This document provides an overview of the anatomy of the larynx. It describes the skeletal framework including cartilages like the thyroid, cricoid, epiglottis and arytenoid cartilages. It outlines the joints, ligaments, muscles, interior spaces and divisions of the larynx. Key structures are the true and false vocal cords that make up the glottis. The document also briefly discusses the physiology, functions, blood supply and development of the larynx.
External ear,tympanic membrane and auditory tube Dr.N.Mugunthan.M.S.,mgmcri1234
External ear,tympanic membrane and auditory tube - Lecture by Dr.N.Mugunthan.M.S.,Associate Professor, Mahatma Gandhi Medical College & Research Institute, Pondicherry,
Sri Balaji Vidyapeeth University.
External ear,tympanic membrane and auditory tube Dr.N.Mugunthan.M.S.,mgmcri1234
External ear,tympanic membrane and auditory tube - Lecture by Dr.N.Mugunthan.M.S.,Associate Professor, Mahatma Gandhi Medical College & Research Institute, Pondicherry,
Sri Balaji Vidyapeeth University.
Anatomy of larynx is a complicated topic for many students. This is our attempt at making the topic a little easier for them to understand with the practical aspects of learning the anatomy.
Larynx is the voice box present in the neck above trachea and also forms an important pathway for air passage for breathing. The most important structure in the neck so as to support our survival nad the disease which are quite common causes of change in voice as a complaint, it becomes even more important to understand it's exact anatomy for students in medical field so as to diagnose and treat the patient correctly. As they say you can only diagnose a disease when you know what a normal structure looks like. Anatomy of neck is very sophisticated in ways it accomodates many evident blood vessels and nerves along with the thyroid gland which all reside in close proximity with larynx. And all the structures pertaining to larynx as in cartilages, ligaments, vocal folds and epiglottis are equally delicate and can have injury if person operating does not have the correct knowledge of anatomy of larynx along with its physiology. The most common of pathologies of larynx relate to the vocal cord dysfunction due to physiological or anatomical disturbance in their structure and can be very distressing to the patient, hence the need to understand it's anatomy and physiology.
Anatomy and physiology of larynx presentation for MBBS 3rd year. This ppt presents the most detailed presentation of anatomy and physiology of larynx. Presenter was third year MBBS students of Nepalgunj Medical College and teaching hospital, Nepalgunj Nepal. Niraj Prasad Sah won the best presentation award for this during ENT posting. Have fun and check this out.
The Larynx: Anatomy, Function, and Disorders
Introduction
The larynx, commonly known as the voice box, is a vital structure in the human body responsible for a multitude of functions, the most prominent of which is voice production. This complex organ plays a crucial role in breathing, swallowing, and protecting the airway. Understanding the anatomy, function, and common disorders of the larynx is essential for grasping its significance in our daily lives. In this comprehensive 2000-word essay, we will explore the larynx in detail, delving into its anatomy, function, the mechanics of voice production, common laryngeal disorders, and their treatment.
I. Anatomy of the Larynx
The larynx is a complex structure located in the neck, connecting the lower part of the pharynx to the trachea. It comprises several cartilages, muscles, ligaments, and other anatomical components that work together to facilitate various functions. To understand the larynx better, it is crucial to break down its anatomy into its constituent parts.
Cartilages
A. Thyroid Cartilage: The thyroid cartilage, often referred to as the Adam's apple, is the most prominent and easily palpable cartilage of the larynx. It is made up of two fused plates and provides structural support to the front of the larynx.
B. Cricoid Cartilage: The cricoid cartilage is a ring-like structure that sits just below the thyroid cartilage. It plays a crucial role in connecting the larynx to the trachea and provides structural support.
C. Epiglottis: The epiglottis is a leaf-shaped cartilage located behind the tongue root. It acts as a lid to cover the entrance of the trachea during swallowing, preventing food and liquids from entering the airway.
D. Arytenoid Cartilages: These paired cartilages are located on top of the cricoid cartilage. They play a pivotal role in controlling vocal cord tension and movement.
