Clinical anatomy of the layrnx Flashcards
what is the airway divided into
- upper airway and the lower airway
what separates the upper and lower airways
- the larynx
how many cartilages make up the larynx
9
- 3 paired
- 3 unpaired
where is the larynx in terms of spinal segments
- Resits at C3-C6
what does the larynx continue with above and below
Connected to the
- Hyoid bone superiorly
- Trachea inferiorly
it is continuous with the pharynx superiorly as well
what are the main cartilages of the larynx
paired
- arytenoid
- corniculate
- cuneiform
unpaired
- thyroid
- epiglottis
- cricoid
describe the structure of the epiglottis
- Its tip rises about 1cm above the body of the hyoid at the back of the tongue
- Its ‘stalk ’ is attached to the back of the anterior aspect of the thyroid cartilage.
what is the largest cartilage of the larynx
thyroid cartilage
describe the attachments fo the thyroid cartilage
- lies just beneath the hyoid bone
- Composed of two sheets (laminae), which fuse anteriorly to form thelaryngeal prominence(Adam’s apple).
- The posterior border of each sheet projectsuperiorly and inferiorly to form the superior and inferior horns (also known as cornu).
- The superior hornsare connected to the hyoid bone via the lateral thyrohyoid ligament, while the inferior horns articulate with the cricoid cartilage.
where does the cricoid cartilage sit
- It articulates with the inferior horns of the thyroid cartilage superiorly
- Posteriorly it is connected to the two arytenoid cartilages by synovial joints
- Inferiorly it is attached to the trachea
what is special about the cricoid cartilage
It is the only completely ring of cartilage in the larynx, the front of it is quite narrow whereas the back part of it is quite tall
where do the arytenoids sit
- they sit on top of the cricoid cartilage
what is the lower respiratory tract made up of
Lower airway – essentially everything beyond the trachea
what are the three parts of the pharynx
naso, oro, laryngo-
what is the role of the nasal cavity
- Warms and humidifies inspired air
- Removes and traps pathogens from inspired air
- Sense of smell
- Drains paranasal sinuses and lacrimal ducts
where does the nasal cavity extend from
It extends from the vestibule of the nose to the nasopharynx, and has three divisions
what are the parts of the nasal cavity
- Vestibule– the area surrounding the anterior external opening (nostrils) to the nasal cavity.
- Respiratory region– lined by a ciliated psudeostratifiedepithelium, interspersed with mucus-secreting goblet cells. Responsible for trapping pathogens and particulates within inspired air.
- Olfactory region– located at the apex of the nasal cavity. It is lined by olfactory cells with olfactory receptors. Special sensory innervation refers to the ability of the nose to smell. This is carried out by the olfactory nerves. The olfactory bulb, part of the brain, lies on the superior surface of the cribriform plate, above the nasal cavity. Branches of the olfactory nerve run through the cribriform plate to provide special sensory innervation to the nose.
where does the oral cavity extend
Spans between oral fissure anteriorly and the opening of the oropharynx posteriorly.
what are the two divisions of the oral cavity
Two major divisions of the oral cavity:
Vestibule
Oral Cavity Proper
what is the sensory innervation of the oral cavity
Sensory innervation of the oral cavity is supplied by branches of the trigeminal nerve (CN V)
what is the function of the oral cavity
Function of the oral cavity:
Digestion
Communication
Breathing
what is the vestibule
Vestibule - horseshoe-shaped vestibule is situated anteriorly. It is the space between the lips/cheeks, and the gums/teeth
where does the oral cavity proper sit
- Lies posteriorly to the vestibule.
- It is bordered by a roof, a floor, and the cheeks.
- The tongue fills a large proportion of the cavity of the mouth proper.
what does the roof of the oral cavity consist of
Roof consists of anterior hard palate and posterior soft palate.
describe the hard plate and what is separates and what mucosa lines it
- The hard plate separates the nasal cavity from the oral cavity.
- It is covered superiorly by respiratorymucosa (ciliated pseudostratified columnar epithelium) and inferiorly by oral mucosa (stratified squamous epithelium).
- has a contribution from the palatine bone
describe the soft palate
The soft palate is a muscular (not bony) continuation of the hard palate posteriorly
what are the cheeks formed by
Cheeks formed by the buccinator muscle, which is lined internally by the oral mucous membrane.
what is the bony skeleton of the oral cavity made up of
The bony skeleton of the oral cavity is made up of the maxilla and mandible which house the upper and lower teeth respectively
what makes up walders ring
- uvula
- paltoglossal arch
- palto pharygneal arch
- paltine tonsils
what is the pharynx
Muscular tube connecting oral and nasal cavities to the trachea and oesophagus
what is the shape of the pharynx controlled by
Shape of pharynx and propulsion of food into oesophagus controlled by two sets of pharyngeal muscles – circular and longitudinal muscles
what are the two sets of pharyngeal muscles
circular and longitudinal
where is the nasopharynx found
Nasopharynx - found between the base of the skull and the soft palate.
what is the role of the nasopharynx
It is continuous withthe nasal cavity, and performs a respiratory function by conditioning inspired air and propagating it into the larynx.
what epithelium of nasopharynx lined with
Lined with respiratory epithelium; ciliated pseudostratified columnar epithelium with goblet cells
where is the oropharynx located
Oropharynx – The middle part of the pharynx, located between the soft palate and the superior border of the epiglottis.
what structures does the oropharynx contain
It contains the following structures:
- Posterior 1/3 of the tongue.
- Lingual tonsils – lymphoid tissue at the base of the tongue.
- Palatine tonsils – lymphoid tissue located in the tonsillar fossa (between the palatoglossal and palatopharyngeal arches of the oral cavity).
- Superior constrictor muscle
Waldeyer’s ring is the ring of lymphoid tissue in the naso- and oropharynx formed by the paired palatine tonsils, the adenoid tonsils and lingual tonsil.
what is the role of the oropharynx
The oropharynx is involved in the voluntary and involuntary phases of swallowing.
where is the laryngopharyx located
The most distal part of the pharynx, the laryngopharynx is located between the superior border of the epiglottis and inferior border of the cricoid cartilage (C6). It is continuous inferiorly with theoesophagus.
what does the laryngopharyx contain
The laryngopharynx contains the middle and inferior pharyngeal constrictors.
what does the layryx contain
Composed of 9 cartilages with connecting ligaments, muscles and vocal cords and lined by mucous membrane
what happens to the larynx after puberty in men
After puberty the male larynx enlarges with the saggital diameter nearly doubling and all the cartilages increase in both size and weight,
what skeletal level does the hyoid sit at
C3
what supports the larynx cartilages
The laryngeal membranes and ligaments supportthis cartilaginous skeleton of the larynx.
what does the intrinsic muscles of the larynx do
The intrinsic laryngeal muscles act to move the components of the larynx for phonation and breathing.
what are the corniculate, cuneiform, tritiate and epiglottic cartilages and the apices of the arytenoid composed of
The corniculate, cuneiform, tritiate and epiglottic cartilages and the apices of the arytenoid are composed of elastic fibrocartilage, with little tendency to calcify
what cartilages are composed of hyaline cartilage
- The thyroid, cricoid and the greater part of the arytenoid cartilages consist of hyaline cartilage and may undergo mottled calcification as age advances,
- starting about the twenty-fifth year in the thyroid cartilage and somewhat later in the cricoid and arytenoids.
- By the sixty-fifth year, these cartilages commonly appear patchily dense in radiographs
what is the epiglottis composed of
It is composed of yellow cartilage and never calcifies.