Anatomy of the Larynx Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary muscle responsible for normal tidal volume respiration?

External intercostal muscles

Abdominal muscles

Internal intercostal muscles

Diaphragm (correct)

Which of the following statements about the diaphragm is true?

It moves upward during inspiration

It is a smooth muscle

It is responsible for forced expiration

It is a skeletal muscle that can be paralyzed (correct)

What is the normal range of diaphragm movement during deep breathing?

1-2 cm

3-6 cm

7-13 cm (correct)

14-20 cm

Which of the following factors can affect the position of the diaphragm?

All of the above Signup and view all the answers

What is the primary function of the external intercostal muscles?

Responsible for up to 25% of tidal volume during normal breathing Signup and view all the answers

What is the primary function of the internal intercostal muscles?

Assist in forced expiration Signup and view all the answers

Which of the following is an inwardly directed force in the alveoli that must be overcome during inspiration?

Surface tension Signup and view all the answers

What is the term used to describe the ease with which the lungs and thoracic wall can be expanded?

Compliance Signup and view all the answers

Which of the following is responsible for decreasing the size of the alveoli during expiration?

Elastic recoil Signup and view all the answers

Which law relates the pressure and volume of a gas?

Boyle's Law Signup and view all the answers

Which of the following is the least common anatomical variation of the ribs?

Lumbar ribs - elongation of transverse process of lumbar vertebrae Signup and view all the answers

What is the significance of the sternal angle (of Louis) in relation to the trachea?

It indicates the midpoint of the trachea and the ideal location for the distal tip of an endotracheal tube. Signup and view all the answers

Which of the following is the primary function of the nasal conchae and paranasal sinuses?

To warm, clean, and moisten air for the lungs Signup and view all the answers

What is the significance of the trachea being posterior to and in line with the jugular notch?

It signifies the level at which the trachea lies in the same horizontal plane as the second thoracic vertebra (T2). Signup and view all the answers

What is the primary function of the ala nasi, the flared portion of the lateral wall of each nostril?

To provide bony and cartilaginous support to the nose Signup and view all the answers

What is the primary function of the arytenoid cartilages in the larynx?

To control the opening and closing of the vocal cords during phonation Signup and view all the answers

What is the significance of the cricoid cartilage in the pediatric airway?

It is the narrowest portion of the airway in children Signup and view all the answers

Which of the following statements about the anatomical differences between the adult and pediatric larynx is true?

The laryngeal cavity is more funnel-shaped in children than in adults Signup and view all the answers

What is the primary function of the corniculate cartilages in the larynx?

To support the soft tissue between the arytenoid and epiglottic cartilages Signup and view all the answers

What is the significance of the rima glottidis in the larynx?

It is the opening between the true vocal cords and the arytenoid cartilages Signup and view all the answers

Which of the following statements about the trachea is correct?

It is a fibrocartilaginous tube approximately 20-30 cm long and 15 mm in diameter. Signup and view all the answers

What is the primary function of the carina?

To divide the trachea into the primary bronchi. Signup and view all the answers

Which of the following statements about the bronchial circulation is correct?

It mixes with alveolar venous return, causing an anatomic shunt. Signup and view all the answers

Which of the following structures is responsible for the turbulent flow that helps trap inhaled particles in the respiratory system?

The nasal cavity Signup and view all the answers

Which of the following statements about the innervation of the larynx is correct?

The interior branch of the superior laryngeal nerve provides sensation for the upper portion of the larynx down to and including the upper half of the vocal cords. Signup and view all the answers

Which of the following is a characteristic of the human sternum?

It is a flat, elongated bone that connects to the ribs Signup and view all the answers

What is the purpose of the sternal angle (angle of Louis) on the human sternum?

It indicates the junction between the manubrium and body of the sternum Signup and view all the answers

Which of the following is a true statement about the human trachea?

It is lined with pseudostratified columnar epithelium that contains goblet cells Signup and view all the answers

What is the primary function of the nose in the human upper airway?

It warms, humidifies, and filters the air before it reaches the lungs Signup and view all the answers

What is the anatomical term used to describe the presence of extra ribs arising from the lumbar vertebrae?

Lumbar ribs Signup and view all the answers

Study Notes

Larynx

Located in adults between C3-C6, and C3-C5 in children
Framework formed by 9 total pieces of cartilage (3 paired, 3 unpaired)
Epiglottic cartilage: most superior
Thyroid cartilage: largest, forms laryngeal prominence at C5
Cricoid cartilage: connects larynx to trachea
Arytenoid cartilages (2): posterior to thyroid cartilage
Corniculate cartilages (2): attached to arytenoid cartilages
Cuneiform cartilages (2): support soft tissue between arytenoids and epiglottis

Laryngeal Cavity

Rima glottidis: opening between true vocal cords and arytenoid cartilages
Narrowest portion of the airway
Glottis: true vocal cords and the rima glottidis