E. Corniculate and Cuneiform Cartilages: These smaller cartilages are positioned within the aryepiglottic folds and aid in maintaining the laryngeal structure.
Muscles
A. Intrinsic Laryngeal Muscles: These muscles are responsible for controlling the position and tension of the vocal cords. Key intrinsic muscles include the cricothyroid, thyroarytenoid, lateral cricoarytenoid, posterior cricoarytenoid, and interarytenoid muscles.
B. Extrinsic Laryngeal Muscles: Extrinsic muscles are responsible for moving the larynx as a whole, helping with functions such as swallowing and speech. The sternothyroid, thyrohyoid, and omohyoid muscles are examples of extrinsic laryngeal muscles.
Vocal Cords
The vocal cords, or vocal folds, are a pair of muscular structures located within the larynx. They are composed of layers of mucous membrane, muscle, and connective tissue. The true vocal cords, also known as the vocal ligaments, are the structures primarily responsible for sound production. They are capable of opening and closing rapidly to produce sound when air flows through them.
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Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
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Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
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Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
8. HYOID BONE
U-SHAPED.
It is situated just above the thyroid
cartilage.
BODY- Quadrilateral , anterior & posterior
surface with superior & inferior borders .
SUPERIOR BORDER- Hyoepiglottic &
Thyrohyoid membrane.
It is attached to mandible & skullbase by
stylohyoid ligament , digastric, mylohyoid,
stylohyoid , geniohyoid , hyoglossus muscles
hence helping in raising larynx during
deglutition & phonation .
9. IMPORTANCE
In suspected case of homicide , fracture of hyoid strongly indicates
throttling & strangulation .
During excision of thyroglossal cyst , sistrunk operation reduces
recurrence rate.
Serves as a site of access to supraglottic larynx & pharynx
In Tracheal resection & anastomosis , tension free closure of distal
airway .
Physiological functions – breathing, swallowing , speech & to keep
airway open during sleep.
OSA - more inferiorly placed hyoid bone (hyoid suspension
surgery).
10. THYROID CARTILAGE
Hyaline cartilage, largest cartilage of larynx.
2 Lamina ; angle of 90 degree (male-adam’s apple ) & 120 degree (female).
Ala ossification- begins at 25yrs , completes by 65 yrs.
11. External surface- oblique line -----> thyrohyoid, sternothyroid and inferior
constrictor muscles.
The inner surface also gives attachment to the thyroepiglottic, vestibular, and
vocal ligaments, as well as the thyroarytenoid and the vocalis muscles
13. IMPORTANCE
Cartilage is divided in midline to expose endolarynx for various
procedures (eg.partial laryngectomy , laryngotracheoplasty,
arytenoidectomy ).
Cricothyroidotomy – emergency ventilation
Fracture
14. CRICOID CARTILAGE
only complete cartilagenous ring in the
upper airway.
Signet ring shape.
Narrow ARCH anteriorly , broad LAMINA
posteriorly.
15. Cricothyroid joints (on the posterior lateral aspect) and
cricoarytenoid joints (on the superior lateral aspect).
Inferiorly, it is related to the first tracheal ring by
cricotracheal ligament.
The cricothyroid ligament and lateral cricoarytenoid
muscles are attached anteriorly, along the superior surface
of the cricoid arch.
Posteriorly - posterior cricoarytenoid muscles.
The external and lateral surface of the arch - cricothyroid
muscle.
16.
17.
18. IMPORTANCE
Injury to cartilage – perichondritis & sublottic stenosis.
Cricothyroidotomy – through median cricothyroid ligament.
To avoid permanent laryngeal stenosis , it shouls be converted to
tracheostomy within days .
Surgical approaches to to repair lon standing subglottic stenosis
involve expansion of circumference of cricoid ring.
19. EPIGLOTTIS
leaf-like, yellow, elastic cartilage forming anterior wall of
laryngeal inlet.
It is attached inferiorly to the thyroid cartilage, just below the
thyroid notch in the midline, by the thyroepiglottic ligament.
