The larynx is closed during swallowing by: & x20; - RRB Nsg. Superintendent-21 July 2019 (Shift-2nd)

RRB Nsg. Superintendent-21 July 2019 (Shift-2nd)

Applied Physiology

Easy

Appeared in: RRB Nsg. Superintendent-21 July 2019 (Shift-2nd)

Explanation

The epiglottis is a leaf-shaped flap of elastic cartilage located at the base of the tongue.
During swallowing, the entire larynx elevates, causing the epiglottis to fold down and cover the laryngeal inlet (the opening to the airway).
This action acts as a primary protective mechanism, diverting food and liquid into the esophagus and preventing them from entering the trachea (aspiration).
This is a crucial reflex to protect the lower respiratory tract.

Option B: The cricoid cartilage is a ring-shaped structure that forms the inferior wall of the larynx. Its primary function is to provide a stable, foundational attachment point for muscles, ligaments, and the trachea.
Option C: The vocal cords (or vocal folds) are primarily involved in sound production (phonation). While they do adduct (close) tightly during swallowing to provide a secondary layer of airway protection, the epiglottis is the primary structure that covers the entire laryngeal opening.
Option D: The thyroid cartilage is the largest laryngeal cartilage that forms the anterior and lateral walls of the larynx, creating the laryngeal prominence (Adam's apple). Its function is purely protective and structural; it does not move to close the airway.

Visual 1: Diagram - A sagittal view of the head and neck showing the position of the epiglottis in its resting state and during swallowing, clearly illustrating how it covers the laryngeal inlet.
Visual 2: Animation - A short animation depicting the mechanics of deglutition, highlighting the upward movement of the larynx and the downward folding of the epiglottis.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Anatomy and physiology of the larynx, specifically the protective mechanisms during swallowing (deglutition) as background academic context rather than a clinical decision trigger.
Understanding this mechanism is critical for assessing and managing patients with dysphagia (difficulty swallowing), who are at high risk for aspiration.
Aspiration occurs when food, liquid, or saliva enters the airway, which can lead to serious complications like aspiration pneumonia. Nurses must implement aspiration precautions for at-risk patients.
What if? If a patient has nerve damage affecting the larynx (e.g., from a stroke or surgery), the epiglottic reflex may be impaired. The nurse's priority becomes strict aspiration precautions, including diet modification (thickened liquids), specific swallowing techniques (chin tuck), and close monitoring for signs of respiratory distress.

How to Approach the Question

First, identify the key terms in the question: 'larynx', 'closed', and 'swallowing'. This is a factual recall question about anatomy and physiology.
Second, consider the function of each option in the context of swallowing.
Recall or deduce the primary role of each laryngeal cartilage. The thyroid and cricoid cartilages are mainly for structure and support.
Differentiate between the roles of the vocal cords (phonation) and the epiglottis.
Remember that the epiglottis acts like a 'trapdoor' or 'lid' for the airway, which directly answers the question about closing the larynx during swallowing.

Concept Tested & Keywords

Concept Tested: Anatomy and physiology of the larynx, specifically the protective mechanisms during swallowing (deglutition).
Stem keywords: larynx, closed, swallowing
Lead-in keywords: is

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