Problem 117 - Objective Biology for NEET

Question

The activities of gastrointestinal are under (a) Neural control only (b) Hormonal control only (c) Neither hormonal nor neural control (d) Neural and hormonal control

Step-by-Step Solution

Answer

The activities of the gastrointestinal tract are under both Neural and Hormonal control. Therefore, the correct answer is option (d) Neural and Hormonal control.

Step 1: Understand the Gastrointestinal Activities Regulation

The Gastrointestinal tract (GI) is a series of hollow organs joined from the mouth to the anus. Activities of the GI are regulated by both neural control and hormonal control, which respond in different ways. Neural control responds to immediate needs like eating and swallowing, while hormonal control manages longer-term needs like digestion and absorption.

Step 2: Evaluate Each Option

Look at each answer choice. Option (a) is incorrect because while neural control is a part of gastrointestinal regulation, hormonal control also plays a significant role. Option (b) is incorrect for the same reason-- hormonal control plays a part, but only in combination with neural control. Option (c) is inaccurate because it negates both neural and hormonal control, which are both crucial in the regulation of the gastrointestinal activities.

Step 3: Pick the Correct Answer

According to the review in step 2, the only remaining possible answer is option (d) 'neural and hormonal control', which aligns with the concept that both neural and hormonal mechanisms regulate the activities of the gastrointestinal tract.

Key Concepts

Neural Control

The nervous system plays a fundamental role in regulating the gastrointestinal activities. It employs the enteric nervous system (ENS), often referred to as the "brain of the gut," which operates independently but also communicates with the central nervous system. Neural control responds quickly and effectively to immediate needs, essentially managing actions like swallowing, peristalsis, and reflexes.
Key aspects of neural control include:

• Reflexes: Such as the gastrocolic reflex, which is initiated by the stomach stretching and leads to increased motility in the colon.
• Rapid Response: Unlike hormonal control, neural control can react instantly to the presence of food, facilitating the efficient movement of content through the digestive system.
• Coordination of Muscle Contractions: It coordinates the contraction and relaxation of muscles along the gastrointestinal tract, ensuring smooth passage of the food content.

Neural control uses neurotransmitters to signal and regulate these processes. Understanding its role helps comprehend how the body immediately adjusts digestive processes in response to different stimuli.

Hormonal Control

Hormones are chemical messengers that significantly influence gastrointestinal functions by controlling longer-term processes. Unlike neural control, hormonal regulation takes a more systemic approach, addressing digestion and nutrient absorption after immediate neural responses. Hormonal control involves various hormones secreted by specialized cells in the stomach and intestines, coordinating digestive activities.
Key hormones managing GI activities include:

• Gastrin: Encourages secretion of gastric acid and pepsinogen to aid in digestion.
• Secretin: Stimulates the pancreas to release a bicarbonate-rich fluid, neutralizing stomach acid.
• Cholecystokinin (CCK): Facilitates digestion by stimulating the release of digestive enzymes from the pancreas and bile from the gallbladder.
• Gastric Inhibitory Peptide (GIP): Reduces stomach motility and acid secretion, allowing more time for digestion and nutrient absorption.

Hormonal control allows for a more measured response to digestion, ensuring effective nutrient breakdown and ensuring sustained energy release from foods.

Digestive System

The digestive system comprises a complex network of hollow organs and structures that work together to break down food, absorb nutrients, and eliminate waste. It relies on both neural and hormonal controls to function efficiently. From the mouth to the anus, the digestive tract is lined with muscles and glands each performing specific roles in the digestive process.
Key functions of the digestive system include:

• Ingestion: The intake of food through the mouth.
• Digestion: Mechanical and chemical breakdown of food into absorbable molecules.
• Absorption: Nutrients from digested food are absorbed into the bloodstream through walls of the intestines.
• Excretion: Waste materials are expelled through defecation.

Understanding how this system integrates neural and hormonal pathways clarifies how it maintains our body's nutrient balance and functions optimally. The digestive system does more than just digest food; it is fundamental to our overall health and well-being, creating a balance through the combined efforts of both quick neural responses and calculated hormonal signals.