To the hyoid bone anteriorly by the hyoepiglottic ligament.
20.
21. Aryepiglottic folds
Posterior surface- numerous small pits into which mucus
glands project.
Anterior surface -mucous membrane superiorly and forms the
posterior wall of the vallecula.
Posterior surface of epiglottis is concavoconvex—concave
above but convex below forming a bulge called tubercle of
epiglottis, which obstructs view of anterior commissure when
examining larynx by indirect laryngoscopy
22.
23.
24. IMPORTANCE
ACUTE EPIGLOTTITIS – airway obstruction in
children.
Carcinoma involvement.
During swallowing , closes laryngeal inlet.
26. Muscular process - directed laterally to give attachment to
posterior cricoarytenoid and lateral cricoarytenoid muscles .
Vocal process - directed anteriorly, giving attachment to vocal
cord .
Medial surface - covered with mucous membrane and form the
lateral boundary of the posterior glottis.
Posterior surface - covered by the transverse arytenoid muscle.
27. IMPORTANCE
Cricoarytenoid fixation may occur from arthritis or perichondritis
(intubation injury etc.) & limit vocal fold mobility.
Cricoarytenoid subluxation during blind intubation .
Arytenoidectomy through external or endoscopic approach may
alleviate arytenoid fixation or paralysis.
28. CORNICULATE CARTILAGE (SANTORINI)
two small conical nodules of elastic fibrocartilage which
articulate through a synovial joint with the apices of the
arytenoid cartilages.
They are situated in the posterior part of the aryepiglottic fold.
two small elongated flakes of fibroelastic cartilage, one in each
margin of the aryepiglottic fold.
CUNEIFORM CARTILAGE ( WRISBURG )
29. JOINTS
2 in no. ; simple synovial joints .
CRICOTHYROID JOINT –
Each is formed by the inferior cornua of thyroid cartilage with a
facet on the cricoid cartilage.
Movements are across the transverse axis passing through these
joints.
30. CRICOARYTENOID JOINT –
formed between the base of arytenoid and a facet on the upper
border of cricoid lamina.
Two types of movements occur in this joint:
(i) rotatory, in which arytenoid cartilage moves around a
vertical axis, thus abducting or adducting the vocal cord.
(ii) gliding , in which one arytenoid glides towards the other
cartilage or away from it, thus closing or opening the posterior
part of glottis.
31.
32. LIGAMENTS & MEMBRANES
EXTRINSIC MEMBRANES AND LIGAMENTS
(a) Thyrohyoid membrane - It connects thyroid cartilage to
hyoid bone. It is pierced by superior laryngeal vessels and
internal laryngeal nerve.
(b) Cricotracheal membrane - It connects cricoid cartilage to the
first tracheal ring.
(c) Hyoepiglottic ligament - It attaches epiglottis to hyoid.
(d) Thyrohyoid ligaments
(e) Cricotracheal ligament
33. INTRINSIC MEMBRANES AND LIGAMENTS
(a) Cricovocal membrane - It is a triangular fibroelastic membrane.
Its upper border is free and stretches between middle of thyroid angle to
the vocal process of arytenoid and forms the vocal ligament
Its lower border attaches to the arch of cricoid cartilage.
From its lower attachment the membrane proceeds upwards and medially
and thus, with its fellow on the opposite side, forms conus elasticus
where subglottic foreign bodies sometimes get impacted.
(b) Quadrangular membrane - It lies deep to mucosa of aryepiglottic folds
It stretches between the epiglottic and arytenoid cartilages.
Its lower border forms the vestibular ligament which lies in the false
cord.
34. (c) Cricothyroid ligament - The anterior part of cricothyroid
membrane is thickened to form the ligament and its lateral part
forms the cricovocal membrane.
(d) Thyroepiglottic ligament - It attaches epiglottis to thyroid
cartilage.
