Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
In the respiratory tract, columnar epithelium possesses cilia. What is the primary function of these cilia?
To move and push mucus forward to clear it
To provide only mechanical support to the tract
To secrete substances onto the epithelial surface
To increase the surface area for absorption only
To move and push mucus forward to clear it
Ciliated columnar epithelium lines the respiratory tract and uses coordinated beating of cilia to propel a layer of mucus containing trapped pathogens and dust particles toward the pharynx. This process, known as the mucociliary escalator, is a crucial component of the innate immune defense system.
Ciliated columnar epithelium lines the respiratory tract and uses coordinated beating of cilia to propel a layer of mucus containing trapped pathogens and dust particles toward the pharynx. This process, known as the mucociliary escalator, is a crucial component of the innate immune defense system.
Think of it like an automated conveyor belt system in a factory that constantly sweeps trash (dust and microbes) toward a waste collection bin (the stomach/pharynx) to keep the workspace (lungs) clean.
Cilia Clear Clutter (C-C-C): Cilia act to clear the clutter from the tract.
ATPтЖТADP+PiтАЛ+energy тАФ The chemical reaction that powers the mechanical movement of cilia
The mechanism relies on the rhythmic, whip-like movement of the axonemes within the cilia. These structures contain a 9+2 arrangement of microtubules that utilize ATP hydrolysis to create a directional sweeping motion. This motion creates a force vector that shifts the sticky mucus layer against gravity or towards the throat for disposal by swallowing or coughing.
Ciliated epithelium is found in the bronchi, bronchioles, and nasal passages.
Goblet cells found nearby secrete the mucus that traps debris.
Microtubules in cilia consist of tubulin proteins arranged in a 9+2 structure.
Smoking damages these cilia, leading to the accumulation of mucus (smoker's cough).
Prevents infection by moving pathogens out of the lungs
Maintains clear airways for efficient gas exchange
Susceptible to damage from toxins and pollutants
Clearance of inhaled particulate matter
Prevention of respiratory tract infections
The mucus layer is known as the 'mucociliary blanket'.
Option B is incorrect because mechanical support is provided by the basement membrane and structural proteins.
Option C is incorrect because secretion is the primary function of goblet cells, not the cilia itself.
Option D is incorrect because increased surface area for absorption is typically provided by microvilli, not cilia.
A is correct тАФ The primary function of cilia in the respiratory tract is to move and push mucus forward to clear trapped foreign particles.
In exams, distinguish between 'Cilia' (movement/sweeping) and 'Microvilli' (increased surface area for absorption); they are often confused in MCQ options.
Get instant step-by-step AI explanations, full shift Previous Year Papers (SSC GD, RRB, SSC JE), and regional rank analysis on the official Examoogle App.
Free Download тАв 100K+ Aspirants