Q4 Science 8_Module 1

Module Overview

  • Title: Science – Grade 8 Quarter 4 – Module 1: The Digestive System

  • Publisher: Department of Education – Region XI

  • Edition: First Edition, 2021

  • Nature: Self-learning module; not for sale, government property.

Let Us Learn

  • Understand the significance of the digestive system in keeping the body healthy.

Sample Questions

  1. Which part of the digestive system eliminates waste in the body?

    • A. Large intestine

    • B. Liver

    • C. Small intestine

    • D. Stomach

  2. How to maintain a healthy digestive system?

    • A. Eat oily and salty foods.

    • B. Sleep late and wake up early.

    • C. Drink plenty of water and ensure adequate sleep.

    • D. Excessive sweets.

  3. What organ secretes bile?

  4. Types of digestion: Mechanical vs Chemical.

  5. Substances that speed up reactions: Enzymes.

Let Us Study

News Article Analysis

  • March proclaimed as "PH Digestive Health Week" to raise awareness of digestive health issues.

  • Emphasis on education, resources, and public awareness to manage diseases related to digestive health.

  • Leading causes of death mentioned: liver cancer, ulcers, diarrhea, colorectal cancer.

Food is Life

  • Food sustains life and is crucial for energy generation and organism function.

  • Digestive system breaks down food for absorption by cells.

  • Process of Digestion:

    • Mechanical Digestion: Breakdown through chewing, grinding, etc.

    • Chemical Digestion: Breakdown using enzymes and acids.

Components of the Digestive System

  • Two Groups:

    • Gastrointestinal tract (mouth, esophagus, stomach, intestines).

    • Accessory organs (pancreas, liver, gall bladder, salivary glands).

Processes in Digestion

  • Food travels through the digestive tract taking about 18-20 hours from mouth to anus.

  • Ingestion begins at the mouth where food is mechanically broken down.

Organs and Functions

  1. Mouth: Initiates digestion with chewing.

  2. Pharynx: Connects mouth to esophagus.

  3. Esophagus: Transports food via peristalsis.

  4. Stomach: Mixes food with digestive juices to form chyme.

  5. Small Intestine: Site for chemical digestion and nutrient absorption.

  6. Liver: Produces bile for fat digestion.

  7. Gall Bladder: Stores bile.

  8. Pancreas: Secretes enzymes and regulates blood sugar.

  9. Large Intestine: Absorbs water; compacts waste for excretion.

Nutrient Deficiencies

  • Nutritional deficiency occurs when the body doesn’t receive necessary nutrients.

Common Deficiencies

  1. Iron Deficiency: Leads to anemia; fatigue, and shortness of breath.

  2. Zinc Deficiency: Affects immune function and appetite; significant health concern in the Philippines.

  3. Iodine Deficiency: Causes metabolic issues, including goiter.

Common Digestive Diseases

  • Constipation: Infrequent bowel movements.

  • Diarrhea: Loose, watery stools; inability to absorb food.

  • Peptic Ulcers: Sores in stomach lining.

  • Colon Cancer: Tumor growth in the intestine.

Prevention of Digestive Diseases

Recommended Practices

  1. Drink plenty of water for cleansing and absorption.

  2. Maintain a healthy diet rich in fiber.

  3. Eat mindfully; chew well.

  4. Exercise regularly for efficient digestion.

  5. Avoid bad habits like smoking and excessive alcohol consumption.

Activities

  • Activity 1A: Label organs of the Digestive System.

  • Activity 1B: Matching processes with their descriptions.

  • Activity 2: Complete a concept map of digestion processes.

  • Activity 3: Create a poster on preventing digestive problems.

Reflection

  • Importance of food for energy and health.

  • Awareness of food choices and prevention of diseases.

  • Digestive system essential for nutrient delivery to cells.