38. INTRINSIC
(a) Acting on vocal cords :
Abductors: Posterior cricoarytenoid
Adductors: Lateral cricoarytenoid, Interarytenoid (transverse
arytenoid), Thyroarytenoid (external part)
Tensors: Cricothyroid, Vocalis (internal part of thyroarytenoid
(b) Acting on laryngeal inlet :
Openers of laryngeal inlet: Thyroepiglottic (part of
thyroarytenoid)
Closers of laryngeal inlet: Interarytenoid (oblique part),
Aryepiglottic (posterior oblique part of interarytenoids)
39.
40.
41.
42.
43.
44.
45.
46.
47. INTERIOR OF LARYNX
LARYNGEAL INLET –
Above & in front by free margin of epiglottis.
Laterally by aryepiglottic fold.
Posteriorly by interarytenoid region.
EPITHELIUM –
Most of the larynx is lined by pseudo stratified ciliated columnar
'respiratory' -type epithelium.
The upper half of the posterior surface of the epiglottis, the
upper part of the aryepiglottic fold, the posterior glottis & the
vocal folds are covered with nonkeratinizing stratified squamous
epithelium..
52. Vestibule - It extends from laryngeal inlet to vestibular folds. Its
anterior wall is formed by posterior surface of epiglottis; sides by
the aryepiglottic folds and posterior wall by mucous membrane
over the anterior surface of arytenoids.
Inferior limit of supraglottis –
CLINICALLY – imaginary horizontal plane passing through
apex of laryngeal ventricle .
ANATOMICALLY – superior arcuate line where squamous &
respiratory epithelium meet .
53. Marginal zone-
Suprahyoid epiglottis
Aryepiglottic folds
It is recognised because of
Aggressive clinical behaviour of cancer arising in this area .
Lack of embryological separation from adajacent hypopharynx
& it carries worse prognosis among laryngeal cancers .
Mucous glands are abundant in saccule & periarytenoid area .
Early lymphatic spreads of supraglottic cancer is because of
rich vascularity & lymphatics associated with these glands.
54. GLOTTIS
TRUE VOCAL CORDS
ANTERIOR COMMISSURE
POSTERIOR COMMISSURE
The glottis lies between the false and true vocal cords
which cover the vestibular and vocal ligaments, respectively.
Vocal fold – extends from middle of the angle of the thyroid
cartilage to the vocal process of the arytenoid cartilages and
underlying them is the upper border of the conus elasticus.
55. Each fold -
Superficial layer of nonkeratinizing, stratified
squamous epithelium
Lamina propria – 3 distinct layers.
The superficial layer (Reinke's space) - fibrous
substance with similar characteristics to gelatin.
The intermediate layer - elastic fibres and the deep
layer collagen fibres.
The intermediate and deep layers make up the vocal
ligament.
The vocalis muscle, which forms the main body of the
vocal fold, lies lateral and deep.
56.
57. Vestibular folds - two thick folds of mucous membrane each
enclosing a narrow band of fibrous tissue, the vestibular ligament,
which is the lower border of the upper quadrilateral membrane.
It is fixed in front at the angle of the thyroid cartilage just below
the attachment of the epiglottic cartilages and behind the
anterolateral surface of the arytenoid cartilage just above the vocal
process
58. Glottis (rima glottidis) - It is the elongated space between vocal
cords anteriorly, and vocal processes and base of arytenoids
posteriorly .
Anteroposteriorly, glottis is about 24 mm in men and 16mm in
women. It is the narrowest part of laryngeal cavity.
Anterior two-thirds of glottis are formed by membranous cords
while posterior one-third by vocal processes of arytenoids.
59. Ventricle (sinus of larynx) - It is a deep elliptical space between
vestibular and vocal folds, also extending a short distance
above and lateral to vestibular fold.
The saccule is a diverticulum of mucous membrane which
starts from the anterior part of ventricular cavity and extends
upwards between vestibular folds and lamina of thyroid
cartilage.
When abnormally enlarged and distended, it may form a
laryngocele—an air containing sac which may present in the
neck.
There are many mucous glands in the saccule, which help to
lubricate the vocal cords.
60.
