Problem 161 - Objective Biology for NEET

Question

Assertion: We can remove dust particle and some foreign substances inhaled along with the atmospheric air from trachea Reason: Trachea is lined with ciliated epithelium

Step-by-Step Solution

Answer

Yes, the assertion and the reason are both correct. The trachea, lined with ciliated epithelium, plays a critical role in filtering out dust particles and other foreign substances from the air we inhale.

Step 1: Understanding the Trachea structure

Firstly, understand that the trachea, also known as the windpipe, is a key part of the respiratory system that transports inhaled air from the larynx into the bronchi of the lungs. It's lined with ciliated epithelium, which are tiny hair-like structures.

Step 2: Role of Ciliated Epithelium in the Trachea

The role of ciliated epithelium is to move mucus and trapped particles out of the lungs. This is a protective mechanism to keep the airway clear. The movements of these cilia push mucous which traps dust particles and foreign substances up towards the throat, where it can be then swallowed or coughed out.

Step 3: Confirming the Assertion and Reason

Hence, it can be confirmed that the assertion is correct. The dust particles and foreign substances inhaled with the atmospheric air can indeed be removed from the trachea. The reason is also correct; the trachea is lined with ciliated epithelium which helps in the removal of inhaled foreign substances.

Key Concepts

Ciliated Epithelium

In the respiratory system, one fascinating feature is the ciliated epithelium. This lining is comprised of specialized epithelial cells with tiny hair-like projections called cilia. Imagine these as tiny brushes continuously moving back and forth.

These cilia serve a crucial function:

• They beat in a specific rhythm, usually towards the pharynx, an action sometimes described as a "sweeping" motion.
• The primary purpose of this motion is to transport mucus, dust particles, and other foreign materials out of the respiratory tract.
• This process is vital in maintaining a clean and healthy airway, and protecting the deep lung tissues from irritants or pathogens.

The ciliated epithelium, thus acts as a barrier and cleansing mechanism, working tirelessly to keep our respiratory pathways clear of obstruction.

Trachea

The trachea, commonly known as the windpipe, plays a pivotal role in the respiratory system. Structured as a tube, it connects the larynx to the bronchi, enabling the passage of air to and from the lungs.

Let's explore its important features:

• The trachea is reinforced by rings of cartilage that provide structural integrity, ensuring it remains open for air to pass through without collapsing.
• Lined with ciliated epithelium, it employs its inner lining to trap dust and pathogens, playing a key role in airway hygiene.

The trachea is not just a passive pipe; it's an active participant in protecting our lungs by filtering out harmful particles as air transits.

Airway Protection

Airway protection is a defense strategy that the body has developed to ensure the air reaching our lungs is clean and safe. Everyday, with each breath, the air we inhale potentially carries dust, pollutants, and microbes. Here are key protective features of our airway:

• Upon entering through the nasal passages, larger particles are initially captured by nose hairs and sticky mucus, providing a first line of defense.
• As the air travels down the trachea, the ciliated epithelium plays a key role, with cilia pushing unwanted particles upwards towards the throat where they can be expelled.
• Mucus, produced by goblet cells mixed within the ciliated lining, acts as a glue, trapping minute dust and microorganisms.

These mechanisms collectively keep the airways free from blockages and reduce the risk of respiratory infections. Our airway protection is thus a crucial factor in our overall respiratory health.