81. Which one of the following organs is INCORRECTLY paired with its function?
(A) Intestinal villi-absorption
(B) Epiglottis – closure of larynx
(C) Gall bladder – carbohydrate digestion
(D) Parietal cells – hydrochloric acid

The correct answer is (C) Gall bladder – carbohydrate digestion.

This pairing is incorrect because the gall bladder stores and concentrates bile, which emulsifies fats for digestion—it plays no role in breaking down carbohydrates. Below, I’ll explain all options with biological details to clarify why C is the mismatch.

Why Each Option is Paired (or Not) Correctly

• (A) Intestinal villi – absorption: Correct. Villi in the small intestine dramatically increase surface area via microvilli, enabling efficient nutrient absorption into the bloodstream through active and passive transport.

• (B) Epiglottis – closure of larynx: Correct. During swallowing, this cartilage flap folds over the larynx (voice box), preventing food or liquid from entering the airway and directing it to the esophagus.

• (C) Gall bladder – carbohydrate digestion: Incorrect. The gall bladder secretes bile into the duodenum to break down fats (lipids) by emulsification, aiding lipase enzymes. Carbohydrates are digested by salivary amylase (mouth), pancreatic amylase (small intestine), and brush border enzymes like maltase—no gall bladder involvement.

• (D) Parietal cells – hydrochloric acid: Correct. Located in the stomach’s gastric glands, parietal cells secrete HCl, which activates pepsinogen to pepsin for protein digestion and creates an acidic environment to kill pathogens.

This question tests knowledge of digestive system roles, a key topic in human physiology for exams like NEET or board biology.

Understanding Organ Functions in Digestion: MCQ Breakdown

In human physiology, organs have specialized roles, especially in the digestive system. This MCQ highlights a common misconception: gall bladder carbohydrate digestion. Let’s dive into the question and options for clarity.

Correct Answer: Option (C)

The gall bladder does not digest carbohydrates. It stores bile produced by the liver, releasing it to emulsify dietary fats in the small intestine. Bile breaks fat globules into micelles, allowing pancreatic lipase to act—no carbs involved. Carbohydrate digestion starts with salivary amylase in the mouth and continues with pancreatic amylase and intestinal enzymes like sucrase.

Why this trips students up: Many confuse bile’s fat role with broader digestion, but carbs rely on amylases, not bile.

Detailed Explanation of All Options

Intestinal Villi: Masters of Absorption

Intestinal villi line the small intestine, boosting surface area 600-fold with microvilli. They absorb:

• Simple sugars (glucose) via active transport (SGLT1).

• Amino acids and fats as chylomicrons into lacteals.

Function match: Perfect—absorption is their core job.

Epiglottis: Larynx Guardian

The epiglottis is a leaf-shaped cartilage that flips during swallowing, sealing the glottis (larynx opening). This reflex prevents aspiration pneumonia.

Function match: Spot-on for airway protection.

Gall Bladder: Fat Emulsifier, Not Carb Digester

• Stores 30-50 mL bile, concentrated 5-10x.

• Bile salts (e.g., taurocholate) reduce fat surface tension for digestion.

• Carbs? Handled by amylase enzymes upstream/downstream.

Function mismatch: No enzymatic or emulsifying role in carb breakdown. Post-cholecystectomy patients digest carbs fine but may need fat supplements.

Parietal Cells: HCl Powerhouse

In stomach oxyntic glands, parietal cells pump H⁺ and Cl⁻ via H⁺/K⁺-ATPase, creating pH 1-2 HCl.

Functions: Protein digestion (pepsin activation), pathogen kill, vitamin B12 release.

Function match: Direct HCl secretion.

Why This Matters for Biology Students

Mastering organ functions prevents errors in exams testing digestion (e.g., NEET, Class 11/12 CBSE). Organ incorrectly paired with function questions probe precise roles—focus on bile’s lipid specificity.

Pro Tip: Visualize digestion flow: Mouth (carbs) → Stomach (proteins) → Duodenum (bile for fats + amylase for carbs).