61. LOWER LIMIT OF GLOTTIS – Controversial
Horizontal plane passing 1cm below free margin of vocal
cords at anterior commissure & 0.5cm below posterior
commissure .
Horizontal plane 20 mm below anterior commissure .
62. SUBGLOTTIS
Extends inferior to glottis to lower border of cricoid
cartilage .
Rare site of origin of cancer
Highest incidence of extralaryngeal spread
proximity of cricothyroid membrane .
rich postcricoid lymphatics .
63. SPACES OF LARYNX
REINKE’S SPACE –
Submucosal space along most of the length of free edge of true
vocal cord
Extending from superior arcuate line to inferior arcuate line.
Infront by anterior commissure.
Behind by vocal process of arytenoid.
Oedema of this space causes fusiform swelling of the
membranous cords (Reinke’s oedema).
Blood vessels & lymphatics are almost absent preventing early
spread of cancers.
64.
65. PRE-EPIGLOTTIC SPACE OF BOYER
Wedge shaped space.
ANTERIOR – Throhyoid membrane
Thyroid cartilage above thyroepiglottic ligament
• SUPERIOR – Hyoepiglottic ligament
Mucosa of vallecula
• POSTERIOR- Infrahyoid epiglottis
Thyroepiglottic ligament
• CONTENT – FAT
66.
67. It is continuos laterally with paraglottic space deep to
quadrangular membrane & superior to ventricle.
CLINICAL IMPORTANCE -
Cancer on laryngeal surface of infrahyoid epiglottis
spreads readily into this space.
68. PARAGLOTTIC SPACE (tucker’s space)
ANTEROLATERALLY – Thyroid cartilage , cricothyroid
membrane .
SUPEROMEDIALLY – Quadrangular membrane .
INFEROMEDIALLY – Conus elasticus .
POSTERIORLY – Anterior reflection of pyriform sinus mucosa.
It encompasses the laryngeal ventricles and saccules .
69.
70. CLINICAL IMPORTANCE
Space is situated lateral to ventricles; tumor involving ventricle
invades the space & later spreads transglottically.
Space blends with pre-epiglottic space anterosuperiorly.
Lateral supraglottic tumors can travel lateral to ventricle along
inner surface of thyroid ala & thus spread subglottically.
Pyriform sinus malignancy paraglottic space endolarynx
resulting fixation of hemilarynx .
71. PAEDIATRIC LARYNX
STRUCTURE DESCRIPTION
SHAPE Small & conical
POSITION High in the neck level of glottis being opposite to C3 or C4
at rest and reaches C1 or C2 during swallowing.
This high position allows the epiglottis to meet soft palate
and make a nasopharyngeal channel for nasal breathing
during suckling. The milk feed passes separately over the
dorsum of tongue and the sides of epiglottis, thus allowing
breathing and feeding to go on simultaneously.
CARTILAGES Soft & collapse easily.
EPIGLOTTIS Omega shaped with a furled petiole
72. STRUCTURE DESCRIPTION
THYROID It is flat. It also overlaps the cricoid cartilage and is in turn
overlapped by the hyoid bone. Thus cricothyroid and
thyrohyoid spaces are narrow and not easily discernible as
landmarks when performing tracheostomy.
Neither the superior notch nor the laryngeal prominence are
as marked as they are in the adult.
CRICOID Diameter of cricoid cartilage is smaller than the size of
glottis, making subglottis the narrowest part. It has a
bearing in the selection of paediatric endotracheal tube.
ARYTENOID More prominent and the aryepiglottic folds are
disproportionally large.
Covers significant portion of the posterior glottis.
VOCAL CORDS 4–4.5 mm long, which is relatively shorter.
76. NERVE SUPPLY
• SENSORY :
Supraglottis & upper surface of vocal cords – Internal branch of
superior laryngeal nerve .
Subglottis & lower surface of vocal cords – Recurrent laryngeal
nerve.
• MOTOR :
INTRINSIC – All muscles except cricothyroid : recurrent
laryngeal nerve .
Cricothyroid – External branch of superior laryngeal nerve.
