Animal nutrition Absorption Life science UPDADET.pptx

The process of Absorption in Animal nutrition highlighting the significance of the villi in the small intestine.

1. ANIMAL NUTRITION-ABSORPTION LIFE SCIENCES GRADE 11 11 AUGUST 2025 LESSON BY: Mr. K PETLELE

2. Lesson objectives 1. Define the concept of absorption 2. Identify the small intestine as the primary absorption organ. 3.Discuss the impact of malnutrition on the villi. 4.Illustrate and discuss villi adaptations through drawing and annotation.

3. "What do you think happens to food after digestion?"

4. Absorption: The process where digested food molecules move from the digestive system into the bloodstream.

5. The small intestine:

6. Why the small intestine? Large Surface Area: The small intestine's lining is not smooth; it's folded into numerous circular folds called plicae circulares, which are further covered with finger-like projections called villi. These villi, in turn, have even smaller projections called microvilli, creating a vast surface area for absorption. This increased surface area allows for more contact between digested food and the intestinal lining, maximizing nutrient absorption.

7. - Thin Walls : The walls of the small intestine are thin, allowing for efficient diffusion of nutrients into the bloodstream. Specialized Cells : The cells lining the villi are specialized for absorption, containing transporters and other proteins that facilitate the uptake of various nutrients. Long Residence Time : The slow movement of food through the small intestine allows for ample time for digestion and absorption to occur. Enzymatic Digestion : The small intestine also plays a crucial role in digestion, with enzymes from the pancreas and intestinal cells breaking down food into smaller, absorbable units. Specific Absorption Mechanisms : Different regions of the small intestine are specialized for absorbing different nutrients, such as the duodenum for iron and the ileum for vitamin B12 and bile salts.

8. Villi

9. CELIAC DISEASE In celiac disease, the body's immune system mistakenly attacks the small intestine when gluten is consumed, damaging the villi. This attack causes the villi to become inflamed, flattened, or even disappear, a condition known as villous atrophy . 

10. Kahoot! Link : https://kahoot.it/?pin=667479&refer_method=link PIN: 667 479

11. Summary Absorption = Nutrients entering bloodstream from digestive tract Small intestine = Primary absorption site (duodenum, jejunum, ileum) Villi adaptations: • Finger-like shape → ↑ surface area • Thin walls → Faster diffusion • Capillaries + lacteals → Transport nutrients ✓  Why It Matters: Damaged villi (e.g., celiac disease) → Malnutrition