N3 Anatomy and Physiology AY 2023-2024

ACTIVITY 1

1. How does the food change in consistency and form?

The journey of food through the digestive system starts in the oral cavity, where the mechanical forces of chewing initiate the breakdown of food particles, altering their physical consistency. Simultaneously, enzymatic processes, known as hydrolysis, kick in, initiating the molecular breakdown of complex compounds within the food. This dual-action in the oral cavity sets the stage for the formation of a cohesive bolus, a compact unit of partially digested food.

As the bolus progresses down the gastrointestinal tract, it encounters the stomach, a pivotal organ in the digestive process. Here, churning actions akin to those in the oral cavity continue to alter the consistency of the bolus. The stomach's dynamic environment, coupled with ongoing hydrolysis, transforms the bolus into chyme, a more fluid substance. 

2. How could the body absorb the nutrients from the foods we eat? 

The absorption of nutrients in the human body occurs predominantly in the small intestine, a crucial component of the gastrointestinal tract. Following the mechanical and enzymatic breakdown of food in the stomach, resulting in the formation of chyme, the small intestine undertakes the responsibility of nutrient absorption.

The inner lining of the small intestine is intricately designed to facilitate this process. Small, finger-like projections called villi and microvilli vastly increase the surface area available for absorption. These structures act as gatekeepers, selectively permitting the passage of digested nutrients, such as amino acids, fatty acids, vitamins, and minerals, into the bloodstream. The absorbed nutrients are then transported through the circulatory system to various tissues and organs, where they play pivotal roles in supporting growth, maintaining health, and providing energy. 

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