GALEN’S ANASTOMOSIS - Superior & Recurrent laryngeal
nerve .
77.
78. BLOOD SUPPLY
ARTERIAL -
Superior laryngeal branch of superior thyroid artery.
Inferior laryngeal branch of inferior thyroid artery .
Cricothyroid branch of superior thyroid artery.
VENOUS –
Via superior and inferior laryngeal veins which run parallel to the
laryngeal arteries and are tributaries of the superior and inferior
thyroid veins respectively.
The superior thyroid vein drains into the internal jugular vein, and
the inferior thyroid vein usually into the left brachiocephalic vein.
79.
80.
81. LYMPHATIC DRAINAGE
Supraglottic larynx above the vocal cords is drained by lymphatics,
which pierce the thyrohyoid membrane and go to upper deep
cervical nodes (level II, III).
Infraglottic larynx below the vocal cords is drained by lymphatics
which pierce cricothyroid membrane and go to prelaryngeal and
pretracheal nodes and hence to lower deep cervical and mediastinal
nodes.
Some vessels pierce through cricotracheal membrane and drain
directly into lower deep cervical nodes.
Glottis - ‘watershed area’- with poor lymphatics .
Anterior commissure – prelaryngeal (delphian node)
84. PHYSIOLOGY OF LARYNX
FUNCTIONS :
Protection of tracheobronchial tree
Respiration
Phonation
To increase intrathoracic pressure ( effort closure )
Swallowing (deglutition)
Coughing
85. SWALLOWING (Deglutition)
Primary function – to prevent food & liquid entering airway .
Sphincteric action of aryepiglottic folds , true & false vocal cords
which occurs simultaneously with elevation of larynx .
ORAL STAGE
Voluntary
control
PREPARATORY
TRANSPORT
PHARYNGEAL
STAGE
Reflex activity
SWALLOWING
OESOPHAGEAL
STAGE
86. ORAL STAGE : Food bolus is manipulated by tongue &
broken down by teeth before being propelled towards
oropharynx.
PHARYNGEAL STAGE : reflex activity which is initiated as
the bolus reaches the back of the tongue.
During this phase, the glottis is closed by adduction of the
arytenoids and contraction of the lateral cricoarytenoid
muscles, false vocal folds and true vocal folds.
3-Tier system –
1) Closure of laryngeal vestibule by contraction of aryepiglottic
& interarytenoid muscles.
2) Ventricular bands approximation .
3) Adduction of vocal cords by adductors .
87. Epiglottis covers the laryngeal entrance and directs the bolus in two
parts into the valleculae and the pyriform sinuses.
The two columns of the divided bolus meet at the upper border of
the cricopharyngeus muscle which relaxes to allow the bolus to
enter the oesophagus.
Rapid laryngeal elevation occurs during the pharyngeal phase of the
swallow and appears to be essential for normal swallowing.
This manoeuvre produces a drop in pressure and transient negative
pressure in the cricopharyngeal sphincter as the bolus passes from
the pharynx into the oesophagus.
88. A mid-sagittal section of the head
and neck showing the location of
the major structures involved in
swallowing.
A. Hard palate
B. Soft palate
C. Nasopharynx
D. Pharyngeal isthmus
E. Oropharynx
F. Laryngopharynx
G. Cricoid cartilage
H. Thyroid cartilage
I. Hyoid bone
J. Laryngeal inlet.
89. Oral and pharyngeal stages of
a normal swallow:
(a) oral phase, food is
reduced and the bolus
prepared
(b) bolus is moved to the
posterior part of the tongue
(c) bolus contacts
the trigger points in the
oropharynx and the
pharyngeal phase is initiated
(d) bolus is moved past the
closed larynx
(e) Bolus enters the
oesophagus.
90. COUGHING
The process by which material is expelled from the airway.
Preceded by rapid inspiration
forceful closure of both the vocal and vestibular folds
Air pressure builds up below the adducted folds as the
diaphragm ascends spasmodically
until the folds separate explosively and mucus or foreign
material is expelled
91.
