : Visualization of the microscopic structure of tissue { Histology} The macroscopic blocks of the human body • Muscles • Cartilages • Bones • Nerve supply { Afferent /Efferent / PNS/ CNS } • Blood supply { Oxygenated arterial/ Venous deoxygenated} • Tendons • Covering surfaces { mucosa/skin} • Organs {liver/ lung} ; parts with a specific vital function The microscopic blocks of the human body • All structures of the body are made from specialized cells that are adapted for the specific function performed by that structure { muscles are formed from muscle cells} • All cells require to be supported as they perform their function. The support needed is structural and metabolic . This is performed by the extracellular matrix • Every group of similar cells , and their extracellular matrix that collectively carry the same function is described as a tissue. The amount of extracellular matrix varies from one tissue to the other, and between tissue subtypes There are four main tissues of the human body 1. 2. 3. 4. Connective tissue Muscular tissue Nervous tissue Epithelial tissue They are listed from tissue layer with most amount of extracellular matrix , to tissue with least amount of extracellular matrix. Epithelial tissue • Epithelium is composed of cells laid in sheets and layers , connected to each other by Cellular junctions. The cells making the epithelium differ according to function. Epithelium Forms the boundary between different environments, its functions include : 1. Protection 2. Absorption 3. Regulation and excretion of chemicals 4. Sensation 5. Secretion Connective tissue • Is made of Cells and an extracellular Matrix of Fibers and Blood Vessels • The classification of connective tissue type changes as the components change either in cell type, fiber type and vascularity. Bone Cartilage Cell Type Osteocyte Chondrocyte Vascularity High Low Matrix Hard , non flexible fibers , Higher Calcium Fibrous , flexible Fibers • Nervous tissue : Central and peripheral nervous system vary in the composition of their cellular and extracellular components • Muscle tissue : Vary by muscle type : Types of muscle Smooth muscle : { visceral muscles } , non-voluntary contraction , subconscious regulation . E.g. Muscles in the digestive tract transferring food from one place to another. Striated : { skeletal } , Voluntary controlled E.g. kick, walk . Jump Cardiac : Highly specialized , striated involuntary, with pacemaker The Larynx The larynx is the portion of the respiratory tract that contains the vocal folds. It is a 2-inch-long, tube-shaped structure, that opens into the laryngeal part of the pharynx above and opens into the trachea below. It lies anterior to the third to sixth cervical vertebrae. The Functions of the Larynx 1. Respiration (breathing) 2. Airway protection (coughing) 3. Deglutition (swallowing) 4. Phonation (voice production) 5. Sphincteric function (straining & fine motor movements) Structural Components of the Larynx 1 - A cartilaginous skeleton {connective tissue} 2 - Membranes and ligaments {connective tissue} 3 - Intrinsic and extrinsic muscles {muscle tissue} 4 - Mucosal lining {epithelial tissue} Epiglottis Hyoid Tritiate Cuneiforms Corniculate Arytenoid Thyroid Cricoid 1st tracheal Ring Epiglottis Hyoid Thyroid Cricoid 1st tracheal ring Greater horn of hyoid bone Lesser horn of hyoid bone Body of hyoid bone • Only bone in the body that does not articulate with any other bone; horse-shoe shaped • Provides attachment to the muscles of the floor of the mouth, the tongue, the larynx, and the pharynx • Its free mobility and sling-like function allows a wider range of movement for the tongue as well as pharyngeal and laryngeal movements • During swallowing it is elevated, pulling the larynx upward with it through their connective tissue ligaments and membrane connection; helping protect the airway from the entry of food. This also aids in opening the junction between the pharynx and the esophagus; helping food to move toward the esophagus The Cartilaginous Skeleton 3 single Cartilages 1. Thyroid-Hyaline 2. Cricoid-Hyaline 3. Epiglottis-Elastic 4 Paired Cartilages 1. Arytenoids - Hyaline 2. Corniculates- Elastic 3. Cuneiforms - Elastic 4. Tritiate- Hyaline • Cartilages of the body are made from Hyaline Cartilage or Elastic Cartilage • Elastic cartilage has greater flexibility and can withstand bending (like the outer ear) • Elastic cartilage does not ossify • Hyaline cartilage is firmer and maintains a more stable shape • The cartilages of the larynx are connected by joints, membranes and ligaments; they are moved by muscles When skeletal structures articulate with each other there are three types of connections: 1. Sutures: As between the two parietal bones resulting in a fixed joint at the location of the connection. The two bones are connected with fixed, white fibrous tissue in between. 