Question

Assertion: During swallowing food can't enter in larynx. Reason: During swallowing open of larynx glottis is covered by epiglottis

Short answer

The assertion is correct, and the reason given accurately explains why food cannot enter the larynx during swallowing. The epiglottis covers the glottis to prevent food or liquid from entering the larynx and therefore the windpipe and lungs.

Step-by-step solution

Understanding the Assertion

In the first step, it is crucial to understand the claim made. It asserts that during swallowing, food cannot enter the larynx, which is a part of the throat that houses the vocal cords.

Understanding the Reason

The second step is to comprehend the reason offered for this claim. The glottis is the part of the larynx that includes the vocal cords and the opening between them. The reason claims that the 'epiglottis', a leaf-shaped flap in the throat, covers the glottis during swallowing.

Linking Assertion and Reason

Finally, assess the connection between the observation and the explanation. When swallowing, the epiglottis covers the glottis to prevent food from entering the larynx and instead directs it towards the oesophagus, a tube that leads to the stomach. When we are not eating or drinking, the epiglottis stays upright and leaves the larynx open for air to travel into the lungs.

Key concepts

Larynx

The larynx, often referred to as the "voice box," plays a crucial role in human anatomy. It is located in the throat and houses the vocal cords, which are essential for producing sound. The larynx connects the pharynx and trachea and is a key structure involved in breathing, sound production, and protecting the airway during swallowing.

The larynx is mainly made up of cartilage, muscles, and ligaments which support the creation of voice by vibrating vocal cords. Its primary functions include:

• Enabling speech and vocal sounds
• Routing air to the lungs
• Protecting the airway by preventing food and liquids from entering while swallowing

Understanding the structure and function of the larynx helps illuminate its vital role in the swallowing process.

Epiglottis

The epiglottis is a small but mighty component of the human anatomy, shaped like a leaf, and it serves as a cap over the larynx. Positioned just above the glottis (the opening of the larynx), the epiglottis plays a critical role in safeguarding the airway during eating.

Here are several notable functions of the epiglottis:

• During swallowing, it acts as a flap that folds down to cover the glottis, effectively shielding the windpipe from food and liquid.
• When not swallowing, the epiglottis stays upright, allowing air to pass freely into the trachea and reach the lungs.
• It helps coordinate the passage of food and air, maintaining a clear distinction between the respiratory and digestive pathways.

The protective action of the epiglottis ensures that the food is directed away from the airway, which is crucial for safe and effective swallowing.

Swallowing Mechanism

Swallowing is a complex process that involves the coordinated action of multiple anatomical structures to safely move food from the mouth to the stomach. This essential mechanism occurs in three phases: oral, pharyngeal, and esophageal.

1. **Oral Phase**: This phase begins when food is chewed and mixed with saliva to form a bolus. The tongue then pushes the bolus toward the back of the throat.

2. **Pharyngeal Phase**: At this stage, the epiglottis swings downward to cover the glottis, ensuring that the bolus is directed towards the esophagus instead of the trachea. This movement prevents choking and food aspiration. Simultaneously, the larynx moves upward and forward, enhancing the closure of the airway.

3. **Esophageal Phase**: Once the bolus enters the esophagus, a series of muscle contractions known as peristalsis moves it towards the stomach for digestion.

Understanding the swallowing mechanism highlights the coordinated efforts of the larynx and epiglottis in protecting the airway while allowing for the seamless passage of food. This mechanism is essential for nutrition and safety in daily life.