92. EFFORT CLOSURE
Laryngeal structure has evolved in order to contain intrathoracic
pressure, so as to provide a stable fulcrum for the upper limbs.
Expiratory effort against a closed glottis is known as the Valsalva
manoeuvre.
During any form of exertion involving use of the arms, the vocal
folds are firmly adducted preventing expulsion of air and collapse
of the chest walls, thus providing a fixed origin for the arm and
shoulder muscles.
To increase intrathoracic pressure : Fixation of chest by glottic
closure essential for straining , climbing etc.
97. • Immediately before phonation, the vocal folds
rapidly abduct to allow the intake of air.
• Vocal folds are adducted by the contraction of
the lateral cricoarytenoid muscles.
• The vocal note is generated by pulmonic air
(air from the lungs) as it is exhaled between
the adducted vocal folds.
98. Subglottic air pressure increases below the adducted vocal
folds until it reaches a level which overcomes their resistance
and blows them apart, thus setting in motion the vibratory
cycles which result in phonation.
101. As the increased subglottic pressure overcomes the
resistance of the adducted vocal folds at the onset of
phonation, the vocal folds peel apart from their inferior
border.
When they finally separate at their superior margin, a puff
of air is released.
The resulting negative pressure in the glottis, caused by
the Bernoulli effect, results in the vocal folds closing
rapidly as they are sucked together, the inferior vocal fold
margins closing first.
102. The Bernouilli effect is a drop in pressure dependent on
particle velocity.
In relation to the vocal tract,when air passes from one large
space to another (e.g. from lung to pharynx), through a
constriction (the glottis), the velocity will be greatest and the
pressure least at the site of the constriction.
As a result of the drop in pressure at the glottis, the vocal fold
mucosa is drawn into space between the vocal folds.
Contact between the vocal folds increases until the subglottic
air pressure is high enough to blow the vocal folds apart again,
and the cycle recommences.
103.
104.
105. COVER/ BODY THEORY
Each cycle of adduction, separation and recoil is the manifestation
of a mucosal wave travelling from the inferior to the superior
surface of each vocal fold.
The process by which this undulating wave of movement of the
mucous membrane occurs is dependent on what is known as the
cover/body theory
Vocalis muscle provides the firm body of the vocal fold over
which the mucous membrane cover of the vocal fold is blown by
the expiratory air stream.
106.
107. Periods of vocal fold contact & lack of contact in
one vibratory cycle
PHASE DESCRIPTION
CLOSING The vocal folds begin to close rapidly from their lower
margin.
CLOSED The medial edges of the vocal folds are in full contact.
OPENING The vocal folds begin to separate from their lower
margin and gradually peel apart.
The superior margin remains in contact until the end of
this phase.
OPEN The vocal folds are separated, the longest part of a
normal vibratory cycle.
108.
109. VOCAL REGISTERS
CHARACTERISTICS OF VOCAL FOLD ADDUCTION AND
VIBRATION
Hollien's suggestion that registers should be defined in terms of
laryngeal behaviour, rather than in acoustic terms, as registers are
governed by the degree of contraction of the vocalis muscle.
LOFT REGISTER
MODAL REGISTER
PULSE REGISTER
They describe the vibratory pattern of the vocal folds and the
acoustic parameters being produced.
110. REGISTERS FEATURES VOCAL
FOLDS
FO
RANGE (Hz)
LOFT
REGISTER
(Falsetto )
Highest vocal
frequencies
Thin, Tense,
Lengthened,
Minimal
vibration
275 - 1100
MODAL
REGISTER
(Chest,head,
middle, heavy
voice)
Range of
fundamental
frequencies
(speaking, singing
etc.)
Complete
Adduction
100 - 300
PULSE
REGISTER
(Vocal fry,
glottal fry ,
creaky voice)
Lowest range of
vocal frequencies ;
laryngeal output is
perceived as
pulsatile
Long closed
phase
20 - 60
111. NEUROANATOMY OF PHONATION
Depends on integrated functioning of CNS & PNS.