Pediatric Airway Differences

In pediatric patients, cricoid was considered the narrowest portion of the airway
Newer studies suggest the glottic opening may be the narrowest in pediatric patients
Shapes and locations of structures also vary between infant and adult

Intubation

Easy to insert laryngoscope blade too deep in children
Must be careful not to hide the larynx

Larynx Innervation

Innervation of the larynx: CN X (Vagus)
Sensory: Interior Branch of Superior laryngeal nerve provides sensation for upper portion of the larynx down to and including upper half of the vocal cords
Recurrent laryngeal nerve transmits sensation below the true cords and lower half of the cords
Motor: ALL intrinsic muscles except the cricothyroid are innervated by the RECURRENT LARYNGEAL nerve
Cricothyroid muscle is innervated by superior laryngeal nerve

Trachea

Fibrocartilaginous tube, approximately 10-20cm long and 12mm in diameter
Begins at the end of the larynx (C6) and extends to T5-6
Supported by 16-20 C-shaped rings of cartilage with smooth muscle posteriorly
The carina is the lowermost portion of the trachea where it divides into primary bronchi
Lined with ciliated pseudostratified epithelium which functions as mucociliary escalator

Removing Inhaled Particles

The lungs produce 100mL of mucous per day
Turbulent flow helps trap precipitate
Cough Reflex: mucociliary escalator mechanism
Impaired by endotracheal intubation and volatile anesthetics
Ciliated epithelial cells beat particles up the airway to be swallowed in the oropharynx

Branching of Tracheobronchial Tree

Conducting Zone: no gas exchange
Respiratory Zone: gas exchange occurs
Dead Space: area where no gas exchange occurs
Secondary (Lobar) Bronchi: three on the right, two on the left
Segmental Bronchi: ten on the right, eight on the left
Terminal Bronchioles: diameter of 1 mm, contains no cartilage
Relatively thick smooth muscle wall compared to lumen
Can contract during asthma attack
No goblet cells

Bronchial Circulation

Supplied by systemic circulation
Some mixes with alveolar venous return, causing an anatomic shunt
AV shunt causes slight dilution of PO2 (bronchial venous mixes with pulmonary vein blood)### Alveolar-Arterial Gradient
PA - Pa ~ 5-15mmHg, useful in determining the cause of restrictive lung disease
Normal gradient: blame the chest wall (extrinsic restrictive disease)
Increased gradient: problem is in the lung (intrinsic restrictive lung disease)

Bronchial Innervation

Sensory and motor innervation via vagus
Parasympathetic: Acetylcholine (Ach) causes bronchoconstriction via M3 (Gq) receptors
Sympathetic: Epinephrine/Norepinephrine causes bronchodilation via B2 (Gs) receptors

Respiratory Zone

Composed of: acinus (terminal respiratory unit), respiratory bronchioles, alveolar ducts, and alveoli
Alveoli form from birth to age 4 and continue to maximize expansion until age 8
Respiratory bronchioles: first segment of airway where gas exchange occurs (transitional zone)
Alveolar ducts: walls completely lined with alveoli
Alveolar sac: located at end of each 3rd generation of alveolar ducts

Gas Exchange

Diffusion: main mechanism for gas exchange from alveoli into blood
More lipid-soluble anesthetics diffuse easier, resulting in build-up in bloodstream
Diffusion = Area/Thickness
Normal lung: area of blood-gas interface is about the size of a tennis court

Alveoli

300 million in adult lungs, polygon shape maximizes surface area
Surrounded by 1,000 pulmonary capillaries each
Type I alveolar cells: squamous, form walls, involved with gas exchange
Type II alveolar cells: cuboidal, produce surfactant
Alveolar macrophages: eliminate foreign debris
Alveolar pores (pores of Kohn): allow for collateral ventilation

Alveolar Stability

Alveoli have tendency to collapse, prevented by: surfactant, alveolar pores, and interdependence

Lungs

Cone-shaped structures located in thorax, occupying all of thoracic cavity except mediastinum
Right lung has three lobes, left lung has two lobes, and is more narrow
Lungs innervated by pulmonary plexus, sympathetic fibers (T2-T6), and parasympathetic fibers from vagus
Few to no pain receptors in lungs

Lungs Perfusion and Ventilation

Normal perfusion and ventilation (V/Q) difference between the two lungs due to different surface areas
Right lung has three lobes and receives 60% of cardiac output to lungs
Parasympathetic fibers produce constriction of airways and increase mucus secretion by mucus glands
Sympathetic hormones produce dilation of airways (beta-2 response)

Pleural Membranes

Serous membranes that line thoracic cavity and cover lungs
10cc of pleural fluid produced per lung, prevents friction in pleural cavity

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge of the anatomy of the larynx, including cartilages like thyroid, cricoid, and arytenoid. Learn about the position of the larynx in adults and children, as well as the framework formed by different cartilages.