2. Synovial Joints: A smooth, convex articular surface on one bone moves against a smooth, concave surface of another {TMJ}, allowing relatively wide range of movement. 3. Cartilaginous Joint: Two bones with relatively flat, articular surfaces allowing limited movement. The Epiglottis • The Epiglottis is a Leaf-shaped {upper edge, lateral margins, a stalk, anterior surface and posterior surface} elastic cartilaginous structure, situated behind the root of the tongue. 1. The front of epiglottis connects with the body of the hyoid bone by the hyoepiglottic ligament . The mucosa of the Anterior surface of the epiglottis is reflected onto the tongue forming three glossoepiglottic folds . The 3 folds result in 2 valleculae 2. The stalk is connected to the inner surface of the thyroid cartilage by the thyroepiglottic ligament 3. Laterally gives attachment to Aryepiglottic fold 4. The upper edge and posterior surface are free from attachments and are covered with mucosa https://www.youtube.com/wa tch?v=tiIrPJ3bwGo The Thyroid Cartilage • The thyroid cartilage is made from two quadrangular plates {laminae}. They meet in the midline and form a prominent angle; the laryngeal prominence (Adam’s apple). There is a superior thyroid notch in the midline above the laryngeal prominence. • The posterior border of each lamina forms two horns; the superior & inferior cornu • Outer surface of each lamina shows an oblique line which gives attachment to thyrohyoid, sternothyroid, & inferior constrictor of the pharynx • The superior border gives attachment to the thyrohyoid membrane The Cricoid Cartilage • The cricoid cartilage lies below the thyroid cartilage and is continuous below with the trachea • Forms a complete ring with a narrow anterior arch & a broad posterior lamina • The superior border of the anterior arch is connected to the inferior border of the thyroid cartilage via the cricothyroid membrane • There are two articular facets on each side of the cricoid cartilage: 1. Lateral surface for articulation with inferior cornu of the thyroid cartilage (a synovial joint) 2. Upper border for articulation with base of arytenoid cartilage (a synovial joint) Ligaments attaching the inferior horn of thyroid Cartilage to the Cricoid cartilage Posterior ceratocricoid ligament Anterior ceratocricoid ligament Lateral ceratocricoid ligament The arytenoid Cartilage The Arytenoid Cartilages • The arytenoid cartilage has the shape of a small 3-surfaced pyramid • The base articulates with the upper border of the cricoid cartilage • The apex is attached to the corniculate cartilage • There is a vocal process projecting forward, giving attachment to the vocal ligament • There is a muscular process projecting laterally, giving attachment to muscles that move the arytenoid cartilage • The posterior surface is smooth and concave, and covered by the transverse arytenoid muscle • The medial surface is smooth, flat, and narrow and covered by mucosa • The anterolateral surface is convex and rough; it gives attachment to the vestibular ligament, and the Vocalis muscle Corniculate and Cuneiform Cartilages Corniculate Cartilages {Cartilages of Santorini} • 2 small, conical nodules of elastic cartilage which articulate with the summits of the arytenoids • They are situated in the posterior parts of the Aryepiglottic folds Cuneiform Cartilages {Cartilages of Wrisberg} • 2 small, club-shaped structures of elastic cartilage • They do not articulate with any other cartilage and are located within the Aryepiglottic folds under the surface of the mucosa in front of the corniculate cartilages Both cartilage pairs serve in supporting the maintenance of the arched shape of the Aryepiglottic folds; this is important for the physiology of respiration. The Glottis The red line is clearly showing that the cricoid articular surface is convex while the Arytenoid base, on top of the Cricoid Lamina is concave The Cricoarytenoid Joint lies between the facets of the Arytenoid and the Cricoid The Arytenoid Facet is Concave 3.2 x 4mm The Cricoid Facet is cylindrical 2.8 x 6 mm There is no rotational movement around the vertical axis of the arytenoid Gliding movement of the arytenoids along the longitudinal axis of the cricoid facet to close the space between the two arytenoids The other movement at the joint is described as the rocking movement It occurs in two directions The dorso-medio cranial & ventro-latero caudal. The directions describe the directions of movement of the apex of each arytenoid as the base is moving on the transverse axis of the cylinder shaped underlying Cricoid Facet The vocal process and their attached vocal ligaments will move in the opposite direction Dorso-medio cranial opens the Glottis Ventro-latero caudal closes the Glottis Thank you