PAG (Periaqueductal grey matter) – midbrain
The motor activity for vocalization appears to be integrated
through a projection from the PAG to a column of neurones,
known as the nucleus retroambigualis(NRA) which plays a
significant role in generating respiratory pressure and laryngeal
adduction, which occurs in both vocalization and vegetative
manoeuvres, such as coughing.
112. Precentral gyrus of motor cortex of both cerebral hemispheres.
Medulla oblongata
Cortico-bulbar tract (part of
pyramidal system) / DIRECT
ACTIVATION TRACT
Ipsilateral vagus nucleus Contralateral vagus nucleus
Nucleus ambiguus ( reticular formation of medulla )
Also contains IX & XI CN elements
Ipsilateral vagus Contralateral vagus
SUPPLY LARYNGEAL MUSCULATURE THROUGH
THEIR BRANCHES
Some fibres Some fibres decussate
113. The indirect neurones of the pyramidal tract have multiple
offshoots and synapses with the basal ganglia and reticular
formation in the brainstem.
They appear to contribute to temporospatial orientation while the
direct system is related to discrete movement.
The frontobulbar portions of the pyramidal tracts connect with
cranial nerves IX to XII (as well as I to VIII), thus controlling
articulation, phonation and respiration.
The extrapyramidal system (the basal ganglia in the cerebral
hemispheres,the substantia nigra and subthalamic nucleus in the
upper brainstem, the cerebellum and the thalamus among other
structures.
114. The extrinsic and intrinsic muscles of the larynx are under
voluntary cortical control.
They are responsible for the prephonatory tuning which precedes
phonation and is followed by the phasic, tonic and volitional
contractions and also maintenance of length, tension, bulk and
position of the vocal folds.
The phonatory modulations which take place in speech - finely
coordinated system of reflex controls over the laryngeal muscles
and over the abdominal and intercostal muscles that maintain
subglottic air pressure at appropriate levels.
115. LARYNGEAL MECHANORECEPTORS
Wyke postulated that mechanoreceptors are found in three sites:
1) The mucosal lining of the larynx (subglottic mucosal
mechanoreceptors):
The corpuscular nerve endings in the subglottic mucous membrane
covering the surface of the vocal folds - sensitive to the stimuli of
muscle stretch, air pressure level, liquid and touch.
They discharge impulses into the afferent fibres of the vagus.
116. 2) The capsules of the articulatory joints (articular
mechanoreceptors):
The existence and function of this group remain controversial.
3) The extrinsic and laryngeal muscles (myotatic mechanoreceptors):
The tone of the laryngeal muscles depends on the myotatic reflex,
which is a function of the muscle spindles.
The laryngeal muscles contain a large number of muscle spindle.
117. FUNCTIONS :
Sensitive to muscle stretch and airflow pressures.
Some are involved in protecting the airway while others contribute
to the control of phonation.
Reflex closure of the larynx is triggered by tactile receptors in the
glottic and supraglottic mucosa, which evoke reflex contraction of
the laryngeal muscles.
Receptors in the subglottic mucosa elicit laryngeal closure and
cough.
118. REFERENCES
Scottt brown’s otorhinolaryngology, head & neck surgery
Cummings otolaryngology & head & neck surgery (6th edition)
Hazarika textbook of ear,nose ,throat & head & neck surgery
(3rd edition)
Dhingra – disaeases of ear , nose, throat & head & neck surgery
(6th edition)
Gray’s anatomy (40th edition)
Snell’s clinical anatomy (9th edition)
Netter’s atlas of human anatomy ( 6th edition)
Editor's Notes
Laterally, the cricoid cartilage receives the lowermost fibers of the inferior constrictor muscle and the semicircular fibers of the cricopharyngeus muscle.
Vertical ridge in posterior surface of lamina – upper fibres of oesophagus
Between these two processes, the anterolateral surface is irregular and divided into two fossa by a crest running from the apex. The upper triangular fossa gives attachment to the vestibular ligament and the lower to the vocalis and lateral cricoarytenoid muscles.